qemu/crypto/hash.c

201 lines
5.6 KiB
C

/*
* QEMU Crypto hash algorithms
*
* Copyright (c) 2015 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*
*/
#include "crypto/hash.h"
#ifdef CONFIG_GNUTLS_HASH
#include <gnutls/gnutls.h>
#include <gnutls/crypto.h>
static int qcrypto_hash_alg_map[QCRYPTO_HASH_ALG_LAST] = {
[QCRYPTO_HASH_ALG_MD5] = GNUTLS_DIG_MD5,
[QCRYPTO_HASH_ALG_SHA1] = GNUTLS_DIG_SHA1,
[QCRYPTO_HASH_ALG_SHA256] = GNUTLS_DIG_SHA256,
};
gboolean qcrypto_hash_supports(QCryptoHashAlgorithm alg)
{
if (alg < G_N_ELEMENTS(qcrypto_hash_alg_map)) {
return true;
}
return false;
}
int qcrypto_hash_bytesv(QCryptoHashAlgorithm alg,
const struct iovec *iov,
size_t niov,
uint8_t **result,
size_t *resultlen,
Error **errp)
{
int i, ret;
gnutls_hash_hd_t dig;
if (alg >= G_N_ELEMENTS(qcrypto_hash_alg_map)) {
error_setg(errp,
"Unknown hash algorithm %d",
alg);
return -1;
}
ret = gnutls_hash_init(&dig, qcrypto_hash_alg_map[alg]);
if (ret < 0) {
error_setg(errp,
"Unable to initialize hash algorithm: %s",
gnutls_strerror(ret));
return -1;
}
for (i = 0; i < niov; i++) {
ret = gnutls_hash(dig, iov[i].iov_base, iov[i].iov_len);
if (ret < 0) {
error_setg(errp,
"Unable process hash data: %s",
gnutls_strerror(ret));
goto error;
}
}
ret = gnutls_hash_get_len(qcrypto_hash_alg_map[alg]);
if (ret <= 0) {
error_setg(errp,
"Unable to get hash length: %s",
gnutls_strerror(ret));
goto error;
}
if (*resultlen == 0) {
*resultlen = ret;
*result = g_new0(uint8_t, *resultlen);
} else if (*resultlen != ret) {
error_setg(errp,
"Result buffer size %zu is smaller than hash %d",
*resultlen, ret);
goto error;
}
gnutls_hash_deinit(dig, *result);
return 0;
error:
gnutls_hash_deinit(dig, NULL);
return -1;
}
#else /* ! CONFIG_GNUTLS_HASH */
gboolean qcrypto_hash_supports(QCryptoHashAlgorithm alg G_GNUC_UNUSED)
{
return false;
}
int qcrypto_hash_bytesv(QCryptoHashAlgorithm alg,
const struct iovec *iov G_GNUC_UNUSED,
size_t niov G_GNUC_UNUSED,
uint8_t **result G_GNUC_UNUSED,
size_t *resultlen G_GNUC_UNUSED,
Error **errp)
{
error_setg(errp,
"Hash algorithm %d not supported without GNUTLS",
alg);
return -1;
}
#endif /* ! CONFIG_GNUTLS_HASH */
int qcrypto_hash_bytes(QCryptoHashAlgorithm alg,
const char *buf,
size_t len,
uint8_t **result,
size_t *resultlen,
Error **errp)
{
struct iovec iov = { .iov_base = (char *)buf,
.iov_len = len };
return qcrypto_hash_bytesv(alg, &iov, 1, result, resultlen, errp);
}
static const char hex[] = "0123456789abcdef";
int qcrypto_hash_digestv(QCryptoHashAlgorithm alg,
const struct iovec *iov,
size_t niov,
char **digest,
Error **errp)
{
uint8_t *result = NULL;
size_t resultlen = 0;
size_t i;
if (qcrypto_hash_bytesv(alg, iov, niov, &result, &resultlen, errp) < 0) {
return -1;
}
*digest = g_new0(char, (resultlen * 2) + 1);
for (i = 0 ; i < resultlen ; i++) {
(*digest)[(i * 2)] = hex[(result[i] >> 4) & 0xf];
(*digest)[(i * 2) + 1] = hex[result[i] & 0xf];
}
(*digest)[resultlen * 2] = '\0';
g_free(result);
return 0;
}
int qcrypto_hash_digest(QCryptoHashAlgorithm alg,
const char *buf,
size_t len,
char **digest,
Error **errp)
{
struct iovec iov = { .iov_base = (char *)buf, .iov_len = len };
return qcrypto_hash_digestv(alg, &iov, 1, digest, errp);
}
int qcrypto_hash_base64v(QCryptoHashAlgorithm alg,
const struct iovec *iov,
size_t niov,
char **base64,
Error **errp)
{
uint8_t *result = NULL;
size_t resultlen = 0;
if (qcrypto_hash_bytesv(alg, iov, niov, &result, &resultlen, errp) < 0) {
return -1;
}
*base64 = g_base64_encode(result, resultlen);
g_free(result);
return 0;
}
int qcrypto_hash_base64(QCryptoHashAlgorithm alg,
const char *buf,
size_t len,
char **base64,
Error **errp)
{
struct iovec iov = { .iov_base = (char *)buf, .iov_len = len };
return qcrypto_hash_base64v(alg, &iov, 1, base64, errp);
}