crypto/hmac-glib.c

   1 /*
   2  * QEMU Crypto hmac algorithms (based on glib)
   3  *
   4  * Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD.
   5  *
   6  * Authors:
   7  *    Longpeng(Mike) <longpeng2@huawei.com>
   8  *
   9  * This work is licensed under the terms of the GNU GPL, version 2 or
  10  * (at your option) any later version.  See the COPYING file in the
  11  * top-level directory.
  12  *
  13  */
  14
  15 #include "qemu/osdep.h"
  16 #include "qapi/error.h"
  17 #include "crypto/hmac.h"
  18
  19 /* Support for HMAC Algos has been added in GLib 2.30 */
  20 #if GLIB_CHECK_VERSION(2, 30, 0)
  21
  22 static int qcrypto_hmac_alg_map[QCRYPTO_HASH_ALG__MAX] = {
  23     [QCRYPTO_HASH_ALG_MD5] = G_CHECKSUM_MD5,
  24     [QCRYPTO_HASH_ALG_SHA1] = G_CHECKSUM_SHA1,
  25     [QCRYPTO_HASH_ALG_SHA256] = G_CHECKSUM_SHA256,
  26 /* Support for HMAC SHA-512 in GLib 2.42 */
  27 #if GLIB_CHECK_VERSION(2, 42, 0)
  28     [QCRYPTO_HASH_ALG_SHA512] = G_CHECKSUM_SHA512,
  29 #else
  30     [QCRYPTO_HASH_ALG_SHA512] = -1,
  31 #endif
  32     [QCRYPTO_HASH_ALG_SHA224] = -1,
  33     [QCRYPTO_HASH_ALG_SHA384] = -1,
  34     [QCRYPTO_HASH_ALG_RIPEMD160] = -1,
  35 };
  36
  37 typedef struct QCryptoHmacGlib QCryptoHmacGlib;
  38 struct QCryptoHmacGlib {
  39     GHmac *ghmac;
  40 };
  41
  42 bool qcrypto_hmac_supports(QCryptoHashAlgorithm alg)
  43 {
  44     if (alg < G_N_ELEMENTS(qcrypto_hmac_alg_map) &&
  45         qcrypto_hmac_alg_map[alg] != -1) {
  46         return true;
  47     }
  48
  49     return false;
  50 }
  51
  52 QCryptoHmac *qcrypto_hmac_new(QCryptoHashAlgorithm alg,
  53                               const uint8_t *key, size_t nkey,
  54                               Error **errp)
  55 {
  56     QCryptoHmac *hmac;
  57     QCryptoHmacGlib *ctx;
  58
  59     if (!qcrypto_hmac_supports(alg)) {
  60         error_setg(errp, "Unsupported hmac algorithm %s",
  61                    QCryptoHashAlgorithm_lookup[alg]);
  62         return NULL;
  63     }
  64
  65     hmac = g_new0(QCryptoHmac, 1);
  66     hmac->alg = alg;
  67
  68     ctx = g_new0(QCryptoHmacGlib, 1);
  69
  70     ctx->ghmac = g_hmac_new(qcrypto_hmac_alg_map[alg],
  71                             (const uint8_t *)key, nkey);
  72     if (!ctx->ghmac) {
  73         error_setg(errp, "Cannot initialize hmac and set key");
  74         goto error;
  75     }
  76
  77     hmac->opaque = ctx;
  78     return hmac;
  79
  80 error:
  81     g_free(ctx);
  82     g_free(hmac);
  83     return NULL;
  84 }
  85
  86 void qcrypto_hmac_free(QCryptoHmac *hmac)
  87 {
  88     QCryptoHmacGlib *ctx;
  89
  90     if (!hmac) {
  91         return;
  92     }
  93
  94     ctx = hmac->opaque;
  95     g_hmac_unref(ctx->ghmac);
  96
  97     g_free(ctx);
  98     g_free(hmac);
  99 }
 100
 101 int qcrypto_hmac_bytesv(QCryptoHmac *hmac,
 102                         const struct iovec *iov,
 103                         size_t niov,
 104                         uint8_t **result,
 105                         size_t *resultlen,
 106                         Error **errp)
 107 {
 108     QCryptoHmacGlib *ctx;
 109     int i, ret;
 110
 111     ctx = hmac->opaque;
 112
 113     for (i = 0; i < niov; i++) {
 114         g_hmac_update(ctx->ghmac, iov[i].iov_base, iov[i].iov_len);
 115     }
 116
 117     ret = g_checksum_type_get_length(qcrypto_hmac_alg_map[hmac->alg]);
 118     if (ret < 0) {
 119         error_setg(errp, "Unable to get hmac length");
 120         return -1;
 121     }
 122
 123     if (*resultlen == 0) {
 124         *resultlen = ret;
 125         *result = g_new0(uint8_t, *resultlen);
 126     } else if (*resultlen != ret) {
 127         error_setg(errp, "Result buffer size %zu is smaller than hmac %d",
 128                    *resultlen, ret);
 129         return -1;
 130     }
 131
 132     g_hmac_get_digest(ctx->ghmac, *result, resultlen);
 133
 134     return 0;
 135 }
 136
 137 #else
 138
 139 bool qcrypto_hmac_supports(QCryptoHashAlgorithm alg)
 140 {
 141     return false;
 142 }
 143
 144 QCryptoHmac *qcrypto_hmac_new(QCryptoHashAlgorithm alg,
 145                               const uint8_t *key, size_t nkey,
 146                               Error **errp)
 147 {
 148     return NULL;
 149 }
 150
 151 void qcrypto_hmac_free(QCryptoHmac *hmac)
 152 {
 153     return;
 154 }
 155
 156 int qcrypto_hmac_bytesv(QCryptoHmac *hmac,
 157                         const struct iovec *iov,
 158                         size_t niov,
 159                         uint8_t **result,
 160                         size_t *resultlen,
 161                         Error **errp)
 162 {
 163     return -1;
 164 }
 165
 166 #endif