qemu/crypto/hash-gcrypt.c
Daniel P. Berrangé a7e4275232 crypto: perform runtime check for hash/hmac support in gcrypt
gcrypto has the ability to dynamically disable hash/hmac algorithms
at runtime, so QEMU must perform a runtime check.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2024-11-05 18:37:18 +00:00

141 lines
3.9 KiB
C

/*
* QEMU Crypto hash algorithms
*
* Copyright (c) 2024 Seagate Technology LLC and/or its Affiliates
* Copyright (c) 2016 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 2.1 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 "qemu/osdep.h"
#include <gcrypt.h>
#include "qapi/error.h"
#include "crypto/hash.h"
#include "hashpriv.h"
static int qcrypto_hash_alg_map[QCRYPTO_HASH_ALGO__MAX] = {
[QCRYPTO_HASH_ALGO_MD5] = GCRY_MD_MD5,
[QCRYPTO_HASH_ALGO_SHA1] = GCRY_MD_SHA1,
[QCRYPTO_HASH_ALGO_SHA224] = GCRY_MD_SHA224,
[QCRYPTO_HASH_ALGO_SHA256] = GCRY_MD_SHA256,
[QCRYPTO_HASH_ALGO_SHA384] = GCRY_MD_SHA384,
[QCRYPTO_HASH_ALGO_SHA512] = GCRY_MD_SHA512,
[QCRYPTO_HASH_ALGO_RIPEMD160] = GCRY_MD_RMD160,
#ifdef CONFIG_CRYPTO_SM3
[QCRYPTO_HASH_ALGO_SM3] = GCRY_MD_SM3,
#endif
};
gboolean qcrypto_hash_supports(QCryptoHashAlgo alg)
{
if (alg < G_N_ELEMENTS(qcrypto_hash_alg_map) &&
qcrypto_hash_alg_map[alg] != GCRY_MD_NONE) {
return gcry_md_test_algo(qcrypto_hash_alg_map[alg]) == 0;
}
return false;
}
static
QCryptoHash *qcrypto_gcrypt_hash_new(QCryptoHashAlgo alg, Error **errp)
{
QCryptoHash *hash;
gcry_error_t ret;
hash = g_new(QCryptoHash, 1);
hash->alg = alg;
hash->opaque = g_new(gcry_md_hd_t, 1);
ret = gcry_md_open((gcry_md_hd_t *) hash->opaque,
qcrypto_hash_alg_map[alg], 0);
if (ret != 0) {
error_setg(errp,
"Unable to initialize hash algorithm: %s",
gcry_strerror(ret));
g_free(hash->opaque);
g_free(hash);
return NULL;
}
return hash;
}
static
void qcrypto_gcrypt_hash_free(QCryptoHash *hash)
{
gcry_md_hd_t *ctx = hash->opaque;
if (ctx) {
gcry_md_close(*ctx);
g_free(ctx);
}
g_free(hash);
}
static
int qcrypto_gcrypt_hash_update(QCryptoHash *hash,
const struct iovec *iov,
size_t niov,
Error **errp)
{
gcry_md_hd_t *ctx = hash->opaque;
for (int i = 0; i < niov; i++) {
gcry_md_write(*ctx, iov[i].iov_base, iov[i].iov_len);
}
return 0;
}
static
int qcrypto_gcrypt_hash_finalize(QCryptoHash *hash,
uint8_t **result,
size_t *result_len,
Error **errp)
{
int ret;
unsigned char *digest;
gcry_md_hd_t *ctx = hash->opaque;
ret = gcry_md_get_algo_dlen(qcrypto_hash_alg_map[hash->alg]);
if (ret == 0) {
error_setg(errp, "Unable to get hash length");
return -1;
}
if (*result_len == 0) {
*result_len = ret;
*result = g_new(uint8_t, *result_len);
} else if (*result_len != ret) {
error_setg(errp,
"Result buffer size %zu is smaller than hash %d",
*result_len, ret);
return -1;
}
/* Digest is freed by gcry_md_close(), copy it */
digest = gcry_md_read(*ctx, 0);
memcpy(*result, digest, *result_len);
return 0;
}
QCryptoHashDriver qcrypto_hash_lib_driver = {
.hash_new = qcrypto_gcrypt_hash_new,
.hash_update = qcrypto_gcrypt_hash_update,
.hash_finalize = qcrypto_gcrypt_hash_finalize,
.hash_free = qcrypto_gcrypt_hash_free,
};