diff --git a/plugins/fishlim/fish.c b/plugins/fishlim/fish.c index 00ecfbfa..ea46ae49 100644 --- a/plugins/fishlim/fish.c +++ b/plugins/fishlim/fish.c @@ -29,6 +29,7 @@ #include #include +#include #include #include "keystore.h" @@ -60,101 +61,196 @@ static const signed char fish_unbase64[256] = { *((dest)++) = (source) & 0xFF; \ } while (0); +#define GET_LONG(dest, source) do { \ + dest = ((uint8_t)*((source)++) << 24); \ + dest |= ((uint8_t)*((source)++) << 16); \ + dest |= ((uint8_t)*((source)++) << 8); \ + dest |= (uint8_t)*((source)++); \ +} while (0); -char *fish_encrypt(const char *key, size_t keylen, const char *message) { - BF_KEY bfkey; - size_t messagelen; - size_t i; - int j; - char *encrypted; + +/** + * Encode ECB FiSH Base64 + * + * @param [in] message Bytes to encode + * @param [in] message_len Size of bytes to encode + * @return Array of char with encoded string + */ +char *fish_base64_encode(const char *message, int message_len) { + BF_LONG left = 0, right = 0; + int i, j; + char *encoded; char *end; - unsigned char bit; - unsigned char word; - unsigned char d; - BF_set_key(&bfkey, keylen, (const unsigned char*)key); - - messagelen = strlen(message); - if (messagelen == 0) return NULL; - encrypted = g_malloc(((messagelen - 1) / 8) * 12 + 12 + 1); /* each 8-byte block becomes 12 bytes */ - end = encrypted; - - while (*message) { - /* Read 8 bytes (a Blowfish block) */ - BF_LONG binary[2] = { 0, 0 }; - unsigned char c; - for (i = 0; i < 8; i++) { - c = message[i]; - binary[i >> 2] |= c << 8*(3 - (i&3)); - if (c == '\0') break; + char *msg; + + if (message_len == 0) + return NULL; + + encoded = g_malloc(((message_len - 1) / 8) * 12 + 12 + 1); /* each 8-byte block becomes 12 bytes */ + end = encoded; + + for (j = 0; j < message_len; j += 8) { + msg = (char *) message; + + GET_LONG(left, msg); + GET_LONG(right, msg); + + for (i = 0; i < 6; ++i) { + *end++ = fish_base64[right & 0x3fu]; + right = (right >> 6u); } + + for (i = 0; i < 6; ++i) { + *end++ = fish_base64[left & 0x3fu]; + left = (left >> 6u); + } + message += 8; - - /* Encrypt block */ - BF_encrypt(binary, &bfkey); - - /* Emit FiSH-BASE64 */ - bit = 0; - word = 1; - for (j = 0; j < 12; j++) { - d = fish_base64[(binary[word] >> bit) & 63]; - *(end++) = d; - bit += 6; - if (j == 5) { - bit = 0; - word = 0; - } - } - - /* Stop if a null terminator was found */ - if (c == '\0') break; } + *end = '\0'; - return encrypted; + return encoded; +} + +/** + * Decode ECB FiSH Base64 + * + * @param [in] message Base64 encoded string + * @param [out] final_len Real length of message + * @return Array of char with decoded message + */ +char *fish_base64_decode(const char *message, int *final_len) { + BF_LONG left, right; + int i; + char *bytes; + char *msg; + char *byt; + + *final_len = ((strlen(message) - 1) / 12) * 8 + 8 + 1; /* Each 12 bytes becomes 8-byte block */ + (*final_len)--; /* We support binary data */ + + bytes = g_malloc(*final_len); + byt = bytes; + + msg = (char *) message; + + while (*msg) { + right = 0; + left = 0; + for (i = 0; i < 6; i++) right |= (uint8_t) fish_unbase64[*msg++] << (i * 6u); + for (i = 0; i < 6; i++) left |= (uint8_t) fish_unbase64[*msg++] << (i * 6u); + GET_BYTES(byt, left); + GET_BYTES(byt, right); + } + + return bytes; +} + +/** + * Encrypt or decrypt data with Blowfish cipher, support binary data. + * + * Good documentation for EVP: + * + * - https://wiki.openssl.org/index.php/EVP_Symmetric_Encryption_and_Decryption + * + * - https://stackoverflow.com/questions/5727646/what-is-the-length-parameter-of-aes-evp-decrypt + * + * - https://stackoverflow.com/questions/26345175/correct-way-to-free-allocate-the-context-in-the-openssl + * + * - https://stackoverflow.com/questions/29874150/working-with-evp-and-openssl-coding-in-c + * + * @param [in] plaintext Bytes to encrypt or descrypt + * @param [in] plaintext_len Size of plaintext + * @param [in] key Bytes of key + * @param [in] keylen Size of key + * @param [in] encode 1 or encrypt 0 for decrypt + * @param [out] ciphertext_len The bytes writen + * @return Array of char with data crypted or uncrypted + */ +char *fish_cipher(const char *plaintext, int plaintext_len, const char *key, size_t keylen, int encode, int *ciphertext_len) { + EVP_CIPHER_CTX *ctx; + int bytes_written = 0; + unsigned char *ciphertext = NULL; + int block_size = 0; + + /* Zero Padding */ + block_size = plaintext_len; + + if (block_size % 8 != 0) { + block_size = block_size + 8 - (block_size % 8); + } + + ciphertext = (unsigned char *) g_malloc0(block_size); + memcpy(ciphertext, plaintext, plaintext_len); + + /* Create and initialise the context */ + if (!(ctx = EVP_CIPHER_CTX_new())) + return NULL; + + /* Initialise the cipher operation only with mode */ + if (!EVP_CipherInit_ex(ctx, EVP_bf_ecb(), NULL, NULL, NULL, encode)) + return NULL; + + /* Set custom key length */ + if (!EVP_CIPHER_CTX_set_key_length(ctx, keylen)) + return NULL; + + /* Finish the initiation the cipher operation */ + if (1 != EVP_CipherInit_ex(ctx, NULL, NULL, (const unsigned char *) key, NULL, encode)) + return NULL; + + /* We will manage this */ + EVP_CIPHER_CTX_set_padding(ctx, 0); + + /* Do cipher operation */ + if (1 != EVP_CipherUpdate(ctx, ciphertext, &bytes_written, ciphertext, block_size)) + return NULL; + + *ciphertext_len = bytes_written; + + /* Finalise the cipher. Further ciphertext bytes may be written at this stage */ + if (1 != EVP_CipherFinal_ex(ctx, ciphertext + bytes_written, &bytes_written)) + return NULL; + + *ciphertext_len += bytes_written; + + /* Clean up */ + EVP_CIPHER_CTX_free(ctx); + + return (char *) ciphertext; +} + + +char *fish_encrypt(const char *key, size_t keylen, const char *message, size_t message_len) { + int ciphertext_len = 0; + char *ciphertext = NULL; + char *b64 = NULL; + + ciphertext = fish_cipher(message, message_len, key, keylen, 1, &ciphertext_len); + b64 = fish_base64_encode((const char *) ciphertext, ciphertext_len); + g_free(ciphertext); + + return b64; } char *fish_decrypt(const char *key, size_t keylen, const char *data) { - BF_KEY bfkey; - size_t i; - char *decrypted; - char *end; - unsigned char bit; - unsigned char word; - unsigned char d; - BF_set_key(&bfkey, keylen, (const unsigned char*)key); - - decrypted = g_malloc(strlen(data) + 1); - end = decrypted; - - while (*data) { - /* Convert from FiSH-BASE64 */ - BF_LONG binary[2] = { 0, 0 }; - bit = 0; - word = 1; - for (i = 0; i < 12; i++) { - d = fish_unbase64[(const unsigned char)*(data++)]; - if (d == IB) goto decrypt_end; - binary[word] |= (unsigned long)d << bit; - bit += 6; - if (i == 5) { - bit = 0; - word = 0; - } - } - - /* Decrypt block */ - BF_decrypt(binary, &bfkey); - - /* Copy to buffer */ - GET_BYTES(end, binary[0]); - GET_BYTES(end, binary[1]); - } - - decrypt_end: - *end = '\0'; - return decrypted; + int ciphertext_len; + char *ciphertext; + char *plaintext; + char *plaintext_str; + + ciphertext = fish_base64_decode(data, &ciphertext_len); + plaintext = fish_cipher(ciphertext, ciphertext_len, key, keylen, 0, &ciphertext_len); + plaintext_str = g_malloc0(ciphertext_len + 1); + memcpy(plaintext_str, plaintext, ciphertext_len); + g_free(ciphertext); + g_free(plaintext); + + return plaintext_str; } + /** * Encrypts a message (see fish_decrypt). The key is searched for in the * key store. @@ -168,7 +264,7 @@ char *fish_encrypt_for_nick(const char *nick, const char *data) { if (!key) return NULL; /* Encrypt */ - encrypted = fish_encrypt(key, strlen(key), data); + encrypted = fish_encrypt(key, strlen(key), data, strlen(data)); g_free(key); return encrypted; diff --git a/plugins/fishlim/fish.h b/plugins/fishlim/fish.h index 238f52e7..bca31368 100644 --- a/plugins/fishlim/fish.h +++ b/plugins/fishlim/fish.h @@ -29,7 +29,7 @@ #include -char *fish_encrypt(const char *key, size_t keylen, const char *message); +char *fish_encrypt(const char *key, size_t keylen, const char *message, size_t message_len); char *fish_decrypt(const char *key, size_t keylen, const char *data); char *fish_encrypt_for_nick(const char *nick, const char *data); char *fish_decrypt_from_nick(const char *nick, const char *data); diff --git a/plugins/fishlim/keystore.c b/plugins/fishlim/keystore.c index 061faa03..bde9083f 100644 --- a/plugins/fishlim/keystore.c +++ b/plugins/fishlim/keystore.c @@ -204,7 +204,7 @@ gboolean keystore_store_key(const char *nick, const char *key) { password = get_keystore_password(); if (password) { /* Encrypt the password */ - encrypted = fish_encrypt(password, strlen(password), key); + encrypted = fish_encrypt(password, strlen(password), key, strlen(key)); if (!encrypted) goto end; /* Prepend "+OK " */