xref: /openbmc/qemu/crypto/hmac-glib.c (revision f6a51c84)
1 /*
2  * QEMU Crypto hmac algorithms (based on glib)
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 
19 /* Support for HMAC Algos has been added in GLib 2.30 */
20 #if GLIB_CHECK_VERSION(2, 30, 0)
21 
22 static int qcrypto_hmac_alg_map[QCRYPTO_HASH_ALG__MAX] = {
23     [QCRYPTO_HASH_ALG_MD5] = G_CHECKSUM_MD5,
24     [QCRYPTO_HASH_ALG_SHA1] = G_CHECKSUM_SHA1,
25     [QCRYPTO_HASH_ALG_SHA256] = G_CHECKSUM_SHA256,
26 /* Support for HMAC SHA-512 in GLib 2.42 */
27 #if GLIB_CHECK_VERSION(2, 42, 0)
28     [QCRYPTO_HASH_ALG_SHA512] = G_CHECKSUM_SHA512,
29 #else
30     [QCRYPTO_HASH_ALG_SHA512] = -1,
31 #endif
32     [QCRYPTO_HASH_ALG_SHA224] = -1,
33     [QCRYPTO_HASH_ALG_SHA384] = -1,
34     [QCRYPTO_HASH_ALG_RIPEMD160] = -1,
35 };
36 
37 typedef struct QCryptoHmacGlib QCryptoHmacGlib;
38 struct QCryptoHmacGlib {
39     GHmac *ghmac;
40 };
41 
42 bool qcrypto_hmac_supports(QCryptoHashAlgorithm alg)
43 {
44     if (alg < G_N_ELEMENTS(qcrypto_hmac_alg_map) &&
45         qcrypto_hmac_alg_map[alg] != -1) {
46         return true;
47     }
48 
49     return false;
50 }
51 
52 QCryptoHmac *qcrypto_hmac_new(QCryptoHashAlgorithm alg,
53                               const uint8_t *key, size_t nkey,
54                               Error **errp)
55 {
56     QCryptoHmac *hmac;
57     QCryptoHmacGlib *ctx;
58 
59     if (!qcrypto_hmac_supports(alg)) {
60         error_setg(errp, "Unsupported hmac algorithm %s",
61                    QCryptoHashAlgorithm_lookup[alg]);
62         return NULL;
63     }
64 
65     hmac = g_new0(QCryptoHmac, 1);
66     hmac->alg = alg;
67 
68     ctx = g_new0(QCryptoHmacGlib, 1);
69 
70     ctx->ghmac = g_hmac_new(qcrypto_hmac_alg_map[alg],
71                             (const uint8_t *)key, nkey);
72     if (!ctx->ghmac) {
73         error_setg(errp, "Cannot initialize hmac and set key");
74         goto error;
75     }
76 
77     hmac->opaque = ctx;
78     return hmac;
79 
80 error:
81     g_free(ctx);
82     g_free(hmac);
83     return NULL;
84 }
85 
86 void qcrypto_hmac_free(QCryptoHmac *hmac)
87 {
88     QCryptoHmacGlib *ctx;
89 
90     if (!hmac) {
91         return;
92     }
93 
94     ctx = hmac->opaque;
95     g_hmac_unref(ctx->ghmac);
96 
97     g_free(ctx);
98     g_free(hmac);
99 }
100 
101 int qcrypto_hmac_bytesv(QCryptoHmac *hmac,
102                         const struct iovec *iov,
103                         size_t niov,
104                         uint8_t **result,
105                         size_t *resultlen,
106                         Error **errp)
107 {
108     QCryptoHmacGlib *ctx;
109     int i, ret;
110 
111     ctx = hmac->opaque;
112 
113     for (i = 0; i < niov; i++) {
114         g_hmac_update(ctx->ghmac, iov[i].iov_base, iov[i].iov_len);
115     }
116 
117     ret = g_checksum_type_get_length(qcrypto_hmac_alg_map[hmac->alg]);
118     if (ret < 0) {
119         error_setg(errp, "Unable to get hmac length");
120         return -1;
121     }
122 
123     if (*resultlen == 0) {
124         *resultlen = ret;
125         *result = g_new0(uint8_t, *resultlen);
126     } else if (*resultlen != ret) {
127         error_setg(errp, "Result buffer size %zu is smaller than hmac %d",
128                    *resultlen, ret);
129         return -1;
130     }
131 
132     g_hmac_get_digest(ctx->ghmac, *result, resultlen);
133 
134     return 0;
135 }
136 
137 #else
138 
139 bool qcrypto_hmac_supports(QCryptoHashAlgorithm alg)
140 {
141     return false;
142 }
143 
144 QCryptoHmac *qcrypto_hmac_new(QCryptoHashAlgorithm alg,
145                               const uint8_t *key, size_t nkey,
146                               Error **errp)
147 {
148     return NULL;
149 }
150 
151 void qcrypto_hmac_free(QCryptoHmac *hmac)
152 {
153     return;
154 }
155 
156 int qcrypto_hmac_bytesv(QCryptoHmac *hmac,
157                         const struct iovec *iov,
158                         size_t niov,
159                         uint8_t **result,
160                         size_t *resultlen,
161                         Error **errp)
162 {
163     return -1;
164 }
165 
166 #endif
167