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