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
  28 static 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
  38 gboolean 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
  48 static int
  49 qcrypto_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
 114 QCryptoHashDriver qcrypto_hash_lib_driver = {
 115     .hash_bytesv = qcrypto_gcrypt_hash_bytesv,
 116 };