xref: /openbmc/qemu/crypto/hash-gcrypt.c (revision 79e49005)
1 /*
2  * QEMU Crypto hash algorithms
3  *
4  * Copyright (c) 2024 Seagate Technology LLC and/or its Affiliates
5  * Copyright (c) 2016 Red Hat, Inc.
6  *
7  * This library is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * This library is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
19  *
20  */
21 
22 #include "qemu/osdep.h"
23 #include <gcrypt.h>
24 #include "qapi/error.h"
25 #include "crypto/hash.h"
26 #include "hashpriv.h"
27 
28 
29 static int qcrypto_hash_alg_map[QCRYPTO_HASH_ALGO__MAX] = {
30     [QCRYPTO_HASH_ALGO_MD5] = GCRY_MD_MD5,
31     [QCRYPTO_HASH_ALGO_SHA1] = GCRY_MD_SHA1,
32     [QCRYPTO_HASH_ALGO_SHA224] = GCRY_MD_SHA224,
33     [QCRYPTO_HASH_ALGO_SHA256] = GCRY_MD_SHA256,
34     [QCRYPTO_HASH_ALGO_SHA384] = GCRY_MD_SHA384,
35     [QCRYPTO_HASH_ALGO_SHA512] = GCRY_MD_SHA512,
36     [QCRYPTO_HASH_ALGO_RIPEMD160] = GCRY_MD_RMD160,
37 };
38 
39 gboolean qcrypto_hash_supports(QCryptoHashAlgo alg)
40 {
41     if (alg < G_N_ELEMENTS(qcrypto_hash_alg_map) &&
42         qcrypto_hash_alg_map[alg] != GCRY_MD_NONE) {
43         return true;
44     }
45     return false;
46 }
47 
48 static
49 QCryptoHash *qcrypto_gcrypt_hash_new(QCryptoHashAlgo alg, Error **errp)
50 {
51     QCryptoHash *hash;
52     int ret;
53 
54     hash = g_new(QCryptoHash, 1);
55     hash->alg = alg;
56     hash->opaque = g_new(gcry_md_hd_t, 1);
57 
58     ret = gcry_md_open((gcry_md_hd_t *) hash->opaque,
59                        qcrypto_hash_alg_map[alg], 0);
60     if (ret < 0) {
61         error_setg(errp,
62                    "Unable to initialize hash algorithm: %s",
63                    gcry_strerror(ret));
64         g_free(hash->opaque);
65         g_free(hash);
66         return NULL;
67     }
68     return hash;
69 }
70 
71 static
72 void qcrypto_gcrypt_hash_free(QCryptoHash *hash)
73 {
74     gcry_md_hd_t *ctx = hash->opaque;
75 
76     if (ctx) {
77         gcry_md_close(*ctx);
78         g_free(ctx);
79     }
80 
81     g_free(hash);
82 }
83 
84 
85 static
86 int qcrypto_gcrypt_hash_update(QCryptoHash *hash,
87                                const struct iovec *iov,
88                                size_t niov,
89                                Error **errp)
90 {
91     gcry_md_hd_t *ctx = hash->opaque;
92 
93     for (int i = 0; i < niov; i++) {
94         gcry_md_write(*ctx, iov[i].iov_base, iov[i].iov_len);
95     }
96 
97     return 0;
98 }
99 
100 static
101 int qcrypto_gcrypt_hash_finalize(QCryptoHash *hash,
102                                  uint8_t **result,
103                                  size_t *result_len,
104                                  Error **errp)
105 {
106     int ret;
107     unsigned char *digest;
108     gcry_md_hd_t *ctx = hash->opaque;
109 
110     ret = gcry_md_get_algo_dlen(qcrypto_hash_alg_map[hash->alg]);
111     if (ret == 0) {
112         error_setg(errp, "Unable to get hash length");
113         return -1;
114     }
115 
116     if (*result_len == 0) {
117         *result_len = ret;
118         *result = g_new(uint8_t, *result_len);
119     } else if (*result_len != ret) {
120         error_setg(errp,
121                    "Result buffer size %zu is smaller than hash %d",
122                    *result_len, ret);
123         return -1;
124     }
125 
126     /* Digest is freed by gcry_md_close(), copy it */
127     digest = gcry_md_read(*ctx, 0);
128     memcpy(*result, digest, *result_len);
129     return 0;
130 }
131 
132 QCryptoHashDriver qcrypto_hash_lib_driver = {
133     .hash_new      = qcrypto_gcrypt_hash_new,
134     .hash_update   = qcrypto_gcrypt_hash_update,
135     .hash_finalize = qcrypto_gcrypt_hash_finalize,
136     .hash_free     = qcrypto_gcrypt_hash_free,
137 };
138