/* p5_crpt2.c */

/* Written by Dr Stephen N Henson (shenson@bigfoot.com) for the OpenSSL

 * project 1999.

 */

/* ====================================================================

 * 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 <stdio.h>

#include <stdlib.h>

#include "cryptlib.h"

#if !defined(OPENSSL_NO_HMAC) && !defined(OPENSSL_NO_SHA)

#include <openssl/x509.h>

#include <openssl/evp.h>

#include <openssl/hmac.h>

/* set this to print out info about the keygen algorithm */

/* #define DEBUG_PKCS5V2 */

#ifdef DEBUG_PKCS5V2

	static void h__dump (const unsigned char *p, int len);

#endif

/* This is an implementation of PKCS#5 v2.0 password based encryption key

 * derivation function PBKDF2 using the only currently defined function HMAC

 * with SHA1. Verified against test vectors posted by Peter Gutmann

 * <pgut001@cs.auckland.ac.nz> to the PKCS-TNG <pkcs-tng@rsa.com> mailing list.

 */

EXPORT_C int PKCS5_PBKDF2_HMAC_SHA1(const char *pass, int passlen,

			   const unsigned char *salt, int saltlen, int iter,

			   int keylen, unsigned char *out)

{

	unsigned char digtmp[SHA_DIGEST_LENGTH], *p, itmp[4];

	int cplen, j, k, tkeylen;

	unsigned long i = 1;

	HMAC_CTX hctx;

	HMAC_CTX_init(&hctx);

	p = out;

	tkeylen = keylen;

	if(!pass) passlen = 0;

	else if(passlen == -1) passlen = strlen(pass);

	while(tkeylen) {

		if(tkeylen > SHA_DIGEST_LENGTH) cplen = SHA_DIGEST_LENGTH;

		else cplen = tkeylen;

		/* We are unlikely to ever use more than 256 blocks (5120 bits!)

		 * but just in case...

		 */

		itmp[0] = (unsigned char)((i >> 24) & 0xff);

		itmp[1] = (unsigned char)((i >> 16) & 0xff);

		itmp[2] = (unsigned char)((i >> 8) & 0xff);

		itmp[3] = (unsigned char)(i & 0xff);

		HMAC_Init_ex(&hctx, pass, passlen, EVP_sha1(), NULL);

		HMAC_Update(&hctx, salt, saltlen);

		HMAC_Update(&hctx, itmp, 4);

		HMAC_Final(&hctx, digtmp, NULL);

		memcpy(p, digtmp, cplen);

		for(j = 1; j < iter; j++) {

			HMAC(EVP_sha1(), pass, passlen,

				 digtmp, SHA_DIGEST_LENGTH, digtmp, NULL);

			for(k = 0; k < cplen; k++) p[k] ^= digtmp[k];

		}

		tkeylen-= cplen;

		i++;

		p+= cplen;

	}

	HMAC_CTX_cleanup(&hctx);

#ifdef DEBUG_PKCS5V2

	fprintf(stderr, "Password:\n");

	h__dump (pass, passlen);

	fprintf(stderr, "Salt:\n");

	h__dump (salt, saltlen);

	fprintf(stderr, "Iteration count %d\n", iter);

	fprintf(stderr, "Key:\n");

	h__dump (out, keylen);

#endif

	return 1;

}

#ifdef DO_TEST

main()

{

	unsigned char out[4];

	unsigned char salt[] = {0x12, 0x34, 0x56, 0x78};

	PKCS5_PBKDF2_HMAC_SHA1("password", -1, salt, 4, 5, 4, out);

	fprintf(stderr, "Out %02X %02X %02X %02X\n",

					 out[0], out[1], out[2], out[3]);

}

#endif

/* Now the key derivation function itself. This is a bit evil because

 * it has to check the ASN1 parameters are valid: and there are quite a

 * few of them...

 */

EXPORT_C int PKCS5_v2_PBE_keyivgen(EVP_CIPHER_CTX *ctx, const char *pass, int passlen,

                         ASN1_TYPE *param, const EVP_CIPHER *c, const EVP_MD *md,

                         int en_de)

{

	unsigned char *salt, key[EVP_MAX_KEY_LENGTH];

	const unsigned char *pbuf;

	int saltlen, iter, plen;

	unsigned int keylen;

	PBE2PARAM *pbe2 = NULL;

	const EVP_CIPHER *cipher;

	PBKDF2PARAM *kdf = NULL;

	if (param == NULL || param->type != V_ASN1_SEQUENCE ||

	    param->value.sequence == NULL) {

		EVPerr(EVP_F_PKCS5_V2_PBE_KEYIVGEN,EVP_R_DECODE_ERROR);

		return 0;

	}

	pbuf = param->value.sequence->data;

	plen = param->value.sequence->length;

	if(!(pbe2 = d2i_PBE2PARAM(NULL, &pbuf, plen))) {

		EVPerr(EVP_F_PKCS5_V2_PBE_KEYIVGEN,EVP_R_DECODE_ERROR);

		return 0;

	}

	/* See if we recognise the key derivation function */

	if(OBJ_obj2nid(pbe2->keyfunc->algorithm) != NID_id_pbkdf2) {

		EVPerr(EVP_F_PKCS5_V2_PBE_KEYIVGEN,

				EVP_R_UNSUPPORTED_KEY_DERIVATION_FUNCTION);

		goto err;

	}

	/* lets see if we recognise the encryption algorithm.

	 */

	cipher = EVP_get_cipherbyname(

			OBJ_nid2sn(OBJ_obj2nid(pbe2->encryption->algorithm)));

	if(!cipher) {

		EVPerr(EVP_F_PKCS5_V2_PBE_KEYIVGEN,

						EVP_R_UNSUPPORTED_CIPHER);

		goto err;

	}

	/* Fixup cipher based on AlgorithmIdentifier */

	EVP_CipherInit_ex(ctx, cipher, NULL, NULL, NULL, en_de);

	if(EVP_CIPHER_asn1_to_param(ctx, pbe2->encryption->parameter) < 0) {

		EVPerr(EVP_F_PKCS5_V2_PBE_KEYIVGEN,

					EVP_R_CIPHER_PARAMETER_ERROR);

		goto err;

	}

	keylen = EVP_CIPHER_CTX_key_length(ctx);

	OPENSSL_assert(keylen <= sizeof key);

	/* Now decode key derivation function */

	if(!pbe2->keyfunc->parameter ||

		 (pbe2->keyfunc->parameter->type != V_ASN1_SEQUENCE))

		{

		EVPerr(EVP_F_PKCS5_V2_PBE_KEYIVGEN,EVP_R_DECODE_ERROR);

		goto err;

		}

	pbuf = pbe2->keyfunc->parameter->value.sequence->data;

	plen = pbe2->keyfunc->parameter->value.sequence->length;

	if(!(kdf = d2i_PBKDF2PARAM(NULL, &pbuf, plen)) ) {

		EVPerr(EVP_F_PKCS5_V2_PBE_KEYIVGEN,EVP_R_DECODE_ERROR);

		goto err;

	}

	PBE2PARAM_free(pbe2);

	pbe2 = NULL;

	/* Now check the parameters of the kdf */

	if(kdf->keylength && (ASN1_INTEGER_get(kdf->keylength) != (int)keylen)){

		EVPerr(EVP_F_PKCS5_V2_PBE_KEYIVGEN,

						EVP_R_UNSUPPORTED_KEYLENGTH);

		goto err;

	}

	if(kdf->prf && (OBJ_obj2nid(kdf->prf->algorithm) != NID_hmacWithSHA1)) {

		EVPerr(EVP_F_PKCS5_V2_PBE_KEYIVGEN, EVP_R_UNSUPPORTED_PRF);

		goto err;

	}

	if(kdf->salt->type != V_ASN1_OCTET_STRING) {

		EVPerr(EVP_F_PKCS5_V2_PBE_KEYIVGEN,

						EVP_R_UNSUPPORTED_SALT_TYPE);

		goto err;

	}

	/* it seems that its all OK */

	salt = kdf->salt->value.octet_string->data;

	saltlen = kdf->salt->value.octet_string->length;

	iter = ASN1_INTEGER_get(kdf->iter);

	PKCS5_PBKDF2_HMAC_SHA1(pass, passlen, salt, saltlen, iter, keylen, key);

	EVP_CipherInit_ex(ctx, NULL, NULL, key, NULL, en_de);

	OPENSSL_cleanse(key, keylen);

	PBKDF2PARAM_free(kdf);

	return 1;

	err:

	PBE2PARAM_free(pbe2);

	PBKDF2PARAM_free(kdf);

	return 0;

}

#ifdef DEBUG_PKCS5V2

static void h__dump (const unsigned char *p, int len)

{

        for (; len --; p++) fprintf(stderr, "%02X ", *p);

        fprintf(stderr, "\n");

}

#endif

#endif