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/*
* Copyright (C) 2014 Cisco and/or its affiliates. All rights reserved.
*
* Author: Shawn Webb
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301, USA.
*/
#if HAVE_CONF_H
#include "clamav-config.h"
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <math.h>
#include <sys/types.h>
#include "clamav.h"
#include <openssl/bio.h>
#include <openssl/evp.h>
#include "libclamav/conv.h"
/** Get the expected decoded length of a base64-encoded string
* @param[in] data Base64-encoded string
* @param[in] len length of the string
* @return The expected decoded length of the base64-encoded string
*/
static size_t base64_len(const char *data, size_t len)
{
int padding=0;
size_t i;
if (!len)
return 0;
for (i=len-1; i > 0 && data[i] == '='; i--)
padding++;
return (size_t)((3*len)/4 - padding);
}
/** Decode a base64-encoded string
* @param[in] data The base64-encoded string
* @param[in] len Length of the base64-encoded string
* @param[out] obuf If obuf is not set to NULL, store the decoded data in obuf. Otherwise, the decoded data is stored in a dynamically-allocated buffer.
* @param[out] olen The length of the decoded data
* @return The base64-decoded data
*/
void *cl_base64_decode(char *data, size_t len, void *obuf, size_t *olen, int oneline)
{
BIO *bio, *b64;
void *buf;
buf = (obuf) ? obuf : malloc(base64_len(data, len)+1);
if (!(buf))
return NULL;
b64 = BIO_new(BIO_f_base64());
if (!(b64)) {
if (!(obuf))
free(buf);
return NULL;
}
bio = BIO_new_mem_buf(data, len);
if (!(bio)) {
BIO_free(b64);
if (!(obuf))
free(buf);
return NULL;
}
bio = BIO_push(b64, bio);
if (oneline)
BIO_set_flags(bio, BIO_FLAGS_BASE64_NO_NL);
*olen = BIO_read(bio, buf, base64_len(data, len));
BIO_free_all(bio);
return buf;
}
/** Base64-encode data
* @param[in] data The data to be encoded
* @param[in] len The length of the data
* @return A pointer to the base64-encoded data. The data is stored in a dynamically-allocated buffer.
*/
char *cl_base64_encode(void *data, size_t len)
{
BIO *bio, *b64;
char *buf, *p;
size_t elen;
b64 = BIO_new(BIO_f_base64());
if (!(b64))
return NULL;
bio = BIO_new(BIO_s_mem());
if (!(bio)) {
BIO_free(b64);
return NULL;
}
bio = BIO_push(b64, bio);
BIO_write(bio, data, len);
BIO_flush(bio);
elen = (size_t)BIO_get_mem_data(bio, &buf);
/* Ensure we're dealing with a NULL-terminated string */
p = (char *)malloc(elen+1);
memcpy((void *)p, (void *)buf, elen);
p[elen] = 0x00;
buf = p;
BIO_free_all(bio);
return buf;
}
#if defined(CONV_SELF_TEST)
int main(int argc, char *argv[])
{
char *plaintext, *encoded, *decoded;
unsigned char *sha_plaintext, *sha_decoded;
size_t len;
int ret=0;
unsigned int shalen;
initialize_crypto();
plaintext = (argv[1]) ? argv[1] : "Hello. This is dog";
sha_plaintext = sha256(plaintext, strlen(plaintext), NULL, NULL);
if (!(sha_plaintext)) {
fprintf(stderr, "Could not generate sha256 of plaintext\n");
return 1;
}
encoded = base64_encode(plaintext, strlen(plaintext));
if (!(encoded)) {
fprintf(stderr, "Could not base64 encode plaintest\n");
return 1;
}
fprintf(stderr, "Base64 encoded: %s\n", encoded);
decoded = base64_decode(encoded, strlen(encoded), NULL, &len);
if (!(decoded)) {
fprintf(stderr, "Could not base64 decoded string\n");
return 1;
}
sha_decoded = sha256(decoded, len, NULL, &shalen);
if (!(sha_decoded)) {
fprintf(stderr, "Could not generate sha256 of decoded data\n");
return 1;
}
if (memcmp(sha_plaintext, sha_decoded, shalen)) {
fprintf(stderr, "Decoded does not match plaintext: %s\n", decoded);
ret = 1;
}
free(sha_decoded);
free(sha_plaintext);
free(encoded);
free(decoded);
cleanup_crypto();
return ret;
}
#endif
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