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 #include "hmacpriv.h"
  19
  20 /* Support for HMAC Algos has been added in GLib 2.30 */
  21 #if GLIB_CHECK_VERSION(2, 30, 0)
  22
  23 static int qcrypto_hmac_alg_map[QCRYPTO_HASH_ALG__MAX] = {
  24     [QCRYPTO_HASH_ALG_MD5] = G_CHECKSUM_MD5,
  25     [QCRYPTO_HASH_ALG_SHA1] = G_CHECKSUM_SHA1,
  26     [QCRYPTO_HASH_ALG_SHA256] = G_CHECKSUM_SHA256,
  27 /* Support for HMAC SHA-512 in GLib 2.42 */
  28 #if GLIB_CHECK_VERSION(2, 42, 0)
  29     [QCRYPTO_HASH_ALG_SHA512] = G_CHECKSUM_SHA512,
  30 #else
  31     [QCRYPTO_HASH_ALG_SHA512] = -1,
  32 #endif
  33     [QCRYPTO_HASH_ALG_SHA224] = -1,
  34     [QCRYPTO_HASH_ALG_SHA384] = -1,
  35     [QCRYPTO_HASH_ALG_RIPEMD160] = -1,
  36 };
  37
  38 typedef struct QCryptoHmacGlib QCryptoHmacGlib;
  39 struct QCryptoHmacGlib {
  40     GHmac *ghmac;
  41 };
  42
  43 bool qcrypto_hmac_supports(QCryptoHashAlgorithm alg)
  44 {
  45     if (alg < G_N_ELEMENTS(qcrypto_hmac_alg_map) &&
  46         qcrypto_hmac_alg_map[alg] != -1) {
  47         return true;
  48     }
  49
  50     return false;
  51 }
  52
  53 void *qcrypto_hmac_ctx_new(QCryptoHashAlgorithm alg,
  54                            const uint8_t *key, size_t nkey,
  55                            Error **errp)
  56 {
  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     ctx = g_new0(QCryptoHmacGlib, 1);
  66
  67     ctx->ghmac = g_hmac_new(qcrypto_hmac_alg_map[alg],
  68                             (const uint8_t *)key, nkey);
  69     if (!ctx->ghmac) {
  70         error_setg(errp, "Cannot initialize hmac and set key");
  71         goto error;
  72     }
  73
  74     return ctx;
  75
  76 error:
  77     g_free(ctx);
  78     return NULL;
  79 }
  80
  81 static void
  82 qcrypto_glib_hmac_ctx_free(QCryptoHmac *hmac)
  83 {
  84     QCryptoHmacGlib *ctx;
  85
  86     ctx = hmac->opaque;
  87     g_hmac_unref(ctx->ghmac);
  88
  89     g_free(ctx);
  90 }
  91
  92 static int
  93 qcrypto_glib_hmac_bytesv(QCryptoHmac *hmac,
  94                          const struct iovec *iov,
  95                          size_t niov,
  96                          uint8_t **result,
  97                          size_t *resultlen,
  98                          Error **errp)
  99 {
 100     QCryptoHmacGlib *ctx;
 101     int i, ret;
 102
 103     ctx = hmac->opaque;
 104
 105     for (i = 0; i < niov; i++) {
 106         g_hmac_update(ctx->ghmac, iov[i].iov_base, iov[i].iov_len);
 107     }
 108
 109     ret = g_checksum_type_get_length(qcrypto_hmac_alg_map[hmac->alg]);
 110     if (ret < 0) {
 111         error_setg(errp, "Unable to get hmac length");
 112         return -1;
 113     }
 114
 115     if (*resultlen == 0) {
 116         *resultlen = ret;
 117         *result = g_new0(uint8_t, *resultlen);
 118     } else if (*resultlen != ret) {
 119         error_setg(errp, "Result buffer size %zu is smaller than hmac %d",
 120                    *resultlen, ret);
 121         return -1;
 122     }
 123
 124     g_hmac_get_digest(ctx->ghmac, *result, resultlen);
 125
 126     return 0;
 127 }
 128
 129 #else
 130
 131 bool qcrypto_hmac_supports(QCryptoHashAlgorithm alg)
 132 {
 133     return false;
 134 }
 135
 136 void *qcrypto_hmac_ctx_new(QCryptoHashAlgorithm alg,
 137                            const uint8_t *key, size_t nkey,
 138                            Error **errp)
 139 {
 140     return NULL;
 141 }
 142
 143 static void
 144 qcrypto_glib_hmac_ctx_free(QCryptoHmac *hmac)
 145 {
 146     return;
 147 }
 148
 149 static int
 150 qcrypto_glib_hmac_bytesv(QCryptoHmac *hmac,
 151                          const struct iovec *iov,
 152                          size_t niov,
 153                          uint8_t **result,
 154                          size_t *resultlen,
 155                          Error **errp)
 156 {
 157     return -1;
 158 }
 159
 160 #endif
 161
 162 QCryptoHmacDriver qcrypto_hmac_lib_driver = {
 163     .hmac_bytesv = qcrypto_glib_hmac_bytesv,
 164     .hmac_free = qcrypto_glib_hmac_ctx_free,
 165 };