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 "crypto/hash.h"
  22
  23 #ifdef CONFIG_GNUTLS_HASH
  24 #include <gnutls/gnutls.h>
  25 #include <gnutls/crypto.h>
  26
  27 static int qcrypto_hash_alg_map[QCRYPTO_HASH_ALG__MAX] = {
  28     [QCRYPTO_HASH_ALG_MD5] = GNUTLS_DIG_MD5,
  29     [QCRYPTO_HASH_ALG_SHA1] = GNUTLS_DIG_SHA1,
  30     [QCRYPTO_HASH_ALG_SHA256] = GNUTLS_DIG_SHA256,
  31 };
  32
  33 static size_t qcrypto_hash_alg_size[QCRYPTO_HASH_ALG__MAX] = {
  34     [QCRYPTO_HASH_ALG_MD5] = 16,
  35     [QCRYPTO_HASH_ALG_SHA1] = 20,
  36     [QCRYPTO_HASH_ALG_SHA256] = 32,
  37 };
  38
  39 gboolean qcrypto_hash_supports(QCryptoHashAlgorithm alg)
  40 {
  41     if (alg < G_N_ELEMENTS(qcrypto_hash_alg_map)) {
  42         return true;
  43     }
  44     return false;
  45 }
  46
  47 size_t qcrypto_hash_digest_len(QCryptoHashAlgorithm alg)
  48 {
  49     if (alg >= G_N_ELEMENTS(qcrypto_hash_alg_size)) {
  50         return 0;
  51     }
  52     return qcrypto_hash_alg_size[alg];
  53 }
  54
  55
  56 int qcrypto_hash_bytesv(QCryptoHashAlgorithm alg,
  57                         const struct iovec *iov,
  58                         size_t niov,
  59                         uint8_t **result,
  60                         size_t *resultlen,
  61                         Error **errp)
  62 {
  63     int i, ret;
  64     gnutls_hash_hd_t dig;
  65
  66     if (alg >= G_N_ELEMENTS(qcrypto_hash_alg_map)) {
  67         error_setg(errp,
  68                    "Unknown hash algorithm %d",
  69                    alg);
  70         return -1;
  71     }
  72
  73     ret = gnutls_hash_init(&dig, qcrypto_hash_alg_map[alg]);
  74
  75     if (ret < 0) {
  76         error_setg(errp,
  77                    "Unable to initialize hash algorithm: %s",
  78                    gnutls_strerror(ret));
  79         return -1;
  80     }
  81
  82     for (i = 0; i < niov; i++) {
  83         ret = gnutls_hash(dig, iov[i].iov_base, iov[i].iov_len);
  84         if (ret < 0) {
  85             error_setg(errp,
  86                        "Unable process hash data: %s",
  87                        gnutls_strerror(ret));
  88             goto error;
  89         }
  90     }
  91
  92     ret = gnutls_hash_get_len(qcrypto_hash_alg_map[alg]);
  93     if (ret <= 0) {
  94         error_setg(errp,
  95                    "Unable to get hash length: %s",
  96                    gnutls_strerror(ret));
  97         goto error;
  98     }
  99     if (*resultlen == 0) {
 100         *resultlen = ret;
 101         *result = g_new0(uint8_t, *resultlen);
 102     } else if (*resultlen != ret) {
 103         error_setg(errp,
 104                    "Result buffer size %zu is smaller than hash %d",
 105                    *resultlen, ret);
 106         goto error;
 107     }
 108
 109     gnutls_hash_deinit(dig, *result);
 110     return 0;
 111
 112  error:
 113     gnutls_hash_deinit(dig, NULL);
 114     return -1;
 115 }
 116
 117 #else /* ! CONFIG_GNUTLS_HASH */
 118
 119 gboolean qcrypto_hash_supports(QCryptoHashAlgorithm alg G_GNUC_UNUSED)
 120 {
 121     return false;
 122 }
 123
 124 int qcrypto_hash_bytesv(QCryptoHashAlgorithm alg,
 125                         const struct iovec *iov G_GNUC_UNUSED,
 126                         size_t niov G_GNUC_UNUSED,
 127                         uint8_t **result G_GNUC_UNUSED,
 128                         size_t *resultlen G_GNUC_UNUSED,
 129                         Error **errp)
 130 {
 131     error_setg(errp,
 132                "Hash algorithm %d not supported without GNUTLS",
 133                alg);
 134     return -1;
 135 }
 136
 137 #endif /* ! CONFIG_GNUTLS_HASH */
 138
 139 int qcrypto_hash_bytes(QCryptoHashAlgorithm alg,
 140                        const char *buf,
 141                        size_t len,
 142                        uint8_t **result,
 143                        size_t *resultlen,
 144                        Error **errp)
 145 {
 146     struct iovec iov = { .iov_base = (char *)buf,
 147                          .iov_len = len };
 148     return qcrypto_hash_bytesv(alg, &iov, 1, result, resultlen, errp);
 149 }
 150
 151 static const char hex[] = "0123456789abcdef";
 152
 153 int qcrypto_hash_digestv(QCryptoHashAlgorithm alg,
 154                          const struct iovec *iov,
 155                          size_t niov,
 156                          char **digest,
 157                          Error **errp)
 158 {
 159     uint8_t *result = NULL;
 160     size_t resultlen = 0;
 161     size_t i;
 162
 163     if (qcrypto_hash_bytesv(alg, iov, niov, &result, &resultlen, errp) < 0) {
 164         return -1;
 165     }
 166
 167     *digest = g_new0(char, (resultlen * 2) + 1);
 168     for (i = 0 ; i < resultlen ; i++) {
 169         (*digest)[(i * 2)] = hex[(result[i] >> 4) & 0xf];
 170         (*digest)[(i * 2) + 1] = hex[result[i] & 0xf];
 171     }
 172     (*digest)[resultlen * 2] = '\0';
 173     g_free(result);
 174     return 0;
 175 }
 176
 177 int qcrypto_hash_digest(QCryptoHashAlgorithm alg,
 178                         const char *buf,
 179                         size_t len,
 180                         char **digest,
 181                         Error **errp)
 182 {
 183     struct iovec iov = { .iov_base = (char *)buf, .iov_len = len };
 184
 185     return qcrypto_hash_digestv(alg, &iov, 1, digest, errp);
 186 }
 187
 188 int qcrypto_hash_base64v(QCryptoHashAlgorithm alg,
 189                          const struct iovec *iov,
 190                          size_t niov,
 191                          char **base64,
 192                          Error **errp)
 193 {
 194     uint8_t *result = NULL;
 195     size_t resultlen = 0;
 196
 197     if (qcrypto_hash_bytesv(alg, iov, niov, &result, &resultlen, errp) < 0) {
 198         return -1;
 199     }
 200
 201     *base64 = g_base64_encode(result, resultlen);
 202     g_free(result);
 203     return 0;
 204 }
 205
 206 int qcrypto_hash_base64(QCryptoHashAlgorithm alg,
 207                         const char *buf,
 208                         size_t len,
 209                         char **base64,
 210                         Error **errp)
 211 {
 212     struct iovec iov = { .iov_base = (char *)buf, .iov_len = len };
 213
 214     return qcrypto_hash_base64v(alg, &iov, 1, base64, errp);
 215 }