#include "bn.h"

#ifndef WITH_LIBCRYPTO
//FIXME Not checked on threadsafety yet; after checking please remove this line
/* crypto/bn/bn_print.c */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young (eay@cryptsoft.com).
 * The implementation was written so as to conform with Netscapes SSL.
 *
 * This library is free for commercial and non-commercial use as long as
 * the following conditions are aheared to.  The following conditions
 * apply to all code found in this distribution, be it the RC4, RSA,
 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
 * included with this distribution is covered by the same copyright terms
 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
 *
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * If this package is used in a product, Eric Young should be given attribution
 * as the author of the parts of the library used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 *
 * 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 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 acknowledgement:
 *    "This product includes cryptographic software written by
 *     Eric Young (eay@cryptsoft.com)"
 *    The word 'cryptographic' can be left out if the rouines from the library
 *    being used are not cryptographic related :-).
 * 4. If you include any Windows specific code (or a derivative thereof) from
 *    the apps directory (application code) you must include an acknowledgement:
 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
 *
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
 * ANY EXPRESS 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 AUTHOR OR 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.
 *
 * The license and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution license
 * [including the GNU Public License.]
 */

#include <stdio.h>
#include <ctype.h>
#include "bn_lcl.h"
#include "buffer.h"
#include "openssl_mods.h"

static const char *Hex = "0123456789ABCDEF";

/* Must 'OPENSSL_free' the returned data */
char *BN_bn2hex(const BIGNUM *a)
{
	int i, j, v, z = 0;
	char *buf;
	char *p;

	buf = (char *)OPENSSL_malloc(a->top * BN_BYTES * 2 + 2);
	if(buf == NULL)
	{
		goto err;
	}
	p = buf;
	if(a->neg) { *(p++) = '-'; }
	if(a->top == 0) { *(p++) = '0'; }
	for(i = a->top - 1; i >= 0; i--)
	{
		for(j = BN_BITS2 - 8; j >= 0; j -= 8)
		{
			/* strip leading zeros */
			v = ((int)(a->d[i] >> (long)j)) & 0xff;
			if(z || (v != 0))
			{
				*(p++) = Hex[v >> 4];
				*(p++) = Hex[v & 0x0f];
				z = 1;
			}
		}
	}
	*p = '\0';
err:
	return (buf);
}

/* Must 'OPENSSL_free' the returned data */
char *BN_bn2dec(const BIGNUM *a)
{
	int i = 0, num;
	char *buf = NULL;
	char *p;
	BIGNUM *t = NULL;
	BN_ULONG *bn_data = NULL, *lp;

	i = BN_num_bits(a) * 3;
	num = (i / 10 + i / 1000 + 3) + 1;
	bn_data = (BN_ULONG *)OPENSSL_malloc((num / BN_DEC_NUM + 1) * sizeof(BN_ULONG));
	buf = (char *)OPENSSL_malloc(num + 3);
	if((buf == NULL) || (bn_data == NULL))
	{
		goto err;
	}
	if((t = BN_dup(a)) == NULL) { goto err; }

	p = buf;
	lp = bn_data;
	if(t->neg) { *(p++) = '-'; }
	if(t->top == 0)
	{
		*(p++) = '0';
		*(p++) = '\0';
	}
	else
	{
		while(!BN_is_zero(t))
		{
			*lp = BN_div_word(t, BN_DEC_CONV);
			lp++;
		}
		lp--;
		/* We now have a series of blocks, BN_DEC_NUM chars
		 * in length, where the last one needs truncation.
		 * The blocks need to be reversed in order. */
		snprintf(p, num + 3 - (p - buf), BN_DEC_FMT1, *lp);
		while(*p) { p++; }
		while(lp != bn_data)
		{
			lp--;
			snprintf(p, num + 3 - (p - buf), BN_DEC_FMT2, *lp);
			while(*p) { p++; }
		}
	}
err:
	if(bn_data != NULL) { OPENSSL_free(bn_data); }
	if(t != NULL) { BN_free(t); }
	return (buf);
}

int BN_hex2bn(BIGNUM **bn, const char *a)
{
	BIGNUM *ret = NULL;
	BN_ULONG l = 0;
	int neg = 0, h, i, j, k, c;
	int m = 0;
	int num;

	if((a == NULL) || (*a == '\0')) { return (0); }

	if(*a == '-')
	{
		neg = 1;
		a++;
	}

	for(i = 0; isxdigit((unsigned char) a[i]); i++)
		{ ; }

	num = i + neg;
	if(bn == NULL) { return (num); }

	/* a is the start of the hex digits, and it is 'i' long */
	if(*bn == NULL)
	{
		if((ret = BN_new()) == NULL) { return (0); }
	}
	else
	{
		ret = *bn;
		BN_zero(ret);
	}

	/* i is the number of hex digests; */
	if(bn_expand(ret, i * 4) == NULL) { goto err; }

	j = i; /* least significant 'hex' */
	h = 0;
	while(j > 0)
	{
		m = ((BN_BYTES * 2) <= j) ? (BN_BYTES * 2) : j;
		l = 0;
		for(;;)
		{
			c = a[j - m];
			if((c >= '0') && (c <= '9')) { k = c - '0'; }
			else if((c >= 'a') && (c <= 'f')) { k = c - 'a' + 10; }
			else if((c >= 'A') && (c <= 'F')) { k = c - 'A' + 10; }
			else { k = 0; } /* paranoia */
			l = (l << 4) | k;

			if(--m <= 0)
			{
				ret->d[h++] = l;
				break;
			}
		}
		j -= (BN_BYTES * 2);
	}
	ret->top = h;
	bn_fix_top(ret);
	ret->neg = neg;

	*bn = ret;
	return (num);
err:
	if(*bn == NULL) { BN_free(ret); }
	return (0);
}

int BN_dec2bn(BIGNUM **bn, const char *a)
{
	BIGNUM *ret = NULL;
	BN_ULONG l = 0;
	int neg = 0, i, j;
	int num;

	if((a == NULL) || (*a == '\0')) { return (0); }
	if(*a == '-')
	{
		neg = 1;
		a++;
	}

	for(i = 0; isdigit((unsigned char) a[i]); i++)
		{ ; }

	num = i + neg;
	if(bn == NULL) { return (num); }

	/* a is the start of the digits, and it is 'i' long.
	 * We chop it into BN_DEC_NUM digits at a time */
	if(*bn == NULL)
	{
		if((ret = BN_new()) == NULL) { return (0); }
	}
	else
	{
		ret = *bn;
		BN_zero(ret);
	}

	/* i is the number of digests, a bit of an over expand; */
	if(bn_expand(ret, i * 4) == NULL) { goto err; }

	j = BN_DEC_NUM - (i % BN_DEC_NUM);
	if(j == BN_DEC_NUM) { j = 0; }
	l = 0;
	while(*a)
	{
		l *= 10;
		l += *a - '0';
		a++;
		if(++j == BN_DEC_NUM)
		{
			BN_mul_word(ret, BN_DEC_CONV);
			BN_add_word(ret, l);
			l = 0;
			j = 0;
		}
	}
	ret->neg = neg;

	bn_fix_top(ret);
	*bn = ret;
	return (num);
err:
	if(*bn == NULL) { BN_free(ret); }
	return (0);
}

#ifdef BN_DEBUG
void bn_dump1(FILE *o, const char *a, BN_ULONG *b, int n)
{
	int i;
	fprintf(o, "%s=", a);
	for(i = n - 1; i >= 0; i--)
		{ fprintf(o, "%08lX", b[i]); } /* assumes 32-bit BN_ULONG */
	fprintf(o, "\n");
}
#endif
#endif