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
qcrypto_hmac_supports(QCryptoHashAlgo alg)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
qcrypto_hmac_ctx_new(QCryptoHashAlgo alg,const uint8_t * key,size_t nkey,Error ** errp)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
qcrypto_gcrypt_hmac_ctx_free(QCryptoHmac * hmac)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
qcrypto_gcrypt_hmac_bytesv(QCryptoHmac * hmac,const struct iovec * iov,size_t niov,uint8_t ** result,size_t * resultlen,Error ** errp)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