2019-05-25 16:50:57 -05:00

104 lines
3.2 KiB
C

/*
MIT License
Copyright (c) 2013 Barry Steyn
Copyright (c) 2019 <bakasura@protonmail.ch>
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/
#include "base64.h"
#include <stdio.h>
#include <string.h>
#include <openssl/bio.h>
#include <openssl/evp.h>
#include <openssl/buffer.h>
#include <stdint.h>
static const char base64_chars[65] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
size_t calcDecodeLength(const char *b64input) { //Calculates the length of a decoded string
size_t len = strlen(b64input),
padding = 0;
if (b64input[len - 1] == '=' && b64input[len - 2] == '=') //last two chars are =
padding = 2;
else if (b64input[len - 1] == '=') //last char is =
padding = 1;
return (len * 3) / 4 - padding;
}
int base64_encode(const unsigned char *buffer, size_t length, char **b64text) { //Encodes a binary safe base 64 string
BIO *bio, *b64;
BUF_MEM *bufferPtr;
b64 = BIO_new(BIO_f_base64());
bio = BIO_new(BIO_s_mem());
bio = BIO_push(b64, bio);
BIO_set_flags(bio, BIO_FLAGS_BASE64_NO_NL); //Ignore newlines - write everything in one line
BIO_set_close(bio, BIO_CLOSE);
BIO_write(bio, buffer, length);
BIO_flush(bio);
BIO_get_mem_ptr(bio, &bufferPtr);
*b64text = (char *) g_malloc0((*bufferPtr).length + 1);
memcpy(*b64text, (*bufferPtr).data, (*bufferPtr).length);
BIO_free_all(bio);
return (0); //success
}
int base64_decode(const char *b64message, unsigned char **buffer, size_t *length) { //Decodes a base64 encoded string
BIO *bio = NULL, *b64 = NULL;
int decodeLen = 0;
if (strspn(b64message, base64_chars) != strlen(b64message))
return -1;
decodeLen = calcDecodeLength(b64message);
if (decodeLen == 0)
return -1;
*buffer = (unsigned char *) malloc(decodeLen + 1);
(*buffer)[decodeLen] = '\0';
bio = BIO_new_mem_buf(b64message, -1);
b64 = BIO_new(BIO_f_base64());
bio = BIO_push(b64, bio);
BIO_set_flags(bio, BIO_FLAGS_BASE64_NO_NL); //Do not use newlines to flush buffer
*length = BIO_read(bio, *buffer, strlen(b64message));
BIO_free_all(bio);
if (*length == decodeLen) {
return 0;
} else {
*length = 0;
free(*buffer);
return -1;
}
}