Add KDF for DH.

Add X9.42 DH KDF. Move sharedinfo generation code to CMS library as the
same structure is used by DH and ECDH.

Move ASN1_OBJECT typedef to ossl_typ.h so it can be picked up by dh headers
without the need to use ASN1.

3 files changed, 206 insertions, 2 deletions

diff --git a/crypto/dh/Makefile b/crypto/dh/Makefile
index 9dd08d617b..ca01f373b4 100644
--- a/crypto/dh/Makefile
+++ b/crypto/dh/Makefile
@@ -18,9 +18,9 @@ APPS=
 
 LIB=$(TOP)/libcrypto.a
 LIBSRC= dh_asn1.c dh_gen.c dh_key.c dh_lib.c dh_check.c dh_err.c dh_depr.c \
-	dh_ameth.c dh_pmeth.c dh_prn.c dh_rfc5114.c
+	dh_ameth.c dh_pmeth.c dh_prn.c dh_rfc5114.c dh_kdf.c
 LIBOBJ= dh_asn1.o dh_gen.o dh_key.o dh_lib.o dh_check.o dh_err.o dh_depr.o \
-	dh_ameth.o dh_pmeth.o dh_prn.o dh_rfc5114.o
+	dh_ameth.o dh_pmeth.o dh_prn.o dh_rfc5114.o dh_kdf.o
 
 SRC= $(LIBSRC)
 
diff --git a/crypto/dh/dh.h b/crypto/dh/dh.h
index 53f9f26566..a86c64db01 100644
--- a/crypto/dh/dh.h
+++ b/crypto/dh/dh.h
@@ -239,6 +239,13 @@ DH *DH_get_1024_160(void);
 DH *DH_get_2048_224(void);
 DH *DH_get_2048_256(void);
 
+/* RFC2631 KDF */
+int DH_KDF_X9_42(unsigned char *out, size_t outlen, 
+		const unsigned char *Z, size_t Zlen,
+		ASN1_OBJECT *key_oid,
+		const unsigned char *ukm, size_t ukmlen,
+		const EVP_MD *md);
+
 #define EVP_PKEY_CTX_set_dh_paramgen_prime_len(ctx, len) \
 	EVP_PKEY_CTX_ctrl(ctx, EVP_PKEY_DH, EVP_PKEY_OP_PARAMGEN, \
 			EVP_PKEY_CTRL_DH_PARAMGEN_PRIME_LEN, len, NULL)
diff --git a/crypto/dh/dh_kdf.c b/crypto/dh/dh_kdf.c
new file mode 100644
index 0000000000..dbdd0b9ba6
--- /dev/null
+++ b/crypto/dh/dh_kdf.c
@@ -0,0 +1,197 @@
+/* crypto/dh/dh_kdf.c */
+/*
+ * Written by Stephen Henson for the OpenSSL project.
+ */
+/* ====================================================================
+ * Copyright (c) 2013 The OpenSSL Project.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer. 
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. All advertising materials mentioning features or use of this
+ *    software must display the following acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
+ *
+ * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
+ *    endorse or promote products derived from this software without
+ *    prior written permission. For written permission, please contact
+ *    openssl-core@openssl.org.
+ *
+ * 5. Products derived from this software may not be called "OpenSSL"
+ *    nor may "OpenSSL" appear in their names without prior written
+ *    permission of the OpenSSL Project.
+ *
+ * 6. Redistributions of any form whatsoever must retain the following
+ *    acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
+ * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ * ====================================================================
+ */
+
+#include <string.h>
+#include <openssl/dh.h>
+#include <openssl/evp.h>
+#include <openssl/asn1.h>
+#include <openssl/cms.h>
+
+
+/* Key derivation from X9.42/RFC2631 */
+
+#define DH_KDF_MAX	(1L << 30)
+
+/* Skip past an ASN1 structure: for OBJECT skip content octets too */
+
+static int skip_asn1(unsigned char **pp, long *plen, int exptag)
+	{
+	const unsigned char *q = *pp;
+	int i, tag, xclass;
+	long tmplen;
+	i = ASN1_get_object(&q, &tmplen, &tag, &xclass, *plen);
+	if (i & 0x80)
+		return 0;
+	if (tag != exptag || xclass != V_ASN1_UNIVERSAL)
+		return 0;
+	if (tag == V_ASN1_OBJECT)
+		q += tmplen;
+	*plen -= q - *pp;
+	*pp = (unsigned char *)q;
+	return 1;
+	}
+
+/* Encode the DH shared info structure, return an offset to the counter
+ * value so we can update the structure without reencoding it.
+ */
+
+
+static int dh_sharedinfo_encode(unsigned char **pder, unsigned char **pctr,
+			ASN1_OBJECT *key_oid, size_t outlen,
+			const unsigned char *ukm, size_t ukmlen)
+	{
+	unsigned char *p;
+	int derlen;
+	long tlen;
+	/* "magic" value to check offset is sane */
+	static unsigned char ctr[4] = {0xF3, 0x17, 0x22, 0x53};
+	X509_ALGOR atmp;
+	ASN1_OCTET_STRING ctr_oct, ukm_oct, *pukm_oct;
+	ASN1_TYPE ctr_atype;
+	if (ukmlen > DH_KDF_MAX || outlen > DH_KDF_MAX)
+		return 0;
+	ctr_oct.data = ctr;
+	ctr_oct.length = 4;
+	ctr_oct.flags = 0;
+	ctr_oct.type = V_ASN1_OCTET_STRING;
+	ctr_atype.type = V_ASN1_OCTET_STRING;
+	ctr_atype.value.octet_string = &ctr_oct;
+	atmp.algorithm = key_oid;
+	atmp.parameter = &ctr_atype;
+	if (ukm)
+		{
+		ukm_oct.type = V_ASN1_OCTET_STRING;
+		ukm_oct.flags = 0;
+		ukm_oct.data = (unsigned char *)ukm;
+		ukm_oct.length = ukmlen;
+		pukm_oct = &ukm_oct;
+		}
+	else
+		pukm_oct = NULL;
+	derlen = CMS_SharedInfo_encode(pder, &atmp, pukm_oct, outlen);
+	if (derlen <= 0)
+		return 0;
+	p = *pder;
+	tlen = derlen;
+	if (!skip_asn1(&p, &tlen, V_ASN1_SEQUENCE))
+		return 0;
+	if (!skip_asn1(&p, &tlen, V_ASN1_SEQUENCE))
+		return 0;
+	if (!skip_asn1(&p, &tlen, V_ASN1_OBJECT))
+		return 0;
+	if (!skip_asn1(&p, &tlen, V_ASN1_OCTET_STRING))
+		return 0;
+	if (memcmp(p, ctr, 4))
+		return 0;
+	*pctr = p;
+	return derlen;
+	}
+
+int DH_KDF_X9_42(unsigned char *out, size_t outlen, 
+		const unsigned char *Z, size_t Zlen,
+		ASN1_OBJECT *key_oid,
+		const unsigned char *ukm, size_t ukmlen,
+		const EVP_MD *md)
+	{
+	EVP_MD_CTX mctx;
+	int rv = 0;
+	unsigned int i;
+	size_t mdlen;
+	unsigned char *der = NULL, *ctr;
+	int derlen;
+	if (Zlen > DH_KDF_MAX)
+		return 0;
+	mdlen = EVP_MD_size(md);
+	EVP_MD_CTX_init(&mctx);
+	derlen = dh_sharedinfo_encode(&der, &ctr, key_oid, outlen,
+						ukm, ukmlen);
+	if (derlen == 0)
+		goto err;
+	for (i = 1;;i++)
+		{
+		unsigned char mtmp[EVP_MAX_MD_SIZE];
+		EVP_DigestInit_ex(&mctx, md, NULL);
+		if (!EVP_DigestUpdate(&mctx, Z, Zlen))
+			goto err;
+		ctr[3] = i & 0xFF;
+		ctr[2] = (i >> 8) & 0xFF;
+		ctr[1] = (i >> 16) & 0xFF;
+		ctr[0] = (i >> 24) & 0xFF;
+		if (!EVP_DigestUpdate(&mctx, der, derlen))
+			goto err;
+		if (outlen >= mdlen)
+			{
+			if (!EVP_DigestFinal(&mctx, out, NULL))
+				goto err;
+			outlen -= mdlen;
+			if (outlen == 0)
+				break;
+			out += mdlen;
+			}
+		else
+			{
+			if (!EVP_DigestFinal(&mctx, mtmp, NULL))
+				goto err;
+			memcpy(out, mtmp, outlen);
+			OPENSSL_cleanse(mtmp, mdlen);
+			break;
+			}
+		}
+	rv = 1;
+	err:
+	if (der)
+		OPENSSL_free(der);
+	EVP_MD_CTX_cleanup(&mctx);
+	return rv;
+	}
+