2 * Written by Stephen Henson for the OpenSSL project.
4 /* ====================================================================
5 * Copyright (c) 2013 The OpenSSL Project. All rights reserved.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in
16 * the documentation and/or other materials provided with the
19 * 3. All advertising materials mentioning features or use of this
20 * software must display the following acknowledgment:
21 * "This product includes software developed by the OpenSSL Project
22 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
24 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
25 * endorse or promote products derived from this software without
26 * prior written permission. For written permission, please contact
27 * openssl-core@openssl.org.
29 * 5. Products derived from this software may not be called "OpenSSL"
30 * nor may "OpenSSL" appear in their names without prior written
31 * permission of the OpenSSL Project.
33 * 6. Redistributions of any form whatsoever must retain the following
35 * "This product includes software developed by the OpenSSL Project
36 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
38 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
39 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
40 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
41 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
42 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
43 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
44 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
45 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
46 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
47 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
48 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
49 * OF THE POSSIBILITY OF SUCH DAMAGE.
50 * ====================================================================
55 #ifndef OPENSSL_NO_CMS
57 #include <openssl/dh.h>
58 #include <openssl/evp.h>
59 #include <openssl/asn1.h>
60 #include <openssl/cms.h>
63 /* Key derivation from X9.42/RFC2631 */
64 /* Uses CMS functions, hence the #ifdef wrapper. */
66 #define DH_KDF_MAX (1L << 30)
68 /* Skip past an ASN1 structure: for OBJECT skip content octets too */
70 static int skip_asn1(unsigned char **pp, long *plen, int exptag)
72 const unsigned char *q = *pp;
75 i = ASN1_get_object(&q, &tmplen, &tag, &xclass, *plen);
78 if (tag != exptag || xclass != V_ASN1_UNIVERSAL)
80 if (tag == V_ASN1_OBJECT)
83 *pp = (unsigned char *)q;
88 * Encode the DH shared info structure, return an offset to the counter value
89 * so we can update the structure without reencoding it.
92 static int dh_sharedinfo_encode(unsigned char **pder, unsigned char **pctr,
93 ASN1_OBJECT *key_oid, size_t outlen,
94 const unsigned char *ukm, size_t ukmlen)
99 /* "magic" value to check offset is sane */
100 static unsigned char ctr[4] = { 0xF3, 0x17, 0x22, 0x53 };
102 ASN1_OCTET_STRING ctr_oct, ukm_oct, *pukm_oct;
104 if (ukmlen > DH_KDF_MAX || outlen > DH_KDF_MAX)
109 ctr_oct.type = V_ASN1_OCTET_STRING;
110 ctr_atype.type = V_ASN1_OCTET_STRING;
111 ctr_atype.value.octet_string = &ctr_oct;
112 atmp.algorithm = key_oid;
113 atmp.parameter = &ctr_atype;
115 ukm_oct.type = V_ASN1_OCTET_STRING;
117 ukm_oct.data = (unsigned char *)ukm;
118 ukm_oct.length = ukmlen;
122 derlen = CMS_SharedInfo_encode(pder, &atmp, pukm_oct, outlen);
127 if (!skip_asn1(&p, &tlen, V_ASN1_SEQUENCE))
129 if (!skip_asn1(&p, &tlen, V_ASN1_SEQUENCE))
131 if (!skip_asn1(&p, &tlen, V_ASN1_OBJECT))
133 if (!skip_asn1(&p, &tlen, V_ASN1_OCTET_STRING))
135 if (CRYPTO_memcmp(p, ctr, 4))
141 int DH_KDF_X9_42(unsigned char *out, size_t outlen,
142 const unsigned char *Z, size_t Zlen,
143 ASN1_OBJECT *key_oid,
144 const unsigned char *ukm, size_t ukmlen, const EVP_MD *md)
146 EVP_MD_CTX *mctx = NULL;
150 unsigned char *der = NULL, *ctr;
152 if (Zlen > DH_KDF_MAX)
154 mctx = EVP_MD_CTX_new();
157 mdlen = EVP_MD_size(md);
158 derlen = dh_sharedinfo_encode(&der, &ctr, key_oid, outlen, ukm, ukmlen);
162 unsigned char mtmp[EVP_MAX_MD_SIZE];
163 EVP_DigestInit_ex(mctx, md, NULL);
164 if (!EVP_DigestUpdate(mctx, Z, Zlen))
167 ctr[2] = (i >> 8) & 0xFF;
168 ctr[1] = (i >> 16) & 0xFF;
169 ctr[0] = (i >> 24) & 0xFF;
170 if (!EVP_DigestUpdate(mctx, der, derlen))
172 if (outlen >= mdlen) {
173 if (!EVP_DigestFinal(mctx, out, NULL))
180 if (!EVP_DigestFinal(mctx, mtmp, NULL))
182 memcpy(out, mtmp, outlen);
183 OPENSSL_cleanse(mtmp, mdlen);
190 EVP_MD_CTX_free(mctx);