xref: /openbmc/qemu/crypto/hmac-glib.c (revision dd873966)
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 #include "hmacpriv.h"
19 
20 /* Support for HMAC Algos has been added in GLib 2.30 */
21 #if GLIB_CHECK_VERSION(2, 30, 0)
22 
23 static int qcrypto_hmac_alg_map[QCRYPTO_HASH_ALG__MAX] = {
24     [QCRYPTO_HASH_ALG_MD5] = G_CHECKSUM_MD5,
25     [QCRYPTO_HASH_ALG_SHA1] = G_CHECKSUM_SHA1,
26     [QCRYPTO_HASH_ALG_SHA256] = G_CHECKSUM_SHA256,
27 /* Support for HMAC SHA-512 in GLib 2.42 */
28 #if GLIB_CHECK_VERSION(2, 42, 0)
29     [QCRYPTO_HASH_ALG_SHA512] = G_CHECKSUM_SHA512,
30 #else
31     [QCRYPTO_HASH_ALG_SHA512] = -1,
32 #endif
33     [QCRYPTO_HASH_ALG_SHA224] = -1,
34     [QCRYPTO_HASH_ALG_SHA384] = -1,
35     [QCRYPTO_HASH_ALG_RIPEMD160] = -1,
36 };
37 
38 typedef struct QCryptoHmacGlib QCryptoHmacGlib;
39 struct QCryptoHmacGlib {
40     GHmac *ghmac;
41 };
42 
43 bool qcrypto_hmac_supports(QCryptoHashAlgorithm alg)
44 {
45     if (alg < G_N_ELEMENTS(qcrypto_hmac_alg_map) &&
46         qcrypto_hmac_alg_map[alg] != -1) {
47         return true;
48     }
49 
50     return false;
51 }
52 
53 void *qcrypto_hmac_ctx_new(QCryptoHashAlgorithm alg,
54                            const uint8_t *key, size_t nkey,
55                            Error **errp)
56 {
57     QCryptoHmacGlib *ctx;
58 
59     if (!qcrypto_hmac_supports(alg)) {
60         error_setg(errp, "Unsupported hmac algorithm %s",
61                    QCryptoHashAlgorithm_str(alg));
62         return NULL;
63     }
64 
65     ctx = g_new0(QCryptoHmacGlib, 1);
66 
67     ctx->ghmac = g_hmac_new(qcrypto_hmac_alg_map[alg],
68                             (const uint8_t *)key, nkey);
69     if (!ctx->ghmac) {
70         error_setg(errp, "Cannot initialize hmac and set key");
71         goto error;
72     }
73 
74     return ctx;
75 
76 error:
77     g_free(ctx);
78     return NULL;
79 }
80 
81 static void
82 qcrypto_glib_hmac_ctx_free(QCryptoHmac *hmac)
83 {
84     QCryptoHmacGlib *ctx;
85 
86     ctx = hmac->opaque;
87     g_hmac_unref(ctx->ghmac);
88 
89     g_free(ctx);
90 }
91 
92 static int
93 qcrypto_glib_hmac_bytesv(QCryptoHmac *hmac,
94                          const struct iovec *iov,
95                          size_t niov,
96                          uint8_t **result,
97                          size_t *resultlen,
98                          Error **errp)
99 {
100     QCryptoHmacGlib *ctx;
101     int i, ret;
102 
103     ctx = hmac->opaque;
104 
105     for (i = 0; i < niov; i++) {
106         g_hmac_update(ctx->ghmac, iov[i].iov_base, iov[i].iov_len);
107     }
108 
109     ret = g_checksum_type_get_length(qcrypto_hmac_alg_map[hmac->alg]);
110     if (ret < 0) {
111         error_setg(errp, "Unable to get hmac length");
112         return -1;
113     }
114 
115     if (*resultlen == 0) {
116         *resultlen = ret;
117         *result = g_new0(uint8_t, *resultlen);
118     } else if (*resultlen != ret) {
119         error_setg(errp, "Result buffer size %zu is smaller than hmac %d",
120                    *resultlen, ret);
121         return -1;
122     }
123 
124     g_hmac_get_digest(ctx->ghmac, *result, resultlen);
125 
126     return 0;
127 }
128 
129 #else
130 
131 bool qcrypto_hmac_supports(QCryptoHashAlgorithm alg)
132 {
133     return false;
134 }
135 
136 void *qcrypto_hmac_ctx_new(QCryptoHashAlgorithm alg,
137                            const uint8_t *key, size_t nkey,
138                            Error **errp)
139 {
140     return NULL;
141 }
142 
143 static void
144 qcrypto_glib_hmac_ctx_free(QCryptoHmac *hmac)
145 {
146     return;
147 }
148 
149 static int
150 qcrypto_glib_hmac_bytesv(QCryptoHmac *hmac,
151                          const struct iovec *iov,
152                          size_t niov,
153                          uint8_t **result,
154                          size_t *resultlen,
155                          Error **errp)
156 {
157     return -1;
158 }
159 
160 #endif
161 
162 QCryptoHmacDriver qcrypto_hmac_lib_driver = {
163     .hmac_bytesv = qcrypto_glib_hmac_bytesv,
164     .hmac_free = qcrypto_glib_hmac_ctx_free,
165 };
166