source: trunk/cscrypt/bn_print.c@ 1

/* 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 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 <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
        {
        i=0;
        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. */
        sprintf(p,BN_DEC_FMT1,*lp);
        while (*p) p++;
        while (lp != bn_data)
            {
            lp--;
            sprintf(p,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,m,i,j,k,c;
    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' */
    m=0;
    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