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_ALG__MAX] = {
22 [QCRYPTO_HASH_ALG_MD5] = GCRY_MAC_HMAC_MD5,
23 [QCRYPTO_HASH_ALG_SHA1] = GCRY_MAC_HMAC_SHA1,
24 [QCRYPTO_HASH_ALG_SHA224] = GCRY_MAC_HMAC_SHA224,
25 [QCRYPTO_HASH_ALG_SHA256] = GCRY_MAC_HMAC_SHA256,
26 [QCRYPTO_HASH_ALG_SHA384] = GCRY_MAC_HMAC_SHA384,
27 [QCRYPTO_HASH_ALG_SHA512] = GCRY_MAC_HMAC_SHA512,
28 [QCRYPTO_HASH_ALG_RIPEMD160] = GCRY_MAC_HMAC_RMD160,
29 };
30
31 typedef struct QCryptoHmacGcrypt QCryptoHmacGcrypt;
32 struct QCryptoHmacGcrypt {
33 gcry_mac_hd_t handle;
34 };
35
qcrypto_hmac_supports(QCryptoHashAlgorithm alg)36 bool qcrypto_hmac_supports(QCryptoHashAlgorithm 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
qcrypto_hmac_ctx_new(QCryptoHashAlgorithm alg,const uint8_t * key,size_t nkey,Error ** errp)46 void *qcrypto_hmac_ctx_new(QCryptoHashAlgorithm 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 QCryptoHashAlgorithm_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
qcrypto_gcrypt_hmac_ctx_free(QCryptoHmac * hmac)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
qcrypto_gcrypt_hmac_bytesv(QCryptoHmac * hmac,const struct iovec * iov,size_t niov,uint8_t ** result,size_t * resultlen,Error ** errp)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