Merge remote-tracking branch 'remotes/kraxel/tags/pull-vga-20170103-1' into staging
[qemu.git] / crypto / hmac-gcrypt.c
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 <gcrypt.h>
19
20 static int qcrypto_hmac_alg_map[QCRYPTO_HASH_ALG__MAX] = {
21 [QCRYPTO_HASH_ALG_MD5] = GCRY_MAC_HMAC_MD5,
22 [QCRYPTO_HASH_ALG_SHA1] = GCRY_MAC_HMAC_SHA1,
23 [QCRYPTO_HASH_ALG_SHA224] = GCRY_MAC_HMAC_SHA224,
24 [QCRYPTO_HASH_ALG_SHA256] = GCRY_MAC_HMAC_SHA256,
25 [QCRYPTO_HASH_ALG_SHA384] = GCRY_MAC_HMAC_SHA384,
26 [QCRYPTO_HASH_ALG_SHA512] = GCRY_MAC_HMAC_SHA512,
27 [QCRYPTO_HASH_ALG_RIPEMD160] = GCRY_MAC_HMAC_RMD160,
28 };
29
30 typedef struct QCryptoHmacGcrypt QCryptoHmacGcrypt;
31 struct QCryptoHmacGcrypt {
32 gcry_mac_hd_t handle;
33 };
34
35 bool qcrypto_hmac_supports(QCryptoHashAlgorithm alg)
36 {
37 if (alg < G_N_ELEMENTS(qcrypto_hmac_alg_map) &&
38 qcrypto_hmac_alg_map[alg] != GCRY_MAC_NONE) {
39 return true;
40 }
41
42 return false;
43 }
44
45 QCryptoHmac *qcrypto_hmac_new(QCryptoHashAlgorithm alg,
46 const uint8_t *key, size_t nkey,
47 Error **errp)
48 {
49 QCryptoHmac *hmac;
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_lookup[alg]);
56 return NULL;
57 }
58
59 hmac = g_new0(QCryptoHmac, 1);
60 hmac->alg = alg;
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 goto error;
77 }
78
79 hmac->opaque = ctx;
80 return hmac;
81
82 error:
83 g_free(ctx);
84 g_free(hmac);
85 return NULL;
86 }
87
88 void qcrypto_hmac_free(QCryptoHmac *hmac)
89 {
90 QCryptoHmacGcrypt *ctx;
91
92 if (!hmac) {
93 return;
94 }
95
96 ctx = hmac->opaque;
97 gcry_mac_close(ctx->handle);
98
99 g_free(ctx);
100 g_free(hmac);
101 }
102
103 int qcrypto_hmac_bytesv(QCryptoHmac *hmac,
104 const struct iovec *iov,
105 size_t niov,
106 uint8_t **result,
107 size_t *resultlen,
108 Error **errp)
109 {
110 QCryptoHmacGcrypt *ctx;
111 gcry_error_t err;
112 uint32_t ret;
113 int i;
114
115 ctx = hmac->opaque;
116
117 for (i = 0; i < niov; i++) {
118 gcry_mac_write(ctx->handle, iov[i].iov_base, iov[i].iov_len);
119 }
120
121 ret = gcry_mac_get_algo_maclen(qcrypto_hmac_alg_map[hmac->alg]);
122 if (ret <= 0) {
123 error_setg(errp, "Unable to get hmac length: %s",
124 gcry_strerror(ret));
125 return -1;
126 }
127
128 if (*resultlen == 0) {
129 *resultlen = ret;
130 *result = g_new0(uint8_t, *resultlen);
131 } else if (*resultlen != ret) {
132 error_setg(errp, "Result buffer size %zu is smaller than hmac %d",
133 *resultlen, ret);
134 return -1;
135 }
136
137 err = gcry_mac_read(ctx->handle, *result, resultlen);
138 if (err != 0) {
139 error_setg(errp, "Cannot get result: %s",
140 gcry_strerror(err));
141 return -1;
142 }
143
144 err = gcry_mac_reset(ctx->handle);
145 if (err != 0) {
146 error_setg(errp, "Cannot reset hmac context: %s",
147 gcry_strerror(err));
148 return -1;
149 }
150
151 return 0;
152 }