LXR qemu/crypto/hash-gcrypt.c

   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};
 117