crypto/hash.c

   1 /*
   2  * QEMU Crypto hash algorithms
   3  *
   4  * Copyright (c) 2015 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 "crypto/hash.h"
  23
  24 #ifdef CONFIG_GNUTLS_HASH
  25 #include <gnutls/gnutls.h>
  26 #include <gnutls/crypto.h>
  27
  28 static int qcrypto_hash_alg_map[QCRYPTO_HASH_ALG__MAX] = {
  29     [QCRYPTO_HASH_ALG_MD5] = GNUTLS_DIG_MD5,
  30     [QCRYPTO_HASH_ALG_SHA1] = GNUTLS_DIG_SHA1,
  31     [QCRYPTO_HASH_ALG_SHA256] = GNUTLS_DIG_SHA256,
  32 };
  33
  34 static size_t qcrypto_hash_alg_size[QCRYPTO_HASH_ALG__MAX] = {
  35     [QCRYPTO_HASH_ALG_MD5] = 16,
  36     [QCRYPTO_HASH_ALG_SHA1] = 20,
  37     [QCRYPTO_HASH_ALG_SHA256] = 32,
  38 };
  39
  40 gboolean qcrypto_hash_supports(QCryptoHashAlgorithm alg)
  41 {
  42     if (alg < G_N_ELEMENTS(qcrypto_hash_alg_map)) {
  43         return true;
  44     }
  45     return false;
  46 }
  47
  48 size_t qcrypto_hash_digest_len(QCryptoHashAlgorithm alg)
  49 {
  50     if (alg >= G_N_ELEMENTS(qcrypto_hash_alg_size)) {
  51         return 0;
  52     }
  53     return qcrypto_hash_alg_size[alg];
  54 }
  55
  56
  57 int qcrypto_hash_bytesv(QCryptoHashAlgorithm alg,
  58                         const struct iovec *iov,
  59                         size_t niov,
  60                         uint8_t **result,
  61                         size_t *resultlen,
  62                         Error **errp)
  63 {
  64     int i, ret;
  65     gnutls_hash_hd_t dig;
  66
  67     if (alg >= G_N_ELEMENTS(qcrypto_hash_alg_map)) {
  68         error_setg(errp,
  69                    "Unknown hash algorithm %d",
  70                    alg);
  71         return -1;
  72     }
  73
  74     ret = gnutls_hash_init(&dig, qcrypto_hash_alg_map[alg]);
  75
  76     if (ret < 0) {
  77         error_setg(errp,
  78                    "Unable to initialize hash algorithm: %s",
  79                    gnutls_strerror(ret));
  80         return -1;
  81     }
  82
  83     for (i = 0; i < niov; i++) {
  84         ret = gnutls_hash(dig, iov[i].iov_base, iov[i].iov_len);
  85         if (ret < 0) {
  86             error_setg(errp,
  87                        "Unable process hash data: %s",
  88                        gnutls_strerror(ret));
  89             goto error;
  90         }
  91     }
  92
  93     ret = gnutls_hash_get_len(qcrypto_hash_alg_map[alg]);
  94     if (ret <= 0) {
  95         error_setg(errp,
  96                    "Unable to get hash length: %s",
  97                    gnutls_strerror(ret));
  98         goto error;
  99     }
 100     if (*resultlen == 0) {
 101         *resultlen = ret;
 102         *result = g_new0(uint8_t, *resultlen);
 103     } else if (*resultlen != ret) {
 104         error_setg(errp,
 105                    "Result buffer size %zu is smaller than hash %d",
 106                    *resultlen, ret);
 107         goto error;
 108     }
 109
 110     gnutls_hash_deinit(dig, *result);
 111     return 0;
 112
 113  error:
 114     gnutls_hash_deinit(dig, NULL);
 115     return -1;
 116 }
 117
 118 #else /* ! CONFIG_GNUTLS_HASH */
 119
 120 gboolean qcrypto_hash_supports(QCryptoHashAlgorithm alg G_GNUC_UNUSED)
 121 {
 122     return false;
 123 }
 124
 125 int qcrypto_hash_bytesv(QCryptoHashAlgorithm alg,
 126                         const struct iovec *iov G_GNUC_UNUSED,
 127                         size_t niov G_GNUC_UNUSED,
 128                         uint8_t **result G_GNUC_UNUSED,
 129                         size_t *resultlen G_GNUC_UNUSED,
 130                         Error **errp)
 131 {
 132     error_setg(errp,
 133                "Hash algorithm %d not supported without GNUTLS",
 134                alg);
 135     return -1;
 136 }
 137
 138 #endif /* ! CONFIG_GNUTLS_HASH */
 139
 140 int qcrypto_hash_bytes(QCryptoHashAlgorithm alg,
 141                        const char *buf,
 142                        size_t len,
 143                        uint8_t **result,
 144                        size_t *resultlen,
 145                        Error **errp)
 146 {
 147     struct iovec iov = { .iov_base = (char *)buf,
 148                          .iov_len = len };
 149     return qcrypto_hash_bytesv(alg, &iov, 1, result, resultlen, errp);
 150 }
 151
 152 static const char hex[] = "0123456789abcdef";
 153
 154 int qcrypto_hash_digestv(QCryptoHashAlgorithm alg,
 155                          const struct iovec *iov,
 156                          size_t niov,
 157                          char **digest,
 158                          Error **errp)
 159 {
 160     uint8_t *result = NULL;
 161     size_t resultlen = 0;
 162     size_t i;
 163
 164     if (qcrypto_hash_bytesv(alg, iov, niov, &result, &resultlen, errp) < 0) {
 165         return -1;
 166     }
 167
 168     *digest = g_new0(char, (resultlen * 2) + 1);
 169     for (i = 0 ; i < resultlen ; i++) {
 170         (*digest)[(i * 2)] = hex[(result[i] >> 4) & 0xf];
 171         (*digest)[(i * 2) + 1] = hex[result[i] & 0xf];
 172     }
 173     (*digest)[resultlen * 2] = '\0';
 174     g_free(result);
 175     return 0;
 176 }
 177
 178 int qcrypto_hash_digest(QCryptoHashAlgorithm alg,
 179                         const char *buf,
 180                         size_t len,
 181                         char **digest,
 182                         Error **errp)
 183 {
 184     struct iovec iov = { .iov_base = (char *)buf, .iov_len = len };
 185
 186     return qcrypto_hash_digestv(alg, &iov, 1, digest, errp);
 187 }
 188
 189 int qcrypto_hash_base64v(QCryptoHashAlgorithm alg,
 190                          const struct iovec *iov,
 191                          size_t niov,
 192                          char **base64,
 193                          Error **errp)
 194 {
 195     uint8_t *result = NULL;
 196     size_t resultlen = 0;
 197
 198     if (qcrypto_hash_bytesv(alg, iov, niov, &result, &resultlen, errp) < 0) {
 199         return -1;
 200     }
 201
 202     *base64 = g_base64_encode(result, resultlen);
 203     g_free(result);
 204     return 0;
 205 }
 206
 207 int qcrypto_hash_base64(QCryptoHashAlgorithm alg,
 208                         const char *buf,
 209                         size_t len,
 210                         char **base64,
 211                         Error **errp)
 212 {
 213     struct iovec iov = { .iov_base = (char *)buf, .iov_len = len };
 214
 215     return qcrypto_hash_base64v(alg, &iov, 1, base64, errp);
 216 }