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 static int qcrypto_hmac_alg_map[QCRYPTO_HASH_ALG__MAX] = {
  21     [QCRYPTO_HASH_ALG_MD5] = G_CHECKSUM_MD5,
  22     [QCRYPTO_HASH_ALG_SHA1] = G_CHECKSUM_SHA1,
  23     [QCRYPTO_HASH_ALG_SHA256] = G_CHECKSUM_SHA256,
  24 /* Support for HMAC SHA-512 in GLib 2.42 */
  25 #if GLIB_CHECK_VERSION(2, 42, 0)
  26     [QCRYPTO_HASH_ALG_SHA512] = G_CHECKSUM_SHA512,
  27 #else
  28     [QCRYPTO_HASH_ALG_SHA512] = -1,
  29 #endif
  30     [QCRYPTO_HASH_ALG_SHA224] = -1,
  31     [QCRYPTO_HASH_ALG_SHA384] = -1,
  32     [QCRYPTO_HASH_ALG_RIPEMD160] = -1,
  33 };
  34
  35 typedef struct QCryptoHmacGlib QCryptoHmacGlib;
  36 struct QCryptoHmacGlib {
  37     GHmac *ghmac;
  38 };
  39
  40 bool qcrypto_hmac_supports(QCryptoHashAlgorithm alg)
  41 {
  42     if (alg < G_N_ELEMENTS(qcrypto_hmac_alg_map) &&
  43         qcrypto_hmac_alg_map[alg] != -1) {
  44         return true;
  45     }
  46
  47     return false;
  48 }
  49
  50 void *qcrypto_hmac_ctx_new(QCryptoHashAlgorithm alg,
  51                            const uint8_t *key, size_t nkey,
  52                            Error **errp)
  53 {
  54     QCryptoHmacGlib *ctx;
  55
  56     if (!qcrypto_hmac_supports(alg)) {
  57         error_setg(errp, "Unsupported hmac algorithm %s",
  58                    QCryptoHashAlgorithm_str(alg));
  59         return NULL;
  60     }
  61
  62     ctx = g_new0(QCryptoHmacGlib, 1);
  63
  64     ctx->ghmac = g_hmac_new(qcrypto_hmac_alg_map[alg],
  65                             (const uint8_t *)key, nkey);
  66     if (!ctx->ghmac) {
  67         error_setg(errp, "Cannot initialize hmac and set key");
  68         goto error;
  69     }
  70
  71     return ctx;
  72
  73 error:
  74     g_free(ctx);
  75     return NULL;
  76 }
  77
  78 static void
  79 qcrypto_glib_hmac_ctx_free(QCryptoHmac *hmac)
  80 {
  81     QCryptoHmacGlib *ctx;
  82
  83     ctx = hmac->opaque;
  84     g_hmac_unref(ctx->ghmac);
  85
  86     g_free(ctx);
  87 }
  88
  89 static int
  90 qcrypto_glib_hmac_bytesv(QCryptoHmac *hmac,
  91                          const struct iovec *iov,
  92                          size_t niov,
  93                          uint8_t **result,
  94                          size_t *resultlen,
  95                          Error **errp)
  96 {
  97     QCryptoHmacGlib *ctx;
  98     int i, ret;
  99
 100     ctx = hmac->opaque;
 101
 102     for (i = 0; i < niov; i++) {
 103         g_hmac_update(ctx->ghmac, iov[i].iov_base, iov[i].iov_len);
 104     }
 105
 106     ret = g_checksum_type_get_length(qcrypto_hmac_alg_map[hmac->alg]);
 107     if (ret < 0) {
 108         error_setg(errp, "Unable to get hmac length");
 109         return -1;
 110     }
 111
 112     if (*resultlen == 0) {
 113         *resultlen = ret;
 114         *result = g_new0(uint8_t, *resultlen);
 115     } else if (*resultlen != ret) {
 116         error_setg(errp, "Result buffer size %zu is smaller than hmac %d",
 117                    *resultlen, ret);
 118         return -1;
 119     }
 120
 121     g_hmac_get_digest(ctx->ghmac, *result, resultlen);
 122
 123     return 0;
 124 }
 125
 126 QCryptoHmacDriver qcrypto_hmac_lib_driver = {
 127     .hmac_bytesv = qcrypto_glib_hmac_bytesv,
 128     .hmac_free = qcrypto_glib_hmac_ctx_free,
 129 };