/* p12_key.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 "cryptlib.h"
#include <openssl/pkcs12.h>


/* Uncomment out this line to get debugging info about key generation */
/*#define DEBUG_KEYGEN*/
#ifdef DEBUG_KEYGEN
#include <openssl/bio.h>
extern BIO *bio_err;
void h__dump (unsigned char *p, int len);
#endif

/* PKCS12 compatible key/IV generation */
#ifndef min
#define min(a,b) ((a) < (b) ? (a) : (b))
#endif

int PKCS12_key_gen_asc (const char *pass, int passlen, unsigned char *salt,
	     int saltlen, int id, int iter, int n, unsigned char *out,
	     const EVP_MD *md_type)
{
	int ret;
	unsigned char *unipass;
	int uniplen;
	if (!asc2uni (pass, &unipass, &uniplen)) {
		PKCS12err(PKCS12_F_PKCS12_KEY_GEN_ASC,ERR_R_MALLOC_FAILURE);
		return 0;
	}
	ret = PKCS12_key_gen_uni (unipass, uniplen, salt, saltlen,
						 id, iter, n, out, md_type);
	memset(unipass, 0, uniplen);	/* Clear password from memory */
	Free(unipass);
	return ret;
}

int PKCS12_key_gen_uni (unsigned char *pass, int passlen, unsigned char *salt,
	     int saltlen, int id, int iter, int n, unsigned char *out,
	     const EVP_MD *md_type)
{
	unsigned char *B, *D, *I, *p, *Ai;
	int Slen, Plen, Ilen;
	int i, j, u, v;
	BIGNUM *Ij, *Bpl1;	/* These hold Ij and B + 1 */
	EVP_MD_CTX ctx;
#ifdef  DEBUG_KEYGEN
	unsigned char *tmpout = out;
	int tmpn = n;
	fprintf(stderr, "KEYGEN DEBUG\n");
	fprintf(stderr, "ID %d, ITER %d\n", id, iter);
	fprintf(stderr, "Password (length %d):\n", passlen);
	h__dump(pass, passlen);
	fprintf(stderr, "Salt (length %d):\n", saltlen);
	h__dump(salt, saltlen);
#endif
	v = EVP_MD_block_size (md_type);
	u = EVP_MD_size (md_type);
	D = Malloc (v);
	Ai = Malloc (u);
	B = Malloc (v + 1);
	Slen = v * ((saltlen+v-1)/v);
	Plen = v * ((passlen+v-1)/v);
	Ilen = Slen + Plen;
	I = Malloc (Ilen);
	Ij = BN_new();
	Bpl1 = BN_new();
	if (!D || !Ai || !B || !I || !Ij || !Bpl1) {
		PKCS12err(PKCS12_F_PKCS12_KEY_GEN_UNI,ERR_R_MALLOC_FAILURE);
		return 0;
	}
	for (i = 0; i < v; i++) D[i] = id;
	p = I;
	for (i = 0; i < Slen; i++) *p++ = salt[i % saltlen];
	for (i = 0; i < Plen; i++) *p++ = pass[i % passlen];
	for (;;) {
		EVP_DigestInit (&ctx, md_type);
		EVP_DigestUpdate (&ctx, D, v);
		EVP_DigestUpdate (&ctx, I, Ilen);
		EVP_DigestFinal (&ctx, Ai, NULL);
		for (j = 1; j < iter; j++) {
			EVP_DigestInit (&ctx, md_type);
			EVP_DigestUpdate (&ctx, Ai, u);
			EVP_DigestFinal (&ctx, Ai, NULL);
		}
		memcpy (out, Ai, min (n, u));
		if (u >= n) {
			Free (Ai);
			Free (B);
			Free (D);
			Free (I);
			BN_free (Ij);
			BN_free (Bpl1);
#ifdef DEBUG_KEYGEN
			fprintf(stderr, "Output KEY (length %d)\n", tmpn);
			h__dump(tmpout, tmpn);
#endif
			return 1;	
		}
		n -= u;
		out += u;
		for (j = 0; j < v; j++) B[j] = Ai[j % u];
		/* Work out B + 1 first then can use B as tmp space */
		BN_bin2bn (B, v, Bpl1);
		BN_add_word (Bpl1, 1);
		for (j = 0; j < Ilen ; j+=v) {
			BN_bin2bn (I + j, v, Ij);
			BN_add (Ij, Ij, Bpl1);
			BN_bn2bin (Ij, B);
			/* If more than 2^(v*8) - 1 cut off MSB */
			if (BN_num_bytes (Ij) > v) {
				BN_bn2bin (Ij, B);
				memcpy (I + j, B + 1, v);
			} else BN_bn2bin (Ij, I + j);
		}
	}
}
#ifdef DEBUG_KEYGEN
void h__dump (unsigned char *p, int len)
{
	for (; len --; p++) fprintf(stderr, "%02X", *p);
	fprintf(stderr, "\n");	
}
#endif