crypto/pkcs8/p5_pbev2.c - boringssl - Git at Google

 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
  * project 1999-2004.
  */
 /* ====================================================================
  * Copyright (c) 1999 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
  *    licensing@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.
  * ====================================================================
  *
  * This product includes cryptographic software written by Eric Young
  * (eay@cryptsoft.com).  This product includes software written by Tim
  * Hudson (tjh@cryptsoft.com). */


 #include <openssl/asn1t.h>
 #include <openssl/cipher.h>
 #include <openssl/err.h>
 #include <openssl/mem.h>
 #include <openssl/pkcs8.h>
 #include <openssl/rand.h>
 #include <openssl/x509.h>

 #include "internal.h"


 /* PKCS#5 v2.0 password based encryption structures */

 ASN1_SEQUENCE(PBE2PARAM) = {
 	ASN1_SIMPLE(PBE2PARAM, keyfunc, X509_ALGOR),
 	ASN1_SIMPLE(PBE2PARAM, encryption, X509_ALGOR)
 } ASN1_SEQUENCE_END(PBE2PARAM)

 IMPLEMENT_ASN1_FUNCTIONS(PBE2PARAM)

 ASN1_SEQUENCE(PBKDF2PARAM) = {
 	ASN1_SIMPLE(PBKDF2PARAM, salt, ASN1_ANY),
 	ASN1_SIMPLE(PBKDF2PARAM, iter, ASN1_INTEGER),
 	ASN1_OPT(PBKDF2PARAM, keylength, ASN1_INTEGER),
 	ASN1_OPT(PBKDF2PARAM, prf, X509_ALGOR)
 } ASN1_SEQUENCE_END(PBKDF2PARAM)

 IMPLEMENT_ASN1_FUNCTIONS(PBKDF2PARAM);

 static int ASN1_TYPE_set_octetstring(ASN1_TYPE *a, unsigned char *data, int len)
 	{
 	ASN1_STRING *os;

 	if ((os=M_ASN1_OCTET_STRING_new()) == NULL) return(0);
 	if (!M_ASN1_OCTET_STRING_set(os,data,len)) return(0);
 	ASN1_TYPE_set(a,V_ASN1_OCTET_STRING,os);
 	return(1);
 	}

 static int param_to_asn1(EVP_CIPHER_CTX *c, ASN1_TYPE *type)
 	{
 	unsigned iv_len;

 	iv_len = EVP_CIPHER_CTX_iv_length(c);
 	return ASN1_TYPE_set_octetstring(type, c->oiv, iv_len);
 	}

 /* Return an algorithm identifier for a PKCS#5 v2.0 PBE algorithm:
  * yes I know this is horrible!
  *
  * Extended version to allow application supplied PRF NID and IV. */

 X509_ALGOR *PKCS5_pbe2_set_iv(const EVP_CIPHER *cipher, int iter,
 				 unsigned char *salt, int saltlen,
 				 unsigned char *aiv, int prf_nid)
 {
 	X509_ALGOR *scheme = NULL, *kalg = NULL, *ret = NULL;
 	int alg_nid, keylen;
 	EVP_CIPHER_CTX ctx;
 	unsigned char iv[EVP_MAX_IV_LENGTH];
 	PBE2PARAM *pbe2 = NULL;
 	const ASN1_OBJECT *obj;

 	alg_nid = EVP_CIPHER_nid(cipher);
 	if(alg_nid == NID_undef) {
 		OPENSSL_PUT_ERROR(PKCS8, PKCS5_pbe2_set_iv, PKCS8_R_CIPHER_HAS_NO_OBJECT_IDENTIFIER);
 		goto err;
 	}
 	obj = OBJ_nid2obj(alg_nid);

 	if(!(pbe2 = PBE2PARAM_new())) goto merr;

 	/* Setup the AlgorithmIdentifier for the encryption scheme */
 	scheme = pbe2->encryption;

 	scheme->algorithm = (ASN1_OBJECT*) obj;
 	if(!(scheme->parameter = ASN1_TYPE_new())) goto merr;

 	/* Create random IV */
 	if (EVP_CIPHER_iv_length(cipher))
 		{
 		if (aiv)
 			memcpy(iv, aiv, EVP_CIPHER_iv_length(cipher));
 		else if (RAND_pseudo_bytes(iv, EVP_CIPHER_iv_length(cipher)) < 0)
   			goto err;
 		}

 	EVP_CIPHER_CTX_init(&ctx);

 	/* Dummy cipherinit to just setup the IV, and PRF */
 	if (!EVP_CipherInit_ex(&ctx, cipher, NULL, NULL, iv, 0))
 		goto err;
 	if(param_to_asn1(&ctx, scheme->parameter) < 0) {
 		OPENSSL_PUT_ERROR(PKCS8, PKCS5_pbe2_set_iv, PKCS8_R_ERROR_SETTING_CIPHER_PARAMS);
 		EVP_CIPHER_CTX_cleanup(&ctx);
 		goto err;
 	}
 	/* If prf NID unspecified see if cipher has a preference.
 	 * An error is OK here: just means use default PRF.
 	 */
 	if ((prf_nid == -1) &&
 	EVP_CIPHER_CTX_ctrl(&ctx, EVP_CTRL_PBE_PRF_NID, 0, &prf_nid) <= 0)
 		{
 		ERR_clear_error();
 		prf_nid = NID_hmacWithSHA1;
 		}
 	EVP_CIPHER_CTX_cleanup(&ctx);

 	/* If its RC2 then we'd better setup the key length */

 	if(alg_nid == NID_rc2_cbc)
 		keylen = EVP_CIPHER_key_length(cipher);
 	else
 		keylen = -1;

 	/* Setup keyfunc */

 	X509_ALGOR_free(pbe2->keyfunc);

 	pbe2->keyfunc = PKCS5_pbkdf2_set(iter, salt, saltlen, prf_nid, keylen);

 	if (!pbe2->keyfunc)
 		goto merr;

 	/* Now set up top level AlgorithmIdentifier */

 	if(!(ret = X509_ALGOR_new())) goto merr;
 	if(!(ret->parameter = ASN1_TYPE_new())) goto merr;

 	ret->algorithm = (ASN1_OBJECT*) OBJ_nid2obj(NID_pbes2);

 	/* Encode PBE2PARAM into parameter */

 	if(!ASN1_item_pack(pbe2, ASN1_ITEM_rptr(PBE2PARAM),
 				 &ret->parameter->value.sequence)) goto merr;
 	ret->parameter->type = V_ASN1_SEQUENCE;

 	PBE2PARAM_free(pbe2);
 	pbe2 = NULL;

 	return ret;

 	merr:
 	OPENSSL_PUT_ERROR(PKCS8, PKCS5_pbe2_set_iv, ERR_R_MALLOC_FAILURE);

 	err:
 	PBE2PARAM_free(pbe2);
 	/* Note 'scheme' is freed as part of pbe2 */
 	X509_ALGOR_free(kalg);
 	X509_ALGOR_free(ret);

 	return NULL;

 }

 X509_ALGOR *PKCS5_pbe2_set(const EVP_CIPHER *cipher, int iter,
 				 unsigned char *salt, int saltlen)
 	{
 	return PKCS5_pbe2_set_iv(cipher, iter, salt, saltlen, NULL, -1);
 	}

 X509_ALGOR *PKCS5_pbkdf2_set(int iter, unsigned char *salt, int saltlen,
 				int prf_nid, int keylen)
 	{
 	X509_ALGOR *keyfunc = NULL;
 	PBKDF2PARAM *kdf = NULL;
 	ASN1_OCTET_STRING *osalt = NULL;

 	if(!(kdf = PBKDF2PARAM_new()))
 		goto merr;
 	if(!(osalt = M_ASN1_OCTET_STRING_new()))
 		goto merr;

 	kdf->salt->value.octet_string = osalt;
 	kdf->salt->type = V_ASN1_OCTET_STRING;

 	if (!saltlen)
 		saltlen = PKCS5_SALT_LEN;
 	if (!(osalt->data = OPENSSL_malloc (saltlen)))
 		goto merr;

 	osalt->length = saltlen;

 	if (salt)
 		memcpy (osalt->data, salt, saltlen);
 	else if (RAND_pseudo_bytes (osalt->data, saltlen) < 0)
 		goto merr;

 	if(iter <= 0)
 		iter = PKCS5_DEFAULT_ITERATIONS;

 	if(!ASN1_INTEGER_set(kdf->iter, iter))
 		goto merr;

 	/* If have a key len set it up */

 	if(keylen > 0)
 		{
 		if(!(kdf->keylength = M_ASN1_INTEGER_new()))
 			goto merr;
 		if(!ASN1_INTEGER_set (kdf->keylength, keylen))
 			goto merr;
 		}

 	/* prf can stay NULL if we are using hmacWithSHA1 */
 	if (prf_nid > 0 && prf_nid != NID_hmacWithSHA1)
 		{
 		kdf->prf = X509_ALGOR_new();
 		if (!kdf->prf)
 			goto merr;
 		X509_ALGOR_set0(kdf->prf, OBJ_nid2obj(prf_nid),
 					V_ASN1_NULL, NULL);
 		}

 	/* Finally setup the keyfunc structure */

 	keyfunc = X509_ALGOR_new();
 	if (!keyfunc)
 		goto merr;

 	keyfunc->algorithm = (ASN1_OBJECT*) OBJ_nid2obj(NID_id_pbkdf2);

 	/* Encode PBKDF2PARAM into parameter of pbe2 */

 	if(!(keyfunc->parameter = ASN1_TYPE_new()))
 		goto merr;

 	if(!ASN1_item_pack(kdf, ASN1_ITEM_rptr(PBKDF2PARAM),
 			 &keyfunc->parameter->value.sequence))
 		goto merr;
 	keyfunc->parameter->type = V_ASN1_SEQUENCE;

 	PBKDF2PARAM_free(kdf);
 	return keyfunc;

 	merr:
 	OPENSSL_PUT_ERROR(PKCS8, PKCS5_pbkdf2_set, ERR_R_MALLOC_FAILURE);
 	PBKDF2PARAM_free(kdf);
 	X509_ALGOR_free(keyfunc);
 	return NULL;
 	}
	/* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
	* project 1999-2004.
	*/
	/* ====================================================================
	* Copyright (c) 1999 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
	* licensing@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.
	* ====================================================================
	*
	* This product includes cryptographic software written by Eric Young
	* (eay@cryptsoft.com). This product includes software written by Tim
	* Hudson (tjh@cryptsoft.com). */


	#include <openssl/asn1t.h>
	#include <openssl/cipher.h>
	#include <openssl/err.h>
	#include <openssl/mem.h>
	#include <openssl/pkcs8.h>
	#include <openssl/rand.h>
	#include <openssl/x509.h>

	#include "internal.h"


	/* PKCS#5 v2.0 password based encryption structures */

	ASN1_SEQUENCE(PBE2PARAM) = {
	ASN1_SIMPLE(PBE2PARAM, keyfunc, X509_ALGOR),
	ASN1_SIMPLE(PBE2PARAM, encryption, X509_ALGOR)
	} ASN1_SEQUENCE_END(PBE2PARAM)

	IMPLEMENT_ASN1_FUNCTIONS(PBE2PARAM)

	ASN1_SEQUENCE(PBKDF2PARAM) = {
	ASN1_SIMPLE(PBKDF2PARAM, salt, ASN1_ANY),
	ASN1_SIMPLE(PBKDF2PARAM, iter, ASN1_INTEGER),
	ASN1_OPT(PBKDF2PARAM, keylength, ASN1_INTEGER),
	ASN1_OPT(PBKDF2PARAM, prf, X509_ALGOR)
	} ASN1_SEQUENCE_END(PBKDF2PARAM)

	IMPLEMENT_ASN1_FUNCTIONS(PBKDF2PARAM);

	static int ASN1_TYPE_set_octetstring(ASN1_TYPE a, unsigned char data, int len)
	{
	ASN1_STRING *os;

	if ((os=M_ASN1_OCTET_STRING_new()) == NULL) return(0);
	if (!M_ASN1_OCTET_STRING_set(os,data,len)) return(0);
	ASN1_TYPE_set(a,V_ASN1_OCTET_STRING,os);
	return(1);
	}

	static int param_to_asn1(EVP_CIPHER_CTX c, ASN1_TYPE type)
	{
	unsigned iv_len;

	iv_len = EVP_CIPHER_CTX_iv_length(c);
	return ASN1_TYPE_set_octetstring(type, c->oiv, iv_len);
	}

	/* Return an algorithm identifier for a PKCS#5 v2.0 PBE algorithm:
	* yes I know this is horrible!
	*
	* Extended version to allow application supplied PRF NID and IV. */

	X509_ALGOR PKCS5_pbe2_set_iv(const EVP_CIPHER cipher, int iter,
	unsigned char *salt, int saltlen,
	unsigned char *aiv, int prf_nid)
	{
	X509_ALGOR scheme = NULL, kalg = NULL, *ret = NULL;
	int alg_nid, keylen;
	EVP_CIPHER_CTX ctx;
	unsigned char iv[EVP_MAX_IV_LENGTH];
	PBE2PARAM *pbe2 = NULL;
	const ASN1_OBJECT *obj;

	alg_nid = EVP_CIPHER_nid(cipher);
	if(alg_nid == NID_undef) {
	OPENSSL_PUT_ERROR(PKCS8, PKCS5_pbe2_set_iv, PKCS8_R_CIPHER_HAS_NO_OBJECT_IDENTIFIER);
	goto err;
	}
	obj = OBJ_nid2obj(alg_nid);

	if(!(pbe2 = PBE2PARAM_new())) goto merr;

	/* Setup the AlgorithmIdentifier for the encryption scheme */
	scheme = pbe2->encryption;

	scheme->algorithm = (ASN1_OBJECT*) obj;
	if(!(scheme->parameter = ASN1_TYPE_new())) goto merr;

	/* Create random IV */
	if (EVP_CIPHER_iv_length(cipher))
	{
	if (aiv)
	memcpy(iv, aiv, EVP_CIPHER_iv_length(cipher));
	else if (RAND_pseudo_bytes(iv, EVP_CIPHER_iv_length(cipher)) < 0)
	goto err;
	}

	EVP_CIPHER_CTX_init(&ctx);

	/* Dummy cipherinit to just setup the IV, and PRF */
	if (!EVP_CipherInit_ex(&ctx, cipher, NULL, NULL, iv, 0))
	goto err;
	if(param_to_asn1(&ctx, scheme->parameter) < 0) {
	OPENSSL_PUT_ERROR(PKCS8, PKCS5_pbe2_set_iv, PKCS8_R_ERROR_SETTING_CIPHER_PARAMS);
	EVP_CIPHER_CTX_cleanup(&ctx);
	goto err;
	}
	/* If prf NID unspecified see if cipher has a preference.
	* An error is OK here: just means use default PRF.
	*/
	if ((prf_nid == -1) &&
	EVP_CIPHER_CTX_ctrl(&ctx, EVP_CTRL_PBE_PRF_NID, 0, &prf_nid) <= 0)
	{
	ERR_clear_error();
	prf_nid = NID_hmacWithSHA1;
	}
	EVP_CIPHER_CTX_cleanup(&ctx);

	/* If its RC2 then we'd better setup the key length */

	if(alg_nid == NID_rc2_cbc)
	keylen = EVP_CIPHER_key_length(cipher);
	else
	keylen = -1;

	/* Setup keyfunc */

	X509_ALGOR_free(pbe2->keyfunc);

	pbe2->keyfunc = PKCS5_pbkdf2_set(iter, salt, saltlen, prf_nid, keylen);

	if (!pbe2->keyfunc)
	goto merr;

	/* Now set up top level AlgorithmIdentifier */

	if(!(ret = X509_ALGOR_new())) goto merr;
	if(!(ret->parameter = ASN1_TYPE_new())) goto merr;

	ret->algorithm = (ASN1_OBJECT*) OBJ_nid2obj(NID_pbes2);

	/* Encode PBE2PARAM into parameter */

	if(!ASN1_item_pack(pbe2, ASN1_ITEM_rptr(PBE2PARAM),
	&ret->parameter->value.sequence)) goto merr;
	ret->parameter->type = V_ASN1_SEQUENCE;

	PBE2PARAM_free(pbe2);
	pbe2 = NULL;

	return ret;

	merr:
	OPENSSL_PUT_ERROR(PKCS8, PKCS5_pbe2_set_iv, ERR_R_MALLOC_FAILURE);

	err:
	PBE2PARAM_free(pbe2);
	/* Note 'scheme' is freed as part of pbe2 */
	X509_ALGOR_free(kalg);
	X509_ALGOR_free(ret);

	return NULL;

	}

	X509_ALGOR PKCS5_pbe2_set(const EVP_CIPHER cipher, int iter,
	unsigned char *salt, int saltlen)
	{
	return PKCS5_pbe2_set_iv(cipher, iter, salt, saltlen, NULL, -1);
	}

	X509_ALGOR PKCS5_pbkdf2_set(int iter, unsigned char salt, int saltlen,
	int prf_nid, int keylen)
	{
	X509_ALGOR *keyfunc = NULL;
	PBKDF2PARAM *kdf = NULL;
	ASN1_OCTET_STRING *osalt = NULL;

	if(!(kdf = PBKDF2PARAM_new()))
	goto merr;
	if(!(osalt = M_ASN1_OCTET_STRING_new()))
	goto merr;

	kdf->salt->value.octet_string = osalt;
	kdf->salt->type = V_ASN1_OCTET_STRING;

	if (!saltlen)
	saltlen = PKCS5_SALT_LEN;
	if (!(osalt->data = OPENSSL_malloc (saltlen)))
	goto merr;

	osalt->length = saltlen;

	if (salt)
	memcpy (osalt->data, salt, saltlen);
	else if (RAND_pseudo_bytes (osalt->data, saltlen) < 0)
	goto merr;

	if(iter <= 0)
	iter = PKCS5_DEFAULT_ITERATIONS;

	if(!ASN1_INTEGER_set(kdf->iter, iter))
	goto merr;

	/* If have a key len set it up */

	if(keylen > 0)
	{
	if(!(kdf->keylength = M_ASN1_INTEGER_new()))
	goto merr;
	if(!ASN1_INTEGER_set (kdf->keylength, keylen))
	goto merr;
	}

	/* prf can stay NULL if we are using hmacWithSHA1 */
	if (prf_nid > 0 && prf_nid != NID_hmacWithSHA1)
	{
	kdf->prf = X509_ALGOR_new();
	if (!kdf->prf)
	goto merr;
	X509_ALGOR_set0(kdf->prf, OBJ_nid2obj(prf_nid),
	V_ASN1_NULL, NULL);
	}

	/* Finally setup the keyfunc structure */

	keyfunc = X509_ALGOR_new();
	if (!keyfunc)
	goto merr;

	keyfunc->algorithm = (ASN1_OBJECT*) OBJ_nid2obj(NID_id_pbkdf2);

	/* Encode PBKDF2PARAM into parameter of pbe2 */

	if(!(keyfunc->parameter = ASN1_TYPE_new()))
	goto merr;

	if(!ASN1_item_pack(kdf, ASN1_ITEM_rptr(PBKDF2PARAM),
	&keyfunc->parameter->value.sequence))
	goto merr;
	keyfunc->parameter->type = V_ASN1_SEQUENCE;

	PBKDF2PARAM_free(kdf);
	return keyfunc;

	merr:
	OPENSSL_PUT_ERROR(PKCS8, PKCS5_pbkdf2_set, ERR_R_MALLOC_FAILURE);
	PBKDF2PARAM_free(kdf);
	X509_ALGOR_free(keyfunc);
	return NULL;
	}