qemu-e2k/crypto/hmac-gcrypt.c

151 lines
3.8 KiB
C

/*
* QEMU Crypto hmac algorithms (based on libgcrypt)
*
* Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD.
*
* Authors:
* Longpeng(Mike) <longpeng2@huawei.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or
* (at your option) any later version. See the COPYING file in the
* top-level directory.
*
*/
#include "qemu/osdep.h"
#include "qapi/error.h"
#include "crypto/hmac.h"
#include "hmacpriv.h"
#include <gcrypt.h>
static int qcrypto_hmac_alg_map[QCRYPTO_HASH_ALG__MAX] = {
[QCRYPTO_HASH_ALG_MD5] = GCRY_MAC_HMAC_MD5,
[QCRYPTO_HASH_ALG_SHA1] = GCRY_MAC_HMAC_SHA1,
[QCRYPTO_HASH_ALG_SHA224] = GCRY_MAC_HMAC_SHA224,
[QCRYPTO_HASH_ALG_SHA256] = GCRY_MAC_HMAC_SHA256,
[QCRYPTO_HASH_ALG_SHA384] = GCRY_MAC_HMAC_SHA384,
[QCRYPTO_HASH_ALG_SHA512] = GCRY_MAC_HMAC_SHA512,
[QCRYPTO_HASH_ALG_RIPEMD160] = GCRY_MAC_HMAC_RMD160,
};
typedef struct QCryptoHmacGcrypt QCryptoHmacGcrypt;
struct QCryptoHmacGcrypt {
gcry_mac_hd_t handle;
};
bool qcrypto_hmac_supports(QCryptoHashAlgorithm alg)
{
if (alg < G_N_ELEMENTS(qcrypto_hmac_alg_map) &&
qcrypto_hmac_alg_map[alg] != GCRY_MAC_NONE) {
return true;
}
return false;
}
void *qcrypto_hmac_ctx_new(QCryptoHashAlgorithm alg,
const uint8_t *key, size_t nkey,
Error **errp)
{
QCryptoHmacGcrypt *ctx;
gcry_error_t err;
if (!qcrypto_hmac_supports(alg)) {
error_setg(errp, "Unsupported hmac algorithm %s",
QCryptoHashAlgorithm_str(alg));
return NULL;
}
ctx = g_new0(QCryptoHmacGcrypt, 1);
err = gcry_mac_open(&ctx->handle, qcrypto_hmac_alg_map[alg],
GCRY_MAC_FLAG_SECURE, NULL);
if (err != 0) {
error_setg(errp, "Cannot initialize hmac: %s",
gcry_strerror(err));
goto error;
}
err = gcry_mac_setkey(ctx->handle, (const void *)key, nkey);
if (err != 0) {
error_setg(errp, "Cannot set key: %s",
gcry_strerror(err));
gcry_mac_close(ctx->handle);
goto error;
}
return ctx;
error:
g_free(ctx);
return NULL;
}
static void
qcrypto_gcrypt_hmac_ctx_free(QCryptoHmac *hmac)
{
QCryptoHmacGcrypt *ctx;
ctx = hmac->opaque;
gcry_mac_close(ctx->handle);
g_free(ctx);
}
static int
qcrypto_gcrypt_hmac_bytesv(QCryptoHmac *hmac,
const struct iovec *iov,
size_t niov,
uint8_t **result,
size_t *resultlen,
Error **errp)
{
QCryptoHmacGcrypt *ctx;
gcry_error_t err;
uint32_t ret;
int i;
ctx = hmac->opaque;
for (i = 0; i < niov; i++) {
gcry_mac_write(ctx->handle, iov[i].iov_base, iov[i].iov_len);
}
ret = gcry_mac_get_algo_maclen(qcrypto_hmac_alg_map[hmac->alg]);
if (ret <= 0) {
error_setg(errp, "Unable to get hmac length: %s",
gcry_strerror(ret));
return -1;
}
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 hmac %d",
*resultlen, ret);
return -1;
}
err = gcry_mac_read(ctx->handle, *result, resultlen);
if (err != 0) {
error_setg(errp, "Cannot get result: %s",
gcry_strerror(err));
return -1;
}
err = gcry_mac_reset(ctx->handle);
if (err != 0) {
error_setg(errp, "Cannot reset hmac context: %s",
gcry_strerror(err));
return -1;
}
return 0;
}
QCryptoHmacDriver qcrypto_hmac_lib_driver = {
.hmac_bytesv = qcrypto_gcrypt_hmac_bytesv,
.hmac_free = qcrypto_gcrypt_hmac_ctx_free,
};