1 /*
2 * Copyright 2007-2021 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the OpenSSL license (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10 #include <stdio.h>
11 #include "internal/cryptlib.h"
12 #include <openssl/evp.h>
13 #include "crypto/asn1.h"
14 #include "crypto/evp.h"
15
16 /*
17 * HMAC "ASN1" method. This is just here to indicate the maximum HMAC output
18 * length and to free up an HMAC key.
19 */
20
hmac_size(const EVP_PKEY * pkey)21 static int hmac_size(const EVP_PKEY *pkey)
22 {
23 return EVP_MAX_MD_SIZE;
24 }
25
hmac_key_free(EVP_PKEY * pkey)26 static void hmac_key_free(EVP_PKEY *pkey)
27 {
28 ASN1_OCTET_STRING *os = EVP_PKEY_get0(pkey);
29 if (os) {
30 if (os->data)
31 OPENSSL_cleanse(os->data, os->length);
32 ASN1_OCTET_STRING_free(os);
33 }
34 }
35
hmac_pkey_ctrl(EVP_PKEY * pkey,int op,long arg1,void * arg2)36 static int hmac_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
37 {
38 switch (op) {
39 case ASN1_PKEY_CTRL_DEFAULT_MD_NID:
40 *(int *)arg2 = NID_sha256;
41 return 1;
42
43 default:
44 return -2;
45 }
46 }
47
hmac_pkey_public_cmp(const EVP_PKEY * a,const EVP_PKEY * b)48 static int hmac_pkey_public_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
49 {
50 /* the ameth pub_cmp must return 1 on match, 0 on mismatch */
51 return ASN1_OCTET_STRING_cmp(EVP_PKEY_get0(a), EVP_PKEY_get0(b)) == 0;
52 }
53
hmac_set_priv_key(EVP_PKEY * pkey,const unsigned char * priv,size_t len)54 static int hmac_set_priv_key(EVP_PKEY *pkey, const unsigned char *priv,
55 size_t len)
56 {
57 ASN1_OCTET_STRING *os;
58
59 if (pkey->pkey.ptr != NULL)
60 return 0;
61
62 os = ASN1_OCTET_STRING_new();
63 if (os == NULL)
64 return 0;
65
66
67 if (!ASN1_OCTET_STRING_set(os, priv, len)) {
68 ASN1_OCTET_STRING_free(os);
69 return 0;
70 }
71
72 pkey->pkey.ptr = os;
73 return 1;
74 }
75
hmac_get_priv_key(const EVP_PKEY * pkey,unsigned char * priv,size_t * len)76 static int hmac_get_priv_key(const EVP_PKEY *pkey, unsigned char *priv,
77 size_t *len)
78 {
79 ASN1_OCTET_STRING *os = (ASN1_OCTET_STRING *)pkey->pkey.ptr;
80
81 if (priv == NULL) {
82 *len = ASN1_STRING_length(os);
83 return 1;
84 }
85
86 if (os == NULL || *len < (size_t)ASN1_STRING_length(os))
87 return 0;
88
89 *len = ASN1_STRING_length(os);
90 memcpy(priv, ASN1_STRING_get0_data(os), *len);
91
92 return 1;
93 }
94
95 const EVP_PKEY_ASN1_METHOD hmac_asn1_meth = {
96 EVP_PKEY_HMAC,
97 EVP_PKEY_HMAC,
98 0,
99
100 "HMAC",
101 "OpenSSL HMAC method",
102
103 0, 0, hmac_pkey_public_cmp, 0,
104
105 0, 0, 0,
106
107 hmac_size,
108 0, 0,
109 0, 0, 0, 0, 0, 0, 0,
110
111 hmac_key_free,
112 hmac_pkey_ctrl,
113 NULL,
114 NULL,
115
116 NULL,
117 NULL,
118 NULL,
119
120 NULL,
121 NULL,
122 NULL,
123
124 hmac_set_priv_key,
125 NULL,
126 hmac_get_priv_key,
127 NULL,
128 };
129