1 /* 2 * QEMU Crypto hmac algorithms (based on libgcrypt) 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 #include <gcrypt.h> 20 21 static int qcrypto_hmac_alg_map[QCRYPTO_HASH_ALGO__MAX] = { 22 [QCRYPTO_HASH_ALGO_MD5] = GCRY_MAC_HMAC_MD5, 23 [QCRYPTO_HASH_ALGO_SHA1] = GCRY_MAC_HMAC_SHA1, 24 [QCRYPTO_HASH_ALGO_SHA224] = GCRY_MAC_HMAC_SHA224, 25 [QCRYPTO_HASH_ALGO_SHA256] = GCRY_MAC_HMAC_SHA256, 26 [QCRYPTO_HASH_ALGO_SHA384] = GCRY_MAC_HMAC_SHA384, 27 [QCRYPTO_HASH_ALGO_SHA512] = GCRY_MAC_HMAC_SHA512, 28 [QCRYPTO_HASH_ALGO_RIPEMD160] = GCRY_MAC_HMAC_RMD160, 29 }; 30 31 typedef struct QCryptoHmacGcrypt QCryptoHmacGcrypt; 32 struct QCryptoHmacGcrypt { 33 gcry_mac_hd_t handle; 34 }; 35 36 bool qcrypto_hmac_supports(QCryptoHashAlgo alg) 37 { 38 if (alg < G_N_ELEMENTS(qcrypto_hmac_alg_map) && 39 qcrypto_hmac_alg_map[alg] != GCRY_MAC_NONE) { 40 return true; 41 } 42 43 return false; 44 } 45 46 void *qcrypto_hmac_ctx_new(QCryptoHashAlgo alg, 47 const uint8_t *key, size_t nkey, 48 Error **errp) 49 { 50 QCryptoHmacGcrypt *ctx; 51 gcry_error_t err; 52 53 if (!qcrypto_hmac_supports(alg)) { 54 error_setg(errp, "Unsupported hmac algorithm %s", 55 QCryptoHashAlgo_str(alg)); 56 return NULL; 57 } 58 59 ctx = g_new0(QCryptoHmacGcrypt, 1); 60 61 err = gcry_mac_open(&ctx->handle, qcrypto_hmac_alg_map[alg], 62 GCRY_MAC_FLAG_SECURE, NULL); 63 if (err != 0) { 64 error_setg(errp, "Cannot initialize hmac: %s", 65 gcry_strerror(err)); 66 goto error; 67 } 68 69 err = gcry_mac_setkey(ctx->handle, (const void *)key, nkey); 70 if (err != 0) { 71 error_setg(errp, "Cannot set key: %s", 72 gcry_strerror(err)); 73 gcry_mac_close(ctx->handle); 74 goto error; 75 } 76 77 return ctx; 78 79 error: 80 g_free(ctx); 81 return NULL; 82 } 83 84 static void 85 qcrypto_gcrypt_hmac_ctx_free(QCryptoHmac *hmac) 86 { 87 QCryptoHmacGcrypt *ctx; 88 89 ctx = hmac->opaque; 90 gcry_mac_close(ctx->handle); 91 92 g_free(ctx); 93 } 94 95 static int 96 qcrypto_gcrypt_hmac_bytesv(QCryptoHmac *hmac, 97 const struct iovec *iov, 98 size_t niov, 99 uint8_t **result, 100 size_t *resultlen, 101 Error **errp) 102 { 103 QCryptoHmacGcrypt *ctx; 104 gcry_error_t err; 105 uint32_t ret; 106 int i; 107 108 ctx = hmac->opaque; 109 110 for (i = 0; i < niov; i++) { 111 gcry_mac_write(ctx->handle, iov[i].iov_base, iov[i].iov_len); 112 } 113 114 ret = gcry_mac_get_algo_maclen(qcrypto_hmac_alg_map[hmac->alg]); 115 if (ret <= 0) { 116 error_setg(errp, "Unable to get hmac length: %s", 117 gcry_strerror(ret)); 118 return -1; 119 } 120 121 if (*resultlen == 0) { 122 *resultlen = ret; 123 *result = g_new0(uint8_t, *resultlen); 124 } else if (*resultlen != ret) { 125 error_setg(errp, "Result buffer size %zu is smaller than hmac %d", 126 *resultlen, ret); 127 return -1; 128 } 129 130 err = gcry_mac_read(ctx->handle, *result, resultlen); 131 if (err != 0) { 132 error_setg(errp, "Cannot get result: %s", 133 gcry_strerror(err)); 134 return -1; 135 } 136 137 err = gcry_mac_reset(ctx->handle); 138 if (err != 0) { 139 error_setg(errp, "Cannot reset hmac context: %s", 140 gcry_strerror(err)); 141 return -1; 142 } 143 144 return 0; 145 } 146 147 QCryptoHmacDriver qcrypto_hmac_lib_driver = { 148 .hmac_bytesv = qcrypto_gcrypt_hmac_bytesv, 149 .hmac_free = qcrypto_gcrypt_hmac_ctx_free, 150 }; 151