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v/thirdparty/mbedtls/library/psa_crypto.c

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/*
* PSA crypto layer on top of Mbed TLS crypto
*/
/*
* Copyright The Mbed TLS Contributors
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "common.h"
#if defined(MBEDTLS_PSA_CRYPTO_C)
#if defined(MBEDTLS_PSA_CRYPTO_CONFIG)
#include "check_crypto_config.h"
#endif
#include "psa/crypto.h"
#include "psa/crypto_values.h"
#include "psa_crypto_cipher.h"
#include "psa_crypto_core.h"
#include "psa_crypto_invasive.h"
#include "psa_crypto_driver_wrappers.h"
#include "psa_crypto_ecp.h"
#include "psa_crypto_hash.h"
#include "psa_crypto_mac.h"
#include "psa_crypto_rsa.h"
#include "psa_crypto_ecp.h"
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
#include "psa_crypto_se.h"
#endif
#include "psa_crypto_slot_management.h"
/* Include internal declarations that are useful for implementing persistently
* stored keys. */
#include "psa_crypto_storage.h"
#include "psa_crypto_random_impl.h"
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include "mbedtls/platform.h"
#if !defined(MBEDTLS_PLATFORM_C)
#define mbedtls_calloc calloc
#define mbedtls_free free
#endif
#include "mbedtls/aes.h"
#include "mbedtls/asn1.h"
#include "mbedtls/asn1write.h"
#include "mbedtls/bignum.h"
#include "mbedtls/camellia.h"
#include "mbedtls/chacha20.h"
#include "mbedtls/chachapoly.h"
#include "mbedtls/cipher.h"
#include "mbedtls/ccm.h"
#include "mbedtls/cmac.h"
#include "mbedtls/des.h"
#include "mbedtls/ecdh.h"
#include "mbedtls/ecp.h"
#include "mbedtls/entropy.h"
#include "mbedtls/error.h"
#include "mbedtls/gcm.h"
#include "mbedtls/md5.h"
#include "mbedtls/md.h"
#include "md_wrap.h"
#include "mbedtls/pk.h"
#include "pk_wrap.h"
#include "mbedtls/platform_util.h"
#include "mbedtls/error.h"
#include "mbedtls/ripemd160.h"
#include "mbedtls/rsa.h"
#include "mbedtls/sha1.h"
#include "mbedtls/sha256.h"
#include "mbedtls/sha512.h"
#define ARRAY_LENGTH( array ) ( sizeof( array ) / sizeof( *( array ) ) )
#if defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXTRACT) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXPAND)
#define BUILTIN_ALG_ANY_HKDF 1
#endif
/****************************************************************/
/* Global data, support functions and library management */
/****************************************************************/
static int key_type_is_raw_bytes( psa_key_type_t type )
{
return( PSA_KEY_TYPE_IS_UNSTRUCTURED( type ) );
}
/* Values for psa_global_data_t::rng_state */
#define RNG_NOT_INITIALIZED 0
#define RNG_INITIALIZED 1
#define RNG_SEEDED 2
typedef struct
{
unsigned initialized : 1;
unsigned rng_state : 2;
mbedtls_psa_random_context_t rng;
} psa_global_data_t;
static psa_global_data_t global_data;
#if !defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG)
mbedtls_psa_drbg_context_t *const mbedtls_psa_random_state =
&global_data.rng.drbg;
#endif
#define GUARD_MODULE_INITIALIZED \
if( global_data.initialized == 0 ) \
return( PSA_ERROR_BAD_STATE );
psa_status_t mbedtls_to_psa_error( int ret )
{
/* Mbed TLS error codes can combine a high-level error code and a
* low-level error code. The low-level error usually reflects the
* root cause better, so dispatch on that preferably. */
int low_level_ret = - ( -ret & 0x007f );
switch( low_level_ret != 0 ? low_level_ret : ret )
{
case 0:
return( PSA_SUCCESS );
case MBEDTLS_ERR_AES_INVALID_KEY_LENGTH:
case MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH:
return( PSA_ERROR_NOT_SUPPORTED );
case MBEDTLS_ERR_ASN1_OUT_OF_DATA:
case MBEDTLS_ERR_ASN1_UNEXPECTED_TAG:
case MBEDTLS_ERR_ASN1_INVALID_LENGTH:
case MBEDTLS_ERR_ASN1_LENGTH_MISMATCH:
case MBEDTLS_ERR_ASN1_INVALID_DATA:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_ASN1_ALLOC_FAILED:
return( PSA_ERROR_INSUFFICIENT_MEMORY );
case MBEDTLS_ERR_ASN1_BUF_TOO_SMALL:
return( PSA_ERROR_BUFFER_TOO_SMALL );
#if defined(MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA)
case MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA:
#endif
case MBEDTLS_ERR_CAMELLIA_INVALID_INPUT_LENGTH:
return( PSA_ERROR_NOT_SUPPORTED );
case MBEDTLS_ERR_CCM_BAD_INPUT:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_CCM_AUTH_FAILED:
return( PSA_ERROR_INVALID_SIGNATURE );
case MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_CHACHAPOLY_BAD_STATE:
return( PSA_ERROR_BAD_STATE );
case MBEDTLS_ERR_CHACHAPOLY_AUTH_FAILED:
return( PSA_ERROR_INVALID_SIGNATURE );
case MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE:
return( PSA_ERROR_NOT_SUPPORTED );
case MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_CIPHER_ALLOC_FAILED:
return( PSA_ERROR_INSUFFICIENT_MEMORY );
case MBEDTLS_ERR_CIPHER_INVALID_PADDING:
return( PSA_ERROR_INVALID_PADDING );
case MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_CIPHER_AUTH_FAILED:
return( PSA_ERROR_INVALID_SIGNATURE );
case MBEDTLS_ERR_CIPHER_INVALID_CONTEXT:
return( PSA_ERROR_CORRUPTION_DETECTED );
#if !( defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG) || \
defined(MBEDTLS_PSA_HMAC_DRBG_MD_TYPE) )
/* Only check CTR_DRBG error codes if underlying mbedtls_xxx
* functions are passed a CTR_DRBG instance. */
case MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED:
return( PSA_ERROR_INSUFFICIENT_ENTROPY );
case MBEDTLS_ERR_CTR_DRBG_REQUEST_TOO_BIG:
case MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG:
return( PSA_ERROR_NOT_SUPPORTED );
case MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR:
return( PSA_ERROR_INSUFFICIENT_ENTROPY );
#endif
case MBEDTLS_ERR_DES_INVALID_INPUT_LENGTH:
return( PSA_ERROR_NOT_SUPPORTED );
case MBEDTLS_ERR_ENTROPY_NO_SOURCES_DEFINED:
case MBEDTLS_ERR_ENTROPY_NO_STRONG_SOURCE:
case MBEDTLS_ERR_ENTROPY_SOURCE_FAILED:
return( PSA_ERROR_INSUFFICIENT_ENTROPY );
case MBEDTLS_ERR_GCM_AUTH_FAILED:
return( PSA_ERROR_INVALID_SIGNATURE );
case MBEDTLS_ERR_GCM_BUFFER_TOO_SMALL:
return( PSA_ERROR_BUFFER_TOO_SMALL );
case MBEDTLS_ERR_GCM_BAD_INPUT:
return( PSA_ERROR_INVALID_ARGUMENT );
#if !defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG) && \
defined(MBEDTLS_PSA_HMAC_DRBG_MD_TYPE)
/* Only check HMAC_DRBG error codes if underlying mbedtls_xxx
* functions are passed a HMAC_DRBG instance. */
case MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED:
return( PSA_ERROR_INSUFFICIENT_ENTROPY );
case MBEDTLS_ERR_HMAC_DRBG_REQUEST_TOO_BIG:
case MBEDTLS_ERR_HMAC_DRBG_INPUT_TOO_BIG:
return( PSA_ERROR_NOT_SUPPORTED );
case MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR:
return( PSA_ERROR_INSUFFICIENT_ENTROPY );
#endif
case MBEDTLS_ERR_MD_FEATURE_UNAVAILABLE:
return( PSA_ERROR_NOT_SUPPORTED );
case MBEDTLS_ERR_MD_BAD_INPUT_DATA:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_MD_ALLOC_FAILED:
return( PSA_ERROR_INSUFFICIENT_MEMORY );
case MBEDTLS_ERR_MD_FILE_IO_ERROR:
return( PSA_ERROR_STORAGE_FAILURE );
case MBEDTLS_ERR_MPI_FILE_IO_ERROR:
return( PSA_ERROR_STORAGE_FAILURE );
case MBEDTLS_ERR_MPI_BAD_INPUT_DATA:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_MPI_INVALID_CHARACTER:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_MPI_BUFFER_TOO_SMALL:
return( PSA_ERROR_BUFFER_TOO_SMALL );
case MBEDTLS_ERR_MPI_NEGATIVE_VALUE:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_MPI_DIVISION_BY_ZERO:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_MPI_NOT_ACCEPTABLE:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_MPI_ALLOC_FAILED:
return( PSA_ERROR_INSUFFICIENT_MEMORY );
case MBEDTLS_ERR_PK_ALLOC_FAILED:
return( PSA_ERROR_INSUFFICIENT_MEMORY );
case MBEDTLS_ERR_PK_TYPE_MISMATCH:
case MBEDTLS_ERR_PK_BAD_INPUT_DATA:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_PK_FILE_IO_ERROR:
return( PSA_ERROR_STORAGE_FAILURE );
case MBEDTLS_ERR_PK_KEY_INVALID_VERSION:
case MBEDTLS_ERR_PK_KEY_INVALID_FORMAT:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_PK_UNKNOWN_PK_ALG:
return( PSA_ERROR_NOT_SUPPORTED );
case MBEDTLS_ERR_PK_PASSWORD_REQUIRED:
case MBEDTLS_ERR_PK_PASSWORD_MISMATCH:
return( PSA_ERROR_NOT_PERMITTED );
case MBEDTLS_ERR_PK_INVALID_PUBKEY:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_PK_INVALID_ALG:
case MBEDTLS_ERR_PK_UNKNOWN_NAMED_CURVE:
case MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE:
return( PSA_ERROR_NOT_SUPPORTED );
case MBEDTLS_ERR_PK_SIG_LEN_MISMATCH:
return( PSA_ERROR_INVALID_SIGNATURE );
case MBEDTLS_ERR_PK_BUFFER_TOO_SMALL:
return( PSA_ERROR_BUFFER_TOO_SMALL );
case MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED:
return( PSA_ERROR_HARDWARE_FAILURE );
case MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED:
return( PSA_ERROR_NOT_SUPPORTED );
case MBEDTLS_ERR_RSA_BAD_INPUT_DATA:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_RSA_INVALID_PADDING:
return( PSA_ERROR_INVALID_PADDING );
case MBEDTLS_ERR_RSA_KEY_GEN_FAILED:
return( PSA_ERROR_HARDWARE_FAILURE );
case MBEDTLS_ERR_RSA_KEY_CHECK_FAILED:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_RSA_PUBLIC_FAILED:
case MBEDTLS_ERR_RSA_PRIVATE_FAILED:
return( PSA_ERROR_CORRUPTION_DETECTED );
case MBEDTLS_ERR_RSA_VERIFY_FAILED:
return( PSA_ERROR_INVALID_SIGNATURE );
case MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE:
return( PSA_ERROR_BUFFER_TOO_SMALL );
case MBEDTLS_ERR_RSA_RNG_FAILED:
return( PSA_ERROR_INSUFFICIENT_ENTROPY );
case MBEDTLS_ERR_ECP_BAD_INPUT_DATA:
case MBEDTLS_ERR_ECP_INVALID_KEY:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL:
return( PSA_ERROR_BUFFER_TOO_SMALL );
case MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE:
return( PSA_ERROR_NOT_SUPPORTED );
case MBEDTLS_ERR_ECP_SIG_LEN_MISMATCH:
case MBEDTLS_ERR_ECP_VERIFY_FAILED:
return( PSA_ERROR_INVALID_SIGNATURE );
case MBEDTLS_ERR_ECP_ALLOC_FAILED:
return( PSA_ERROR_INSUFFICIENT_MEMORY );
case MBEDTLS_ERR_ECP_RANDOM_FAILED:
return( PSA_ERROR_INSUFFICIENT_ENTROPY );
case MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED:
return( PSA_ERROR_CORRUPTION_DETECTED );
default:
return( PSA_ERROR_GENERIC_ERROR );
}
}
/****************************************************************/
/* Key management */
/****************************************************************/
#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) || \
defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_ECDH)
mbedtls_ecp_group_id mbedtls_ecc_group_of_psa( psa_ecc_family_t curve,
size_t bits,
int bits_is_sloppy )
{
switch( curve )
{
case PSA_ECC_FAMILY_SECP_R1:
switch( bits )
{
#if defined(PSA_WANT_ECC_SECP_R1_192)
case 192:
return( MBEDTLS_ECP_DP_SECP192R1 );
#endif
#if defined(PSA_WANT_ECC_SECP_R1_224)
case 224:
return( MBEDTLS_ECP_DP_SECP224R1 );
#endif
#if defined(PSA_WANT_ECC_SECP_R1_256)
case 256:
return( MBEDTLS_ECP_DP_SECP256R1 );
#endif
#if defined(PSA_WANT_ECC_SECP_R1_384)
case 384:
return( MBEDTLS_ECP_DP_SECP384R1 );
#endif
#if defined(PSA_WANT_ECC_SECP_R1_521)
case 521:
return( MBEDTLS_ECP_DP_SECP521R1 );
case 528:
if( bits_is_sloppy )
return( MBEDTLS_ECP_DP_SECP521R1 );
break;
#endif
}
break;
case PSA_ECC_FAMILY_BRAINPOOL_P_R1:
switch( bits )
{
#if defined(PSA_WANT_ECC_BRAINPOOL_P_R1_256)
case 256:
return( MBEDTLS_ECP_DP_BP256R1 );
#endif
#if defined(PSA_WANT_ECC_BRAINPOOL_P_R1_384)
case 384:
return( MBEDTLS_ECP_DP_BP384R1 );
#endif
#if defined(PSA_WANT_ECC_BRAINPOOL_P_R1_512)
case 512:
return( MBEDTLS_ECP_DP_BP512R1 );
#endif
}
break;
case PSA_ECC_FAMILY_MONTGOMERY:
switch( bits )
{
#if defined(PSA_WANT_ECC_MONTGOMERY_255)
case 255:
return( MBEDTLS_ECP_DP_CURVE25519 );
case 256:
if( bits_is_sloppy )
return( MBEDTLS_ECP_DP_CURVE25519 );
break;
#endif
#if defined(PSA_WANT_ECC_MONTGOMERY_448)
case 448:
return( MBEDTLS_ECP_DP_CURVE448 );
#endif
}
break;
case PSA_ECC_FAMILY_SECP_K1:
switch( bits )
{
#if defined(PSA_WANT_ECC_SECP_K1_192)
case 192:
return( MBEDTLS_ECP_DP_SECP192K1 );
#endif
#if defined(PSA_WANT_ECC_SECP_K1_224)
case 224:
return( MBEDTLS_ECP_DP_SECP224K1 );
#endif
#if defined(PSA_WANT_ECC_SECP_K1_256)
case 256:
return( MBEDTLS_ECP_DP_SECP256K1 );
#endif
}
break;
}
(void) bits_is_sloppy;
return( MBEDTLS_ECP_DP_NONE );
}
#endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) ||
defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY) ||
defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) ||
defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) ||
defined(MBEDTLS_PSA_BUILTIN_ALG_ECDH) */
psa_status_t psa_validate_unstructured_key_bit_size( psa_key_type_t type,
size_t bits )
{
/* Check that the bit size is acceptable for the key type */
switch( type )
{
case PSA_KEY_TYPE_RAW_DATA:
case PSA_KEY_TYPE_HMAC:
case PSA_KEY_TYPE_DERIVE:
break;
#if defined(PSA_WANT_KEY_TYPE_AES)
case PSA_KEY_TYPE_AES:
if( bits != 128 && bits != 192 && bits != 256 )
return( PSA_ERROR_INVALID_ARGUMENT );
break;
#endif
#if defined(PSA_WANT_KEY_TYPE_ARIA)
case PSA_KEY_TYPE_ARIA:
if( bits != 128 && bits != 192 && bits != 256 )
return( PSA_ERROR_INVALID_ARGUMENT );
break;
#endif
#if defined(PSA_WANT_KEY_TYPE_CAMELLIA)
case PSA_KEY_TYPE_CAMELLIA:
if( bits != 128 && bits != 192 && bits != 256 )
return( PSA_ERROR_INVALID_ARGUMENT );
break;
#endif
#if defined(PSA_WANT_KEY_TYPE_DES)
case PSA_KEY_TYPE_DES:
if( bits != 64 && bits != 128 && bits != 192 )
return( PSA_ERROR_INVALID_ARGUMENT );
break;
#endif
#if defined(PSA_WANT_KEY_TYPE_CHACHA20)
case PSA_KEY_TYPE_CHACHA20:
if( bits != 256 )
return( PSA_ERROR_INVALID_ARGUMENT );
break;
#endif
default:
return( PSA_ERROR_NOT_SUPPORTED );
}
if( bits % 8 != 0 )
return( PSA_ERROR_INVALID_ARGUMENT );
return( PSA_SUCCESS );
}
/** Check whether a given key type is valid for use with a given MAC algorithm
*
* Upon successful return of this function, the behavior of #PSA_MAC_LENGTH
* when called with the validated \p algorithm and \p key_type is well-defined.
*
* \param[in] algorithm The specific MAC algorithm (can be wildcard).
* \param[in] key_type The key type of the key to be used with the
* \p algorithm.
*
* \retval #PSA_SUCCESS
* The \p key_type is valid for use with the \p algorithm
* \retval #PSA_ERROR_INVALID_ARGUMENT
* The \p key_type is not valid for use with the \p algorithm
*/
MBEDTLS_STATIC_TESTABLE psa_status_t psa_mac_key_can_do(
psa_algorithm_t algorithm,
psa_key_type_t key_type )
{
if( PSA_ALG_IS_HMAC( algorithm ) )
{
if( key_type == PSA_KEY_TYPE_HMAC )
return( PSA_SUCCESS );
}
if( PSA_ALG_IS_BLOCK_CIPHER_MAC( algorithm ) )
{
/* Check that we're calling PSA_BLOCK_CIPHER_BLOCK_LENGTH with a cipher
* key. */
if( ( key_type & PSA_KEY_TYPE_CATEGORY_MASK ) ==
PSA_KEY_TYPE_CATEGORY_SYMMETRIC )
{
/* PSA_BLOCK_CIPHER_BLOCK_LENGTH returns 1 for stream ciphers and
* the block length (larger than 1) for block ciphers. */
if( PSA_BLOCK_CIPHER_BLOCK_LENGTH( key_type ) > 1 )
return( PSA_SUCCESS );
}
}
return( PSA_ERROR_INVALID_ARGUMENT );
}
psa_status_t psa_allocate_buffer_to_slot( psa_key_slot_t *slot,
size_t buffer_length )
{
if( slot->key.data != NULL )
return( PSA_ERROR_ALREADY_EXISTS );
slot->key.data = mbedtls_calloc( 1, buffer_length );
if( slot->key.data == NULL )
return( PSA_ERROR_INSUFFICIENT_MEMORY );
slot->key.bytes = buffer_length;
return( PSA_SUCCESS );
}
psa_status_t psa_copy_key_material_into_slot( psa_key_slot_t *slot,
const uint8_t* data,
size_t data_length )
{
psa_status_t status = psa_allocate_buffer_to_slot( slot,
data_length );
if( status != PSA_SUCCESS )
return( status );
memcpy( slot->key.data, data, data_length );
return( PSA_SUCCESS );
}
psa_status_t psa_import_key_into_slot(
const psa_key_attributes_t *attributes,
const uint8_t *data, size_t data_length,
uint8_t *key_buffer, size_t key_buffer_size,
size_t *key_buffer_length, size_t *bits )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_key_type_t type = attributes->core.type;
/* zero-length keys are never supported. */
if( data_length == 0 )
return( PSA_ERROR_NOT_SUPPORTED );
if( key_type_is_raw_bytes( type ) )
{
*bits = PSA_BYTES_TO_BITS( data_length );
status = psa_validate_unstructured_key_bit_size( attributes->core.type,
*bits );
if( status != PSA_SUCCESS )
return( status );
/* Copy the key material. */
memcpy( key_buffer, data, data_length );
*key_buffer_length = data_length;
(void)key_buffer_size;
return( PSA_SUCCESS );
}
else if( PSA_KEY_TYPE_IS_ASYMMETRIC( type ) )
{
#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) || \
defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY)
if( PSA_KEY_TYPE_IS_ECC( type ) )
{
return( mbedtls_psa_ecp_import_key( attributes,
data, data_length,
key_buffer, key_buffer_size,
key_buffer_length,
bits ) );
}
#endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) ||
* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY) */
#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) || \
defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY)
if( PSA_KEY_TYPE_IS_RSA( type ) )
{
return( mbedtls_psa_rsa_import_key( attributes,
data, data_length,
key_buffer, key_buffer_size,
key_buffer_length,
bits ) );
}
#endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) ||
* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY) */
}
return( PSA_ERROR_NOT_SUPPORTED );
}
/** Calculate the intersection of two algorithm usage policies.
*
* Return 0 (which allows no operation) on incompatibility.
*/
static psa_algorithm_t psa_key_policy_algorithm_intersection(
psa_key_type_t key_type,
psa_algorithm_t alg1,
psa_algorithm_t alg2 )
{
/* Common case: both sides actually specify the same policy. */
if( alg1 == alg2 )
return( alg1 );
/* If the policies are from the same hash-and-sign family, check
* if one is a wildcard. If so the other has the specific algorithm. */
if( PSA_ALG_IS_SIGN_HASH( alg1 ) &&
PSA_ALG_IS_SIGN_HASH( alg2 ) &&
( alg1 & ~PSA_ALG_HASH_MASK ) == ( alg2 & ~PSA_ALG_HASH_MASK ) )
{
if( PSA_ALG_SIGN_GET_HASH( alg1 ) == PSA_ALG_ANY_HASH )
return( alg2 );
if( PSA_ALG_SIGN_GET_HASH( alg2 ) == PSA_ALG_ANY_HASH )
return( alg1 );
}
/* If the policies are from the same AEAD family, check whether
* one of them is a minimum-tag-length wildcard. Calculate the most
* restrictive tag length. */
if( PSA_ALG_IS_AEAD( alg1 ) && PSA_ALG_IS_AEAD( alg2 ) &&
( PSA_ALG_AEAD_WITH_SHORTENED_TAG( alg1, 0 ) ==
PSA_ALG_AEAD_WITH_SHORTENED_TAG( alg2, 0 ) ) )
{
size_t alg1_len = PSA_ALG_AEAD_GET_TAG_LENGTH( alg1 );
size_t alg2_len = PSA_ALG_AEAD_GET_TAG_LENGTH( alg2 );
size_t restricted_len = alg1_len > alg2_len ? alg1_len : alg2_len;
/* If both are wildcards, return most restrictive wildcard */
if( ( ( alg1 & PSA_ALG_AEAD_AT_LEAST_THIS_LENGTH_FLAG ) != 0 ) &&
( ( alg2 & PSA_ALG_AEAD_AT_LEAST_THIS_LENGTH_FLAG ) != 0 ) )
{
return( PSA_ALG_AEAD_WITH_AT_LEAST_THIS_LENGTH_TAG(
alg1, restricted_len ) );
}
/* If only one is a wildcard, return specific algorithm if compatible. */
if( ( ( alg1 & PSA_ALG_AEAD_AT_LEAST_THIS_LENGTH_FLAG ) != 0 ) &&
( alg1_len <= alg2_len ) )
{
return( alg2 );
}
if( ( ( alg2 & PSA_ALG_AEAD_AT_LEAST_THIS_LENGTH_FLAG ) != 0 ) &&
( alg2_len <= alg1_len ) )
{
return( alg1 );
}
}
/* If the policies are from the same MAC family, check whether one
* of them is a minimum-MAC-length policy. Calculate the most
* restrictive tag length. */
if( PSA_ALG_IS_MAC( alg1 ) && PSA_ALG_IS_MAC( alg2 ) &&
( PSA_ALG_FULL_LENGTH_MAC( alg1 ) ==
PSA_ALG_FULL_LENGTH_MAC( alg2 ) ) )
{
/* Validate the combination of key type and algorithm. Since the base
* algorithm of alg1 and alg2 are the same, we only need this once. */
if( PSA_SUCCESS != psa_mac_key_can_do( alg1, key_type ) )
return( 0 );
/* Get the (exact or at-least) output lengths for both sides of the
* requested intersection. None of the currently supported algorithms
* have an output length dependent on the actual key size, so setting it
* to a bogus value of 0 is currently OK.
*
* Note that for at-least-this-length wildcard algorithms, the output
* length is set to the shortest allowed length, which allows us to
* calculate the most restrictive tag length for the intersection. */
size_t alg1_len = PSA_MAC_LENGTH( key_type, 0, alg1 );
size_t alg2_len = PSA_MAC_LENGTH( key_type, 0, alg2 );
size_t restricted_len = alg1_len > alg2_len ? alg1_len : alg2_len;
/* If both are wildcards, return most restrictive wildcard */
if( ( ( alg1 & PSA_ALG_MAC_AT_LEAST_THIS_LENGTH_FLAG ) != 0 ) &&
( ( alg2 & PSA_ALG_MAC_AT_LEAST_THIS_LENGTH_FLAG ) != 0 ) )
{
return( PSA_ALG_AT_LEAST_THIS_LENGTH_MAC( alg1, restricted_len ) );
}
/* If only one is an at-least-this-length policy, the intersection would
* be the other (fixed-length) policy as long as said fixed length is
* equal to or larger than the shortest allowed length. */
if( ( alg1 & PSA_ALG_MAC_AT_LEAST_THIS_LENGTH_FLAG ) != 0 )
{
return( ( alg1_len <= alg2_len ) ? alg2 : 0 );
}
if( ( alg2 & PSA_ALG_MAC_AT_LEAST_THIS_LENGTH_FLAG ) != 0 )
{
return( ( alg2_len <= alg1_len ) ? alg1 : 0 );
}
/* If none of them are wildcards, check whether they define the same tag
* length. This is still possible here when one is default-length and
* the other specific-length. Ensure to always return the
* specific-length version for the intersection. */
if( alg1_len == alg2_len )
return( PSA_ALG_TRUNCATED_MAC( alg1, alg1_len ) );
}
/* If the policies are incompatible, allow nothing. */
return( 0 );
}
static int psa_key_algorithm_permits( psa_key_type_t key_type,
psa_algorithm_t policy_alg,
psa_algorithm_t requested_alg )
{
/* Common case: the policy only allows requested_alg. */
if( requested_alg == policy_alg )
return( 1 );
/* If policy_alg is a hash-and-sign with a wildcard for the hash,
* and requested_alg is the same hash-and-sign family with any hash,
* then requested_alg is compliant with policy_alg. */
if( PSA_ALG_IS_SIGN_HASH( requested_alg ) &&
PSA_ALG_SIGN_GET_HASH( policy_alg ) == PSA_ALG_ANY_HASH )
{
return( ( policy_alg & ~PSA_ALG_HASH_MASK ) ==
( requested_alg & ~PSA_ALG_HASH_MASK ) );
}
/* If policy_alg is a wildcard AEAD algorithm of the same base as
* the requested algorithm, check the requested tag length to be
* equal-length or longer than the wildcard-specified length. */
if( PSA_ALG_IS_AEAD( policy_alg ) &&
PSA_ALG_IS_AEAD( requested_alg ) &&
( PSA_ALG_AEAD_WITH_SHORTENED_TAG( policy_alg, 0 ) ==
PSA_ALG_AEAD_WITH_SHORTENED_TAG( requested_alg, 0 ) ) &&
( ( policy_alg & PSA_ALG_AEAD_AT_LEAST_THIS_LENGTH_FLAG ) != 0 ) )
{
return( PSA_ALG_AEAD_GET_TAG_LENGTH( policy_alg ) <=
PSA_ALG_AEAD_GET_TAG_LENGTH( requested_alg ) );
}
/* If policy_alg is a MAC algorithm of the same base as the requested
* algorithm, check whether their MAC lengths are compatible. */
if( PSA_ALG_IS_MAC( policy_alg ) &&
PSA_ALG_IS_MAC( requested_alg ) &&
( PSA_ALG_FULL_LENGTH_MAC( policy_alg ) ==
PSA_ALG_FULL_LENGTH_MAC( requested_alg ) ) )
{
/* Validate the combination of key type and algorithm. Since the policy
* and requested algorithms are the same, we only need this once. */
if( PSA_SUCCESS != psa_mac_key_can_do( policy_alg, key_type ) )
return( 0 );
/* Get both the requested output length for the algorithm which is to be
* verified, and the default output length for the base algorithm.
* Note that none of the currently supported algorithms have an output
* length dependent on actual key size, so setting it to a bogus value
* of 0 is currently OK. */
size_t requested_output_length = PSA_MAC_LENGTH(
key_type, 0, requested_alg );
size_t default_output_length = PSA_MAC_LENGTH(
key_type, 0,
PSA_ALG_FULL_LENGTH_MAC( requested_alg ) );
/* If the policy is default-length, only allow an algorithm with
* a declared exact-length matching the default. */
if( PSA_MAC_TRUNCATED_LENGTH( policy_alg ) == 0 )
return( requested_output_length == default_output_length );
/* If the requested algorithm is default-length, allow it if the policy
* length exactly matches the default length. */
if( PSA_MAC_TRUNCATED_LENGTH( requested_alg ) == 0 &&
PSA_MAC_TRUNCATED_LENGTH( policy_alg ) == default_output_length )
{
return( 1 );
}
/* If policy_alg is an at-least-this-length wildcard MAC algorithm,
* check for the requested MAC length to be equal to or longer than the
* minimum allowed length. */
if( ( policy_alg & PSA_ALG_MAC_AT_LEAST_THIS_LENGTH_FLAG ) != 0 )
{
return( PSA_MAC_TRUNCATED_LENGTH( policy_alg ) <=
requested_output_length );
}
}
/* If policy_alg is a generic key agreement operation, then using it for
* a key derivation with that key agreement should also be allowed. This
* behaviour is expected to be defined in a future specification version. */
if( PSA_ALG_IS_RAW_KEY_AGREEMENT( policy_alg ) &&
PSA_ALG_IS_KEY_AGREEMENT( requested_alg ) )
{
return( PSA_ALG_KEY_AGREEMENT_GET_BASE( requested_alg ) ==
policy_alg );
}
/* If it isn't explicitly permitted, it's forbidden. */
return( 0 );
}
/** Test whether a policy permits an algorithm.
*
* The caller must test usage flags separately.
*
* \note This function requires providing the key type for which the policy is
* being validated, since some algorithm policy definitions (e.g. MAC)
* have different properties depending on what kind of cipher it is
* combined with.
*
* \retval PSA_SUCCESS When \p alg is a specific algorithm
* allowed by the \p policy.
* \retval PSA_ERROR_INVALID_ARGUMENT When \p alg is not a specific algorithm
* \retval PSA_ERROR_NOT_PERMITTED When \p alg is a specific algorithm, but
* the \p policy does not allow it.
*/
static psa_status_t psa_key_policy_permits( const psa_key_policy_t *policy,
psa_key_type_t key_type,
psa_algorithm_t alg )
{
/* '0' is not a valid algorithm */
if( alg == 0 )
return( PSA_ERROR_INVALID_ARGUMENT );
/* A requested algorithm cannot be a wildcard. */
if( PSA_ALG_IS_WILDCARD( alg ) )
return( PSA_ERROR_INVALID_ARGUMENT );
if( psa_key_algorithm_permits( key_type, policy->alg, alg ) ||
psa_key_algorithm_permits( key_type, policy->alg2, alg ) )
return( PSA_SUCCESS );
else
return( PSA_ERROR_NOT_PERMITTED );
}
/** Restrict a key policy based on a constraint.
*
* \note This function requires providing the key type for which the policy is
* being restricted, since some algorithm policy definitions (e.g. MAC)
* have different properties depending on what kind of cipher it is
* combined with.
*
* \param[in] key_type The key type for which to restrict the policy
* \param[in,out] policy The policy to restrict.
* \param[in] constraint The policy constraint to apply.
*
* \retval #PSA_SUCCESS
* \c *policy contains the intersection of the original value of
* \c *policy and \c *constraint.
* \retval #PSA_ERROR_INVALID_ARGUMENT
* \c key_type, \c *policy and \c *constraint are incompatible.
* \c *policy is unchanged.
*/
static psa_status_t psa_restrict_key_policy(
psa_key_type_t key_type,
psa_key_policy_t *policy,
const psa_key_policy_t *constraint )
{
psa_algorithm_t intersection_alg =
psa_key_policy_algorithm_intersection( key_type, policy->alg,
constraint->alg );
psa_algorithm_t intersection_alg2 =
psa_key_policy_algorithm_intersection( key_type, policy->alg2,
constraint->alg2 );
if( intersection_alg == 0 && policy->alg != 0 && constraint->alg != 0 )
return( PSA_ERROR_INVALID_ARGUMENT );
if( intersection_alg2 == 0 && policy->alg2 != 0 && constraint->alg2 != 0 )
return( PSA_ERROR_INVALID_ARGUMENT );
policy->usage &= constraint->usage;
policy->alg = intersection_alg;
policy->alg2 = intersection_alg2;
return( PSA_SUCCESS );
}
/** Get the description of a key given its identifier and policy constraints
* and lock it.
*
* The key must have allow all the usage flags set in \p usage. If \p alg is
* nonzero, the key must allow operations with this algorithm. If \p alg is
* zero, the algorithm is not checked.
*
* In case of a persistent key, the function loads the description of the key
* into a key slot if not already done.
*
* On success, the returned key slot is locked. It is the responsibility of
* the caller to unlock the key slot when it does not access it anymore.
*/
static psa_status_t psa_get_and_lock_key_slot_with_policy(
mbedtls_svc_key_id_t key,
psa_key_slot_t **p_slot,
psa_key_usage_t usage,
psa_algorithm_t alg )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_key_slot_t *slot;
status = psa_get_and_lock_key_slot( key, p_slot );
if( status != PSA_SUCCESS )
return( status );
slot = *p_slot;
/* Enforce that usage policy for the key slot contains all the flags
* required by the usage parameter. There is one exception: public
* keys can always be exported, so we treat public key objects as
* if they had the export flag. */
if( PSA_KEY_TYPE_IS_PUBLIC_KEY( slot->attr.type ) )
usage &= ~PSA_KEY_USAGE_EXPORT;
if( ( slot->attr.policy.usage & usage ) != usage )
{
status = PSA_ERROR_NOT_PERMITTED;
goto error;
}
/* Enforce that the usage policy permits the requested algorithm. */
if( alg != 0 )
{
status = psa_key_policy_permits( &slot->attr.policy,
slot->attr.type,
alg );
if( status != PSA_SUCCESS )
goto error;
}
return( PSA_SUCCESS );
error:
*p_slot = NULL;
psa_unlock_key_slot( slot );
return( status );
}
/** Get a key slot containing a transparent key and lock it.
*
* A transparent key is a key for which the key material is directly
* available, as opposed to a key in a secure element and/or to be used
* by a secure element.
*
* This is a temporary function that may be used instead of
* psa_get_and_lock_key_slot_with_policy() when there is no opaque key support
* for a cryptographic operation.
*
* On success, the returned key slot is locked. It is the responsibility of the
* caller to unlock the key slot when it does not access it anymore.
*/
static psa_status_t psa_get_and_lock_transparent_key_slot_with_policy(
mbedtls_svc_key_id_t key,
psa_key_slot_t **p_slot,
psa_key_usage_t usage,
psa_algorithm_t alg )
{
psa_status_t status = psa_get_and_lock_key_slot_with_policy( key, p_slot,
usage, alg );
if( status != PSA_SUCCESS )
return( status );
if( psa_key_lifetime_is_external( (*p_slot)->attr.lifetime ) )
{
psa_unlock_key_slot( *p_slot );
*p_slot = NULL;
return( PSA_ERROR_NOT_SUPPORTED );
}
return( PSA_SUCCESS );
}
psa_status_t psa_remove_key_data_from_memory( psa_key_slot_t *slot )
{
/* Data pointer will always be either a valid pointer or NULL in an
* initialized slot, so we can just free it. */
if( slot->key.data != NULL )
mbedtls_platform_zeroize( slot->key.data, slot->key.bytes);
mbedtls_free( slot->key.data );
slot->key.data = NULL;
slot->key.bytes = 0;
return( PSA_SUCCESS );
}
/** Completely wipe a slot in memory, including its policy.
* Persistent storage is not affected. */
psa_status_t psa_wipe_key_slot( psa_key_slot_t *slot )
{
psa_status_t status = psa_remove_key_data_from_memory( slot );
/*
* As the return error code may not be handled in case of multiple errors,
* do our best to report an unexpected lock counter. Assert with
* MBEDTLS_TEST_HOOK_TEST_ASSERT that the lock counter is equal to one:
* if the MBEDTLS_TEST_HOOKS configuration option is enabled and the
* function is called as part of the execution of a test suite, the
* execution of the test suite is stopped in error if the assertion fails.
*/
if( slot->lock_count != 1 )
{
MBEDTLS_TEST_HOOK_TEST_ASSERT( slot->lock_count == 1 );
status = PSA_ERROR_CORRUPTION_DETECTED;
}
/* Multipart operations may still be using the key. This is safe
* because all multipart operation objects are independent from
* the key slot: if they need to access the key after the setup
* phase, they have a copy of the key. Note that this means that
* key material can linger until all operations are completed. */
/* At this point, key material and other type-specific content has
* been wiped. Clear remaining metadata. We can call memset and not
* zeroize because the metadata is not particularly sensitive. */
memset( slot, 0, sizeof( *slot ) );
return( status );
}
psa_status_t psa_destroy_key( mbedtls_svc_key_id_t key )
{
psa_key_slot_t *slot;
psa_status_t status; /* status of the last operation */
psa_status_t overall_status = PSA_SUCCESS;
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
psa_se_drv_table_entry_t *driver;
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
if( mbedtls_svc_key_id_is_null( key ) )
return( PSA_SUCCESS );
/*
* Get the description of the key in a key slot. In case of a persistent
* key, this will load the key description from persistent memory if not
* done yet. We cannot avoid this loading as without it we don't know if
* the key is operated by an SE or not and this information is needed by
* the current implementation.
*/
status = psa_get_and_lock_key_slot( key, &slot );
if( status != PSA_SUCCESS )
return( status );
/*
* If the key slot containing the key description is under access by the
* library (apart from the present access), the key cannot be destroyed
* yet. For the time being, just return in error. Eventually (to be
* implemented), the key should be destroyed when all accesses have
* stopped.
*/
if( slot->lock_count > 1 )
{
psa_unlock_key_slot( slot );
return( PSA_ERROR_GENERIC_ERROR );
}
if( PSA_KEY_LIFETIME_IS_READ_ONLY( slot->attr.lifetime ) )
{
/* Refuse the destruction of a read-only key (which may or may not work
* if we attempt it, depending on whether the key is merely read-only
* by policy or actually physically read-only).
* Just do the best we can, which is to wipe the copy in memory
* (done in this function's cleanup code). */
overall_status = PSA_ERROR_NOT_PERMITTED;
goto exit;
}
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
driver = psa_get_se_driver_entry( slot->attr.lifetime );
if( driver != NULL )
{
/* For a key in a secure element, we need to do three things:
* remove the key file in internal storage, destroy the
* key inside the secure element, and update the driver's
* persistent data. Start a transaction that will encompass these
* three actions. */
psa_crypto_prepare_transaction( PSA_CRYPTO_TRANSACTION_DESTROY_KEY );
psa_crypto_transaction.key.lifetime = slot->attr.lifetime;
psa_crypto_transaction.key.slot = psa_key_slot_get_slot_number( slot );
psa_crypto_transaction.key.id = slot->attr.id;
status = psa_crypto_save_transaction( );
if( status != PSA_SUCCESS )
{
(void) psa_crypto_stop_transaction( );
/* We should still try to destroy the key in the secure
* element and the key metadata in storage. This is especially
* important if the error is that the storage is full.
* But how to do it exactly without risking an inconsistent
* state after a reset?
* https://github.com/ARMmbed/mbed-crypto/issues/215
*/
overall_status = status;
goto exit;
}
status = psa_destroy_se_key( driver,
psa_key_slot_get_slot_number( slot ) );
if( overall_status == PSA_SUCCESS )
overall_status = status;
}
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
#if defined(MBEDTLS_PSA_CRYPTO_STORAGE_C)
if( ! PSA_KEY_LIFETIME_IS_VOLATILE( slot->attr.lifetime ) )
{
status = psa_destroy_persistent_key( slot->attr.id );
if( overall_status == PSA_SUCCESS )
overall_status = status;
/* TODO: other slots may have a copy of the same key. We should
* invalidate them.
* https://github.com/ARMmbed/mbed-crypto/issues/214
*/
}
#endif /* defined(MBEDTLS_PSA_CRYPTO_STORAGE_C) */
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
if( driver != NULL )
{
status = psa_save_se_persistent_data( driver );
if( overall_status == PSA_SUCCESS )
overall_status = status;
status = psa_crypto_stop_transaction( );
if( overall_status == PSA_SUCCESS )
overall_status = status;
}
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
exit:
status = psa_wipe_key_slot( slot );
/* Prioritize CORRUPTION_DETECTED from wiping over a storage error */
if( status != PSA_SUCCESS )
overall_status = status;
return( overall_status );
}
#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) || \
defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY)
static psa_status_t psa_get_rsa_public_exponent(
const mbedtls_rsa_context *rsa,
psa_key_attributes_t *attributes )
{
mbedtls_mpi mpi;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
uint8_t *buffer = NULL;
size_t buflen;
mbedtls_mpi_init( &mpi );
ret = mbedtls_rsa_export( rsa, NULL, NULL, NULL, NULL, &mpi );
if( ret != 0 )
goto exit;
if( mbedtls_mpi_cmp_int( &mpi, 65537 ) == 0 )
{
/* It's the default value, which is reported as an empty string,
* so there's nothing to do. */
goto exit;
}
buflen = mbedtls_mpi_size( &mpi );
buffer = mbedtls_calloc( 1, buflen );
if( buffer == NULL )
{
ret = MBEDTLS_ERR_MPI_ALLOC_FAILED;
goto exit;
}
ret = mbedtls_mpi_write_binary( &mpi, buffer, buflen );
if( ret != 0 )
goto exit;
attributes->domain_parameters = buffer;
attributes->domain_parameters_size = buflen;
exit:
mbedtls_mpi_free( &mpi );
if( ret != 0 )
mbedtls_free( buffer );
return( mbedtls_to_psa_error( ret ) );
}
#endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) ||
* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY) */
/** Retrieve all the publicly-accessible attributes of a key.
*/
psa_status_t psa_get_key_attributes( mbedtls_svc_key_id_t key,
psa_key_attributes_t *attributes )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
psa_key_slot_t *slot;
psa_reset_key_attributes( attributes );
status = psa_get_and_lock_key_slot_with_policy( key, &slot, 0, 0 );
if( status != PSA_SUCCESS )
return( status );
attributes->core = slot->attr;
attributes->core.flags &= ( MBEDTLS_PSA_KA_MASK_EXTERNAL_ONLY |
MBEDTLS_PSA_KA_MASK_DUAL_USE );
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
if( psa_get_se_driver_entry( slot->attr.lifetime ) != NULL )
psa_set_key_slot_number( attributes,
psa_key_slot_get_slot_number( slot ) );
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
switch( slot->attr.type )
{
#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) || \
defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY)
case PSA_KEY_TYPE_RSA_KEY_PAIR:
case PSA_KEY_TYPE_RSA_PUBLIC_KEY:
/* TODO: reporting the public exponent for opaque keys
* is not yet implemented.
* https://github.com/ARMmbed/mbed-crypto/issues/216
*/
if( ! psa_key_lifetime_is_external( slot->attr.lifetime ) )
{
mbedtls_rsa_context *rsa = NULL;
status = mbedtls_psa_rsa_load_representation(
slot->attr.type,
slot->key.data,
slot->key.bytes,
&rsa );
if( status != PSA_SUCCESS )
break;
status = psa_get_rsa_public_exponent( rsa,
attributes );
mbedtls_rsa_free( rsa );
mbedtls_free( rsa );
}
break;
#endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) ||
* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY) */
default:
/* Nothing else to do. */
break;
}
if( status != PSA_SUCCESS )
psa_reset_key_attributes( attributes );
unlock_status = psa_unlock_key_slot( slot );
return( ( status == PSA_SUCCESS ) ? unlock_status : status );
}
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
psa_status_t psa_get_key_slot_number(
const psa_key_attributes_t *attributes,
psa_key_slot_number_t *slot_number )
{
if( attributes->core.flags & MBEDTLS_PSA_KA_FLAG_HAS_SLOT_NUMBER )
{
*slot_number = attributes->slot_number;
return( PSA_SUCCESS );
}
else
return( PSA_ERROR_INVALID_ARGUMENT );
}
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
static psa_status_t psa_export_key_buffer_internal( const uint8_t *key_buffer,
size_t key_buffer_size,
uint8_t *data,
size_t data_size,
size_t *data_length )
{
if( key_buffer_size > data_size )
return( PSA_ERROR_BUFFER_TOO_SMALL );
memcpy( data, key_buffer, key_buffer_size );
memset( data + key_buffer_size, 0,
data_size - key_buffer_size );
*data_length = key_buffer_size;
return( PSA_SUCCESS );
}
psa_status_t psa_export_key_internal(
const psa_key_attributes_t *attributes,
const uint8_t *key_buffer, size_t key_buffer_size,
uint8_t *data, size_t data_size, size_t *data_length )
{
psa_key_type_t type = attributes->core.type;
if( key_type_is_raw_bytes( type ) ||
PSA_KEY_TYPE_IS_RSA( type ) ||
PSA_KEY_TYPE_IS_ECC( type ) )
{
return( psa_export_key_buffer_internal(
key_buffer, key_buffer_size,
data, data_size, data_length ) );
}
else
{
/* This shouldn't happen in the reference implementation, but
it is valid for a special-purpose implementation to omit
support for exporting certain key types. */
return( PSA_ERROR_NOT_SUPPORTED );
}
}
psa_status_t psa_export_key( mbedtls_svc_key_id_t key,
uint8_t *data,
size_t data_size,
size_t *data_length )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
psa_key_slot_t *slot;
/* Reject a zero-length output buffer now, since this can never be a
* valid key representation. This way we know that data must be a valid
* pointer and we can do things like memset(data, ..., data_size). */
if( data_size == 0 )
return( PSA_ERROR_BUFFER_TOO_SMALL );
/* Set the key to empty now, so that even when there are errors, we always
* set data_length to a value between 0 and data_size. On error, setting
* the key to empty is a good choice because an empty key representation is
* unlikely to be accepted anywhere. */
*data_length = 0;
/* Export requires the EXPORT flag. There is an exception for public keys,
* which don't require any flag, but
* psa_get_and_lock_key_slot_with_policy() takes care of this.
*/
status = psa_get_and_lock_key_slot_with_policy( key, &slot,
PSA_KEY_USAGE_EXPORT, 0 );
if( status != PSA_SUCCESS )
return( status );
psa_key_attributes_t attributes = {
.core = slot->attr
};
status = psa_driver_wrapper_export_key( &attributes,
slot->key.data, slot->key.bytes,
data, data_size, data_length );
unlock_status = psa_unlock_key_slot( slot );
return( ( status == PSA_SUCCESS ) ? unlock_status : status );
}
psa_status_t psa_export_public_key_internal(
const psa_key_attributes_t *attributes,
const uint8_t *key_buffer,
size_t key_buffer_size,
uint8_t *data,
size_t data_size,
size_t *data_length )
{
psa_key_type_t type = attributes->core.type;
if( PSA_KEY_TYPE_IS_RSA( type ) || PSA_KEY_TYPE_IS_ECC( type ) )
{
if( PSA_KEY_TYPE_IS_PUBLIC_KEY( type ) )
{
/* Exporting public -> public */
return( psa_export_key_buffer_internal(
key_buffer, key_buffer_size,
data, data_size, data_length ) );
}
if( PSA_KEY_TYPE_IS_RSA( type ) )
{
#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) || \
defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY)
return( mbedtls_psa_rsa_export_public_key( attributes,
key_buffer,
key_buffer_size,
data,
data_size,
data_length ) );
#else
/* We don't know how to convert a private RSA key to public. */
return( PSA_ERROR_NOT_SUPPORTED );
#endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) ||
* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY) */
}
else
{
#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) || \
defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY)
return( mbedtls_psa_ecp_export_public_key( attributes,
key_buffer,
key_buffer_size,
data,
data_size,
data_length ) );
#else
/* We don't know how to convert a private ECC key to public */
return( PSA_ERROR_NOT_SUPPORTED );
#endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) ||
* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY) */
}
}
else
{
/* This shouldn't happen in the reference implementation, but
it is valid for a special-purpose implementation to omit
support for exporting certain key types. */
return( PSA_ERROR_NOT_SUPPORTED );
}
}
psa_status_t psa_export_public_key( mbedtls_svc_key_id_t key,
uint8_t *data,
size_t data_size,
size_t *data_length )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
psa_key_slot_t *slot;
/* Reject a zero-length output buffer now, since this can never be a
* valid key representation. This way we know that data must be a valid
* pointer and we can do things like memset(data, ..., data_size). */
if( data_size == 0 )
return( PSA_ERROR_BUFFER_TOO_SMALL );
/* Set the key to empty now, so that even when there are errors, we always
* set data_length to a value between 0 and data_size. On error, setting
* the key to empty is a good choice because an empty key representation is
* unlikely to be accepted anywhere. */
*data_length = 0;
/* Exporting a public key doesn't require a usage flag. */
status = psa_get_and_lock_key_slot_with_policy( key, &slot, 0, 0 );
if( status != PSA_SUCCESS )
return( status );
if( ! PSA_KEY_TYPE_IS_ASYMMETRIC( slot->attr.type ) )
{
status = PSA_ERROR_INVALID_ARGUMENT;
goto exit;
}
psa_key_attributes_t attributes = {
.core = slot->attr
};
status = psa_driver_wrapper_export_public_key(
&attributes, slot->key.data, slot->key.bytes,
data, data_size, data_length );
exit:
unlock_status = psa_unlock_key_slot( slot );
return( ( status == PSA_SUCCESS ) ? unlock_status : status );
}
#if defined(static_assert)
static_assert( ( MBEDTLS_PSA_KA_MASK_EXTERNAL_ONLY & MBEDTLS_PSA_KA_MASK_DUAL_USE ) == 0,
"One or more key attribute flag is listed as both external-only and dual-use" );
static_assert( ( PSA_KA_MASK_INTERNAL_ONLY & MBEDTLS_PSA_KA_MASK_DUAL_USE ) == 0,
"One or more key attribute flag is listed as both internal-only and dual-use" );
static_assert( ( PSA_KA_MASK_INTERNAL_ONLY & MBEDTLS_PSA_KA_MASK_EXTERNAL_ONLY ) == 0,
"One or more key attribute flag is listed as both internal-only and external-only" );
#endif
/** Validate that a key policy is internally well-formed.
*
* This function only rejects invalid policies. It does not validate the
* consistency of the policy with respect to other attributes of the key
* such as the key type.
*/
static psa_status_t psa_validate_key_policy( const psa_key_policy_t *policy )
{
if( ( policy->usage & ~( PSA_KEY_USAGE_EXPORT |
PSA_KEY_USAGE_COPY |
PSA_KEY_USAGE_ENCRYPT |
PSA_KEY_USAGE_DECRYPT |
PSA_KEY_USAGE_SIGN_MESSAGE |
PSA_KEY_USAGE_VERIFY_MESSAGE |
PSA_KEY_USAGE_SIGN_HASH |
PSA_KEY_USAGE_VERIFY_HASH |
PSA_KEY_USAGE_VERIFY_DERIVATION |
PSA_KEY_USAGE_DERIVE ) ) != 0 )
return( PSA_ERROR_INVALID_ARGUMENT );
return( PSA_SUCCESS );
}
/** Validate the internal consistency of key attributes.
*
* This function only rejects invalid attribute values. If does not
* validate the consistency of the attributes with any key data that may
* be involved in the creation of the key.
*
* Call this function early in the key creation process.
*
* \param[in] attributes Key attributes for the new key.
* \param[out] p_drv On any return, the driver for the key, if any.
* NULL for a transparent key.
*
*/
static psa_status_t psa_validate_key_attributes(
const psa_key_attributes_t *attributes,
psa_se_drv_table_entry_t **p_drv )
{
psa_status_t status = PSA_ERROR_INVALID_ARGUMENT;
psa_key_lifetime_t lifetime = psa_get_key_lifetime( attributes );
mbedtls_svc_key_id_t key = psa_get_key_id( attributes );
status = psa_validate_key_location( lifetime, p_drv );
if( status != PSA_SUCCESS )
return( status );
status = psa_validate_key_persistence( lifetime );
if( status != PSA_SUCCESS )
return( status );
if ( PSA_KEY_LIFETIME_IS_VOLATILE( lifetime ) )
{
if( MBEDTLS_SVC_KEY_ID_GET_KEY_ID( key ) != 0 )
return( PSA_ERROR_INVALID_ARGUMENT );
}
else
{
if( !psa_is_valid_key_id( psa_get_key_id( attributes ), 0 ) )
return( PSA_ERROR_INVALID_ARGUMENT );
}
status = psa_validate_key_policy( &attributes->core.policy );
if( status != PSA_SUCCESS )
return( status );
/* Refuse to create overly large keys.
* Note that this doesn't trigger on import if the attributes don't
* explicitly specify a size (so psa_get_key_bits returns 0), so
* psa_import_key() needs its own checks. */
if( psa_get_key_bits( attributes ) > PSA_MAX_KEY_BITS )
return( PSA_ERROR_NOT_SUPPORTED );
/* Reject invalid flags. These should not be reachable through the API. */
if( attributes->core.flags & ~ ( MBEDTLS_PSA_KA_MASK_EXTERNAL_ONLY |
MBEDTLS_PSA_KA_MASK_DUAL_USE ) )
return( PSA_ERROR_INVALID_ARGUMENT );
return( PSA_SUCCESS );
}
/** Prepare a key slot to receive key material.
*
* This function allocates a key slot and sets its metadata.
*
* If this function fails, call psa_fail_key_creation().
*
* This function is intended to be used as follows:
* -# Call psa_start_key_creation() to allocate a key slot, prepare
* it with the specified attributes, and in case of a volatile key assign it
* a volatile key identifier.
* -# Populate the slot with the key material.
* -# Call psa_finish_key_creation() to finalize the creation of the slot.
* In case of failure at any step, stop the sequence and call
* psa_fail_key_creation().
*
* On success, the key slot is locked. It is the responsibility of the caller
* to unlock the key slot when it does not access it anymore.
*
* \param method An identification of the calling function.
* \param[in] attributes Key attributes for the new key.
* \param[out] p_slot On success, a pointer to the prepared slot.
* \param[out] p_drv On any return, the driver for the key, if any.
* NULL for a transparent key.
*
* \retval #PSA_SUCCESS
* The key slot is ready to receive key material.
* \return If this function fails, the key slot is an invalid state.
* You must call psa_fail_key_creation() to wipe and free the slot.
*/
static psa_status_t psa_start_key_creation(
psa_key_creation_method_t method,
const psa_key_attributes_t *attributes,
psa_key_slot_t **p_slot,
psa_se_drv_table_entry_t **p_drv )
{
psa_status_t status;
psa_key_id_t volatile_key_id;
psa_key_slot_t *slot;
(void) method;
*p_drv = NULL;
status = psa_validate_key_attributes( attributes, p_drv );
if( status != PSA_SUCCESS )
return( status );
status = psa_get_empty_key_slot( &volatile_key_id, p_slot );
if( status != PSA_SUCCESS )
return( status );
slot = *p_slot;
/* We're storing the declared bit-size of the key. It's up to each
* creation mechanism to verify that this information is correct.
* It's automatically correct for mechanisms that use the bit-size as
* an input (generate, device) but not for those where the bit-size
* is optional (import, copy). In case of a volatile key, assign it the
* volatile key identifier associated to the slot returned to contain its
* definition. */
slot->attr = attributes->core;
if( PSA_KEY_LIFETIME_IS_VOLATILE( slot->attr.lifetime ) )
{
#if !defined(MBEDTLS_PSA_CRYPTO_KEY_ID_ENCODES_OWNER)
slot->attr.id = volatile_key_id;
#else
slot->attr.id.key_id = volatile_key_id;
#endif
}
/* Erase external-only flags from the internal copy. To access
* external-only flags, query `attributes`. Thanks to the check
* in psa_validate_key_attributes(), this leaves the dual-use
* flags and any internal flag that psa_get_empty_key_slot()
* may have set. */
slot->attr.flags &= ~MBEDTLS_PSA_KA_MASK_EXTERNAL_ONLY;
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
/* For a key in a secure element, we need to do three things
* when creating or registering a persistent key:
* create the key file in internal storage, create the
* key inside the secure element, and update the driver's
* persistent data. This is done by starting a transaction that will
* encompass these three actions.
* For registering a volatile key, we just need to find an appropriate
* slot number inside the SE. Since the key is designated volatile, creating
* a transaction is not required. */
/* The first thing to do is to find a slot number for the new key.
* We save the slot number in persistent storage as part of the
* transaction data. It will be needed to recover if the power
* fails during the key creation process, to clean up on the secure
* element side after restarting. Obtaining a slot number from the
* secure element driver updates its persistent state, but we do not yet
* save the driver's persistent state, so that if the power fails,
* we can roll back to a state where the key doesn't exist. */
if( *p_drv != NULL )
{
psa_key_slot_number_t slot_number;
status = psa_find_se_slot_for_key( attributes, method, *p_drv,
&slot_number );
if( status != PSA_SUCCESS )
return( status );
if( ! PSA_KEY_LIFETIME_IS_VOLATILE( attributes->core.lifetime ) )
{
psa_crypto_prepare_transaction( PSA_CRYPTO_TRANSACTION_CREATE_KEY );
psa_crypto_transaction.key.lifetime = slot->attr.lifetime;
psa_crypto_transaction.key.slot = slot_number;
psa_crypto_transaction.key.id = slot->attr.id;
status = psa_crypto_save_transaction( );
if( status != PSA_SUCCESS )
{
(void) psa_crypto_stop_transaction( );
return( status );
}
}
status = psa_copy_key_material_into_slot(
slot, (uint8_t *)( &slot_number ), sizeof( slot_number ) );
}
if( *p_drv == NULL && method == PSA_KEY_CREATION_REGISTER )
{
/* Key registration only makes sense with a secure element. */
return( PSA_ERROR_INVALID_ARGUMENT );
}
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
return( PSA_SUCCESS );
}
/** Finalize the creation of a key once its key material has been set.
*
* This entails writing the key to persistent storage.
*
* If this function fails, call psa_fail_key_creation().
* See the documentation of psa_start_key_creation() for the intended use
* of this function.
*
* If the finalization succeeds, the function unlocks the key slot (it was
* locked by psa_start_key_creation()) and the key slot cannot be accessed
* anymore as part of the key creation process.
*
* \param[in,out] slot Pointer to the slot with key material.
* \param[in] driver The secure element driver for the key,
* or NULL for a transparent key.
* \param[out] key On success, identifier of the key. Note that the
* key identifier is also stored in the key slot.
*
* \retval #PSA_SUCCESS
* The key was successfully created.
* \retval #PSA_ERROR_INSUFFICIENT_MEMORY
* \retval #PSA_ERROR_INSUFFICIENT_STORAGE
* \retval #PSA_ERROR_ALREADY_EXISTS
* \retval #PSA_ERROR_DATA_INVALID
* \retval #PSA_ERROR_DATA_CORRUPT
* \retval #PSA_ERROR_STORAGE_FAILURE
*
* \return If this function fails, the key slot is an invalid state.
* You must call psa_fail_key_creation() to wipe and free the slot.
*/
static psa_status_t psa_finish_key_creation(
psa_key_slot_t *slot,
psa_se_drv_table_entry_t *driver,
mbedtls_svc_key_id_t *key)
{
psa_status_t status = PSA_SUCCESS;
(void) slot;
(void) driver;
#if defined(MBEDTLS_PSA_CRYPTO_STORAGE_C)
if( ! PSA_KEY_LIFETIME_IS_VOLATILE( slot->attr.lifetime ) )
{
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
if( driver != NULL )
{
psa_se_key_data_storage_t data;
psa_key_slot_number_t slot_number =
psa_key_slot_get_slot_number( slot ) ;
#if defined(static_assert)
static_assert( sizeof( slot_number ) ==
sizeof( data.slot_number ),
"Slot number size does not match psa_se_key_data_storage_t" );
#endif
memcpy( &data.slot_number, &slot_number, sizeof( slot_number ) );
status = psa_save_persistent_key( &slot->attr,
(uint8_t*) &data,
sizeof( data ) );
}
else
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
{
/* Key material is saved in export representation in the slot, so
* just pass the slot buffer for storage. */
status = psa_save_persistent_key( &slot->attr,
slot->key.data,
slot->key.bytes );
}
}
#endif /* defined(MBEDTLS_PSA_CRYPTO_STORAGE_C) */
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
/* Finish the transaction for a key creation. This does not
* happen when registering an existing key. Detect this case
* by checking whether a transaction is in progress (actual
* creation of a persistent key in a secure element requires a transaction,
* but registration or volatile key creation doesn't use one). */
if( driver != NULL &&
psa_crypto_transaction.unknown.type == PSA_CRYPTO_TRANSACTION_CREATE_KEY )
{
status = psa_save_se_persistent_data( driver );
if( status != PSA_SUCCESS )
{
psa_destroy_persistent_key( slot->attr.id );
return( status );
}
status = psa_crypto_stop_transaction( );
}
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
if( status == PSA_SUCCESS )
{
*key = slot->attr.id;
status = psa_unlock_key_slot( slot );
if( status != PSA_SUCCESS )
*key = MBEDTLS_SVC_KEY_ID_INIT;
}
return( status );
}
/** Abort the creation of a key.
*
* You may call this function after calling psa_start_key_creation(),
* or after psa_finish_key_creation() fails. In other circumstances, this
* function may not clean up persistent storage.
* See the documentation of psa_start_key_creation() for the intended use
* of this function.
*
* \param[in,out] slot Pointer to the slot with key material.
* \param[in] driver The secure element driver for the key,
* or NULL for a transparent key.
*/
static void psa_fail_key_creation( psa_key_slot_t *slot,
psa_se_drv_table_entry_t *driver )
{
(void) driver;
if( slot == NULL )
return;
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
/* TODO: If the key has already been created in the secure
* element, and the failure happened later (when saving metadata
* to internal storage), we need to destroy the key in the secure
* element.
* https://github.com/ARMmbed/mbed-crypto/issues/217
*/
/* Abort the ongoing transaction if any (there may not be one if
* the creation process failed before starting one, or if the
* key creation is a registration of a key in a secure element).
* Earlier functions must already have done what it takes to undo any
* partial creation. All that's left is to update the transaction data
* itself. */
(void) psa_crypto_stop_transaction( );
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
psa_wipe_key_slot( slot );
}
/** Validate optional attributes during key creation.
*
* Some key attributes are optional during key creation. If they are
* specified in the attributes structure, check that they are consistent
* with the data in the slot.
*
* This function should be called near the end of key creation, after
* the slot in memory is fully populated but before saving persistent data.
*/
static psa_status_t psa_validate_optional_attributes(
const psa_key_slot_t *slot,
const psa_key_attributes_t *attributes )
{
if( attributes->core.type != 0 )
{
if( attributes->core.type != slot->attr.type )
return( PSA_ERROR_INVALID_ARGUMENT );
}
if( attributes->domain_parameters_size != 0 )
{
#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) || \
defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY)
if( PSA_KEY_TYPE_IS_RSA( slot->attr.type ) )
{
mbedtls_rsa_context *rsa = NULL;
mbedtls_mpi actual, required;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
psa_status_t status = mbedtls_psa_rsa_load_representation(
slot->attr.type,
slot->key.data,
slot->key.bytes,
&rsa );
if( status != PSA_SUCCESS )
return( status );
mbedtls_mpi_init( &actual );
mbedtls_mpi_init( &required );
ret = mbedtls_rsa_export( rsa,
NULL, NULL, NULL, NULL, &actual );
mbedtls_rsa_free( rsa );
mbedtls_free( rsa );
if( ret != 0 )
goto rsa_exit;
ret = mbedtls_mpi_read_binary( &required,
attributes->domain_parameters,
attributes->domain_parameters_size );
if( ret != 0 )
goto rsa_exit;
if( mbedtls_mpi_cmp_mpi( &actual, &required ) != 0 )
ret = MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
rsa_exit:
mbedtls_mpi_free( &actual );
mbedtls_mpi_free( &required );
if( ret != 0)
return( mbedtls_to_psa_error( ret ) );
}
else
#endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) ||
* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_PUBLIC_KEY) */
{
return( PSA_ERROR_INVALID_ARGUMENT );
}
}
if( attributes->core.bits != 0 )
{
if( attributes->core.bits != slot->attr.bits )
return( PSA_ERROR_INVALID_ARGUMENT );
}
return( PSA_SUCCESS );
}
psa_status_t psa_import_key( const psa_key_attributes_t *attributes,
const uint8_t *data,
size_t data_length,
mbedtls_svc_key_id_t *key )
{
psa_status_t status;
psa_key_slot_t *slot = NULL;
psa_se_drv_table_entry_t *driver = NULL;
size_t bits;
size_t storage_size = data_length;
*key = MBEDTLS_SVC_KEY_ID_INIT;
/* Reject zero-length symmetric keys (including raw data key objects).
* This also rejects any key which might be encoded as an empty string,
* which is never valid. */
if( data_length == 0 )
return( PSA_ERROR_INVALID_ARGUMENT );
/* Ensure that the bytes-to-bits conversion cannot overflow. */
if( data_length > SIZE_MAX / 8 )
return( PSA_ERROR_NOT_SUPPORTED );
status = psa_start_key_creation( PSA_KEY_CREATION_IMPORT, attributes,
&slot, &driver );
if( status != PSA_SUCCESS )
goto exit;
/* In the case of a transparent key or an opaque key stored in local
* storage ( thus not in the case of importing a key in a secure element
* with storage ( MBEDTLS_PSA_CRYPTO_SE_C ) ),we have to allocate a
* buffer to hold the imported key material. */
if( slot->key.data == NULL )
{
if( psa_key_lifetime_is_external( attributes->core.lifetime ) )
{
status = psa_driver_wrapper_get_key_buffer_size_from_key_data(
attributes, data, data_length, &storage_size );
if( status != PSA_SUCCESS )
goto exit;
}
status = psa_allocate_buffer_to_slot( slot, storage_size );
if( status != PSA_SUCCESS )
goto exit;
}
bits = slot->attr.bits;
status = psa_driver_wrapper_import_key( attributes,
data, data_length,
slot->key.data,
slot->key.bytes,
&slot->key.bytes, &bits );
if( status != PSA_SUCCESS )
goto exit;
if( slot->attr.bits == 0 )
slot->attr.bits = (psa_key_bits_t) bits;
else if( bits != slot->attr.bits )
{
status = PSA_ERROR_INVALID_ARGUMENT;
goto exit;
}
/* Enforce a size limit, and in particular ensure that the bit
* size fits in its representation type.*/
if( bits > PSA_MAX_KEY_BITS )
{
status = PSA_ERROR_NOT_SUPPORTED;
goto exit;
}
status = psa_validate_optional_attributes( slot, attributes );
if( status != PSA_SUCCESS )
goto exit;
status = psa_finish_key_creation( slot, driver, key );
exit:
if( status != PSA_SUCCESS )
psa_fail_key_creation( slot, driver );
return( status );
}
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
psa_status_t mbedtls_psa_register_se_key(
const psa_key_attributes_t *attributes )
{
psa_status_t status;
psa_key_slot_t *slot = NULL;
psa_se_drv_table_entry_t *driver = NULL;
mbedtls_svc_key_id_t key = MBEDTLS_SVC_KEY_ID_INIT;
/* Leaving attributes unspecified is not currently supported.
* It could make sense to query the key type and size from the
* secure element, but not all secure elements support this
* and the driver HAL doesn't currently support it. */
if( psa_get_key_type( attributes ) == PSA_KEY_TYPE_NONE )
return( PSA_ERROR_NOT_SUPPORTED );
if( psa_get_key_bits( attributes ) == 0 )
return( PSA_ERROR_NOT_SUPPORTED );
status = psa_start_key_creation( PSA_KEY_CREATION_REGISTER, attributes,
&slot, &driver );
if( status != PSA_SUCCESS )
goto exit;
status = psa_finish_key_creation( slot, driver, &key );
exit:
if( status != PSA_SUCCESS )
psa_fail_key_creation( slot, driver );
/* Registration doesn't keep the key in RAM. */
psa_close_key( key );
return( status );
}
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
psa_status_t psa_copy_key( mbedtls_svc_key_id_t source_key,
const psa_key_attributes_t *specified_attributes,
mbedtls_svc_key_id_t *target_key )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
psa_key_slot_t *source_slot = NULL;
psa_key_slot_t *target_slot = NULL;
psa_key_attributes_t actual_attributes = *specified_attributes;
psa_se_drv_table_entry_t *driver = NULL;
size_t storage_size = 0;
*target_key = MBEDTLS_SVC_KEY_ID_INIT;
status = psa_get_and_lock_key_slot_with_policy(
source_key, &source_slot, PSA_KEY_USAGE_COPY, 0 );
if( status != PSA_SUCCESS )
goto exit;
status = psa_validate_optional_attributes( source_slot,
specified_attributes );
if( status != PSA_SUCCESS )
goto exit;
/* The target key type and number of bits have been validated by
* psa_validate_optional_attributes() to be either equal to zero or
* equal to the ones of the source key. So it is safe to inherit
* them from the source key now."
* */
actual_attributes.core.bits = source_slot->attr.bits;
actual_attributes.core.type = source_slot->attr.type;
status = psa_restrict_key_policy( source_slot->attr.type,
&actual_attributes.core.policy,
&source_slot->attr.policy );
if( status != PSA_SUCCESS )
goto exit;
status = psa_start_key_creation( PSA_KEY_CREATION_COPY, &actual_attributes,
&target_slot, &driver );
if( status != PSA_SUCCESS )
goto exit;
if( PSA_KEY_LIFETIME_GET_LOCATION( target_slot->attr.lifetime ) !=
PSA_KEY_LIFETIME_GET_LOCATION( source_slot->attr.lifetime ) )
{
/*
* If the source and target keys are stored in different locations,
* the source key would need to be exported as plaintext and re-imported
* in the other location. This has security implications which have not
* been fully mapped. For now, this can be achieved through
* appropriate API invocations from the application, if needed.
* */
status = PSA_ERROR_NOT_SUPPORTED;
goto exit;
}
/*
* When the source and target keys are within the same location,
* - For transparent keys it is a blind copy without any driver invocation,
* - For opaque keys this translates to an invocation of the drivers'
* copy_key entry point through the dispatch layer.
* */
if( psa_key_lifetime_is_external( actual_attributes.core.lifetime ) )
{
status = psa_driver_wrapper_get_key_buffer_size( &actual_attributes,
&storage_size );
if( status != PSA_SUCCESS )
goto exit;
status = psa_allocate_buffer_to_slot( target_slot, storage_size );
if( status != PSA_SUCCESS )
goto exit;
status = psa_driver_wrapper_copy_key( &actual_attributes,
source_slot->key.data,
source_slot->key.bytes,
target_slot->key.data,
target_slot->key.bytes,
&target_slot->key.bytes );
if( status != PSA_SUCCESS )
goto exit;
}
else
{
status = psa_copy_key_material_into_slot( target_slot,
source_slot->key.data,
source_slot->key.bytes );
if( status != PSA_SUCCESS )
goto exit;
}
status = psa_finish_key_creation( target_slot, driver, target_key );
exit:
if( status != PSA_SUCCESS )
psa_fail_key_creation( target_slot, driver );
unlock_status = psa_unlock_key_slot( source_slot );
return( ( status == PSA_SUCCESS ) ? unlock_status : status );
}
/****************************************************************/
/* Message digests */
/****************************************************************/
psa_status_t psa_hash_abort( psa_hash_operation_t *operation )
{
/* Aborting a non-active operation is allowed */
if( operation->id == 0 )
return( PSA_SUCCESS );
psa_status_t status = psa_driver_wrapper_hash_abort( operation );
operation->id = 0;
return( status );
}
psa_status_t psa_hash_setup( psa_hash_operation_t *operation,
psa_algorithm_t alg )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
/* A context must be freshly initialized before it can be set up. */
if( operation->id != 0 )
{
status = PSA_ERROR_BAD_STATE;
goto exit;
}
if( !PSA_ALG_IS_HASH( alg ) )
{
status = PSA_ERROR_INVALID_ARGUMENT;
goto exit;
}
/* Ensure all of the context is zeroized, since PSA_HASH_OPERATION_INIT only
* directly zeroes the int-sized dummy member of the context union. */
memset( &operation->ctx, 0, sizeof( operation->ctx ) );
status = psa_driver_wrapper_hash_setup( operation, alg );
exit:
if( status != PSA_SUCCESS )
psa_hash_abort( operation );
return status;
}
psa_status_t psa_hash_update( psa_hash_operation_t *operation,
const uint8_t *input,
size_t input_length )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
if( operation->id == 0 )
{
status = PSA_ERROR_BAD_STATE;
goto exit;
}
/* Don't require hash implementations to behave correctly on a
* zero-length input, which may have an invalid pointer. */
if( input_length == 0 )
return( PSA_SUCCESS );
status = psa_driver_wrapper_hash_update( operation, input, input_length );
exit:
if( status != PSA_SUCCESS )
psa_hash_abort( operation );
return( status );
}
psa_status_t psa_hash_finish( psa_hash_operation_t *operation,
uint8_t *hash,
size_t hash_size,
size_t *hash_length )
{
*hash_length = 0;
if( operation->id == 0 )
return( PSA_ERROR_BAD_STATE );
psa_status_t status = psa_driver_wrapper_hash_finish(
operation, hash, hash_size, hash_length );
psa_hash_abort( operation );
return( status );
}
psa_status_t psa_hash_verify( psa_hash_operation_t *operation,
const uint8_t *hash,
size_t hash_length )
{
uint8_t actual_hash[PSA_HASH_MAX_SIZE];
size_t actual_hash_length;
psa_status_t status = psa_hash_finish(
operation,
actual_hash, sizeof( actual_hash ),
&actual_hash_length );
if( status != PSA_SUCCESS )
goto exit;
if( actual_hash_length != hash_length )
{
status = PSA_ERROR_INVALID_SIGNATURE;
goto exit;
}
if( mbedtls_psa_safer_memcmp( hash, actual_hash, actual_hash_length ) != 0 )
status = PSA_ERROR_INVALID_SIGNATURE;
exit:
mbedtls_platform_zeroize( actual_hash, sizeof( actual_hash ) );
if( status != PSA_SUCCESS )
psa_hash_abort(operation);
return( status );
}
psa_status_t psa_hash_compute( psa_algorithm_t alg,
const uint8_t *input, size_t input_length,
uint8_t *hash, size_t hash_size,
size_t *hash_length )
{
*hash_length = 0;
if( !PSA_ALG_IS_HASH( alg ) )
return( PSA_ERROR_INVALID_ARGUMENT );
return( psa_driver_wrapper_hash_compute( alg, input, input_length,
hash, hash_size, hash_length ) );
}
psa_status_t psa_hash_compare( psa_algorithm_t alg,
const uint8_t *input, size_t input_length,
const uint8_t *hash, size_t hash_length )
{
uint8_t actual_hash[PSA_HASH_MAX_SIZE];
size_t actual_hash_length;
if( !PSA_ALG_IS_HASH( alg ) )
return( PSA_ERROR_INVALID_ARGUMENT );
psa_status_t status = psa_driver_wrapper_hash_compute(
alg, input, input_length,
actual_hash, sizeof(actual_hash),
&actual_hash_length );
if( status != PSA_SUCCESS )
goto exit;
if( actual_hash_length != hash_length )
{
status = PSA_ERROR_INVALID_SIGNATURE;
goto exit;
}
if( mbedtls_psa_safer_memcmp( hash, actual_hash, actual_hash_length ) != 0 )
status = PSA_ERROR_INVALID_SIGNATURE;
exit:
mbedtls_platform_zeroize( actual_hash, sizeof( actual_hash ) );
return( status );
}
psa_status_t psa_hash_clone( const psa_hash_operation_t *source_operation,
psa_hash_operation_t *target_operation )
{
if( source_operation->id == 0 ||
target_operation->id != 0 )
{
return( PSA_ERROR_BAD_STATE );
}
psa_status_t status = psa_driver_wrapper_hash_clone( source_operation,
target_operation );
if( status != PSA_SUCCESS )
psa_hash_abort( target_operation );
return( status );
}
/****************************************************************/
/* MAC */
/****************************************************************/
psa_status_t psa_mac_abort( psa_mac_operation_t *operation )
{
/* Aborting a non-active operation is allowed */
if( operation->id == 0 )
return( PSA_SUCCESS );
psa_status_t status = psa_driver_wrapper_mac_abort( operation );
operation->mac_size = 0;
operation->is_sign = 0;
operation->id = 0;
return( status );
}
static psa_status_t psa_mac_finalize_alg_and_key_validation(
psa_algorithm_t alg,
const psa_key_attributes_t *attributes,
uint8_t *mac_size )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_key_type_t key_type = psa_get_key_type( attributes );
size_t key_bits = psa_get_key_bits( attributes );
if( ! PSA_ALG_IS_MAC( alg ) )
return( PSA_ERROR_INVALID_ARGUMENT );
/* Validate the combination of key type and algorithm */
status = psa_mac_key_can_do( alg, key_type );
if( status != PSA_SUCCESS )
return( status );
/* Get the output length for the algorithm and key combination */
*mac_size = PSA_MAC_LENGTH( key_type, key_bits, alg );
if( *mac_size < 4 )
{
/* A very short MAC is too short for security since it can be
* brute-forced. Ancient protocols with 32-bit MACs do exist,
* so we make this our minimum, even though 32 bits is still
* too small for security. */
return( PSA_ERROR_NOT_SUPPORTED );
}
if( *mac_size > PSA_MAC_LENGTH( key_type, key_bits,
PSA_ALG_FULL_LENGTH_MAC( alg ) ) )
{
/* It's impossible to "truncate" to a larger length than the full length
* of the algorithm. */
return( PSA_ERROR_INVALID_ARGUMENT );
}
if( *mac_size > PSA_MAC_MAX_SIZE )
{
/* PSA_MAC_LENGTH returns the correct length even for a MAC algorithm
* that is disabled in the compile-time configuration. The result can
* therefore be larger than PSA_MAC_MAX_SIZE, which does take the
* configuration into account. In this case, force a return of
* PSA_ERROR_NOT_SUPPORTED here. Otherwise psa_mac_verify(), or
* psa_mac_compute(mac_size=PSA_MAC_MAX_SIZE), would return
* PSA_ERROR_BUFFER_TOO_SMALL for an unsupported algorithm whose MAC size
* is larger than PSA_MAC_MAX_SIZE, which is misleading and which breaks
* systematically generated tests. */
return( PSA_ERROR_NOT_SUPPORTED );
}
return( PSA_SUCCESS );
}
static psa_status_t psa_mac_setup( psa_mac_operation_t *operation,
mbedtls_svc_key_id_t key,
psa_algorithm_t alg,
int is_sign )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
psa_key_slot_t *slot = NULL;
/* A context must be freshly initialized before it can be set up. */
if( operation->id != 0 )
{
status = PSA_ERROR_BAD_STATE;
goto exit;
}
status = psa_get_and_lock_key_slot_with_policy(
key,
&slot,
is_sign ? PSA_KEY_USAGE_SIGN_MESSAGE : PSA_KEY_USAGE_VERIFY_MESSAGE,
alg );
if( status != PSA_SUCCESS )
goto exit;
psa_key_attributes_t attributes = {
.core = slot->attr
};
status = psa_mac_finalize_alg_and_key_validation( alg, &attributes,
&operation->mac_size );
if( status != PSA_SUCCESS )
goto exit;
operation->is_sign = is_sign;
/* Dispatch the MAC setup call with validated input */
if( is_sign )
{
status = psa_driver_wrapper_mac_sign_setup( operation,
&attributes,
slot->key.data,
slot->key.bytes,
alg );
}
else
{
status = psa_driver_wrapper_mac_verify_setup( operation,
&attributes,
slot->key.data,
slot->key.bytes,
alg );
}
exit:
if( status != PSA_SUCCESS )
psa_mac_abort( operation );
unlock_status = psa_unlock_key_slot( slot );
return( ( status == PSA_SUCCESS ) ? unlock_status : status );
}
psa_status_t psa_mac_sign_setup( psa_mac_operation_t *operation,
mbedtls_svc_key_id_t key,
psa_algorithm_t alg )
{
return( psa_mac_setup( operation, key, alg, 1 ) );
}
psa_status_t psa_mac_verify_setup( psa_mac_operation_t *operation,
mbedtls_svc_key_id_t key,
psa_algorithm_t alg )
{
return( psa_mac_setup( operation, key, alg, 0 ) );
}
psa_status_t psa_mac_update( psa_mac_operation_t *operation,
const uint8_t *input,
size_t input_length )
{
if( operation->id == 0 )
return( PSA_ERROR_BAD_STATE );
/* Don't require hash implementations to behave correctly on a
* zero-length input, which may have an invalid pointer. */
if( input_length == 0 )
return( PSA_SUCCESS );
psa_status_t status = psa_driver_wrapper_mac_update( operation,
input, input_length );
if( status != PSA_SUCCESS )
psa_mac_abort( operation );
return( status );
}
psa_status_t psa_mac_sign_finish( psa_mac_operation_t *operation,
uint8_t *mac,
size_t mac_size,
size_t *mac_length )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_status_t abort_status = PSA_ERROR_CORRUPTION_DETECTED;
if( operation->id == 0 )
{
status = PSA_ERROR_BAD_STATE;
goto exit;
}
if( ! operation->is_sign )
{
status = PSA_ERROR_BAD_STATE;
goto exit;
}
/* Sanity check. This will guarantee that mac_size != 0 (and so mac != NULL)
* once all the error checks are done. */
if( operation->mac_size == 0 )
{
status = PSA_ERROR_BAD_STATE;
goto exit;
}
if( mac_size < operation->mac_size )
{
status = PSA_ERROR_BUFFER_TOO_SMALL;
goto exit;
}
status = psa_driver_wrapper_mac_sign_finish( operation,
mac, operation->mac_size,
mac_length );
exit:
/* In case of success, set the potential excess room in the output buffer
* to an invalid value, to avoid potentially leaking a longer MAC.
* In case of error, set the output length and content to a safe default,
* such that in case the caller misses an error check, the output would be
* an unachievable MAC.
*/
if( status != PSA_SUCCESS )
{
*mac_length = mac_size;
operation->mac_size = 0;
}
if( mac_size > operation->mac_size )
memset( &mac[operation->mac_size], '!',
mac_size - operation->mac_size );
abort_status = psa_mac_abort( operation );
return( status == PSA_SUCCESS ? abort_status : status );
}
psa_status_t psa_mac_verify_finish( psa_mac_operation_t *operation,
const uint8_t *mac,
size_t mac_length )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_status_t abort_status = PSA_ERROR_CORRUPTION_DETECTED;
if( operation->id == 0 )
{
status = PSA_ERROR_BAD_STATE;
goto exit;
}
if( operation->is_sign )
{
status = PSA_ERROR_BAD_STATE;
goto exit;
}
if( operation->mac_size != mac_length )
{
status = PSA_ERROR_INVALID_SIGNATURE;
goto exit;
}
status = psa_driver_wrapper_mac_verify_finish( operation,
mac, mac_length );
exit:
abort_status = psa_mac_abort( operation );
return( status == PSA_SUCCESS ? abort_status : status );
}
static psa_status_t psa_mac_compute_internal( mbedtls_svc_key_id_t key,
psa_algorithm_t alg,
const uint8_t *input,
size_t input_length,
uint8_t *mac,
size_t mac_size,
size_t *mac_length,
int is_sign )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
psa_key_slot_t *slot;
uint8_t operation_mac_size = 0;
status = psa_get_and_lock_key_slot_with_policy(
key,
&slot,
is_sign ? PSA_KEY_USAGE_SIGN_MESSAGE : PSA_KEY_USAGE_VERIFY_MESSAGE,
alg );
if( status != PSA_SUCCESS )
goto exit;
psa_key_attributes_t attributes = {
.core = slot->attr
};
status = psa_mac_finalize_alg_and_key_validation( alg, &attributes,
&operation_mac_size );
if( status != PSA_SUCCESS )
goto exit;
if( mac_size < operation_mac_size )
{
status = PSA_ERROR_BUFFER_TOO_SMALL;
goto exit;
}
status = psa_driver_wrapper_mac_compute(
&attributes,
slot->key.data, slot->key.bytes,
alg,
input, input_length,
mac, operation_mac_size, mac_length );
exit:
/* In case of success, set the potential excess room in the output buffer
* to an invalid value, to avoid potentially leaking a longer MAC.
* In case of error, set the output length and content to a safe default,
* such that in case the caller misses an error check, the output would be
* an unachievable MAC.
*/
if( status != PSA_SUCCESS )
{
*mac_length = mac_size;
operation_mac_size = 0;
}
if( mac_size > operation_mac_size )
memset( &mac[operation_mac_size], '!', mac_size - operation_mac_size );
unlock_status = psa_unlock_key_slot( slot );
return( ( status == PSA_SUCCESS ) ? unlock_status : status );
}
psa_status_t psa_mac_compute( mbedtls_svc_key_id_t key,
psa_algorithm_t alg,
const uint8_t *input,
size_t input_length,
uint8_t *mac,
size_t mac_size,
size_t *mac_length)
{
return( psa_mac_compute_internal( key, alg,
input, input_length,
mac, mac_size, mac_length, 1 ) );
}
psa_status_t psa_mac_verify( mbedtls_svc_key_id_t key,
psa_algorithm_t alg,
const uint8_t *input,
size_t input_length,
const uint8_t *mac,
size_t mac_length)
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
uint8_t actual_mac[PSA_MAC_MAX_SIZE];
size_t actual_mac_length;
status = psa_mac_compute_internal( key, alg,
input, input_length,
actual_mac, sizeof( actual_mac ),
&actual_mac_length, 0 );
if( status != PSA_SUCCESS )
goto exit;
if( mac_length != actual_mac_length )
{
status = PSA_ERROR_INVALID_SIGNATURE;
goto exit;
}
if( mbedtls_psa_safer_memcmp( mac, actual_mac, actual_mac_length ) != 0 )
{
status = PSA_ERROR_INVALID_SIGNATURE;
goto exit;
}
exit:
mbedtls_platform_zeroize( actual_mac, sizeof( actual_mac ) );
return ( status );
}
/****************************************************************/
/* Asymmetric cryptography */
/****************************************************************/
static psa_status_t psa_sign_verify_check_alg( int input_is_message,
psa_algorithm_t alg )
{
if( input_is_message )
{
if( ! PSA_ALG_IS_SIGN_MESSAGE( alg ) )
return( PSA_ERROR_INVALID_ARGUMENT );
if ( PSA_ALG_IS_SIGN_HASH( alg ) )
{
if( ! PSA_ALG_IS_HASH( PSA_ALG_SIGN_GET_HASH( alg ) ) )
return( PSA_ERROR_INVALID_ARGUMENT );
}
}
else
{
if( ! PSA_ALG_IS_SIGN_HASH( alg ) )
return( PSA_ERROR_INVALID_ARGUMENT );
}
return( PSA_SUCCESS );
}
static psa_status_t psa_sign_internal( mbedtls_svc_key_id_t key,
int input_is_message,
psa_algorithm_t alg,
const uint8_t * input,
size_t input_length,
uint8_t * signature,
size_t signature_size,
size_t * signature_length )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
psa_key_slot_t *slot;
*signature_length = 0;
status = psa_sign_verify_check_alg( input_is_message, alg );
if( status != PSA_SUCCESS )
return status;
/* Immediately reject a zero-length signature buffer. This guarantees
* that signature must be a valid pointer. (On the other hand, the input
* buffer can in principle be empty since it doesn't actually have
* to be a hash.) */
if( signature_size == 0 )
return( PSA_ERROR_BUFFER_TOO_SMALL );
status = psa_get_and_lock_key_slot_with_policy(
key, &slot,
input_is_message ? PSA_KEY_USAGE_SIGN_MESSAGE :
PSA_KEY_USAGE_SIGN_HASH,
alg );
if( status != PSA_SUCCESS )
goto exit;
if( ! PSA_KEY_TYPE_IS_KEY_PAIR( slot->attr.type ) )
{
status = PSA_ERROR_INVALID_ARGUMENT;
goto exit;
}
psa_key_attributes_t attributes = {
.core = slot->attr
};
if( input_is_message )
{
status = psa_driver_wrapper_sign_message(
&attributes, slot->key.data, slot->key.bytes,
alg, input, input_length,
signature, signature_size, signature_length );
}
else
{
status = psa_driver_wrapper_sign_hash(
&attributes, slot->key.data, slot->key.bytes,
alg, input, input_length,
signature, signature_size, signature_length );
}
exit:
/* Fill the unused part of the output buffer (the whole buffer on error,
* the trailing part on success) with something that isn't a valid signature
* (barring an attack on the signature and deliberately-crafted input),
* in case the caller doesn't check the return status properly. */
if( status == PSA_SUCCESS )
memset( signature + *signature_length, '!',
signature_size - *signature_length );
else
memset( signature, '!', signature_size );
/* If signature_size is 0 then we have nothing to do. We must not call
* memset because signature may be NULL in this case. */
unlock_status = psa_unlock_key_slot( slot );
return( ( status == PSA_SUCCESS ) ? unlock_status : status );
}
static psa_status_t psa_verify_internal( mbedtls_svc_key_id_t key,
int input_is_message,
psa_algorithm_t alg,
const uint8_t * input,
size_t input_length,
const uint8_t * signature,
size_t signature_length )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
psa_key_slot_t *slot;
status = psa_sign_verify_check_alg( input_is_message, alg );
if( status != PSA_SUCCESS )
return status;
status = psa_get_and_lock_key_slot_with_policy(
key, &slot,
input_is_message ? PSA_KEY_USAGE_VERIFY_MESSAGE :
PSA_KEY_USAGE_VERIFY_HASH,
alg );
if( status != PSA_SUCCESS )
return( status );
psa_key_attributes_t attributes = {
.core = slot->attr
};
if( input_is_message )
{
status = psa_driver_wrapper_verify_message(
&attributes, slot->key.data, slot->key.bytes,
alg, input, input_length,
signature, signature_length );
}
else
{
status = psa_driver_wrapper_verify_hash(
&attributes, slot->key.data, slot->key.bytes,
alg, input, input_length,
signature, signature_length );
}
unlock_status = psa_unlock_key_slot( slot );
return( ( status == PSA_SUCCESS ) ? unlock_status : status );
}
psa_status_t psa_sign_message_builtin(
const psa_key_attributes_t *attributes,
const uint8_t *key_buffer,
size_t key_buffer_size,
psa_algorithm_t alg,
const uint8_t *input,
size_t input_length,
uint8_t *signature,
size_t signature_size,
size_t *signature_length )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
if ( PSA_ALG_IS_SIGN_HASH( alg ) )
{
size_t hash_length;
uint8_t hash[PSA_HASH_MAX_SIZE];
status = psa_driver_wrapper_hash_compute(
PSA_ALG_SIGN_GET_HASH( alg ),
input, input_length,
hash, sizeof( hash ), &hash_length );
if( status != PSA_SUCCESS )
return status;
return psa_driver_wrapper_sign_hash(
attributes, key_buffer, key_buffer_size,
alg, hash, hash_length,
signature, signature_size, signature_length );
}
return( PSA_ERROR_NOT_SUPPORTED );
}
psa_status_t psa_sign_message( mbedtls_svc_key_id_t key,
psa_algorithm_t alg,
const uint8_t * input,
size_t input_length,
uint8_t * signature,
size_t signature_size,
size_t * signature_length )
{
return psa_sign_internal(
key, 1, alg, input, input_length,
signature, signature_size, signature_length );
}
psa_status_t psa_verify_message_builtin(
const psa_key_attributes_t *attributes,
const uint8_t *key_buffer,
size_t key_buffer_size,
psa_algorithm_t alg,
const uint8_t *input,
size_t input_length,
const uint8_t *signature,
size_t signature_length )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
if ( PSA_ALG_IS_SIGN_HASH( alg ) )
{
size_t hash_length;
uint8_t hash[PSA_HASH_MAX_SIZE];
status = psa_driver_wrapper_hash_compute(
PSA_ALG_SIGN_GET_HASH( alg ),
input, input_length,
hash, sizeof( hash ), &hash_length );
if( status != PSA_SUCCESS )
return status;
return psa_driver_wrapper_verify_hash(
attributes, key_buffer, key_buffer_size,
alg, hash, hash_length,
signature, signature_length );
}
return( PSA_ERROR_NOT_SUPPORTED );
}
psa_status_t psa_verify_message( mbedtls_svc_key_id_t key,
psa_algorithm_t alg,
const uint8_t * input,
size_t input_length,
const uint8_t * signature,
size_t signature_length )
{
return psa_verify_internal(
key, 1, alg, input, input_length,
signature, signature_length );
}
psa_status_t psa_sign_hash_builtin(
const psa_key_attributes_t *attributes,
const uint8_t *key_buffer, size_t key_buffer_size,
psa_algorithm_t alg, const uint8_t *hash, size_t hash_length,
uint8_t *signature, size_t signature_size, size_t *signature_length )
{
if( attributes->core.type == PSA_KEY_TYPE_RSA_KEY_PAIR )
{
if( PSA_ALG_IS_RSA_PKCS1V15_SIGN( alg ) ||
PSA_ALG_IS_RSA_PSS( alg) )
{
#if defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_SIGN) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PSS)
return( mbedtls_psa_rsa_sign_hash(
attributes,
key_buffer, key_buffer_size,
alg, hash, hash_length,
signature, signature_size, signature_length ) );
#endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_SIGN) ||
* defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PSS) */
}
else
{
return( PSA_ERROR_INVALID_ARGUMENT );
}
}
else if( PSA_KEY_TYPE_IS_ECC( attributes->core.type ) )
{
if( PSA_ALG_IS_ECDSA( alg ) )
{
#if defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA)
return( mbedtls_psa_ecdsa_sign_hash(
attributes,
key_buffer, key_buffer_size,
alg, hash, hash_length,
signature, signature_size, signature_length ) );
#endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) ||
* defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) */
}
else
{
return( PSA_ERROR_INVALID_ARGUMENT );
}
}
(void)key_buffer;
(void)key_buffer_size;
(void)hash;
(void)hash_length;
(void)signature;
(void)signature_size;
(void)signature_length;
return( PSA_ERROR_NOT_SUPPORTED );
}
psa_status_t psa_sign_hash( mbedtls_svc_key_id_t key,
psa_algorithm_t alg,
const uint8_t *hash,
size_t hash_length,
uint8_t *signature,
size_t signature_size,
size_t *signature_length )
{
return psa_sign_internal(
key, 0, alg, hash, hash_length,
signature, signature_size, signature_length );
}
psa_status_t psa_verify_hash_builtin(
const psa_key_attributes_t *attributes,
const uint8_t *key_buffer, size_t key_buffer_size,
psa_algorithm_t alg, const uint8_t *hash, size_t hash_length,
const uint8_t *signature, size_t signature_length )
{
if( PSA_KEY_TYPE_IS_RSA( attributes->core.type ) )
{
if( PSA_ALG_IS_RSA_PKCS1V15_SIGN( alg ) ||
PSA_ALG_IS_RSA_PSS( alg) )
{
#if defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_SIGN) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PSS)
return( mbedtls_psa_rsa_verify_hash(
attributes,
key_buffer, key_buffer_size,
alg, hash, hash_length,
signature, signature_length ) );
#endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PKCS1V15_SIGN) ||
* defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PSS) */
}
else
{
return( PSA_ERROR_INVALID_ARGUMENT );
}
}
else if( PSA_KEY_TYPE_IS_ECC( attributes->core.type ) )
{
if( PSA_ALG_IS_ECDSA( alg ) )
{
#if defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA)
return( mbedtls_psa_ecdsa_verify_hash(
attributes,
key_buffer, key_buffer_size,
alg, hash, hash_length,
signature, signature_length ) );
#endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) ||
* defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) */
}
else
{
return( PSA_ERROR_INVALID_ARGUMENT );
}
}
(void)key_buffer;
(void)key_buffer_size;
(void)hash;
(void)hash_length;
(void)signature;
(void)signature_length;
return( PSA_ERROR_NOT_SUPPORTED );
}
psa_status_t psa_verify_hash( mbedtls_svc_key_id_t key,
psa_algorithm_t alg,
const uint8_t *hash,
size_t hash_length,
const uint8_t *signature,
size_t signature_length )
{
return psa_verify_internal(
key, 0, alg, hash, hash_length,
signature, signature_length );
}
psa_status_t psa_asymmetric_encrypt( mbedtls_svc_key_id_t key,
psa_algorithm_t alg,
const uint8_t *input,
size_t input_length,
const uint8_t *salt,
size_t salt_length,
uint8_t *output,
size_t output_size,
size_t *output_length )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
psa_key_slot_t *slot;
(void) input;
(void) input_length;
(void) salt;
(void) output;
(void) output_size;
*output_length = 0;
if( ! PSA_ALG_IS_RSA_OAEP( alg ) && salt_length != 0 )
return( PSA_ERROR_INVALID_ARGUMENT );
status = psa_get_and_lock_transparent_key_slot_with_policy(
key, &slot, PSA_KEY_USAGE_ENCRYPT, alg );
if( status != PSA_SUCCESS )
return( status );
if( ! ( PSA_KEY_TYPE_IS_PUBLIC_KEY( slot->attr.type ) ||
PSA_KEY_TYPE_IS_KEY_PAIR( slot->attr.type ) ) )
{
status = PSA_ERROR_INVALID_ARGUMENT;
goto exit;
}
psa_key_attributes_t attributes = {
.core = slot->attr
};
status = psa_driver_wrapper_asymmetric_encrypt(
&attributes, slot->key.data, slot->key.bytes,
alg, input, input_length, salt, salt_length,
output, output_size, output_length );
exit:
unlock_status = psa_unlock_key_slot( slot );
return( ( status == PSA_SUCCESS ) ? unlock_status : status );
}
psa_status_t psa_asymmetric_decrypt( mbedtls_svc_key_id_t key,
psa_algorithm_t alg,
const uint8_t *input,
size_t input_length,
const uint8_t *salt,
size_t salt_length,
uint8_t *output,
size_t output_size,
size_t *output_length )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
psa_key_slot_t *slot;
(void) input;
(void) input_length;
(void) salt;
(void) output;
(void) output_size;
*output_length = 0;
if( ! PSA_ALG_IS_RSA_OAEP( alg ) && salt_length != 0 )
return( PSA_ERROR_INVALID_ARGUMENT );
status = psa_get_and_lock_transparent_key_slot_with_policy(
key, &slot, PSA_KEY_USAGE_DECRYPT, alg );
if( status != PSA_SUCCESS )
return( status );
if( ! PSA_KEY_TYPE_IS_KEY_PAIR( slot->attr.type ) )
{
status = PSA_ERROR_INVALID_ARGUMENT;
goto exit;
}
psa_key_attributes_t attributes = {
.core = slot->attr
};
status = psa_driver_wrapper_asymmetric_decrypt(
&attributes, slot->key.data, slot->key.bytes,
alg, input, input_length, salt, salt_length,
output, output_size, output_length );
exit:
unlock_status = psa_unlock_key_slot( slot );
return( ( status == PSA_SUCCESS ) ? unlock_status : status );
}
/****************************************************************/
/* Symmetric cryptography */
/****************************************************************/
static psa_status_t psa_cipher_setup( psa_cipher_operation_t *operation,
mbedtls_svc_key_id_t key,
psa_algorithm_t alg,
mbedtls_operation_t cipher_operation )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
psa_key_slot_t *slot = NULL;
psa_key_usage_t usage = ( cipher_operation == MBEDTLS_ENCRYPT ?
PSA_KEY_USAGE_ENCRYPT :
PSA_KEY_USAGE_DECRYPT );
/* A context must be freshly initialized before it can be set up. */
if( operation->id != 0 )
{
status = PSA_ERROR_BAD_STATE;
goto exit;
}
if( ! PSA_ALG_IS_CIPHER( alg ) )
{
status = PSA_ERROR_INVALID_ARGUMENT;
goto exit;
}
status = psa_get_and_lock_key_slot_with_policy( key, &slot, usage, alg );
if( status != PSA_SUCCESS )
goto exit;
/* Initialize the operation struct members, except for id. The id member
* is used to indicate to psa_cipher_abort that there are resources to free,
* so we only set it (in the driver wrapper) after resources have been
* allocated/initialized. */
operation->iv_set = 0;
if( alg == PSA_ALG_ECB_NO_PADDING )
operation->iv_required = 0;
else
operation->iv_required = 1;
operation->default_iv_length = PSA_CIPHER_IV_LENGTH( slot->attr.type, alg );
psa_key_attributes_t attributes = {
.core = slot->attr
};
/* Try doing the operation through a driver before using software fallback. */
if( cipher_operation == MBEDTLS_ENCRYPT )
status = psa_driver_wrapper_cipher_encrypt_setup( operation,
&attributes,
slot->key.data,
slot->key.bytes,
alg );
else
status = psa_driver_wrapper_cipher_decrypt_setup( operation,
&attributes,
slot->key.data,
slot->key.bytes,
alg );
exit:
if( status != PSA_SUCCESS )
psa_cipher_abort( operation );
unlock_status = psa_unlock_key_slot( slot );
return( ( status == PSA_SUCCESS ) ? unlock_status : status );
}
psa_status_t psa_cipher_encrypt_setup( psa_cipher_operation_t *operation,
mbedtls_svc_key_id_t key,
psa_algorithm_t alg )
{
return( psa_cipher_setup( operation, key, alg, MBEDTLS_ENCRYPT ) );
}
psa_status_t psa_cipher_decrypt_setup( psa_cipher_operation_t *operation,
mbedtls_svc_key_id_t key,
psa_algorithm_t alg )
{
return( psa_cipher_setup( operation, key, alg, MBEDTLS_DECRYPT ) );
}
psa_status_t psa_cipher_generate_iv( psa_cipher_operation_t *operation,
uint8_t *iv,
size_t iv_size,
size_t *iv_length )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
uint8_t local_iv[PSA_CIPHER_IV_MAX_SIZE];
size_t default_iv_length;
if( operation->id == 0 )
{
status = PSA_ERROR_BAD_STATE;
goto exit;
}
if( operation->iv_set || ! operation->iv_required )
{
status = PSA_ERROR_BAD_STATE;
goto exit;
}
default_iv_length = operation->default_iv_length;
if( iv_size < default_iv_length )
{
status = PSA_ERROR_BUFFER_TOO_SMALL;
goto exit;
}
if( default_iv_length > PSA_CIPHER_IV_MAX_SIZE )
{
status = PSA_ERROR_GENERIC_ERROR;
goto exit;
}
status = psa_generate_random( local_iv, default_iv_length );
if( status != PSA_SUCCESS )
goto exit;
status = psa_driver_wrapper_cipher_set_iv( operation,
local_iv, default_iv_length );
exit:
if( status == PSA_SUCCESS )
{
memcpy( iv, local_iv, default_iv_length );
*iv_length = default_iv_length;
operation->iv_set = 1;
}
else
{
*iv_length = 0;
psa_cipher_abort( operation );
}
return( status );
}
psa_status_t psa_cipher_set_iv( psa_cipher_operation_t *operation,
const uint8_t *iv,
size_t iv_length )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
if( operation->id == 0 )
{
status = PSA_ERROR_BAD_STATE;
goto exit;
}
if( operation->iv_set || ! operation->iv_required )
{
status = PSA_ERROR_BAD_STATE;
goto exit;
}
if( iv_length > PSA_CIPHER_IV_MAX_SIZE )
{
status = PSA_ERROR_INVALID_ARGUMENT;
goto exit;
}
status = psa_driver_wrapper_cipher_set_iv( operation,
iv,
iv_length );
exit:
if( status == PSA_SUCCESS )
operation->iv_set = 1;
else
psa_cipher_abort( operation );
return( status );
}
psa_status_t psa_cipher_update( psa_cipher_operation_t *operation,
const uint8_t *input,
size_t input_length,
uint8_t *output,
size_t output_size,
size_t *output_length )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
if( operation->id == 0 )
{
status = PSA_ERROR_BAD_STATE;
goto exit;
}
if( operation->iv_required && ! operation->iv_set )
{
status = PSA_ERROR_BAD_STATE;
goto exit;
}
status = psa_driver_wrapper_cipher_update( operation,
input,
input_length,
output,
output_size,
output_length );
exit:
if( status != PSA_SUCCESS )
psa_cipher_abort( operation );
return( status );
}
psa_status_t psa_cipher_finish( psa_cipher_operation_t *operation,
uint8_t *output,
size_t output_size,
size_t *output_length )
{
psa_status_t status = PSA_ERROR_GENERIC_ERROR;
if( operation->id == 0 )
{
status = PSA_ERROR_BAD_STATE;
goto exit;
}
if( operation->iv_required && ! operation->iv_set )
{
status = PSA_ERROR_BAD_STATE;
goto exit;
}
status = psa_driver_wrapper_cipher_finish( operation,
output,
output_size,
output_length );
exit:
if( status == PSA_SUCCESS )
return( psa_cipher_abort( operation ) );
else
{
*output_length = 0;
(void) psa_cipher_abort( operation );
return( status );
}
}
psa_status_t psa_cipher_abort( psa_cipher_operation_t *operation )
{
if( operation->id == 0 )
{
/* The object has (apparently) been initialized but it is not (yet)
* in use. It's ok to call abort on such an object, and there's
* nothing to do. */
return( PSA_SUCCESS );
}
psa_driver_wrapper_cipher_abort( operation );
operation->id = 0;
operation->iv_set = 0;
operation->iv_required = 0;
return( PSA_SUCCESS );
}
psa_status_t psa_cipher_encrypt( mbedtls_svc_key_id_t key,
psa_algorithm_t alg,
const uint8_t *input,
size_t input_length,
uint8_t *output,
size_t output_size,
size_t *output_length )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
psa_key_slot_t *slot = NULL;
uint8_t local_iv[PSA_CIPHER_IV_MAX_SIZE];
size_t default_iv_length = 0;
if( ! PSA_ALG_IS_CIPHER( alg ) )
{
status = PSA_ERROR_INVALID_ARGUMENT;
goto exit;
}
status = psa_get_and_lock_key_slot_with_policy( key, &slot,
PSA_KEY_USAGE_ENCRYPT,
alg );
if( status != PSA_SUCCESS )
goto exit;
psa_key_attributes_t attributes = {
.core = slot->attr
};
default_iv_length = PSA_CIPHER_IV_LENGTH( slot->attr.type, alg );
if( default_iv_length > PSA_CIPHER_IV_MAX_SIZE )
{
status = PSA_ERROR_GENERIC_ERROR;
goto exit;
}
if( default_iv_length > 0 )
{
if( output_size < default_iv_length )
{
status = PSA_ERROR_BUFFER_TOO_SMALL;
goto exit;
}
status = psa_generate_random( local_iv, default_iv_length );
if( status != PSA_SUCCESS )
goto exit;
}
status = psa_driver_wrapper_cipher_encrypt(
&attributes, slot->key.data, slot->key.bytes,
alg, local_iv, default_iv_length, input, input_length,
output + default_iv_length, output_size - default_iv_length,
output_length );
exit:
unlock_status = psa_unlock_key_slot( slot );
if( status == PSA_SUCCESS )
status = unlock_status;
if( status == PSA_SUCCESS )
{
if( default_iv_length > 0 )
memcpy( output, local_iv, default_iv_length );
*output_length += default_iv_length;
}
else
*output_length = 0;
return( status );
}
psa_status_t psa_cipher_decrypt( mbedtls_svc_key_id_t key,
psa_algorithm_t alg,
const uint8_t *input,
size_t input_length,
uint8_t *output,
size_t output_size,
size_t *output_length )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
psa_key_slot_t *slot = NULL;
if( ! PSA_ALG_IS_CIPHER( alg ) )
{
status = PSA_ERROR_INVALID_ARGUMENT;
goto exit;
}
status = psa_get_and_lock_key_slot_with_policy( key, &slot,
PSA_KEY_USAGE_DECRYPT,
alg );
if( status != PSA_SUCCESS )
goto exit;
psa_key_attributes_t attributes = {
.core = slot->attr
};
if( alg == PSA_ALG_CCM_STAR_NO_TAG && input_length < PSA_BLOCK_CIPHER_BLOCK_LENGTH( slot->attr.type ) )
{
status = PSA_ERROR_INVALID_ARGUMENT;
goto exit;
}
else if ( input_length < PSA_CIPHER_IV_LENGTH( slot->attr.type, alg ) )
{
status = PSA_ERROR_INVALID_ARGUMENT;
goto exit;
}
status = psa_driver_wrapper_cipher_decrypt(
&attributes, slot->key.data, slot->key.bytes,
alg, input, input_length,
output, output_size, output_length );
exit:
unlock_status = psa_unlock_key_slot( slot );
if( status == PSA_SUCCESS )
status = unlock_status;
if( status != PSA_SUCCESS )
*output_length = 0;
return( status );
}
/****************************************************************/
/* AEAD */
/****************************************************************/
/* Helper function to get the base algorithm from its variants. */
static psa_algorithm_t psa_aead_get_base_algorithm( psa_algorithm_t alg )
{
return PSA_ALG_AEAD_WITH_DEFAULT_LENGTH_TAG( alg );
}
/* Helper function to perform common nonce length checks. */
static psa_status_t psa_aead_check_nonce_length( psa_algorithm_t alg,
size_t nonce_length )
{
psa_algorithm_t base_alg = psa_aead_get_base_algorithm( alg );
switch(base_alg)
{
#if defined(PSA_WANT_ALG_GCM)
case PSA_ALG_GCM:
/* Not checking max nonce size here as GCM spec allows almost
* arbitrarily large nonces. Please note that we do not generally
* recommend the usage of nonces of greater length than
* PSA_AEAD_NONCE_MAX_SIZE, as large nonces are hashed to a shorter
* size, which can then lead to collisions if you encrypt a very
* large number of messages.*/
if( nonce_length != 0 )
return( PSA_SUCCESS );
break;
#endif /* PSA_WANT_ALG_GCM */
#if defined(PSA_WANT_ALG_CCM)
case PSA_ALG_CCM:
if( nonce_length >= 7 && nonce_length <= 13 )
return( PSA_SUCCESS );
break;
#endif /* PSA_WANT_ALG_CCM */
#if defined(PSA_WANT_ALG_CHACHA20_POLY1305)
case PSA_ALG_CHACHA20_POLY1305:
if( nonce_length == 12 )
return( PSA_SUCCESS );
else if( nonce_length == 8 )
return( PSA_ERROR_NOT_SUPPORTED );
break;
#endif /* PSA_WANT_ALG_CHACHA20_POLY1305 */
default:
return( PSA_ERROR_NOT_SUPPORTED );
}
return( PSA_ERROR_INVALID_ARGUMENT );
}
static psa_status_t psa_aead_check_algorithm( psa_algorithm_t alg )
{
if( !PSA_ALG_IS_AEAD( alg ) || PSA_ALG_IS_WILDCARD( alg ) )
return( PSA_ERROR_INVALID_ARGUMENT );
return( PSA_SUCCESS );
}
psa_status_t psa_aead_encrypt( mbedtls_svc_key_id_t key,
psa_algorithm_t alg,
const uint8_t *nonce,
size_t nonce_length,
const uint8_t *additional_data,
size_t additional_data_length,
const uint8_t *plaintext,
size_t plaintext_length,
uint8_t *ciphertext,
size_t ciphertext_size,
size_t *ciphertext_length )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_key_slot_t *slot;
*ciphertext_length = 0;
status = psa_aead_check_algorithm( alg );
if( status != PSA_SUCCESS )
return( status );
status = psa_get_and_lock_key_slot_with_policy(
key, &slot, PSA_KEY_USAGE_ENCRYPT, alg );
if( status != PSA_SUCCESS )
return( status );
psa_key_attributes_t attributes = {
.core = slot->attr
};
status = psa_aead_check_nonce_length( alg, nonce_length );
if( status != PSA_SUCCESS )
goto exit;
status = psa_driver_wrapper_aead_encrypt(
&attributes, slot->key.data, slot->key.bytes,
alg,
nonce, nonce_length,
additional_data, additional_data_length,
plaintext, plaintext_length,
ciphertext, ciphertext_size, ciphertext_length );
if( status != PSA_SUCCESS && ciphertext_size != 0 )
memset( ciphertext, 0, ciphertext_size );
exit:
psa_unlock_key_slot( slot );
return( status );
}
psa_status_t psa_aead_decrypt( mbedtls_svc_key_id_t key,
psa_algorithm_t alg,
const uint8_t *nonce,
size_t nonce_length,
const uint8_t *additional_data,
size_t additional_data_length,
const uint8_t *ciphertext,
size_t ciphertext_length,
uint8_t *plaintext,
size_t plaintext_size,
size_t *plaintext_length )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_key_slot_t *slot;
*plaintext_length = 0;
status = psa_aead_check_algorithm( alg );
if( status != PSA_SUCCESS )
return( status );
status = psa_get_and_lock_key_slot_with_policy(
key, &slot, PSA_KEY_USAGE_DECRYPT, alg );
if( status != PSA_SUCCESS )
return( status );
psa_key_attributes_t attributes = {
.core = slot->attr
};
status = psa_aead_check_nonce_length( alg, nonce_length );
if( status != PSA_SUCCESS )
goto exit;
status = psa_driver_wrapper_aead_decrypt(
&attributes, slot->key.data, slot->key.bytes,
alg,
nonce, nonce_length,
additional_data, additional_data_length,
ciphertext, ciphertext_length,
plaintext, plaintext_size, plaintext_length );
if( status != PSA_SUCCESS && plaintext_size != 0 )
memset( plaintext, 0, plaintext_size );
exit:
psa_unlock_key_slot( slot );
return( status );
}
static psa_status_t psa_validate_tag_length( psa_aead_operation_t *operation,
psa_algorithm_t alg ) {
uint8_t tag_len = 0;
if( psa_driver_get_tag_len( operation, &tag_len ) != PSA_SUCCESS )
{
return( PSA_ERROR_INVALID_ARGUMENT );
}
switch( PSA_ALG_AEAD_WITH_SHORTENED_TAG( alg, 0 ) )
{
#if defined(MBEDTLS_PSA_BUILTIN_ALG_CCM)
case PSA_ALG_AEAD_WITH_SHORTENED_TAG( PSA_ALG_CCM, 0 ):
/* CCM allows the following tag lengths: 4, 6, 8, 10, 12, 14, 16.*/
if( tag_len < 4 || tag_len > 16 || tag_len % 2 )
return( PSA_ERROR_INVALID_ARGUMENT );
break;
#endif /* MBEDTLS_PSA_BUILTIN_ALG_CCM */
#if defined(MBEDTLS_PSA_BUILTIN_ALG_GCM)
case PSA_ALG_AEAD_WITH_SHORTENED_TAG( PSA_ALG_GCM, 0 ):
/* GCM allows the following tag lengths: 4, 8, 12, 13, 14, 15, 16. */
if( tag_len != 4 && tag_len != 8 && ( tag_len < 12 || tag_len > 16 ) )
return( PSA_ERROR_INVALID_ARGUMENT );
break;
#endif /* MBEDTLS_PSA_BUILTIN_ALG_GCM */
#if defined(MBEDTLS_PSA_BUILTIN_ALG_CHACHA20_POLY1305)
case PSA_ALG_AEAD_WITH_SHORTENED_TAG( PSA_ALG_CHACHA20_POLY1305, 0 ):
/* We only support the default tag length. */
if( tag_len != 16 )
return( PSA_ERROR_INVALID_ARGUMENT );
break;
#endif /* MBEDTLS_PSA_BUILTIN_ALG_CHACHA20_POLY1305 */
default:
(void) tag_len;
return( PSA_ERROR_NOT_SUPPORTED );
}
return( PSA_SUCCESS );
}
/* Set the key for a multipart authenticated operation. */
static psa_status_t psa_aead_setup( psa_aead_operation_t *operation,
int is_encrypt,
mbedtls_svc_key_id_t key,
psa_algorithm_t alg )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
psa_key_slot_t *slot = NULL;
psa_key_usage_t key_usage = 0;
status = psa_aead_check_algorithm( alg );
if( status != PSA_SUCCESS )
goto exit;
if( operation->id != 0 )
{
status = PSA_ERROR_BAD_STATE;
goto exit;
}
if( operation->nonce_set || operation->lengths_set ||
operation->ad_started || operation->body_started )
{
status = PSA_ERROR_BAD_STATE;
goto exit;
}
if( is_encrypt )
key_usage = PSA_KEY_USAGE_ENCRYPT;
else
key_usage = PSA_KEY_USAGE_DECRYPT;
status = psa_get_and_lock_key_slot_with_policy( key, &slot, key_usage,
alg );
if( status != PSA_SUCCESS )
goto exit;
psa_key_attributes_t attributes = {
.core = slot->attr
};
if( is_encrypt )
status = psa_driver_wrapper_aead_encrypt_setup( operation,
&attributes,
slot->key.data,
slot->key.bytes,
alg );
else
status = psa_driver_wrapper_aead_decrypt_setup( operation,
&attributes,
slot->key.data,
slot->key.bytes,
alg );
if( status != PSA_SUCCESS )
goto exit;
if( ( status = psa_validate_tag_length( operation, alg ) ) != PSA_SUCCESS )
goto exit;
operation->key_type = psa_get_key_type( &attributes );
exit:
unlock_status = psa_unlock_key_slot( slot );
if( status == PSA_SUCCESS )
{
status = unlock_status;
operation->alg = psa_aead_get_base_algorithm( alg );
operation->is_encrypt = is_encrypt;
}
else
psa_aead_abort( operation );
return( status );
}
/* Set the key for a multipart authenticated encryption operation. */
psa_status_t psa_aead_encrypt_setup( psa_aead_operation_t *operation,
mbedtls_svc_key_id_t key,
psa_algorithm_t alg )
{
return( psa_aead_setup( operation, 1, key, alg ) );
}
/* Set the key for a multipart authenticated decryption operation. */
psa_status_t psa_aead_decrypt_setup( psa_aead_operation_t *operation,
mbedtls_svc_key_id_t key,
psa_algorithm_t alg )
{
return( psa_aead_setup( operation, 0, key, alg ) );
}
/* Generate a random nonce / IV for multipart AEAD operation */
psa_status_t psa_aead_generate_nonce( psa_aead_operation_t *operation,
uint8_t *nonce,
size_t nonce_size,
size_t *nonce_length )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
uint8_t local_nonce[PSA_AEAD_NONCE_MAX_SIZE];
size_t required_nonce_size;
*nonce_length = 0;
if( operation->id == 0 )
{
status = PSA_ERROR_BAD_STATE;
goto exit;
}
if( operation->nonce_set || !operation->is_encrypt )
{
status = PSA_ERROR_BAD_STATE;
goto exit;
}
/* For CCM, this size may not be correct according to the PSA
* specification. The PSA Crypto 1.0.1 specification states:
*
* CCM encodes the plaintext length pLen in L octets, with L the smallest
* integer >= 2 where pLen < 2^(8L). The nonce length is then 15 - L bytes.
*
* However this restriction that L has to be the smallest integer is not
* applied in practice, and it is not implementable here since the
* plaintext length may or may not be known at this time. */
required_nonce_size = PSA_AEAD_NONCE_LENGTH( operation->key_type,
operation->alg );
if( nonce_size < required_nonce_size )
{
status = PSA_ERROR_BUFFER_TOO_SMALL;
goto exit;
}
status = psa_generate_random( local_nonce, required_nonce_size );
if( status != PSA_SUCCESS )
goto exit;
status = psa_aead_set_nonce( operation, local_nonce, required_nonce_size );
exit:
if( status == PSA_SUCCESS )
{
memcpy( nonce, local_nonce, required_nonce_size );
*nonce_length = required_nonce_size;
}
else
psa_aead_abort( operation );
return( status );
}
/* Set the nonce for a multipart authenticated encryption or decryption
operation.*/
psa_status_t psa_aead_set_nonce( psa_aead_operation_t *operation,
const uint8_t *nonce,
size_t nonce_length )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
if( operation->id == 0 )
{
status = PSA_ERROR_BAD_STATE;
goto exit;
}
if( operation->nonce_set )
{
status = PSA_ERROR_BAD_STATE;
goto exit;
}
status = psa_aead_check_nonce_length( operation->alg, nonce_length );
if( status != PSA_SUCCESS )
{
status = PSA_ERROR_INVALID_ARGUMENT;
goto exit;
}
status = psa_driver_wrapper_aead_set_nonce( operation, nonce,
nonce_length );
exit:
if( status == PSA_SUCCESS )
operation->nonce_set = 1;
else
psa_aead_abort( operation );
return( status );
}
/* Declare the lengths of the message and additional data for multipart AEAD. */
psa_status_t psa_aead_set_lengths( psa_aead_operation_t *operation,
size_t ad_length,
size_t plaintext_length )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
if( operation->id == 0 )
{
status = PSA_ERROR_BAD_STATE;
goto exit;
}
if( operation->lengths_set || operation->ad_started ||
operation->body_started )
{
status = PSA_ERROR_BAD_STATE;
goto exit;
}
switch(operation->alg)
{
#if defined(PSA_WANT_ALG_GCM)
case PSA_ALG_GCM:
/* Lengths can only be too large for GCM if size_t is bigger than 32
* bits. Without the guard this code will generate warnings on 32bit
* builds. */
#if SIZE_MAX > UINT32_MAX
if( (( uint64_t ) ad_length ) >> 61 != 0 ||
(( uint64_t ) plaintext_length ) > 0xFFFFFFFE0ull )
{
status = PSA_ERROR_INVALID_ARGUMENT;
goto exit;
}
#endif
break;
#endif /* PSA_WANT_ALG_GCM */
#if defined(PSA_WANT_ALG_CCM)
case PSA_ALG_CCM:
if( ad_length > 0xFF00 )
{
status = PSA_ERROR_INVALID_ARGUMENT;
goto exit;
}
break;
#endif /* PSA_WANT_ALG_CCM */
#if defined(PSA_WANT_ALG_CHACHA20_POLY1305)
case PSA_ALG_CHACHA20_POLY1305:
/* No length restrictions for ChaChaPoly. */
break;
#endif /* PSA_WANT_ALG_CHACHA20_POLY1305 */
default:
break;
}
status = psa_driver_wrapper_aead_set_lengths( operation, ad_length,
plaintext_length );
exit:
if( status == PSA_SUCCESS )
{
operation->ad_remaining = ad_length;
operation->body_remaining = plaintext_length;
operation->lengths_set = 1;
}
else
psa_aead_abort( operation );
return( status );
}
/* Pass additional data to an active multipart AEAD operation. */
psa_status_t psa_aead_update_ad( psa_aead_operation_t *operation,
const uint8_t *input,
size_t input_length )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
if( operation->id == 0 )
{
status = PSA_ERROR_BAD_STATE;
goto exit;
}
if( !operation->nonce_set || operation->body_started )
{
status = PSA_ERROR_BAD_STATE;
goto exit;
}
if( operation->lengths_set )
{
if( operation->ad_remaining < input_length )
{
status = PSA_ERROR_INVALID_ARGUMENT;
goto exit;
}
operation->ad_remaining -= input_length;
}
#if defined(PSA_WANT_ALG_CCM)
else if( operation->alg == PSA_ALG_CCM )
{
status = PSA_ERROR_BAD_STATE;
goto exit;
}
#endif /* PSA_WANT_ALG_CCM */
status = psa_driver_wrapper_aead_update_ad( operation, input,
input_length );
exit:
if( status == PSA_SUCCESS )
operation->ad_started = 1;
else
psa_aead_abort( operation );
return( status );
}
/* Encrypt or decrypt a message fragment in an active multipart AEAD
operation.*/
psa_status_t psa_aead_update( psa_aead_operation_t *operation,
const uint8_t *input,
size_t input_length,
uint8_t *output,
size_t output_size,
size_t *output_length )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
*output_length = 0;
if( operation->id == 0 )
{
status = PSA_ERROR_BAD_STATE;
goto exit;
}
if( !operation->nonce_set )
{
status = PSA_ERROR_BAD_STATE;
goto exit;
}
if( operation->lengths_set )
{
/* Additional data length was supplied, but not all the additional
data was supplied.*/
if( operation->ad_remaining != 0 )
{
status = PSA_ERROR_INVALID_ARGUMENT;
goto exit;
}
/* Too much data provided. */
if( operation->body_remaining < input_length )
{
status = PSA_ERROR_INVALID_ARGUMENT;
goto exit;
}
operation->body_remaining -= input_length;
}
#if defined(PSA_WANT_ALG_CCM)
else if( operation->alg == PSA_ALG_CCM )
{
status = PSA_ERROR_BAD_STATE;
goto exit;
}
#endif /* PSA_WANT_ALG_CCM */
status = psa_driver_wrapper_aead_update( operation, input, input_length,
output, output_size,
output_length );
exit:
if( status == PSA_SUCCESS )
operation->body_started = 1;
else
psa_aead_abort( operation );
return( status );
}
static psa_status_t psa_aead_final_checks( const psa_aead_operation_t *operation )
{
if( operation->id == 0 || !operation->nonce_set )
return( PSA_ERROR_BAD_STATE );
if( operation->lengths_set && ( operation->ad_remaining != 0 ||
operation->body_remaining != 0 ) )
return( PSA_ERROR_INVALID_ARGUMENT );
return( PSA_SUCCESS );
}
/* Finish encrypting a message in a multipart AEAD operation. */
psa_status_t psa_aead_finish( psa_aead_operation_t *operation,
uint8_t *ciphertext,
size_t ciphertext_size,
size_t *ciphertext_length,
uint8_t *tag,
size_t tag_size,
size_t *tag_length )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
*ciphertext_length = 0;
*tag_length = tag_size;
status = psa_aead_final_checks( operation );
if( status != PSA_SUCCESS )
goto exit;
if( !operation->is_encrypt )
{
status = PSA_ERROR_BAD_STATE;
goto exit;
}
status = psa_driver_wrapper_aead_finish( operation, ciphertext,
ciphertext_size,
ciphertext_length,
tag, tag_size, tag_length );
exit:
/* In case the operation fails and the user fails to check for failure or
* the zero tag size, make sure the tag is set to something implausible.
* Even if the operation succeeds, make sure we clear the rest of the
* buffer to prevent potential leakage of anything previously placed in
* the same buffer.*/
if( tag != NULL )
{
if( status != PSA_SUCCESS )
memset( tag, '!', tag_size );
else if( *tag_length < tag_size )
memset( tag + *tag_length, '!', ( tag_size - *tag_length ) );
}
psa_aead_abort( operation );
return( status );
}
/* Finish authenticating and decrypting a message in a multipart AEAD
operation.*/
psa_status_t psa_aead_verify( psa_aead_operation_t *operation,
uint8_t *plaintext,
size_t plaintext_size,
size_t *plaintext_length,
const uint8_t *tag,
size_t tag_length )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
*plaintext_length = 0;
status = psa_aead_final_checks( operation );
if( status != PSA_SUCCESS )
goto exit;
if( operation->is_encrypt )
{
status = PSA_ERROR_BAD_STATE;
goto exit;
}
status = psa_driver_wrapper_aead_verify( operation, plaintext,
plaintext_size,
plaintext_length,
tag, tag_length );
exit:
psa_aead_abort( operation );
return( status );
}
/* Abort an AEAD operation. */
psa_status_t psa_aead_abort( psa_aead_operation_t *operation )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
if( operation->id == 0 )
{
/* The object has (apparently) been initialized but it is not (yet)
* in use. It's ok to call abort on such an object, and there's
* nothing to do. */
return( PSA_SUCCESS );
}
status = psa_driver_wrapper_aead_abort( operation );
memset( operation, 0, sizeof( *operation ) );
return( status );
}
/****************************************************************/
/* Generators */
/****************************************************************/
#if defined(BUILTIN_ALG_ANY_HKDF) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS)
#define AT_LEAST_ONE_BUILTIN_KDF
#endif /* At least one builtin KDF */
#if defined(BUILTIN_ALG_ANY_HKDF) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS)
static psa_status_t psa_key_derivation_start_hmac(
psa_mac_operation_t *operation,
psa_algorithm_t hash_alg,
const uint8_t *hmac_key,
size_t hmac_key_length )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
psa_set_key_type( &attributes, PSA_KEY_TYPE_HMAC );
psa_set_key_bits( &attributes, PSA_BYTES_TO_BITS( hmac_key_length ) );
psa_set_key_usage_flags( &attributes, PSA_KEY_USAGE_SIGN_HASH );
operation->is_sign = 1;
operation->mac_size = PSA_HASH_LENGTH( hash_alg );
status = psa_driver_wrapper_mac_sign_setup( operation,
&attributes,
hmac_key, hmac_key_length,
PSA_ALG_HMAC( hash_alg ) );
psa_reset_key_attributes( &attributes );
return( status );
}
#endif /* KDF algorithms reliant on HMAC */
#define HKDF_STATE_INIT 0 /* no input yet */
#define HKDF_STATE_STARTED 1 /* got salt */
#define HKDF_STATE_KEYED 2 /* got key */
#define HKDF_STATE_OUTPUT 3 /* output started */
static psa_algorithm_t psa_key_derivation_get_kdf_alg(
const psa_key_derivation_operation_t *operation )
{
if ( PSA_ALG_IS_KEY_AGREEMENT( operation->alg ) )
return( PSA_ALG_KEY_AGREEMENT_GET_KDF( operation->alg ) );
else
return( operation->alg );
}
psa_status_t psa_key_derivation_abort( psa_key_derivation_operation_t *operation )
{
psa_status_t status = PSA_SUCCESS;
psa_algorithm_t kdf_alg = psa_key_derivation_get_kdf_alg( operation );
if( kdf_alg == 0 )
{
/* The object has (apparently) been initialized but it is not
* in use. It's ok to call abort on such an object, and there's
* nothing to do. */
}
else
#if defined(BUILTIN_ALG_ANY_HKDF)
if( PSA_ALG_IS_ANY_HKDF( kdf_alg ) )
{
mbedtls_free( operation->ctx.hkdf.info );
status = psa_mac_abort( &operation->ctx.hkdf.hmac );
}
else
#endif /* BUILTIN_ALG_ANY_HKDF */
#if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS)
if( PSA_ALG_IS_TLS12_PRF( kdf_alg ) ||
/* TLS-1.2 PSK-to-MS KDF uses the same core as TLS-1.2 PRF */
PSA_ALG_IS_TLS12_PSK_TO_MS( kdf_alg ) )
{
if( operation->ctx.tls12_prf.secret != NULL )
{
mbedtls_platform_zeroize( operation->ctx.tls12_prf.secret,
operation->ctx.tls12_prf.secret_length );
mbedtls_free( operation->ctx.tls12_prf.secret );
}
if( operation->ctx.tls12_prf.seed != NULL )
{
mbedtls_platform_zeroize( operation->ctx.tls12_prf.seed,
operation->ctx.tls12_prf.seed_length );
mbedtls_free( operation->ctx.tls12_prf.seed );
}
if( operation->ctx.tls12_prf.label != NULL )
{
mbedtls_platform_zeroize( operation->ctx.tls12_prf.label,
operation->ctx.tls12_prf.label_length );
mbedtls_free( operation->ctx.tls12_prf.label );
}
if( operation->ctx.tls12_prf.other_secret != NULL )
{
mbedtls_platform_zeroize( operation->ctx.tls12_prf.other_secret,
operation->ctx.tls12_prf.other_secret_length );
mbedtls_free( operation->ctx.tls12_prf.other_secret );
}
status = PSA_SUCCESS;
/* We leave the fields Ai and output_block to be erased safely by the
* mbedtls_platform_zeroize() in the end of this function. */
}
else
#endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF) ||
* defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS) */
{
status = PSA_ERROR_BAD_STATE;
}
mbedtls_platform_zeroize( operation, sizeof( *operation ) );
return( status );
}
psa_status_t psa_key_derivation_get_capacity(const psa_key_derivation_operation_t *operation,
size_t *capacity)
{
if( operation->alg == 0 )
{
/* This is a blank key derivation operation. */
return( PSA_ERROR_BAD_STATE );
}
*capacity = operation->capacity;
return( PSA_SUCCESS );
}
psa_status_t psa_key_derivation_set_capacity( psa_key_derivation_operation_t *operation,
size_t capacity )
{
if( operation->alg == 0 )
return( PSA_ERROR_BAD_STATE );
if( capacity > operation->capacity )
return( PSA_ERROR_INVALID_ARGUMENT );
operation->capacity = capacity;
return( PSA_SUCCESS );
}
#if defined(BUILTIN_ALG_ANY_HKDF)
/* Read some bytes from an HKDF-based operation. */
static psa_status_t psa_key_derivation_hkdf_read( psa_hkdf_key_derivation_t *hkdf,
psa_algorithm_t kdf_alg,
uint8_t *output,
size_t output_length )
{
psa_algorithm_t hash_alg = PSA_ALG_HKDF_GET_HASH( kdf_alg );
uint8_t hash_length = PSA_HASH_LENGTH( hash_alg );
size_t hmac_output_length;
psa_status_t status;
#if defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXTRACT)
const uint8_t last_block = PSA_ALG_IS_HKDF_EXTRACT( kdf_alg ) ? 0 : 0xff;
#else
const uint8_t last_block = 0xff;
#endif /* MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXTRACT */
if( hkdf->state < HKDF_STATE_KEYED ||
( !hkdf->info_set
#if defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXTRACT)
&& !PSA_ALG_IS_HKDF_EXTRACT( kdf_alg )
#endif /* MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXTRACT */
) )
return( PSA_ERROR_BAD_STATE );
hkdf->state = HKDF_STATE_OUTPUT;
while( output_length != 0 )
{
/* Copy what remains of the current block */
uint8_t n = hash_length - hkdf->offset_in_block;
if( n > output_length )
n = (uint8_t) output_length;
memcpy( output, hkdf->output_block + hkdf->offset_in_block, n );
output += n;
output_length -= n;
hkdf->offset_in_block += n;
if( output_length == 0 )
break;
/* We can't be wanting more output after the last block, otherwise
* the capacity check in psa_key_derivation_output_bytes() would have
* prevented this call. It could happen only if the operation
* object was corrupted or if this function is called directly
* inside the library. */
if( hkdf->block_number == last_block )
return( PSA_ERROR_BAD_STATE );
/* We need a new block */
++hkdf->block_number;
hkdf->offset_in_block = 0;
status = psa_key_derivation_start_hmac( &hkdf->hmac,
hash_alg,
hkdf->prk,
hash_length );
if( status != PSA_SUCCESS )
return( status );
if( hkdf->block_number != 1 )
{
status = psa_mac_update( &hkdf->hmac,
hkdf->output_block,
hash_length );
if( status != PSA_SUCCESS )
return( status );
}
status = psa_mac_update( &hkdf->hmac,
hkdf->info,
hkdf->info_length );
if( status != PSA_SUCCESS )
return( status );
status = psa_mac_update( &hkdf->hmac,
&hkdf->block_number, 1 );
if( status != PSA_SUCCESS )
return( status );
status = psa_mac_sign_finish( &hkdf->hmac,
hkdf->output_block,
sizeof( hkdf->output_block ),
&hmac_output_length );
if( status != PSA_SUCCESS )
return( status );
}
return( PSA_SUCCESS );
}
#endif /* BUILTIN_ALG_ANY_HKDF */
#if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS)
static psa_status_t psa_key_derivation_tls12_prf_generate_next_block(
psa_tls12_prf_key_derivation_t *tls12_prf,
psa_algorithm_t alg )
{
psa_algorithm_t hash_alg = PSA_ALG_HKDF_GET_HASH( alg );
uint8_t hash_length = PSA_HASH_LENGTH( hash_alg );
psa_mac_operation_t hmac = PSA_MAC_OPERATION_INIT;
size_t hmac_output_length;
psa_status_t status, cleanup_status;
/* We can't be wanting more output after block 0xff, otherwise
* the capacity check in psa_key_derivation_output_bytes() would have
* prevented this call. It could happen only if the operation
* object was corrupted or if this function is called directly
* inside the library. */
if( tls12_prf->block_number == 0xff )
return( PSA_ERROR_CORRUPTION_DETECTED );
/* We need a new block */
++tls12_prf->block_number;
tls12_prf->left_in_block = hash_length;
/* Recall the definition of the TLS-1.2-PRF from RFC 5246:
*
* PRF(secret, label, seed) = P_<hash>(secret, label + seed)
*
* P_hash(secret, seed) = HMAC_hash(secret, A(1) + seed) +
* HMAC_hash(secret, A(2) + seed) +
* HMAC_hash(secret, A(3) + seed) + ...
*
* A(0) = seed
* A(i) = HMAC_hash(secret, A(i-1))
*
* The `psa_tls12_prf_key_derivation` structure saves the block
* `HMAC_hash(secret, A(i) + seed)` from which the output
* is currently extracted as `output_block` and where i is
* `block_number`.
*/
status = psa_key_derivation_start_hmac( &hmac,
hash_alg,
tls12_prf->secret,
tls12_prf->secret_length );
if( status != PSA_SUCCESS )
goto cleanup;
/* Calculate A(i) where i = tls12_prf->block_number. */
if( tls12_prf->block_number == 1 )
{
/* A(1) = HMAC_hash(secret, A(0)), where A(0) = seed. (The RFC overloads
* the variable seed and in this instance means it in the context of the
* P_hash function, where seed = label + seed.) */
status = psa_mac_update( &hmac,
tls12_prf->label,
tls12_prf->label_length );
if( status != PSA_SUCCESS )
goto cleanup;
status = psa_mac_update( &hmac,
tls12_prf->seed,
tls12_prf->seed_length );
if( status != PSA_SUCCESS )
goto cleanup;
}
else
{
/* A(i) = HMAC_hash(secret, A(i-1)) */
status = psa_mac_update( &hmac, tls12_prf->Ai, hash_length );
if( status != PSA_SUCCESS )
goto cleanup;
}
status = psa_mac_sign_finish( &hmac,
tls12_prf->Ai, hash_length,
&hmac_output_length );
if( hmac_output_length != hash_length )
status = PSA_ERROR_CORRUPTION_DETECTED;
if( status != PSA_SUCCESS )
goto cleanup;
/* Calculate HMAC_hash(secret, A(i) + label + seed). */
status = psa_key_derivation_start_hmac( &hmac,
hash_alg,
tls12_prf->secret,
tls12_prf->secret_length );
if( status != PSA_SUCCESS )
goto cleanup;
status = psa_mac_update( &hmac, tls12_prf->Ai, hash_length );
if( status != PSA_SUCCESS )
goto cleanup;
status = psa_mac_update( &hmac, tls12_prf->label, tls12_prf->label_length );
if( status != PSA_SUCCESS )
goto cleanup;
status = psa_mac_update( &hmac, tls12_prf->seed, tls12_prf->seed_length );
if( status != PSA_SUCCESS )
goto cleanup;
status = psa_mac_sign_finish( &hmac,
tls12_prf->output_block, hash_length,
&hmac_output_length );
if( status != PSA_SUCCESS )
goto cleanup;
cleanup:
cleanup_status = psa_mac_abort( &hmac );
if( status == PSA_SUCCESS && cleanup_status != PSA_SUCCESS )
status = cleanup_status;
return( status );
}
static psa_status_t psa_key_derivation_tls12_prf_read(
psa_tls12_prf_key_derivation_t *tls12_prf,
psa_algorithm_t alg,
uint8_t *output,
size_t output_length )
{
psa_algorithm_t hash_alg = PSA_ALG_TLS12_PRF_GET_HASH( alg );
uint8_t hash_length = PSA_HASH_LENGTH( hash_alg );
psa_status_t status;
uint8_t offset, length;
switch( tls12_prf->state )
{
case PSA_TLS12_PRF_STATE_LABEL_SET:
tls12_prf->state = PSA_TLS12_PRF_STATE_OUTPUT;
break;
case PSA_TLS12_PRF_STATE_OUTPUT:
break;
default:
return( PSA_ERROR_BAD_STATE );
}
while( output_length != 0 )
{
/* Check if we have fully processed the current block. */
if( tls12_prf->left_in_block == 0 )
{
status = psa_key_derivation_tls12_prf_generate_next_block( tls12_prf,
alg );
if( status != PSA_SUCCESS )
return( status );
continue;
}
if( tls12_prf->left_in_block > output_length )
length = (uint8_t) output_length;
else
length = tls12_prf->left_in_block;
offset = hash_length - tls12_prf->left_in_block;
memcpy( output, tls12_prf->output_block + offset, length );
output += length;
output_length -= length;
tls12_prf->left_in_block -= length;
}
return( PSA_SUCCESS );
}
#endif /* MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF ||
* MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS */
psa_status_t psa_key_derivation_output_bytes(
psa_key_derivation_operation_t *operation,
uint8_t *output,
size_t output_length )
{
psa_status_t status;
psa_algorithm_t kdf_alg = psa_key_derivation_get_kdf_alg( operation );
if( operation->alg == 0 )
{
/* This is a blank operation. */
return( PSA_ERROR_BAD_STATE );
}
if( output_length > operation->capacity )
{
operation->capacity = 0;
/* Go through the error path to wipe all confidential data now
* that the operation object is useless. */
status = PSA_ERROR_INSUFFICIENT_DATA;
goto exit;
}
if( output_length == 0 && operation->capacity == 0 )
{
/* Edge case: this is a finished operation, and 0 bytes
* were requested. The right error in this case could
* be either INSUFFICIENT_CAPACITY or BAD_STATE. Return
* INSUFFICIENT_CAPACITY, which is right for a finished
* operation, for consistency with the case when
* output_length > 0. */
return( PSA_ERROR_INSUFFICIENT_DATA );
}
operation->capacity -= output_length;
#if defined(BUILTIN_ALG_ANY_HKDF)
if( PSA_ALG_IS_ANY_HKDF( kdf_alg ) )
{
status = psa_key_derivation_hkdf_read( &operation->ctx.hkdf, kdf_alg,
output, output_length );
}
else
#endif /* BUILTIN_ALG_ANY_HKDF */
#if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS)
if( PSA_ALG_IS_TLS12_PRF( kdf_alg ) ||
PSA_ALG_IS_TLS12_PSK_TO_MS( kdf_alg ) )
{
status = psa_key_derivation_tls12_prf_read( &operation->ctx.tls12_prf,
kdf_alg, output,
output_length );
}
else
#endif /* MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF ||
* MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS */
{
(void) kdf_alg;
return( PSA_ERROR_BAD_STATE );
}
exit:
if( status != PSA_SUCCESS )
{
/* Preserve the algorithm upon errors, but clear all sensitive state.
* This allows us to differentiate between exhausted operations and
* blank operations, so we can return PSA_ERROR_BAD_STATE on blank
* operations. */
psa_algorithm_t alg = operation->alg;
psa_key_derivation_abort( operation );
operation->alg = alg;
memset( output, '!', output_length );
}
return( status );
}
#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_DES)
static void psa_des_set_key_parity( uint8_t *data, size_t data_size )
{
if( data_size >= 8 )
mbedtls_des_key_set_parity( data );
if( data_size >= 16 )
mbedtls_des_key_set_parity( data + 8 );
if( data_size >= 24 )
mbedtls_des_key_set_parity( data + 16 );
}
#endif /* MBEDTLS_PSA_BUILTIN_KEY_TYPE_DES */
/*
* ECC keys on a Weierstrass elliptic curve require the generation
* of a private key which is an integer
* in the range [1, N - 1], where N is the boundary of the private key domain:
* N is the prime p for Diffie-Hellman, or the order of the
* curve’s base point for ECC.
*
* Let m be the bit size of N, such that 2^m > N >= 2^(m-1).
* This function generates the private key using the following process:
*
* 1. Draw a byte string of length ceiling(m/8) bytes.
* 2. If m is not a multiple of 8, set the most significant
* (8 * ceiling(m/8) - m) bits of the first byte in the string to zero.
* 3. Convert the string to integer k by decoding it as a big-endian byte string.
* 4. If k > N - 2, discard the result and return to step 1.
* 5. Output k + 1 as the private key.
*
* This method allows compliance to NIST standards, specifically the methods titled
* Key-Pair Generation by Testing Candidates in the following publications:
* - NIST Special Publication 800-56A: Recommendation for Pair-Wise Key-Establishment
* Schemes Using Discrete Logarithm Cryptography [SP800-56A] §5.6.1.1.4 for
* Diffie-Hellman keys.
*
* - [SP800-56A] §5.6.1.2.2 or FIPS Publication 186-4: Digital Signature
* Standard (DSS) [FIPS186-4] §B.4.2 for elliptic curve keys.
*
* Note: Function allocates memory for *data buffer, so given *data should be
* always NULL.
*/
#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) || \
defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_ECDH)
static psa_status_t psa_generate_derived_ecc_key_weierstrass_helper(
psa_key_slot_t *slot,
size_t bits,
psa_key_derivation_operation_t *operation,
uint8_t **data
)
{
unsigned key_out_of_range = 1;
mbedtls_mpi k;
mbedtls_mpi diff_N_2;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
mbedtls_mpi_init( &k );
mbedtls_mpi_init( &diff_N_2 );
psa_ecc_family_t curve = PSA_KEY_TYPE_ECC_GET_FAMILY(
slot->attr.type );
mbedtls_ecp_group_id grp_id =
mbedtls_ecc_group_of_psa( curve, bits, 0 );
if( grp_id == MBEDTLS_ECP_DP_NONE )
{
ret = MBEDTLS_ERR_ASN1_INVALID_DATA;
goto cleanup;
}
mbedtls_ecp_group ecp_group;
mbedtls_ecp_group_init( &ecp_group );
MBEDTLS_MPI_CHK( mbedtls_ecp_group_load( &ecp_group, grp_id ) );
/* N is the boundary of the private key domain (ecp_group.N). */
/* Let m be the bit size of N. */
size_t m = ecp_group.nbits;
size_t m_bytes = PSA_BITS_TO_BYTES( m );
/* Calculate N - 2 - it will be needed later. */
MBEDTLS_MPI_CHK( mbedtls_mpi_sub_int( &diff_N_2, &ecp_group.N, 2 ) );
/* Note: This function is always called with *data == NULL and it
* allocates memory for the data buffer. */
*data = mbedtls_calloc( 1, m_bytes );
if( *data == NULL )
{
ret = MBEDTLS_ERR_ASN1_ALLOC_FAILED;
goto cleanup;
}
while( key_out_of_range )
{
/* 1. Draw a byte string of length ceiling(m/8) bytes. */
if( ( status = psa_key_derivation_output_bytes( operation, *data, m_bytes ) ) != 0 )
goto cleanup;
/* 2. If m is not a multiple of 8 */
if( m % 8 != 0 )
{
/* Set the most significant
* (8 * ceiling(m/8) - m) bits of the first byte in
* the string to zero.
*/
uint8_t clear_bit_mask = ( 1 << ( m % 8 ) ) - 1;
(*data)[0] &= clear_bit_mask;
}
/* 3. Convert the string to integer k by decoding it as a
* big-endian byte string.
*/
MBEDTLS_MPI_CHK( mbedtls_mpi_read_binary( &k, *data, m_bytes ) );
/* 4. If k > N - 2, discard the result and return to step 1.
* Result of comparison is returned. When it indicates error
* then this function is called again.
*/
MBEDTLS_MPI_CHK( mbedtls_mpi_lt_mpi_ct( &diff_N_2, &k, &key_out_of_range ) );
}
/* 5. Output k + 1 as the private key. */
MBEDTLS_MPI_CHK( mbedtls_mpi_add_int( &k, &k, 1 ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &k, *data, m_bytes ) );
cleanup:
if( ret != 0 )
status = mbedtls_to_psa_error( ret );
if( status != PSA_SUCCESS ) {
mbedtls_free( *data );
*data = NULL;
}
mbedtls_mpi_free( &k );
mbedtls_mpi_free( &diff_N_2 );
return( status );
}
/* ECC keys on a Montgomery elliptic curve draws a byte string whose length
* is determined by the curve, and sets the mandatory bits accordingly. That is:
*
* - Curve25519 (PSA_ECC_FAMILY_MONTGOMERY, 255 bits):
* draw a 32-byte string and process it as specified in
* Elliptic Curves for Security [RFC7748] §5.
*
* - Curve448 (PSA_ECC_FAMILY_MONTGOMERY, 448 bits):
* draw a 56-byte string and process it as specified in [RFC7748] §5.
*
* Note: Function allocates memory for *data buffer, so given *data should be
* always NULL.
*/
static psa_status_t psa_generate_derived_ecc_key_montgomery_helper(
size_t bits,
psa_key_derivation_operation_t *operation,
uint8_t **data
)
{
size_t output_length;
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
switch( bits )
{
case 255:
output_length = 32;
break;
case 448:
output_length = 56;
break;
default:
return( PSA_ERROR_INVALID_ARGUMENT );
break;
}
*data = mbedtls_calloc( 1, output_length );
if( *data == NULL )
return( PSA_ERROR_INSUFFICIENT_MEMORY );
status = psa_key_derivation_output_bytes( operation, *data, output_length );
if( status != PSA_SUCCESS )
return status;
switch( bits )
{
case 255:
(*data)[0] &= 248;
(*data)[31] &= 127;
(*data)[31] |= 64;
break;
case 448:
(*data)[0] &= 252;
(*data)[55] |= 128;
break;
default:
return( PSA_ERROR_CORRUPTION_DETECTED );
break;
}
return status;
}
#endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) ||
defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY) ||
defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) ||
defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) ||
defined(MBEDTLS_PSA_BUILTIN_ALG_ECDH) */
static psa_status_t psa_generate_derived_key_internal(
psa_key_slot_t *slot,
size_t bits,
psa_key_derivation_operation_t *operation )
{
uint8_t *data = NULL;
size_t bytes = PSA_BITS_TO_BYTES( bits );
size_t storage_size = bytes;
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
if( PSA_KEY_TYPE_IS_PUBLIC_KEY( slot->attr.type ) )
return( PSA_ERROR_INVALID_ARGUMENT );
#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) || \
defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_ECDH)
if( PSA_KEY_TYPE_IS_ECC( slot->attr.type ) )
{
psa_ecc_family_t curve = PSA_KEY_TYPE_ECC_GET_FAMILY( slot->attr.type );
if( PSA_ECC_FAMILY_IS_WEIERSTRASS( curve ) )
{
/* Weierstrass elliptic curve */
status = psa_generate_derived_ecc_key_weierstrass_helper( slot, bits, operation, &data );
if( status != PSA_SUCCESS )
goto exit;
}
else
{
/* Montgomery elliptic curve */
status = psa_generate_derived_ecc_key_montgomery_helper( bits, operation, &data );
if( status != PSA_SUCCESS )
goto exit;
}
} else
#endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) ||
defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY) ||
defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) ||
defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) ||
defined(MBEDTLS_PSA_BUILTIN_ALG_ECDH) */
if( key_type_is_raw_bytes( slot->attr.type ) )
{
if( bits % 8 != 0 )
return( PSA_ERROR_INVALID_ARGUMENT );
data = mbedtls_calloc( 1, bytes );
if( data == NULL )
return( PSA_ERROR_INSUFFICIENT_MEMORY );
status = psa_key_derivation_output_bytes( operation, data, bytes );
if( status != PSA_SUCCESS )
goto exit;
#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_DES)
if( slot->attr.type == PSA_KEY_TYPE_DES )
psa_des_set_key_parity( data, bytes );
#endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_DES) */
}
else
return( PSA_ERROR_NOT_SUPPORTED );
slot->attr.bits = (psa_key_bits_t) bits;
psa_key_attributes_t attributes = {
.core = slot->attr
};
if( psa_key_lifetime_is_external( attributes.core.lifetime ) )
{
status = psa_driver_wrapper_get_key_buffer_size( &attributes,
&storage_size );
if( status != PSA_SUCCESS )
goto exit;
}
status = psa_allocate_buffer_to_slot( slot, storage_size );
if( status != PSA_SUCCESS )
goto exit;
status = psa_driver_wrapper_import_key( &attributes,
data, bytes,
slot->key.data,
slot->key.bytes,
&slot->key.bytes, &bits );
if( bits != slot->attr.bits )
status = PSA_ERROR_INVALID_ARGUMENT;
exit:
mbedtls_free( data );
return( status );
}
psa_status_t psa_key_derivation_output_key( const psa_key_attributes_t *attributes,
psa_key_derivation_operation_t *operation,
mbedtls_svc_key_id_t *key )
{
psa_status_t status;
psa_key_slot_t *slot = NULL;
psa_se_drv_table_entry_t *driver = NULL;
*key = MBEDTLS_SVC_KEY_ID_INIT;
/* Reject any attempt to create a zero-length key so that we don't
* risk tripping up later, e.g. on a malloc(0) that returns NULL. */
if( psa_get_key_bits( attributes ) == 0 )
return( PSA_ERROR_INVALID_ARGUMENT );
if( operation->alg == PSA_ALG_NONE )
return( PSA_ERROR_BAD_STATE );
if( ! operation->can_output_key )
return( PSA_ERROR_NOT_PERMITTED );
status = psa_start_key_creation( PSA_KEY_CREATION_DERIVE, attributes,
&slot, &driver );
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
if( driver != NULL )
{
/* Deriving a key in a secure element is not implemented yet. */
status = PSA_ERROR_NOT_SUPPORTED;
}
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
if( status == PSA_SUCCESS )
{
status = psa_generate_derived_key_internal( slot,
attributes->core.bits,
operation );
}
if( status == PSA_SUCCESS )
status = psa_finish_key_creation( slot, driver, key );
if( status != PSA_SUCCESS )
psa_fail_key_creation( slot, driver );
return( status );
}
/****************************************************************/
/* Key derivation */
/****************************************************************/
#if defined(AT_LEAST_ONE_BUILTIN_KDF)
static int is_kdf_alg_supported( psa_algorithm_t kdf_alg )
{
#if defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF)
if( PSA_ALG_IS_HKDF( kdf_alg ) )
return( 1 );
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXTRACT)
if( PSA_ALG_IS_HKDF_EXTRACT( kdf_alg ) )
return( 1 );
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXPAND)
if( PSA_ALG_IS_HKDF_EXPAND( kdf_alg ) )
return( 1 );
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF)
if( PSA_ALG_IS_TLS12_PRF( kdf_alg ) )
return( 1 );
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS)
if( PSA_ALG_IS_TLS12_PSK_TO_MS( kdf_alg ) )
return( 1 );
#endif
return( 0 );
}
static psa_status_t psa_hash_try_support( psa_algorithm_t alg )
{
psa_hash_operation_t operation = PSA_HASH_OPERATION_INIT;
psa_status_t status = psa_hash_setup( &operation, alg );
psa_hash_abort( &operation );
return( status );
}
static psa_status_t psa_key_derivation_setup_kdf(
psa_key_derivation_operation_t *operation,
psa_algorithm_t kdf_alg )
{
/* Make sure that operation->ctx is properly zero-initialised. (Macro
* initialisers for this union leave some bytes unspecified.) */
memset( &operation->ctx, 0, sizeof( operation->ctx ) );
/* Make sure that kdf_alg is a supported key derivation algorithm. */
if( ! is_kdf_alg_supported( kdf_alg ) )
return( PSA_ERROR_NOT_SUPPORTED );
/* All currently supported key derivation algorithms are based on a
* hash algorithm. */
psa_algorithm_t hash_alg = PSA_ALG_HKDF_GET_HASH( kdf_alg );
size_t hash_size = PSA_HASH_LENGTH( hash_alg );
if( hash_size == 0 )
return( PSA_ERROR_NOT_SUPPORTED );
/* Make sure that hash_alg is a supported hash algorithm. Otherwise
* we might fail later, which is somewhat unfriendly and potentially
* risk-prone. */
psa_status_t status = psa_hash_try_support( hash_alg );
if( status != PSA_SUCCESS )
return( status );
if( ( PSA_ALG_IS_TLS12_PRF( kdf_alg ) ||
PSA_ALG_IS_TLS12_PSK_TO_MS( kdf_alg ) ) &&
! ( hash_alg == PSA_ALG_SHA_256 || hash_alg == PSA_ALG_SHA_384 ) )
{
return( PSA_ERROR_NOT_SUPPORTED );
}
#if defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXTRACT)
if( PSA_ALG_IS_HKDF_EXTRACT( kdf_alg ) )
operation->capacity = hash_size;
else
#endif /* MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXTRACT */
operation->capacity = 255 * hash_size;
return( PSA_SUCCESS );
}
static psa_status_t psa_key_agreement_try_support( psa_algorithm_t alg )
{
#if defined(PSA_WANT_ALG_ECDH)
if( alg == PSA_ALG_ECDH )
return( PSA_SUCCESS );
#endif
(void) alg;
return( PSA_ERROR_NOT_SUPPORTED );
}
#endif /* AT_LEAST_ONE_BUILTIN_KDF */
psa_status_t psa_key_derivation_setup( psa_key_derivation_operation_t *operation,
psa_algorithm_t alg )
{
psa_status_t status;
if( operation->alg != 0 )
return( PSA_ERROR_BAD_STATE );
if( PSA_ALG_IS_RAW_KEY_AGREEMENT( alg ) )
return( PSA_ERROR_INVALID_ARGUMENT );
else if( PSA_ALG_IS_KEY_AGREEMENT( alg ) )
{
#if defined(AT_LEAST_ONE_BUILTIN_KDF)
psa_algorithm_t kdf_alg = PSA_ALG_KEY_AGREEMENT_GET_KDF( alg );
psa_algorithm_t ka_alg = PSA_ALG_KEY_AGREEMENT_GET_BASE( alg );
status = psa_key_agreement_try_support( ka_alg );
if( status != PSA_SUCCESS )
return( status );
status = psa_key_derivation_setup_kdf( operation, kdf_alg );
#else
return( PSA_ERROR_NOT_SUPPORTED );
#endif /* AT_LEAST_ONE_BUILTIN_KDF */
}
else if( PSA_ALG_IS_KEY_DERIVATION( alg ) )
{
#if defined(AT_LEAST_ONE_BUILTIN_KDF)
status = psa_key_derivation_setup_kdf( operation, alg );
#else
return( PSA_ERROR_NOT_SUPPORTED );
#endif /* AT_LEAST_ONE_BUILTIN_KDF */
}
else
return( PSA_ERROR_INVALID_ARGUMENT );
if( status == PSA_SUCCESS )
operation->alg = alg;
return( status );
}
#if defined(BUILTIN_ALG_ANY_HKDF)
static psa_status_t psa_hkdf_input( psa_hkdf_key_derivation_t *hkdf,
psa_algorithm_t kdf_alg,
psa_key_derivation_step_t step,
const uint8_t *data,
size_t data_length )
{
psa_algorithm_t hash_alg = PSA_ALG_HKDF_GET_HASH( kdf_alg );
psa_status_t status;
switch( step )
{
case PSA_KEY_DERIVATION_INPUT_SALT:
#if defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXPAND)
if( PSA_ALG_IS_HKDF_EXPAND( kdf_alg ) )
return( PSA_ERROR_INVALID_ARGUMENT );
#endif /* MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXPAND */
if( hkdf->state != HKDF_STATE_INIT )
return( PSA_ERROR_BAD_STATE );
else
{
status = psa_key_derivation_start_hmac( &hkdf->hmac,
hash_alg,
data, data_length );
if( status != PSA_SUCCESS )
return( status );
hkdf->state = HKDF_STATE_STARTED;
return( PSA_SUCCESS );
}
case PSA_KEY_DERIVATION_INPUT_SECRET:
#if defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXPAND)
if( PSA_ALG_IS_HKDF_EXPAND( kdf_alg ) )
{
/* We shouldn't be in different state as HKDF_EXPAND only allows
* two inputs: SECRET (this case) and INFO which does not modify
* the state. It could happen only if the hkdf
* object was corrupted. */
if( hkdf->state != HKDF_STATE_INIT )
return( PSA_ERROR_BAD_STATE );
/* Allow only input that fits expected prk size */
if( data_length != PSA_HASH_LENGTH( hash_alg ) )
return( PSA_ERROR_INVALID_ARGUMENT );
memcpy( hkdf->prk, data, data_length );
}
else
#endif /* MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXPAND */
{
/* HKDF: If no salt was provided, use an empty salt.
* HKDF-EXTRACT: salt is mandatory. */
if( hkdf->state == HKDF_STATE_INIT )
{
#if defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXTRACT)
if( PSA_ALG_IS_HKDF_EXTRACT( kdf_alg ) )
return( PSA_ERROR_BAD_STATE );
#endif /* MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXTRACT */
status = psa_key_derivation_start_hmac( &hkdf->hmac,
hash_alg,
NULL, 0 );
if( status != PSA_SUCCESS )
return( status );
hkdf->state = HKDF_STATE_STARTED;
}
if( hkdf->state != HKDF_STATE_STARTED )
return( PSA_ERROR_BAD_STATE );
status = psa_mac_update( &hkdf->hmac,
data, data_length );
if( status != PSA_SUCCESS )
return( status );
status = psa_mac_sign_finish( &hkdf->hmac,
hkdf->prk,
sizeof( hkdf->prk ),
&data_length );
if( status != PSA_SUCCESS )
return( status );
}
hkdf->state = HKDF_STATE_KEYED;
hkdf->block_number = 0;
#if defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXTRACT)
if( PSA_ALG_IS_HKDF_EXTRACT( kdf_alg ) )
{
/* The only block of output is the PRK. */
memcpy( hkdf->output_block, hkdf->prk, PSA_HASH_LENGTH( hash_alg ) );
hkdf->offset_in_block = 0;
}
else
#endif /* MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXTRACT */
{
/* Block 0 is empty, and the next block will be
* generated by psa_key_derivation_hkdf_read(). */
hkdf->offset_in_block = PSA_HASH_LENGTH( hash_alg );
}
return( PSA_SUCCESS );
case PSA_KEY_DERIVATION_INPUT_INFO:
#if defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXTRACT)
if( PSA_ALG_IS_HKDF_EXTRACT( kdf_alg ) )
return( PSA_ERROR_INVALID_ARGUMENT );
#endif /* MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXTRACT */
#if defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXPAND)
if( PSA_ALG_IS_HKDF_EXPAND( kdf_alg ) &&
hkdf->state == HKDF_STATE_INIT )
return( PSA_ERROR_BAD_STATE );
#endif /* MBEDTLS_PSA_BUILTIN_ALG_HKDF_EXTRACT */
if( hkdf->state == HKDF_STATE_OUTPUT )
return( PSA_ERROR_BAD_STATE );
if( hkdf->info_set )
return( PSA_ERROR_BAD_STATE );
hkdf->info_length = data_length;
if( data_length != 0 )
{
hkdf->info = mbedtls_calloc( 1, data_length );
if( hkdf->info == NULL )
return( PSA_ERROR_INSUFFICIENT_MEMORY );
memcpy( hkdf->info, data, data_length );
}
hkdf->info_set = 1;
return( PSA_SUCCESS );
default:
return( PSA_ERROR_INVALID_ARGUMENT );
}
}
#endif /* BUILTIN_ALG_ANY_HKDF */
#if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS)
static psa_status_t psa_tls12_prf_set_seed( psa_tls12_prf_key_derivation_t *prf,
const uint8_t *data,
size_t data_length )
{
if( prf->state != PSA_TLS12_PRF_STATE_INIT )
return( PSA_ERROR_BAD_STATE );
if( data_length != 0 )
{
prf->seed = mbedtls_calloc( 1, data_length );
if( prf->seed == NULL )
return( PSA_ERROR_INSUFFICIENT_MEMORY );
memcpy( prf->seed, data, data_length );
prf->seed_length = data_length;
}
prf->state = PSA_TLS12_PRF_STATE_SEED_SET;
return( PSA_SUCCESS );
}
static psa_status_t psa_tls12_prf_set_key( psa_tls12_prf_key_derivation_t *prf,
const uint8_t *data,
size_t data_length )
{
if( prf->state != PSA_TLS12_PRF_STATE_SEED_SET &&
prf->state != PSA_TLS12_PRF_STATE_OTHER_KEY_SET )
return( PSA_ERROR_BAD_STATE );
if( data_length != 0 )
{
prf->secret = mbedtls_calloc( 1, data_length );
if( prf->secret == NULL )
return( PSA_ERROR_INSUFFICIENT_MEMORY );
memcpy( prf->secret, data, data_length );
prf->secret_length = data_length;
}
prf->state = PSA_TLS12_PRF_STATE_KEY_SET;
return( PSA_SUCCESS );
}
static psa_status_t psa_tls12_prf_set_label( psa_tls12_prf_key_derivation_t *prf,
const uint8_t *data,
size_t data_length )
{
if( prf->state != PSA_TLS12_PRF_STATE_KEY_SET )
return( PSA_ERROR_BAD_STATE );
if( data_length != 0 )
{
prf->label = mbedtls_calloc( 1, data_length );
if( prf->label == NULL )
return( PSA_ERROR_INSUFFICIENT_MEMORY );
memcpy( prf->label, data, data_length );
prf->label_length = data_length;
}
prf->state = PSA_TLS12_PRF_STATE_LABEL_SET;
return( PSA_SUCCESS );
}
static psa_status_t psa_tls12_prf_input( psa_tls12_prf_key_derivation_t *prf,
psa_key_derivation_step_t step,
const uint8_t *data,
size_t data_length )
{
switch( step )
{
case PSA_KEY_DERIVATION_INPUT_SEED:
return( psa_tls12_prf_set_seed( prf, data, data_length ) );
case PSA_KEY_DERIVATION_INPUT_SECRET:
return( psa_tls12_prf_set_key( prf, data, data_length ) );
case PSA_KEY_DERIVATION_INPUT_LABEL:
return( psa_tls12_prf_set_label( prf, data, data_length ) );
default:
return( PSA_ERROR_INVALID_ARGUMENT );
}
}
#endif /* MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF) ||
* MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS */
#if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS)
static psa_status_t psa_tls12_prf_psk_to_ms_set_key(
psa_tls12_prf_key_derivation_t *prf,
const uint8_t *data,
size_t data_length )
{
psa_status_t status;
const size_t pms_len = ( prf->state == PSA_TLS12_PRF_STATE_OTHER_KEY_SET ?
4 + data_length + prf->other_secret_length :
4 + 2 * data_length );
if( data_length > PSA_TLS12_PSK_TO_MS_PSK_MAX_SIZE )
return( PSA_ERROR_INVALID_ARGUMENT );
uint8_t *pms = mbedtls_calloc( 1, pms_len );
if( pms == NULL )
return( PSA_ERROR_INSUFFICIENT_MEMORY );
uint8_t *cur = pms;
/* pure-PSK:
* Quoting RFC 4279, Section 2:
*
* The premaster secret is formed as follows: if the PSK is N octets
* long, concatenate a uint16 with the value N, N zero octets, a second
* uint16 with the value N, and the PSK itself.
*
* mixed-PSK:
* In a DHE-PSK, RSA-PSK, ECDHE-PSK the premaster secret is formed as
* follows: concatenate a uint16 with the length of the other secret,
* the other secret itself, uint16 with the length of PSK, and the
* PSK itself.
* For details please check:
* - RFC 4279, Section 4 for the definition of RSA-PSK,
* - RFC 4279, Section 3 for the definition of DHE-PSK,
* - RFC 5489 for the definition of ECDHE-PSK.
*/
if( prf->state == PSA_TLS12_PRF_STATE_OTHER_KEY_SET )
{
*cur++ = MBEDTLS_BYTE_1( prf->other_secret_length );
*cur++ = MBEDTLS_BYTE_0( prf->other_secret_length );
if( prf->other_secret_length != 0 )
{
memcpy( cur, prf->other_secret, prf->other_secret_length );
mbedtls_platform_zeroize( prf->other_secret, prf->other_secret_length );
cur += prf->other_secret_length;
}
}
else
{
*cur++ = MBEDTLS_BYTE_1( data_length );
*cur++ = MBEDTLS_BYTE_0( data_length );
memset( cur, 0, data_length );
cur += data_length;
}
*cur++ = MBEDTLS_BYTE_1( data_length );
*cur++ = MBEDTLS_BYTE_0( data_length );
memcpy( cur, data, data_length );
cur += data_length;
status = psa_tls12_prf_set_key( prf, pms, cur - pms );
mbedtls_platform_zeroize( pms, pms_len );
mbedtls_free( pms );
return( status );
}
static psa_status_t psa_tls12_prf_psk_to_ms_set_other_key(
psa_tls12_prf_key_derivation_t *prf,
const uint8_t *data,
size_t data_length )
{
if( prf->state != PSA_TLS12_PRF_STATE_SEED_SET )
return( PSA_ERROR_BAD_STATE );
if( data_length != 0 )
{
prf->other_secret = mbedtls_calloc( 1, data_length );
if( prf->other_secret == NULL )
return( PSA_ERROR_INSUFFICIENT_MEMORY );
memcpy( prf->other_secret, data, data_length );
prf->other_secret_length = data_length;
}
else
{
prf->other_secret_length = 0;
}
prf->state = PSA_TLS12_PRF_STATE_OTHER_KEY_SET;
return( PSA_SUCCESS );
}
static psa_status_t psa_tls12_prf_psk_to_ms_input(
psa_tls12_prf_key_derivation_t *prf,
psa_key_derivation_step_t step,
const uint8_t *data,
size_t data_length )
{
switch( step )
{
case PSA_KEY_DERIVATION_INPUT_SECRET:
return( psa_tls12_prf_psk_to_ms_set_key( prf,
data, data_length ) );
break;
case PSA_KEY_DERIVATION_INPUT_OTHER_SECRET:
return( psa_tls12_prf_psk_to_ms_set_other_key( prf,
data,
data_length ) );
break;
default:
return( psa_tls12_prf_input( prf, step, data, data_length ) );
break;
}
}
#endif /* MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS */
/** Check whether the given key type is acceptable for the given
* input step of a key derivation.
*
* Secret inputs must have the type #PSA_KEY_TYPE_DERIVE.
* Non-secret inputs must have the type #PSA_KEY_TYPE_RAW_DATA.
* Both secret and non-secret inputs can alternatively have the type
* #PSA_KEY_TYPE_NONE, which is never the type of a key object, meaning
* that the input was passed as a buffer rather than via a key object.
*/
static int psa_key_derivation_check_input_type(
psa_key_derivation_step_t step,
psa_key_type_t key_type )
{
switch( step )
{
case PSA_KEY_DERIVATION_INPUT_SECRET:
if( key_type == PSA_KEY_TYPE_DERIVE )
return( PSA_SUCCESS );
if( key_type == PSA_KEY_TYPE_NONE )
return( PSA_SUCCESS );
break;
case PSA_KEY_DERIVATION_INPUT_OTHER_SECRET:
if( key_type == PSA_KEY_TYPE_DERIVE )
return( PSA_SUCCESS );
if( key_type == PSA_KEY_TYPE_NONE )
return( PSA_SUCCESS );
break;
case PSA_KEY_DERIVATION_INPUT_LABEL:
case PSA_KEY_DERIVATION_INPUT_SALT:
case PSA_KEY_DERIVATION_INPUT_INFO:
case PSA_KEY_DERIVATION_INPUT_SEED:
if( key_type == PSA_KEY_TYPE_RAW_DATA )
return( PSA_SUCCESS );
if( key_type == PSA_KEY_TYPE_NONE )
return( PSA_SUCCESS );
break;
}
return( PSA_ERROR_INVALID_ARGUMENT );
}
static psa_status_t psa_key_derivation_input_internal(
psa_key_derivation_operation_t *operation,
psa_key_derivation_step_t step,
psa_key_type_t key_type,
const uint8_t *data,
size_t data_length )
{
psa_status_t status;
psa_algorithm_t kdf_alg = psa_key_derivation_get_kdf_alg( operation );
status = psa_key_derivation_check_input_type( step, key_type );
if( status != PSA_SUCCESS )
goto exit;
#if defined(BUILTIN_ALG_ANY_HKDF)
if( PSA_ALG_IS_ANY_HKDF( kdf_alg ) )
{
status = psa_hkdf_input( &operation->ctx.hkdf, kdf_alg,
step, data, data_length );
}
else
#endif /* BUILTIN_ALG_ANY_HKDF */
#if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF)
if( PSA_ALG_IS_TLS12_PRF( kdf_alg ) )
{
status = psa_tls12_prf_input( &operation->ctx.tls12_prf,
step, data, data_length );
}
else
#endif /* MBEDTLS_PSA_BUILTIN_ALG_TLS12_PRF */
#if defined(MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS)
if( PSA_ALG_IS_TLS12_PSK_TO_MS( kdf_alg ) )
{
status = psa_tls12_prf_psk_to_ms_input( &operation->ctx.tls12_prf,
step, data, data_length );
}
else
#endif /* MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS */
{
/* This can't happen unless the operation object was not initialized */
(void) data;
(void) data_length;
(void) kdf_alg;
return( PSA_ERROR_BAD_STATE );
}
exit:
if( status != PSA_SUCCESS )
psa_key_derivation_abort( operation );
return( status );
}
psa_status_t psa_key_derivation_input_bytes(
psa_key_derivation_operation_t *operation,
psa_key_derivation_step_t step,
const uint8_t *data,
size_t data_length )
{
return( psa_key_derivation_input_internal( operation, step,
PSA_KEY_TYPE_NONE,
data, data_length ) );
}
psa_status_t psa_key_derivation_input_key(
psa_key_derivation_operation_t *operation,
psa_key_derivation_step_t step,
mbedtls_svc_key_id_t key )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
psa_key_slot_t *slot;
status = psa_get_and_lock_transparent_key_slot_with_policy(
key, &slot, PSA_KEY_USAGE_DERIVE, operation->alg );
if( status != PSA_SUCCESS )
{
psa_key_derivation_abort( operation );
return( status );
}
/* Passing a key object as a SECRET input unlocks the permission
* to output to a key object. */
if( step == PSA_KEY_DERIVATION_INPUT_SECRET )
operation->can_output_key = 1;
status = psa_key_derivation_input_internal( operation,
step, slot->attr.type,
slot->key.data,
slot->key.bytes );
unlock_status = psa_unlock_key_slot( slot );
return( ( status == PSA_SUCCESS ) ? unlock_status : status );
}
/****************************************************************/
/* Key agreement */
/****************************************************************/
#if defined(MBEDTLS_PSA_BUILTIN_ALG_ECDH)
static psa_status_t psa_key_agreement_ecdh( const uint8_t *peer_key,
size_t peer_key_length,
const mbedtls_ecp_keypair *our_key,
uint8_t *shared_secret,
size_t shared_secret_size,
size_t *shared_secret_length )
{
mbedtls_ecp_keypair *their_key = NULL;
mbedtls_ecdh_context ecdh;
psa_status_t status;
size_t bits = 0;
psa_ecc_family_t curve = mbedtls_ecc_group_to_psa( our_key->grp.id, &bits );
mbedtls_ecdh_init( &ecdh );
status = mbedtls_psa_ecp_load_representation(
PSA_KEY_TYPE_ECC_PUBLIC_KEY(curve),
bits,
peer_key,
peer_key_length,
&their_key );
if( status != PSA_SUCCESS )
goto exit;
status = mbedtls_to_psa_error(
mbedtls_ecdh_get_params( &ecdh, their_key, MBEDTLS_ECDH_THEIRS ) );
if( status != PSA_SUCCESS )
goto exit;
status = mbedtls_to_psa_error(
mbedtls_ecdh_get_params( &ecdh, our_key, MBEDTLS_ECDH_OURS ) );
if( status != PSA_SUCCESS )
goto exit;
status = mbedtls_to_psa_error(
mbedtls_ecdh_calc_secret( &ecdh,
shared_secret_length,
shared_secret, shared_secret_size,
mbedtls_psa_get_random,
MBEDTLS_PSA_RANDOM_STATE ) );
if( status != PSA_SUCCESS )
goto exit;
if( PSA_BITS_TO_BYTES( bits ) != *shared_secret_length )
status = PSA_ERROR_CORRUPTION_DETECTED;
exit:
if( status != PSA_SUCCESS )
mbedtls_platform_zeroize( shared_secret, shared_secret_size );
mbedtls_ecdh_free( &ecdh );
mbedtls_ecp_keypair_free( their_key );
mbedtls_free( their_key );
return( status );
}
#endif /* MBEDTLS_PSA_BUILTIN_ALG_ECDH */
#define PSA_KEY_AGREEMENT_MAX_SHARED_SECRET_SIZE MBEDTLS_ECP_MAX_BYTES
static psa_status_t psa_key_agreement_raw_internal( psa_algorithm_t alg,
psa_key_slot_t *private_key,
const uint8_t *peer_key,
size_t peer_key_length,
uint8_t *shared_secret,
size_t shared_secret_size,
size_t *shared_secret_length )
{
switch( alg )
{
#if defined(MBEDTLS_PSA_BUILTIN_ALG_ECDH)
case PSA_ALG_ECDH:
if( ! PSA_KEY_TYPE_IS_ECC_KEY_PAIR( private_key->attr.type ) )
return( PSA_ERROR_INVALID_ARGUMENT );
mbedtls_ecp_keypair *ecp = NULL;
psa_status_t status = mbedtls_psa_ecp_load_representation(
private_key->attr.type,
private_key->attr.bits,
private_key->key.data,
private_key->key.bytes,
&ecp );
if( status != PSA_SUCCESS )
return( status );
status = psa_key_agreement_ecdh( peer_key, peer_key_length,
ecp,
shared_secret, shared_secret_size,
shared_secret_length );
mbedtls_ecp_keypair_free( ecp );
mbedtls_free( ecp );
return( status );
#endif /* MBEDTLS_PSA_BUILTIN_ALG_ECDH */
default:
(void) private_key;
(void) peer_key;
(void) peer_key_length;
(void) shared_secret;
(void) shared_secret_size;
(void) shared_secret_length;
return( PSA_ERROR_NOT_SUPPORTED );
}
}
/* Note that if this function fails, you must call psa_key_derivation_abort()
* to potentially free embedded data structures and wipe confidential data.
*/
static psa_status_t psa_key_agreement_internal( psa_key_derivation_operation_t *operation,
psa_key_derivation_step_t step,
psa_key_slot_t *private_key,
const uint8_t *peer_key,
size_t peer_key_length )
{
psa_status_t status;
uint8_t shared_secret[PSA_KEY_AGREEMENT_MAX_SHARED_SECRET_SIZE];
size_t shared_secret_length = 0;
psa_algorithm_t ka_alg = PSA_ALG_KEY_AGREEMENT_GET_BASE( operation->alg );
/* Step 1: run the secret agreement algorithm to generate the shared
* secret. */
status = psa_key_agreement_raw_internal( ka_alg,
private_key,
peer_key, peer_key_length,
shared_secret,
sizeof( shared_secret ),
&shared_secret_length );
if( status != PSA_SUCCESS )
goto exit;
/* Step 2: set up the key derivation to generate key material from
* the shared secret. A shared secret is permitted wherever a key
* of type DERIVE is permitted. */
status = psa_key_derivation_input_internal( operation, step,
PSA_KEY_TYPE_DERIVE,
shared_secret,
shared_secret_length );
exit:
mbedtls_platform_zeroize( shared_secret, shared_secret_length );
return( status );
}
psa_status_t psa_key_derivation_key_agreement( psa_key_derivation_operation_t *operation,
psa_key_derivation_step_t step,
mbedtls_svc_key_id_t private_key,
const uint8_t *peer_key,
size_t peer_key_length )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
psa_key_slot_t *slot;
if( ! PSA_ALG_IS_KEY_AGREEMENT( operation->alg ) )
return( PSA_ERROR_INVALID_ARGUMENT );
status = psa_get_and_lock_transparent_key_slot_with_policy(
private_key, &slot, PSA_KEY_USAGE_DERIVE, operation->alg );
if( status != PSA_SUCCESS )
return( status );
status = psa_key_agreement_internal( operation, step,
slot,
peer_key, peer_key_length );
if( status != PSA_SUCCESS )
psa_key_derivation_abort( operation );
else
{
/* If a private key has been added as SECRET, we allow the derived
* key material to be used as a key in PSA Crypto. */
if( step == PSA_KEY_DERIVATION_INPUT_SECRET )
operation->can_output_key = 1;
}
unlock_status = psa_unlock_key_slot( slot );
return( ( status == PSA_SUCCESS ) ? unlock_status : status );
}
psa_status_t psa_raw_key_agreement( psa_algorithm_t alg,
mbedtls_svc_key_id_t private_key,
const uint8_t *peer_key,
size_t peer_key_length,
uint8_t *output,
size_t output_size,
size_t *output_length )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
psa_key_slot_t *slot = NULL;
if( ! PSA_ALG_IS_KEY_AGREEMENT( alg ) )
{
status = PSA_ERROR_INVALID_ARGUMENT;
goto exit;
}
status = psa_get_and_lock_transparent_key_slot_with_policy(
private_key, &slot, PSA_KEY_USAGE_DERIVE, alg );
if( status != PSA_SUCCESS )
goto exit;
/* PSA_RAW_KEY_AGREEMENT_OUTPUT_SIZE() is in general an upper bound
* for the output size. The PSA specification only guarantees that this
* function works if output_size >= PSA_RAW_KEY_AGREEMENT_OUTPUT_SIZE(...),
* but it might be nice to allow smaller buffers if the output fits.
* At the time of writing this comment, with only ECDH implemented,
* PSA_RAW_KEY_AGREEMENT_OUTPUT_SIZE() is exact so the point is moot.
* If FFDH is implemented, PSA_RAW_KEY_AGREEMENT_OUTPUT_SIZE() can easily
* be exact for it as well. */
size_t expected_length =
PSA_RAW_KEY_AGREEMENT_OUTPUT_SIZE( slot->attr.type, slot->attr.bits );
if( output_size < expected_length )
{
status = PSA_ERROR_BUFFER_TOO_SMALL;
goto exit;
}
status = psa_key_agreement_raw_internal( alg, slot,
peer_key, peer_key_length,
output, output_size,
output_length );
exit:
if( status != PSA_SUCCESS )
{
/* If an error happens and is not handled properly, the output
* may be used as a key to protect sensitive data. Arrange for such
* a key to be random, which is likely to result in decryption or
* verification errors. This is better than filling the buffer with
* some constant data such as zeros, which would result in the data
* being protected with a reproducible, easily knowable key.
*/
psa_generate_random( output, output_size );
*output_length = output_size;
}
unlock_status = psa_unlock_key_slot( slot );
return( ( status == PSA_SUCCESS ) ? unlock_status : status );
}
/****************************************************************/
/* Random generation */
/****************************************************************/
/** Initialize the PSA random generator.
*/
static void mbedtls_psa_random_init( mbedtls_psa_random_context_t *rng )
{
#if defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG)
memset( rng, 0, sizeof( *rng ) );
#else /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */
/* Set default configuration if
* mbedtls_psa_crypto_configure_entropy_sources() hasn't been called. */
if( rng->entropy_init == NULL )
rng->entropy_init = mbedtls_entropy_init;
if( rng->entropy_free == NULL )
rng->entropy_free = mbedtls_entropy_free;
rng->entropy_init( &rng->entropy );
#if defined(MBEDTLS_PSA_INJECT_ENTROPY) && \
defined(MBEDTLS_NO_DEFAULT_ENTROPY_SOURCES)
/* The PSA entropy injection feature depends on using NV seed as an entropy
* source. Add NV seed as an entropy source for PSA entropy injection. */
mbedtls_entropy_add_source( &rng->entropy,
mbedtls_nv_seed_poll, NULL,
MBEDTLS_ENTROPY_BLOCK_SIZE,
MBEDTLS_ENTROPY_SOURCE_STRONG );
#endif
mbedtls_psa_drbg_init( MBEDTLS_PSA_RANDOM_STATE );
#endif /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */
}
/** Deinitialize the PSA random generator.
*/
static void mbedtls_psa_random_free( mbedtls_psa_random_context_t *rng )
{
#if defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG)
memset( rng, 0, sizeof( *rng ) );
#else /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */
mbedtls_psa_drbg_free( MBEDTLS_PSA_RANDOM_STATE );
rng->entropy_free( &rng->entropy );
#endif /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */
}
/** Seed the PSA random generator.
*/
static psa_status_t mbedtls_psa_random_seed( mbedtls_psa_random_context_t *rng )
{
#if defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG)
/* Do nothing: the external RNG seeds itself. */
(void) rng;
return( PSA_SUCCESS );
#else /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */
const unsigned char drbg_seed[] = "PSA";
int ret = mbedtls_psa_drbg_seed( &rng->entropy,
drbg_seed, sizeof( drbg_seed ) - 1 );
return mbedtls_to_psa_error( ret );
#endif /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */
}
psa_status_t psa_generate_random( uint8_t *output,
size_t output_size )
{
GUARD_MODULE_INITIALIZED;
#if defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG)
size_t output_length = 0;
psa_status_t status = mbedtls_psa_external_get_random( &global_data.rng,
output, output_size,
&output_length );
if( status != PSA_SUCCESS )
return( status );
/* Breaking up a request into smaller chunks is currently not supported
* for the extrernal RNG interface. */
if( output_length != output_size )
return( PSA_ERROR_INSUFFICIENT_ENTROPY );
return( PSA_SUCCESS );
#else /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */
while( output_size > 0 )
{
size_t request_size =
( output_size > MBEDTLS_PSA_RANDOM_MAX_REQUEST ?
MBEDTLS_PSA_RANDOM_MAX_REQUEST :
output_size );
int ret = mbedtls_psa_get_random( MBEDTLS_PSA_RANDOM_STATE,
output, request_size );
if( ret != 0 )
return( mbedtls_to_psa_error( ret ) );
output_size -= request_size;
output += request_size;
}
return( PSA_SUCCESS );
#endif /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */
}
/* Wrapper function allowing the classic API to use the PSA RNG.
*
* `mbedtls_psa_get_random(MBEDTLS_PSA_RANDOM_STATE, ...)` calls
* `psa_generate_random(...)`. The state parameter is ignored since the
* PSA API doesn't support passing an explicit state.
*
* In the non-external case, psa_generate_random() calls an
* `mbedtls_xxx_drbg_random` function which has exactly the same signature
* and semantics as mbedtls_psa_get_random(). As an optimization,
* instead of doing this back-and-forth between the PSA API and the
* classic API, psa_crypto_random_impl.h defines `mbedtls_psa_get_random`
* as a constant function pointer to `mbedtls_xxx_drbg_random`.
*/
#if defined (MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG)
int mbedtls_psa_get_random( void *p_rng,
unsigned char *output,
size_t output_size )
{
/* This function takes a pointer to the RNG state because that's what
* classic mbedtls functions using an RNG expect. The PSA RNG manages
* its own state internally and doesn't let the caller access that state.
* So we just ignore the state parameter, and in practice we'll pass
* NULL. */
(void) p_rng;
psa_status_t status = psa_generate_random( output, output_size );
if( status == PSA_SUCCESS )
return( 0 );
else
return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
}
#endif /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */
#if defined(MBEDTLS_PSA_INJECT_ENTROPY)
#include "entropy_poll.h"
psa_status_t mbedtls_psa_inject_entropy( const uint8_t *seed,
size_t seed_size )
{
if( global_data.initialized )
return( PSA_ERROR_NOT_PERMITTED );
if( ( ( seed_size < MBEDTLS_ENTROPY_MIN_PLATFORM ) ||
( seed_size < MBEDTLS_ENTROPY_BLOCK_SIZE ) ) ||
( seed_size > MBEDTLS_ENTROPY_MAX_SEED_SIZE ) )
return( PSA_ERROR_INVALID_ARGUMENT );
return( mbedtls_psa_storage_inject_entropy( seed, seed_size ) );
}
#endif /* MBEDTLS_PSA_INJECT_ENTROPY */
/** Validate the key type and size for key generation
*
* \param type The key type
* \param bits The number of bits of the key
*
* \retval #PSA_SUCCESS
* The key type and size are valid.
* \retval #PSA_ERROR_INVALID_ARGUMENT
* The size in bits of the key is not valid.
* \retval #PSA_ERROR_NOT_SUPPORTED
* The type and/or the size in bits of the key or the combination of
* the two is not supported.
*/
static psa_status_t psa_validate_key_type_and_size_for_key_generation(
psa_key_type_t type, size_t bits )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
if( key_type_is_raw_bytes( type ) )
{
status = psa_validate_unstructured_key_bit_size( type, bits );
if( status != PSA_SUCCESS )
return( status );
}
else
#if defined(PSA_WANT_KEY_TYPE_RSA_KEY_PAIR)
if( PSA_KEY_TYPE_IS_RSA( type ) && PSA_KEY_TYPE_IS_KEY_PAIR( type ) )
{
if( bits > PSA_VENDOR_RSA_MAX_KEY_BITS )
return( PSA_ERROR_NOT_SUPPORTED );
/* Accept only byte-aligned keys, for the same reasons as
* in psa_import_rsa_key(). */
if( bits % 8 != 0 )
return( PSA_ERROR_NOT_SUPPORTED );
}
else
#endif /* defined(PSA_WANT_KEY_TYPE_RSA_KEY_PAIR) */
#if defined(PSA_WANT_KEY_TYPE_ECC_KEY_PAIR)
if( PSA_KEY_TYPE_IS_ECC( type ) && PSA_KEY_TYPE_IS_KEY_PAIR( type ) )
{
/* To avoid empty block, return successfully here. */
return( PSA_SUCCESS );
}
else
#endif /* defined(PSA_WANT_KEY_TYPE_ECC_KEY_PAIR) */
{
return( PSA_ERROR_NOT_SUPPORTED );
}
return( PSA_SUCCESS );
}
psa_status_t psa_generate_key_internal(
const psa_key_attributes_t *attributes,
uint8_t *key_buffer, size_t key_buffer_size, size_t *key_buffer_length )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
psa_key_type_t type = attributes->core.type;
if( ( attributes->domain_parameters == NULL ) &&
( attributes->domain_parameters_size != 0 ) )
return( PSA_ERROR_INVALID_ARGUMENT );
if( key_type_is_raw_bytes( type ) )
{
status = psa_generate_random( key_buffer, key_buffer_size );
if( status != PSA_SUCCESS )
return( status );
#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_DES)
if( type == PSA_KEY_TYPE_DES )
psa_des_set_key_parity( key_buffer, key_buffer_size );
#endif /* MBEDTLS_PSA_BUILTIN_KEY_TYPE_DES */
}
else
#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR) && \
defined(MBEDTLS_GENPRIME)
if ( type == PSA_KEY_TYPE_RSA_KEY_PAIR )
{
return( mbedtls_psa_rsa_generate_key( attributes,
key_buffer,
key_buffer_size,
key_buffer_length ) );
}
else
#endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_RSA_KEY_PAIR)
* defined(MBEDTLS_GENPRIME) */
#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR)
if ( PSA_KEY_TYPE_IS_ECC( type ) && PSA_KEY_TYPE_IS_KEY_PAIR( type ) )
{
return( mbedtls_psa_ecp_generate_key( attributes,
key_buffer,
key_buffer_size,
key_buffer_length ) );
}
else
#endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR) */
{
(void)key_buffer_length;
return( PSA_ERROR_NOT_SUPPORTED );
}
return( PSA_SUCCESS );
}
psa_status_t psa_generate_key( const psa_key_attributes_t *attributes,
mbedtls_svc_key_id_t *key )
{
psa_status_t status;
psa_key_slot_t *slot = NULL;
psa_se_drv_table_entry_t *driver = NULL;
size_t key_buffer_size;
*key = MBEDTLS_SVC_KEY_ID_INIT;
/* Reject any attempt to create a zero-length key so that we don't
* risk tripping up later, e.g. on a malloc(0) that returns NULL. */
if( psa_get_key_bits( attributes ) == 0 )
return( PSA_ERROR_INVALID_ARGUMENT );
/* Reject any attempt to create a public key. */
if( PSA_KEY_TYPE_IS_PUBLIC_KEY(attributes->core.type) )
return( PSA_ERROR_INVALID_ARGUMENT );
status = psa_start_key_creation( PSA_KEY_CREATION_GENERATE, attributes,
&slot, &driver );
if( status != PSA_SUCCESS )
goto exit;
/* In the case of a transparent key or an opaque key stored in local
* storage ( thus not in the case of generating a key in a secure element
* with storage ( MBEDTLS_PSA_CRYPTO_SE_C ) ),we have to allocate a
* buffer to hold the generated key material. */
if( slot->key.data == NULL )
{
if ( PSA_KEY_LIFETIME_GET_LOCATION( attributes->core.lifetime ) ==
PSA_KEY_LOCATION_LOCAL_STORAGE )
{
status = psa_validate_key_type_and_size_for_key_generation(
attributes->core.type, attributes->core.bits );
if( status != PSA_SUCCESS )
goto exit;
key_buffer_size = PSA_EXPORT_KEY_OUTPUT_SIZE(
attributes->core.type,
attributes->core.bits );
}
else
{
status = psa_driver_wrapper_get_key_buffer_size(
attributes, &key_buffer_size );
if( status != PSA_SUCCESS )
goto exit;
}
status = psa_allocate_buffer_to_slot( slot, key_buffer_size );
if( status != PSA_SUCCESS )
goto exit;
}
status = psa_driver_wrapper_generate_key( attributes,
slot->key.data, slot->key.bytes, &slot->key.bytes );
if( status != PSA_SUCCESS )
psa_remove_key_data_from_memory( slot );
exit:
if( status == PSA_SUCCESS )
status = psa_finish_key_creation( slot, driver, key );
if( status != PSA_SUCCESS )
psa_fail_key_creation( slot, driver );
return( status );
}
/****************************************************************/
/* Module setup */
/****************************************************************/
#if !defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG)
psa_status_t mbedtls_psa_crypto_configure_entropy_sources(
void (* entropy_init )( mbedtls_entropy_context *ctx ),
void (* entropy_free )( mbedtls_entropy_context *ctx ) )
{
if( global_data.rng_state != RNG_NOT_INITIALIZED )
return( PSA_ERROR_BAD_STATE );
global_data.rng.entropy_init = entropy_init;
global_data.rng.entropy_free = entropy_free;
return( PSA_SUCCESS );
}
#endif /* !defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG) */
void mbedtls_psa_crypto_free( void )
{
psa_wipe_all_key_slots( );
if( global_data.rng_state != RNG_NOT_INITIALIZED )
{
mbedtls_psa_random_free( &global_data.rng );
}
/* Wipe all remaining data, including configuration.
* In particular, this sets all state indicator to the value
* indicating "uninitialized". */
mbedtls_platform_zeroize( &global_data, sizeof( global_data ) );
/* Terminate drivers */
psa_driver_wrapper_free( );
}
#if defined(PSA_CRYPTO_STORAGE_HAS_TRANSACTIONS)
/** Recover a transaction that was interrupted by a power failure.
*
* This function is called during initialization, before psa_crypto_init()
* returns. If this function returns a failure status, the initialization
* fails.
*/
static psa_status_t psa_crypto_recover_transaction(
const psa_crypto_transaction_t *transaction )
{
switch( transaction->unknown.type )
{
case PSA_CRYPTO_TRANSACTION_CREATE_KEY:
case PSA_CRYPTO_TRANSACTION_DESTROY_KEY:
/* TODO - fall through to the failure case until this
* is implemented.
* https://github.com/ARMmbed/mbed-crypto/issues/218
*/
default:
/* We found an unsupported transaction in the storage.
* We don't know what state the storage is in. Give up. */
return( PSA_ERROR_DATA_INVALID );
}
}
#endif /* PSA_CRYPTO_STORAGE_HAS_TRANSACTIONS */
psa_status_t psa_crypto_init( void )
{
psa_status_t status;
/* Double initialization is explicitly allowed. */
if( global_data.initialized != 0 )
return( PSA_SUCCESS );
/* Initialize and seed the random generator. */
mbedtls_psa_random_init( &global_data.rng );
global_data.rng_state = RNG_INITIALIZED;
status = mbedtls_psa_random_seed( &global_data.rng );
if( status != PSA_SUCCESS )
goto exit;
global_data.rng_state = RNG_SEEDED;
status = psa_initialize_key_slots( );
if( status != PSA_SUCCESS )
goto exit;
/* Init drivers */
status = psa_driver_wrapper_init( );
if( status != PSA_SUCCESS )
goto exit;
#if defined(PSA_CRYPTO_STORAGE_HAS_TRANSACTIONS)
status = psa_crypto_load_transaction( );
if( status == PSA_SUCCESS )
{
status = psa_crypto_recover_transaction( &psa_crypto_transaction );
if( status != PSA_SUCCESS )
goto exit;
status = psa_crypto_stop_transaction( );
}
else if( status == PSA_ERROR_DOES_NOT_EXIST )
{
/* There's no transaction to complete. It's all good. */
status = PSA_SUCCESS;
}
#endif /* PSA_CRYPTO_STORAGE_HAS_TRANSACTIONS */
/* All done. */
global_data.initialized = 1;
exit:
if( status != PSA_SUCCESS )
mbedtls_psa_crypto_free( );
return( status );
}
#endif /* MBEDTLS_PSA_CRYPTO_C */
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