Import of old SSLeay release: SSLeay 0.8.1b

[thirdparty/openssl.git] / crypto / bn / bn_lib.c

/* crypto/bn/bn_lib.c */
/* Copyright (C) 1995-1997 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"

char *BN_version="Big Number part of SSLeay 0.8.1b 29-Jun-1998";

BIGNUM *BN_value_one()
        {
        static BN_ULONG data_one=1L;
        static BIGNUM const_one={&data_one,1,1,0};

        return(&const_one);
        }

char *BN_options()
        {
        static int init=0;
        static char data[16];

        if (!init)
                {
                init++;
#ifdef BN_LLONG
                sprintf(data,"bn(%d,%d)",(int)sizeof(BN_ULLONG)*8,
                        (int)sizeof(BN_ULONG)*8);
#else
                sprintf(data,"bn(%d,%d)",(int)sizeof(BN_ULONG)*8,
                        (int)sizeof(BN_ULONG)*8);
#endif
                }
        return(data);
        }

int BN_num_bits_word(l)
BN_ULONG l;
        {
        static char bits[256]={
                0,1,2,2,3,3,3,3,4,4,4,4,4,4,4,4,
                5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
                6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
                6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
                7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
                7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
                7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
                7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
                8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
                8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
                8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
                8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
                8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
                8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
                8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
                8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
                };

#ifdef SIXTY_FOUR_BIT_LONG
        if (l & 0xffffffff00000000L)
                {
                if (l & 0xffff000000000000L)
                        {
                        if (l & 0xff00000000000000L)
                                {
                                return(bits[l>>56]+56);
                                }
                        else    return(bits[l>>48]+48);
                        }
                else
                        {
                        if (l & 0x0000ff0000000000L)
                                {
                                return(bits[l>>40]+40);
                                }
                        else    return(bits[l>>32]+32);
                        }
                }
        else
#else
#ifdef SIXTY_FOUR_BIT
        if (l & 0xffffffff00000000LL)
                {
                if (l & 0xffff000000000000LL)
                        {
                        if (l & 0xff00000000000000LL)
                                {
                                return(bits[l>>56]+56);
                                }
                        else    return(bits[l>>48]+48);
                        }
                else
                        {
                        if (l & 0x0000ff0000000000LL)
                                {
                                return(bits[l>>40]+40);
                                }
                        else    return(bits[l>>32]+32);
                        }
                }
        else
#endif
#endif
                {
#if defined(THIRTY_TWO_BIT) || defined(SIXTY_FOUR_BIT) || defined(SIXTY_FOUR_BIT_LONG)
                if (l & 0xffff0000L)
                        {
                        if (l & 0xff000000L)
                                return(bits[l>>24L]+24);
                        else    return(bits[l>>16L]+16);
                        }
                else
#endif
                        {
#if defined(SIXTEEN_BIT) || defined(THIRTY_TWO_BIT) || defined(SIXTY_FOUR_BIT) || defined(SIXTY_FOUR_BIT_LONG)
                        if (l & 0xff00L)
                                return(bits[l>>8]+8);
                        else    
#endif
                                return(bits[l   ]  );
                        }
                }
        }

int BN_num_bits(a)
BIGNUM *a;
        {
        BN_ULONG l;
        int i;

        if (a->top == 0) return(0);
        l=a->d[a->top-1];
        i=(a->top-1)*BN_BITS2;
        if (l == 0)
                {
#ifndef WIN16
                fprintf(stderr,"BAD TOP VALUE\n");
#endif
                abort();
                }
        return(i+BN_num_bits_word(l));
        }

void BN_clear_free(a)
BIGNUM *a;
        {
        if (a == NULL) return;
        if (a->d != NULL)
                {
                memset(a->d,0,a->max*sizeof(a->d[0]));
                Free(a->d);
                }
        memset(a,0,sizeof(BIGNUM));
        Free(a);
        }

void BN_free(a)
BIGNUM *a;
        {
        if (a == NULL) return;
        if (a->d != NULL) Free(a->d);
        Free(a);
        }

BIGNUM *BN_new()
        {
        BIGNUM *ret;
        BN_ULONG *p;

        ret=(BIGNUM *)Malloc(sizeof(BIGNUM));
        if (ret == NULL) goto err;
        ret->top=0;
        ret->neg=0;
        ret->max=(BN_DEFAULT_BITS/BN_BITS2);
        p=(BN_ULONG *)Malloc(sizeof(BN_ULONG)*(ret->max+1));
        if (p == NULL) goto err;
        ret->d=p;

        memset(p,0,(ret->max+1)*sizeof(p[0]));
        return(ret);
err:
        BNerr(BN_F_BN_NEW,ERR_R_MALLOC_FAILURE);
        return(NULL);
        }

BN_CTX *BN_CTX_new()
        {
        BN_CTX *ret;
        BIGNUM *n;
        int i,j;

        ret=(BN_CTX *)Malloc(sizeof(BN_CTX));
        if (ret == NULL) goto err2;

        for (i=0; i<BN_CTX_NUM; i++)
                {
                n=BN_new();
                if (n == NULL) goto err;
                ret->bn[i]=n;
                }

        /* There is actually an extra one, this is for debugging my
         * stuff */
        ret->bn[BN_CTX_NUM]=NULL;

        ret->tos=0;
        return(ret);
err:
        for (j=0; j<i; j++)
                BN_free(ret->bn[j]);
        Free(ret);
err2:
        BNerr(BN_F_BN_CTX_NEW,ERR_R_MALLOC_FAILURE);
        return(NULL);
        }

void BN_CTX_free(c)
BN_CTX *c;
        {
        int i;

        for (i=0; i<BN_CTX_NUM; i++)
                BN_clear_free(c->bn[i]);
        Free(c);
        }

BIGNUM *bn_expand2(b, bits)
BIGNUM *b;
int bits;
        {
        BN_ULONG *p;
        register int n;

        while (bits > b->max*BN_BITS2)
                {
                n=((bits+BN_BITS2-1)/BN_BITS2)*2;
                p=b->d=(BN_ULONG *)Realloc(b->d,sizeof(BN_ULONG)*(n+1));
                if (p == NULL)
                        {
                        BNerr(BN_F_BN_EXPAND2,ERR_R_MALLOC_FAILURE);
                        return(NULL);
                        }
                memset(&(p[b->max]),0,((n+1)-b->max)*sizeof(BN_ULONG));
                b->max=n;
                }
        return(b);
        }

BIGNUM *BN_dup(a)
BIGNUM *a;
        {
        BIGNUM *r;

        r=BN_new();
        if (r == NULL) return(NULL);
        return((BIGNUM *)BN_copy(r,a));
        }

BIGNUM *BN_copy(a, b)
BIGNUM *a;
BIGNUM *b;
        {
        if (bn_expand(a,b->top*BN_BITS2) == NULL) return(NULL);
        memcpy(a->d,b->d,sizeof(b->d[0])*b->top);
/*      memset(&(a->d[b->top]),0,sizeof(a->d[0])*(a->max-b->top));*/
        a->top=b->top;
        a->neg=b->neg;
        return(a);
        }

void BN_clear(a)
BIGNUM *a;
        {
        memset(a->d,0,a->max*sizeof(a->d[0]));
        a->top=0;
        a->neg=0;
        }

unsigned long BN_get_word(a)
BIGNUM *a;
        {
        int i,n;
        unsigned long ret=0;

        n=BN_num_bytes(a);
        if (n > sizeof(unsigned long))
#ifdef SIXTY_FOUR_BIT_LONG
                return(BN_MASK2);
#else
                return(0xFFFFFFFFL);
#endif
        for (i=a->top-1; i>=0; i--)
                {
#ifndef SIXTY_FOUR_BIT /* the data item > unsigned long */
                ret<<=BN_BITS4; /* stops the compiler complaining */
                ret<<=BN_BITS4;
#endif
                ret|=a->d[i];
                }
        return(ret);
        }

int BN_set_word(a,w)
BIGNUM *a;
unsigned long w;
        {
        int i,n;
        if (bn_expand(a,sizeof(unsigned long)*8) == NULL) return(0);

        n=sizeof(unsigned long)/BN_BYTES;
        a->neg=0;
        a->top=0;
        a->d[0]=(BN_ULONG)w&BN_MASK2;
        if (a->d[0] != 0) a->top=1;
        for (i=1; i<n; i++)
                {
                /* the following is done instead of
                 * w>>=BN_BITS2 so compilers don't complain
                 * on builds where sizeof(long) == BN_TYPES */
#ifndef SIXTY_FOUR_BIT /* the data item > unsigned long */
                w>>=BN_BITS4;
                w>>=BN_BITS4;
#endif
                a->d[i]=(BN_ULONG)w&BN_MASK2;
                if (a->d[i] != 0) a->top=i+1;
                }
        return(1);
        }

/* ignore negative */
BIGNUM *BN_bin2bn(s, len, ret)
unsigned char *s;
int len;
BIGNUM *ret;
        {
        unsigned int i,m;
        unsigned int n;
        BN_ULONG l;

        if (ret == NULL) ret=BN_new();
        if (ret == NULL) return(NULL);
        l=0;
        n=len;
        if (n == 0)
                {
                ret->top=0;
                return(ret);
                }
        if (bn_expand(ret,(int)(n+2)*8) == NULL)
                return(NULL);
        i=((n-1)/BN_BYTES)+1;
        m=((n-1)%(BN_BYTES));
        ret->top=i;
        while (n-- > 0)
                {
                l=(l<<8L)| *(s++);
                if (m-- == 0)
                        {
                        ret->d[--i]=l;
                        l=0;
                        m=BN_BYTES-1;
                        }
                }
        /* need to call this due to clear byte at top if avoiding
         * having the top bit set (-ve number) */
        bn_fix_top(ret);
        return(ret);
        }

/* ignore negative */
int BN_bn2bin(a, to)
BIGNUM *a;
unsigned char *to;
        {
        int n,i;
        BN_ULONG l;

        n=i=BN_num_bytes(a);
        while (i-- > 0)
                {
                l=a->d[i/BN_BYTES];
                *(to++)=(unsigned char)(l>>(8*(i%BN_BYTES)))&0xff;
                }
        return(n);
        }

int BN_ucmp(a, b)
BIGNUM *a;
BIGNUM *b;
        {
        int i;
        BN_ULONG t1,t2,*ap,*bp;

        i=a->top-b->top;
        if (i != 0) return(i);
        ap=a->d;
        bp=b->d;
        for (i=a->top-1; i>=0; i--)
                {
                t1= ap[i];
                t2= bp[i];
                if (t1 != t2)
                        return(t1 > t2?1:-1);
                }
        return(0);
        }

int BN_cmp(a, b)
BIGNUM *a;
BIGNUM *b;
        {
        int i;
        int gt,lt;
        BN_ULONG t1,t2;

        if ((a == NULL) || (b == NULL))
                {
                if (a != NULL)
                        return(-1);
                else if (b != NULL)
                        return(1);
                else
                        return(0);
                }
        if (a->neg != b->neg)
                {
                if (a->neg)
                        return(-1);
                else    return(1);
                }
        if (a->neg == 0)
                { gt=1; lt= -1; }
        else    { gt= -1; lt=1; }

        if (a->top > b->top) return(gt);
        if (a->top < b->top) return(lt);
        for (i=a->top-1; i>=0; i--)
                {
                t1=a->d[i];
                t2=b->d[i];
                if (t1 > t2) return(gt);
                if (t1 < t2) return(lt);
                }
        return(0);
        }

int BN_set_bit(a, n)
BIGNUM *a;
int n;
        {
        int i,j;

        i=n/BN_BITS2;
        j=n%BN_BITS2;
        if (a->top <= i) return(0);

        a->d[i]|=(1L<<j);
        return(1);
        }

int BN_clear_bit(a, n)
BIGNUM *a;
int n;
        {
        int i,j;

        i=n/BN_BITS2;
        j=n%BN_BITS2;
        if (a->top <= i) return(0);

        a->d[i]&=(~(1L<<j));
        return(1);
        }

int BN_is_bit_set(a, n)
BIGNUM *a;
int n;
        {
        int i,j;

        if (n < 0) return(0);
        i=n/BN_BITS2;
        j=n%BN_BITS2;
        if (a->top <= i) return(0);
        return((a->d[i]&(((BN_ULONG)1)<<j))?1:0);
        }

int BN_mask_bits(a,n)
BIGNUM *a;
int n;
        {
        int b,w;

        w=n/BN_BITS2;
        b=n%BN_BITS2;
        if (w >= a->top) return(0);
        if (b == 0)
                a->top=w;
        else
                {
                a->top=w+1;
                a->d[w]&= ~(BN_MASK2<<b);
                while ((w >= 0) && (a->d[w] == 0))
                        {
                        a->top--;
                        w--;
                        }
                }
        return(1);
        }