1/*
2 * Copyright 2007-2018 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (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
21static int hmac_size(const EVP_PKEY *pkey)
22{
23 return EVP_MAX_MD_SIZE;
24}
25
26static 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
36static 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
48static int hmac_pkey_public_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
49{
50 return ASN1_OCTET_STRING_cmp(EVP_PKEY_get0(a), EVP_PKEY_get0(b));
51}
52
53static int hmac_set_priv_key(EVP_PKEY *pkey, const unsigned char *priv,
54 size_t len)
55{
56 ASN1_OCTET_STRING *os;
57
58 if (pkey->pkey.ptr != NULL)
59 return 0;
60
61 os = ASN1_OCTET_STRING_new();
62 if (os == NULL)
63 return 0;
64
65
66 if (!ASN1_OCTET_STRING_set(os, priv, len)) {
67 ASN1_OCTET_STRING_free(os);
68 return 0;
69 }
70
71 pkey->pkey.ptr = os;
72 return 1;
73}
74
75static int hmac_get_priv_key(const EVP_PKEY *pkey, unsigned char *priv,
76 size_t *len)
77{
78 ASN1_OCTET_STRING *os = (ASN1_OCTET_STRING *)pkey->pkey.ptr;
79
80 if (priv == NULL) {
81 *len = ASN1_STRING_length(os);
82 return 1;
83 }
84
85 if (os == NULL || *len < (size_t)ASN1_STRING_length(os))
86 return 0;
87
88 *len = ASN1_STRING_length(os);
89 memcpy(priv, ASN1_STRING_get0_data(os), *len);
90
91 return 1;
92}
93
94const EVP_PKEY_ASN1_METHOD hmac_asn1_meth = {
95 EVP_PKEY_HMAC,
96 EVP_PKEY_HMAC,
97 0,
98
99 "HMAC",
100 "OpenSSL HMAC method",
101
102 0, 0, hmac_pkey_public_cmp, 0,
103
104 0, 0, 0,
105
106 hmac_size,
107 0, 0,
108 0, 0, 0, 0, 0, 0, 0,
109
110 hmac_key_free,
111 hmac_pkey_ctrl,
112 NULL,
113 NULL,
114
115 NULL,
116 NULL,
117 NULL,
118
119 NULL,
120 NULL,
121 NULL,
122
123 hmac_set_priv_key,
124 NULL,
125 hmac_get_priv_key,
126 NULL,
127};
128