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 #ifdef CONFIG_CRYPTO_SM3 30 [QCRYPTO_HASH_ALGO_SM3] = GCRY_MAC_HMAC_SM3, 31 #endif 32 }; 33 34 typedef struct QCryptoHmacGcrypt QCryptoHmacGcrypt; 35 struct QCryptoHmacGcrypt { 36 gcry_mac_hd_t handle; 37 }; 38 39 bool qcrypto_hmac_supports(QCryptoHashAlgo alg) 40 { 41 if (alg < G_N_ELEMENTS(qcrypto_hmac_alg_map) && 42 qcrypto_hmac_alg_map[alg] != GCRY_MAC_NONE) { 43 return gcry_mac_test_algo(qcrypto_hmac_alg_map[alg]) == 0; 44 } 45 46 return false; 47 } 48 49 void *qcrypto_hmac_ctx_new(QCryptoHashAlgo alg, 50 const uint8_t *key, size_t nkey, 51 Error **errp) 52 { 53 QCryptoHmacGcrypt *ctx; 54 gcry_error_t err; 55 56 if (!qcrypto_hmac_supports(alg)) { 57 error_setg(errp, "Unsupported hmac algorithm %s", 58 QCryptoHashAlgo_str(alg)); 59 return NULL; 60 } 61 62 ctx = g_new0(QCryptoHmacGcrypt, 1); 63 64 err = gcry_mac_open(&ctx->handle, qcrypto_hmac_alg_map[alg], 65 GCRY_MAC_FLAG_SECURE, NULL); 66 if (err != 0) { 67 error_setg(errp, "Cannot initialize hmac: %s", 68 gcry_strerror(err)); 69 goto error; 70 } 71 72 err = gcry_mac_setkey(ctx->handle, (const void *)key, nkey); 73 if (err != 0) { 74 error_setg(errp, "Cannot set key: %s", 75 gcry_strerror(err)); 76 gcry_mac_close(ctx->handle); 77 goto error; 78 } 79 80 return ctx; 81 82 error: 83 g_free(ctx); 84 return NULL; 85 } 86 87 static void 88 qcrypto_gcrypt_hmac_ctx_free(QCryptoHmac *hmac) 89 { 90 QCryptoHmacGcrypt *ctx; 91 92 ctx = hmac->opaque; 93 gcry_mac_close(ctx->handle); 94 95 g_free(ctx); 96 } 97 98 static int 99 qcrypto_gcrypt_hmac_bytesv(QCryptoHmac *hmac, 100 const struct iovec *iov, 101 size_t niov, 102 uint8_t **result, 103 size_t *resultlen, 104 Error **errp) 105 { 106 QCryptoHmacGcrypt *ctx; 107 gcry_error_t err; 108 uint32_t ret; 109 int i; 110 111 ctx = hmac->opaque; 112 113 for (i = 0; i < niov; i++) { 114 gcry_mac_write(ctx->handle, iov[i].iov_base, iov[i].iov_len); 115 } 116 117 ret = gcry_mac_get_algo_maclen(qcrypto_hmac_alg_map[hmac->alg]); 118 if (ret <= 0) { 119 error_setg(errp, "Unable to get hmac length: %s", 120 gcry_strerror(ret)); 121 return -1; 122 } 123 124 if (*resultlen == 0) { 125 *resultlen = ret; 126 *result = g_new0(uint8_t, *resultlen); 127 } else if (*resultlen != ret) { 128 error_setg(errp, "Result buffer size %zu is smaller than hmac %d", 129 *resultlen, ret); 130 return -1; 131 } 132 133 err = gcry_mac_read(ctx->handle, *result, resultlen); 134 if (err != 0) { 135 error_setg(errp, "Cannot get result: %s", 136 gcry_strerror(err)); 137 return -1; 138 } 139 140 err = gcry_mac_reset(ctx->handle); 141 if (err != 0) { 142 error_setg(errp, "Cannot reset hmac context: %s", 143 gcry_strerror(err)); 144 return -1; 145 } 146 147 return 0; 148 } 149 150 QCryptoHmacDriver qcrypto_hmac_lib_driver = { 151 .hmac_bytesv = qcrypto_gcrypt_hmac_bytesv, 152 .hmac_free = qcrypto_gcrypt_hmac_ctx_free, 153 }; 154