xref: /openbmc/qemu/crypto/hmac-glib.c (revision ffe98631)
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 static int qcrypto_hmac_alg_map[QCRYPTO_HASH_ALG__MAX] = {
21     [QCRYPTO_HASH_ALG_MD5] = G_CHECKSUM_MD5,
22     [QCRYPTO_HASH_ALG_SHA1] = G_CHECKSUM_SHA1,
23     [QCRYPTO_HASH_ALG_SHA256] = G_CHECKSUM_SHA256,
24     [QCRYPTO_HASH_ALG_SHA512] = G_CHECKSUM_SHA512,
25     [QCRYPTO_HASH_ALG_SHA224] = -1,
26     [QCRYPTO_HASH_ALG_SHA384] = -1,
27     [QCRYPTO_HASH_ALG_RIPEMD160] = -1,
28 };
29 
30 typedef struct QCryptoHmacGlib QCryptoHmacGlib;
31 struct QCryptoHmacGlib {
32     GHmac *ghmac;
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] != -1) {
39         return true;
40     }
41 
42     return false;
43 }
44 
45 void *qcrypto_hmac_ctx_new(QCryptoHashAlgorithm alg,
46                            const uint8_t *key, size_t nkey,
47                            Error **errp)
48 {
49     QCryptoHmacGlib *ctx;
50 
51     if (!qcrypto_hmac_supports(alg)) {
52         error_setg(errp, "Unsupported hmac algorithm %s",
53                    QCryptoHashAlgorithm_str(alg));
54         return NULL;
55     }
56 
57     ctx = g_new0(QCryptoHmacGlib, 1);
58 
59     ctx->ghmac = g_hmac_new(qcrypto_hmac_alg_map[alg],
60                             (const uint8_t *)key, nkey);
61     if (!ctx->ghmac) {
62         error_setg(errp, "Cannot initialize hmac and set key");
63         goto error;
64     }
65 
66     return ctx;
67 
68 error:
69     g_free(ctx);
70     return NULL;
71 }
72 
73 static void
74 qcrypto_glib_hmac_ctx_free(QCryptoHmac *hmac)
75 {
76     QCryptoHmacGlib *ctx;
77 
78     ctx = hmac->opaque;
79     g_hmac_unref(ctx->ghmac);
80 
81     g_free(ctx);
82 }
83 
84 static int
85 qcrypto_glib_hmac_bytesv(QCryptoHmac *hmac,
86                          const struct iovec *iov,
87                          size_t niov,
88                          uint8_t **result,
89                          size_t *resultlen,
90                          Error **errp)
91 {
92     QCryptoHmacGlib *ctx;
93     int i, ret;
94 
95     ctx = hmac->opaque;
96 
97     for (i = 0; i < niov; i++) {
98         g_hmac_update(ctx->ghmac, iov[i].iov_base, iov[i].iov_len);
99     }
100 
101     ret = g_checksum_type_get_length(qcrypto_hmac_alg_map[hmac->alg]);
102     if (ret < 0) {
103         error_setg(errp, "Unable to get hmac length");
104         return -1;
105     }
106 
107     if (*resultlen == 0) {
108         *resultlen = ret;
109         *result = g_new0(uint8_t, *resultlen);
110     } else if (*resultlen != ret) {
111         error_setg(errp, "Result buffer size %zu is smaller than hmac %d",
112                    *resultlen, ret);
113         return -1;
114     }
115 
116     g_hmac_get_digest(ctx->ghmac, *result, resultlen);
117 
118     return 0;
119 }
120 
121 QCryptoHmacDriver qcrypto_hmac_lib_driver = {
122     .hmac_bytesv = qcrypto_glib_hmac_bytesv,
123     .hmac_free = qcrypto_glib_hmac_ctx_free,
124 };
125