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 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
  26
  27static int qcrypto_hash_alg_map[QCRYPTO_HASH_ALG__MAX] = {
  28    [QCRYPTO_HASH_ALG_MD5] = GCRY_MD_MD5,
  29    [QCRYPTO_HASH_ALG_SHA1] = GCRY_MD_SHA1,
  30    [QCRYPTO_HASH_ALG_SHA224] = GCRY_MD_SHA224,
  31    [QCRYPTO_HASH_ALG_SHA256] = GCRY_MD_SHA256,
  32    [QCRYPTO_HASH_ALG_SHA384] = GCRY_MD_SHA384,
  33    [QCRYPTO_HASH_ALG_SHA512] = GCRY_MD_SHA512,
  34    [QCRYPTO_HASH_ALG_RIPEMD160] = GCRY_MD_RMD160,
  35};
  36
  37gboolean qcrypto_hash_supports(QCryptoHashAlgorithm alg)
  38{
  39    if (alg < G_N_ELEMENTS(qcrypto_hash_alg_map) &&
  40        qcrypto_hash_alg_map[alg] != GCRY_MD_NONE) {
  41        return true;
  42    }
  43    return false;
  44}
  45
  46
  47int qcrypto_hash_bytesv(QCryptoHashAlgorithm alg,
  48                        const struct iovec *iov,
  49                        size_t niov,
  50                        uint8_t **result,
  51                        size_t *resultlen,
  52                        Error **errp)
  53{
  54    int i, ret;
  55    gcry_md_hd_t md;
  56    unsigned char *digest;
  57
  58    if (!qcrypto_hash_supports(alg)) {
  59        error_setg(errp,
  60                   "Unknown hash algorithm %d",
  61                   alg);
  62        return -1;
  63    }
  64
  65    ret = gcry_md_open(&md, qcrypto_hash_alg_map[alg], 0);
  66
  67    if (ret < 0) {
  68        error_setg(errp,
  69                   "Unable to initialize hash algorithm: %s",
  70                   gcry_strerror(ret));
  71        return -1;
  72    }
  73
  74    for (i = 0; i < niov; i++) {
  75        gcry_md_write(md, iov[i].iov_base, iov[i].iov_len);
  76    }
  77
  78    ret = gcry_md_get_algo_dlen(qcrypto_hash_alg_map[alg]);
  79    if (ret <= 0) {
  80        error_setg(errp,
  81                   "Unable to get hash length: %s",
  82                   gcry_strerror(ret));
  83        goto error;
  84    }
  85    if (*resultlen == 0) {
  86        *resultlen = ret;
  87        *result = g_new0(uint8_t, *resultlen);
  88    } else if (*resultlen != ret) {
  89        error_setg(errp,
  90                   "Result buffer size %zu is smaller than hash %d",
  91                   *resultlen, ret);
  92        goto error;
  93    }
  94
  95    digest = gcry_md_read(md, 0);
  96    if (!digest) {
  97        error_setg(errp,
  98                   "No digest produced");
  99        goto error;
 100    }
 101    memcpy(*result, digest, *resultlen);
 102
 103    gcry_md_close(md);
 104    return 0;
 105
 106 error:
 107    gcry_md_close(md);
 108    return -1;
 109}
 110