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
  27 static 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
  37 gboolean 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
  47 int 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 (alg >= G_N_ELEMENTS(qcrypto_hash_alg_map) ||
  59         qcrypto_hash_alg_map[alg] == GCRY_MD_NONE) {
  60         error_setg(errp,
  61                    "Unknown hash algorithm %d",
  62                    alg);
  63         return -1;
  64     }
  65
  66     ret = gcry_md_open(&md, qcrypto_hash_alg_map[alg], 0);
  67
  68     if (ret < 0) {
  69         error_setg(errp,
  70                    "Unable to initialize hash algorithm: %s",
  71                    gcry_strerror(ret));
  72         return -1;
  73     }
  74
  75     for (i = 0; i < niov; i++) {
  76         gcry_md_write(md, iov[i].iov_base, iov[i].iov_len);
  77     }
  78
  79     ret = gcry_md_get_algo_dlen(qcrypto_hash_alg_map[alg]);
  80     if (ret <= 0) {
  81         error_setg(errp,
  82                    "Unable to get hash length: %s",
  83                    gcry_strerror(ret));
  84         goto error;
  85     }
  86     if (*resultlen == 0) {
  87         *resultlen = ret;
  88         *result = g_new0(uint8_t, *resultlen);
  89     } else if (*resultlen != ret) {
  90         error_setg(errp,
  91                    "Result buffer size %zu is smaller than hash %d",
  92                    *resultlen, ret);
  93         goto error;
  94     }
  95
  96     digest = gcry_md_read(md, 0);
  97     if (!digest) {
  98         error_setg(errp,
  99                    "No digest produced");
 100         goto error;
 101     }
 102     memcpy(*result, digest, *resultlen);
 103
 104     gcry_md_close(md);
 105     return 0;
 106
 107  error:
 108     gcry_md_close(md);
 109     return -1;
 110 }