cachepc-qemu

Fork of AMDESE/qemu with changes for cachepc side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-qemu
Log | Files | Refs | Submodules | LICENSE | sfeed.txt

hash-gcrypt.c (3213B)

      1/*
      2 * QEMU Crypto hash algorithms
      3 *
      4 * Copyright (c) 2016 Red Hat, Inc.
      5 *
      6 * This library is free software; you can redistribute it and/or
      7 * modify it under the terms of the GNU Lesser General Public
      8 * License as published by the Free Software Foundation; either
      9 * version 2.1 of the License, or (at your option) any later version.
     10 *
     11 * This library is distributed in the hope that it will be useful,
     12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
     13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     14 * Lesser General Public License for more details.
     15 *
     16 * You should have received a copy of the GNU Lesser General Public
     17 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
     18 *
     19 */
     20
     21#include "qemu/osdep.h"
     22#include <gcrypt.h>
     23#include "qapi/error.h"
     24#include "crypto/hash.h"
     25#include "hashpriv.h"
     26
     27
     28static int qcrypto_hash_alg_map[QCRYPTO_HASH_ALG__MAX] = {
     29    [QCRYPTO_HASH_ALG_MD5] = GCRY_MD_MD5,
     30    [QCRYPTO_HASH_ALG_SHA1] = GCRY_MD_SHA1,
     31    [QCRYPTO_HASH_ALG_SHA224] = GCRY_MD_SHA224,
     32    [QCRYPTO_HASH_ALG_SHA256] = GCRY_MD_SHA256,
     33    [QCRYPTO_HASH_ALG_SHA384] = GCRY_MD_SHA384,
     34    [QCRYPTO_HASH_ALG_SHA512] = GCRY_MD_SHA512,
     35    [QCRYPTO_HASH_ALG_RIPEMD160] = GCRY_MD_RMD160,
     36};
     37
     38gboolean qcrypto_hash_supports(QCryptoHashAlgorithm alg)
     39{
     40    if (alg < G_N_ELEMENTS(qcrypto_hash_alg_map) &&
     41        qcrypto_hash_alg_map[alg] != GCRY_MD_NONE) {
     42        return true;
     43    }
     44    return false;
     45}
     46
     47
     48static int
     49qcrypto_gcrypt_hash_bytesv(QCryptoHashAlgorithm alg,
     50                           const struct iovec *iov,
     51                           size_t niov,
     52                           uint8_t **result,
     53                           size_t *resultlen,
     54                           Error **errp)
     55{
     56    int i, ret;
     57    gcry_md_hd_t md;
     58    unsigned char *digest;
     59
     60    if (!qcrypto_hash_supports(alg)) {
     61        error_setg(errp,
     62                   "Unknown hash algorithm %d",
     63                   alg);
     64        return -1;
     65    }
     66
     67    ret = gcry_md_open(&md, qcrypto_hash_alg_map[alg], 0);
     68
     69    if (ret < 0) {
     70        error_setg(errp,
     71                   "Unable to initialize hash algorithm: %s",
     72                   gcry_strerror(ret));
     73        return -1;
     74    }
     75
     76    for (i = 0; i < niov; i++) {
     77        gcry_md_write(md, iov[i].iov_base, iov[i].iov_len);
     78    }
     79
     80    ret = gcry_md_get_algo_dlen(qcrypto_hash_alg_map[alg]);
     81    if (ret <= 0) {
     82        error_setg(errp,
     83                   "Unable to get hash length: %s",
     84                   gcry_strerror(ret));
     85        goto error;
     86    }
     87    if (*resultlen == 0) {
     88        *resultlen = ret;
     89        *result = g_new0(uint8_t, *resultlen);
     90    } else if (*resultlen != ret) {
     91        error_setg(errp,
     92                   "Result buffer size %zu is smaller than hash %d",
     93                   *resultlen, ret);
     94        goto error;
     95    }
     96
     97    digest = gcry_md_read(md, 0);
     98    if (!digest) {
     99        error_setg(errp,
    100                   "No digest produced");
    101        goto error;
    102    }
    103    memcpy(*result, digest, *resultlen);
    104
    105    gcry_md_close(md);
    106    return 0;
    107
    108 error:
    109    gcry_md_close(md);
    110    return -1;
    111}
    112
    113
    114QCryptoHashDriver qcrypto_hash_lib_driver = {
    115    .hash_bytesv = qcrypto_gcrypt_hash_bytesv,
    116};