LXR qemu/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
  20static 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
  35typedef struct QCryptoHmacGlib QCryptoHmacGlib;
  36struct QCryptoHmacGlib {
  37    GHmac *ghmac;
  38};
  39
  40bool 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
  50void *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
  73error:
  74    g_free(ctx);
  75    return NULL;
  76}
  77
  78static void
  79qcrypto_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
  89static int
  90qcrypto_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
 126QCryptoHmacDriver qcrypto_hmac_lib_driver = {
 127    .hmac_bytesv = qcrypto_glib_hmac_bytesv,
 128    .hmac_free = qcrypto_glib_hmac_ctx_free,
 129};
 130