/* crypto/bn/bn_mpi.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 licence 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 licence * [including the GNU Public Licence.] */#include <stdio.h>#include "cryptlib.h"#include "bn_lcl.h"int BN_bn2mpi(const BIGNUM *a, unsigned char *d)	{	int bits;	int num=0;	int ext=0;	long l;	bits=BN_num_bits(a);	num=(bits+7)/8;	if (bits > 0)		{		ext=((bits & 0x07) == 0);		}	if (d == NULL)		return(num+4+ext);	l=num+ext;	d[0]=(unsigned char)(l>>24)&0xff;	d[1]=(unsigned char)(l>>16)&0xff;	d[2]=(unsigned char)(l>> 8)&0xff;	d[3]=(unsigned char)(l    )&0xff;	if (ext) d[4]=0;	num=BN_bn2bin(a,&(d[4+ext]));	if (a->neg)		d[4]|=0x80;	return(num+4+ext);	}BIGNUM *BN_mpi2bn(const unsigned char *d, int n, BIGNUM *a)	{	long len;	int neg=0;	if (n < 4)		{		BNerr(BN_F_BN_MPI2BN,BN_R_INVALID_LENGTH);		return(NULL);		}	len=((long)d[0]<<24)|((long)d[1]<<16)|((int)d[2]<<8)|(int)d[3];	if ((len+4) != n)		{		BNerr(BN_F_BN_MPI2BN,BN_R_ENCODING_ERROR);		return(NULL);		}	if (a == NULL) a=BN_new();	if (a == NULL) return(NULL);	if (len == 0)		{		a->neg=0;		a->top=0;		return(a);		}	d+=4;	if ((*d) & 0x80)		neg=1;	if (BN_bin2bn(d,(int)len,a) == NULL)		return(NULL);	a->neg=neg;	if (neg)		{		BN_clear_bit(a,BN_num_bits(a)-1);		}	return(a);	}