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192.168.1.100 / R306 / 2dbc1526a2b84342aa5d5d2a0b7c25c960d13710 / . / ap / lib / libssl / openssl-1.1.1o / crypto / dh / dh_kdf.c
blob: e17122bc82e3aae54514982dd5216ec189eba191 [file] [log] [blame]
yuezonghe824eb0c2024-06-27 02:32:26 -0700[diff] [blame]1/*
2 * Copyright 2013-2016 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 "e_os.h"
11
12#ifndef OPENSSL_NO_CMS
13#include <string.h>
14#include <openssl/dh.h>
15#include <openssl/evp.h>
16#include <openssl/asn1.h>
17#include <openssl/cms.h>
18
19
20/* Key derivation from X9.42/RFC2631 */
21/* Uses CMS functions, hence the #ifdef wrapper. */
22
23#define DH_KDF_MAX (1L << 30)
24
25/* Skip past an ASN1 structure: for OBJECT skip content octets too */
26
27static int skip_asn1(unsigned char **pp, long *plen, int exptag)
28{
29 const unsigned char *q = *pp;
30 int i, tag, xclass;
31 long tmplen;
32 i = ASN1_get_object(&q, &tmplen, &tag, &xclass, *plen);
33 if (i & 0x80)
34 return 0;
35 if (tag != exptag || xclass != V_ASN1_UNIVERSAL)
36 return 0;
37 if (tag == V_ASN1_OBJECT)
38 q += tmplen;
39 *plen -= q - *pp;
40 *pp = (unsigned char *)q;
41 return 1;
42}
43
44/*
45 * Encode the DH shared info structure, return an offset to the counter value
46 * so we can update the structure without reencoding it.
47 */
48
49static int dh_sharedinfo_encode(unsigned char **pder, unsigned char **pctr,
50 ASN1_OBJECT *key_oid, size_t outlen,
51 const unsigned char *ukm, size_t ukmlen)
52{
53 unsigned char *p;
54 int derlen;
55 long tlen;
56 /* "magic" value to check offset is sane */
57 static unsigned char ctr[4] = { 0xF3, 0x17, 0x22, 0x53 };
58 X509_ALGOR atmp;
59 ASN1_OCTET_STRING ctr_oct, ukm_oct, *pukm_oct;
60 ASN1_TYPE ctr_atype;
61 if (ukmlen > DH_KDF_MAX || outlen > DH_KDF_MAX)
62 return 0;
63 ctr_oct.data = ctr;
64 ctr_oct.length = 4;
65 ctr_oct.flags = 0;
66 ctr_oct.type = V_ASN1_OCTET_STRING;
67 ctr_atype.type = V_ASN1_OCTET_STRING;
68 ctr_atype.value.octet_string = &ctr_oct;
69 atmp.algorithm = key_oid;
70 atmp.parameter = &ctr_atype;
71 if (ukm) {
72 ukm_oct.type = V_ASN1_OCTET_STRING;
73 ukm_oct.flags = 0;
74 ukm_oct.data = (unsigned char *)ukm;
75 ukm_oct.length = ukmlen;
76 pukm_oct = &ukm_oct;
77 } else
78 pukm_oct = NULL;
79 derlen = CMS_SharedInfo_encode(pder, &atmp, pukm_oct, outlen);
80 if (derlen <= 0)
81 return 0;
82 p = *pder;
83 tlen = derlen;
84 if (!skip_asn1(&p, &tlen, V_ASN1_SEQUENCE))
85 return 0;
86 if (!skip_asn1(&p, &tlen, V_ASN1_SEQUENCE))
87 return 0;
88 if (!skip_asn1(&p, &tlen, V_ASN1_OBJECT))
89 return 0;
90 if (!skip_asn1(&p, &tlen, V_ASN1_OCTET_STRING))
91 return 0;
92 if (CRYPTO_memcmp(p, ctr, 4))
93 return 0;
94 *pctr = p;
95 return derlen;
96}
97
98int DH_KDF_X9_42(unsigned char *out, size_t outlen,
99 const unsigned char *Z, size_t Zlen,
100 ASN1_OBJECT *key_oid,
101 const unsigned char *ukm, size_t ukmlen, const EVP_MD *md)
102{
103 EVP_MD_CTX *mctx = NULL;
104 int rv = 0;
105 unsigned int i;
106 size_t mdlen;
107 unsigned char *der = NULL, *ctr;
108 int derlen;
109 if (Zlen > DH_KDF_MAX)
110 return 0;
111 mctx = EVP_MD_CTX_new();
112 if (mctx == NULL)
113 return 0;
114 mdlen = EVP_MD_size(md);
115 derlen = dh_sharedinfo_encode(&der, &ctr, key_oid, outlen, ukm, ukmlen);
116 if (derlen == 0)
117 goto err;
118 for (i = 1;; i++) {
119 unsigned char mtmp[EVP_MAX_MD_SIZE];
120 if (!EVP_DigestInit_ex(mctx, md, NULL)
121 || !EVP_DigestUpdate(mctx, Z, Zlen))
122 goto err;
123 ctr[3] = i & 0xFF;
124 ctr[2] = (i >> 8) & 0xFF;
125 ctr[1] = (i >> 16) & 0xFF;
126 ctr[0] = (i >> 24) & 0xFF;
127 if (!EVP_DigestUpdate(mctx, der, derlen))
128 goto err;
129 if (outlen >= mdlen) {
130 if (!EVP_DigestFinal(mctx, out, NULL))
131 goto err;
132 outlen -= mdlen;
133 if (outlen == 0)
134 break;
135 out += mdlen;
136 } else {
137 if (!EVP_DigestFinal(mctx, mtmp, NULL))
138 goto err;
139 memcpy(out, mtmp, outlen);
140 OPENSSL_cleanse(mtmp, mdlen);
141 break;
142 }
143 }
144 rv = 1;
145 err:
146 OPENSSL_free(der);
147 EVP_MD_CTX_free(mctx);
148 return rv;
149}
150#endif