rdesktop/crypto/bn_lib.c

/* crypto/bn/bn_lib.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.]
 */

#ifndef BN_DEBUG
# undef NDEBUG /* avoid conflicting definitions */
# define NDEBUG
#endif

#include <assert.h>
#include <limits.h>
#include <stdio.h>
#include "bn_lcl.h"

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

        return(&const_one);
        }
#endif

int BN_num_bits_word(BN_ULONG l)
        {
        static const 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,
                };

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

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

        bn_check_top(a);

        if (a->top == 0) return(0);
        l=a->d[a->top-1];
        assert(l != 0);
        i=(a->top-1)*BN_BITS2;
        return(i+BN_num_bits_word(l));
        }

void BN_clear_free(BIGNUM *a)
        {
        int i;

        if (a == NULL) return;
        if (a->d != NULL)
                {
                memset(a->d,0,a->dmax*sizeof(a->d[0]));
                if (!(BN_get_flags(a,BN_FLG_STATIC_DATA)))
                        OPENSSL_free(a->d);
                }
        i=BN_get_flags(a,BN_FLG_MALLOCED);
        memset(a,0,sizeof(BIGNUM));
        if (i)
                OPENSSL_free(a);
        }

void BN_free(BIGNUM *a)
        {
        if (a == NULL) return;
        if ((a->d != NULL) && !(BN_get_flags(a,BN_FLG_STATIC_DATA)))
                OPENSSL_free(a->d);
        a->flags|=BN_FLG_FREE; /* REMOVE? */
        if (a->flags & BN_FLG_MALLOCED)
                OPENSSL_free(a);
        }

void BN_init(BIGNUM *a)
        {
        memset(a,0,sizeof(BIGNUM));
        }

#if 0
BIGNUM *BN_new(void)
        {
        BIGNUM *ret;

        if ((ret=(BIGNUM *)OPENSSL_malloc(sizeof(BIGNUM))) == NULL)
                {
                BNerr(BN_F_BN_NEW,ERR_R_MALLOC_FAILURE);
                return(NULL);
                }
        ret->flags=BN_FLG_MALLOCED;
        ret->top=0;
        ret->neg=0;
        ret->dmax=0;
        ret->d=NULL;
        return(ret);
        }
#endif

/* This is an internal function that should not be used in applications.
 * It ensures that 'b' has enough room for a 'words' word number number.
 * It is mostly used by the various BIGNUM routines. If there is an error,
 * NULL is returned. If not, 'b' is returned. */

BIGNUM *bn_expand2(BIGNUM *b, int words)
        {
        BN_ULONG *A,*a;
        const BN_ULONG *B;
        int i;

        bn_check_top(b);

        if (words > b->dmax)
                {
                if (words > (INT_MAX/(4*BN_BITS2)))
                        {
                        BNerr(BN_F_BN_EXPAND2,BN_R_BIGNUM_TOO_LONG);
                        return NULL;
                        }
                        
                bn_check_top(b);        
                if (BN_get_flags(b,BN_FLG_STATIC_DATA))
                        {
                        BNerr(BN_F_BN_EXPAND2,BN_R_EXPAND_ON_STATIC_BIGNUM_DATA);
                        return(NULL);
                        }
                a=A=(BN_ULONG *)OPENSSL_malloc(sizeof(BN_ULONG)*(words+1));
                if (A == NULL)
                        {
                        BNerr(BN_F_BN_EXPAND2,ERR_R_MALLOC_FAILURE);
                        return(NULL);
                        }
#if 1
                B=b->d;
                /* Check if the previous number needs to be copied */
                if (B != NULL)
                        {
#if 0
                        /* This lot is an unrolled loop to copy b->top 
                         * BN_ULONGs from B to A
                         */
/*
 * I have nothing against unrolling but it's usually done for
 * several reasons, namely:
 * - minimize percentage of decision making code, i.e. branches;
 * - avoid cache trashing;
 * - make it possible to schedule loads earlier;
 * Now let's examine the code below. The cornerstone of C is
 * "programmer is always right" and that's what we love it for:-)
 * For this very reason C compilers have to be paranoid when it
 * comes to data aliasing and assume the worst. Yeah, but what
 * does it mean in real life? This means that loop body below will
 * be compiled to sequence of loads immediately followed by stores
 * as compiler assumes the worst, something in A==B+1 style. As a
 * result CPU pipeline is going to starve for incoming data. Secondly
 * if A and B happen to share same cache line such code is going to
 * cause severe cache trashing. Both factors have severe impact on
 * performance of modern CPUs and this is the reason why this
 * particular piece of code is #ifdefed away and replaced by more
 * "friendly" version found in #else section below. This comment
 * also applies to BN_copy function.
 *
 *                                      <appro@fy.chalmers.se>
 */
                        for (i=b->top&(~7); i>0; i-=8)
                                {
                                A[0]=B[0]; A[1]=B[1]; A[2]=B[2]; A[3]=B[3];
                                A[4]=B[4]; A[5]=B[5]; A[6]=B[6]; A[7]=B[7];
                                A+=8;
                                B+=8;
                                }
                        switch (b->top&7)
                                {
                        case 7:
                                A[6]=B[6];
                        case 6:
                                A[5]=B[5];
                        case 5:
                                A[4]=B[4];
                        case 4:
                                A[3]=B[3];
                        case 3:
                                A[2]=B[2];
                        case 2:
                                A[1]=B[1];
                        case 1:
                                A[0]=B[0];
                        case 0:
                                /* I need the 'case 0' entry for utrix cc.
                                 * If the optimizer is turned on, it does the
                                 * switch table by doing
                                 * a=top&7
                                 * a--;
                                 * goto jump_table[a];
                                 * If top is 0, this makes us jump to 0xffffffc 
                                 * which is rather bad :-(.
                                 * eric 23-Apr-1998
                                 */
                                ;
                                }
#else
                        for (i=b->top>>2; i>0; i--,A+=4,B+=4)
                                {
                                /*
                                 * The fact that the loop is unrolled
                                 * 4-wise is a tribute to Intel. It's
                                 * the one that doesn't have enough
                                 * registers to accomodate more data.
                                 * I'd unroll it 8-wise otherwise:-)
                                 *
                                 *              <appro@fy.chalmers.se>
                                 */
                                BN_ULONG a0,a1,a2,a3;
                                a0=B[0]; a1=B[1]; a2=B[2]; a3=B[3];
                                A[0]=a0; A[1]=a1; A[2]=a2; A[3]=a3;
                                }
                        switch (b->top&3)
                                {
                                case 3: A[2]=B[2];
                                case 2: A[1]=B[1];
                                case 1: A[0]=B[0];
                                case 0: ; /* ultrix cc workaround, see above */
                                }
#endif
                        OPENSSL_free(b->d);
                        }

                b->d=a;
                b->dmax=words;

                /* Now need to zero any data between b->top and b->max */

                A= &(b->d[b->top]);
                for (i=(b->dmax - b->top)>>3; i>0; i--,A+=8)
                        {
                        A[0]=0; A[1]=0; A[2]=0; A[3]=0;
                        A[4]=0; A[5]=0; A[6]=0; A[7]=0;
                        }
                for (i=(b->dmax - b->top)&7; i>0; i--,A++)
                        A[0]=0;
#else
                        memset(A,0,sizeof(BN_ULONG)*(words+1));
                        memcpy(A,b->d,sizeof(b->d[0])*b->top);
                        b->d=a;
                        b->max=words;
#endif
                
/*              memset(&(p[b->max]),0,((words+1)-b->max)*sizeof(BN_ULONG)); */
/*      { int i; for (i=b->max; i<words+1; i++) p[i]=i;} */

                }
        return(b);
        }

#if 0
BIGNUM *BN_dup(const BIGNUM *a)
        {
        BIGNUM *r;

        if (a == NULL) return NULL;

        bn_check_top(a);

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

BIGNUM *BN_copy(BIGNUM *a, const BIGNUM *b)
        {
        int i;
        BN_ULONG *A;
        const BN_ULONG *B;

        bn_check_top(b);

        if (a == b) return(a);
        if (bn_wexpand(a,b->top) == NULL) return(NULL);

#if 1
        A=a->d;
        B=b->d;
        for (i=b->top>>2; i>0; i--,A+=4,B+=4)
                {
                BN_ULONG a0,a1,a2,a3;
                a0=B[0]; a1=B[1]; a2=B[2]; a3=B[3];
                A[0]=a0; A[1]=a1; A[2]=a2; A[3]=a3;
                }
        switch (b->top&3)
                {
                case 3: A[2]=B[2];
                case 2: A[1]=B[1];
                case 1: A[0]=B[0];
                case 0: ; /* ultrix cc workaround, see comments in bn_expand2 */
                }
#else
        memcpy(a->d,b->d,sizeof(b->d[0])*b->top);
#endif

/*      memset(&(a->d[b->top]),0,sizeof(a->d[0])*(a->max-b->top));*/
        a->top=b->top;
        if ((a->top == 0) && (a->d != NULL))
                a->d[0]=0;
        a->neg=b->neg;
        return(a);
        }

#if 0
void BN_clear(BIGNUM *a)
        {
        if (a->d != NULL)
                memset(a->d,0,a->dmax*sizeof(a->d[0]));
        a->top=0;
        a->neg=0;
        }

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

        n=BN_num_bytes(a);
        if (n > sizeof(BN_ULONG))
                return(BN_MASK2);
        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;
#else
                ret=0;
#endif
                ret|=a->d[i];
                }
        return(ret);
        }
#endif

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

        n=sizeof(BN_ULONG)/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;
#else
                w=0;
#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(const unsigned char *s, int len, BIGNUM *ret)
        {
        unsigned int i,m;
        unsigned int n;
        BN_ULONG l;

#if 0
        if (ret == NULL) ret=BN_new();
#endif
        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(const 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(const BIGNUM *a, const BIGNUM *b)
        {
        int i;
        BN_ULONG t1,t2,*ap,*bp;

        bn_check_top(a);
        bn_check_top(b);

        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);
        }

#if 0
int BN_cmp(const BIGNUM *a, const 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);
                }

        bn_check_top(a);
        bn_check_top(b);

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

        i=n/BN_BITS2;
        j=n%BN_BITS2;
        if (a->top <= i)
                {
                if (bn_wexpand(a,i+1) == NULL) return(0);
                for(k=a->top; k<i+1; k++)
                        a->d[k]=0;
                a->top=i+1;
                }

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

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

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

        a->d[i]&=(~(((BN_ULONG)1)<<j));
        bn_fix_top(a);
        return(1);
        }
#endif

int BN_is_bit_set(const 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);
        }

#if 0
int BN_mask_bits(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);
                }
        bn_fix_top(a);
        return(1);
        }

int bn_cmp_words(BN_ULONG *a, BN_ULONG *b, int n)
        {
        int i;
        BN_ULONG aa,bb;

        aa=a[n-1];
        bb=b[n-1];
        if (aa != bb) return((aa > bb)?1:-1);
        for (i=n-2; i>=0; i--)
                {
                aa=a[i];
                bb=b[i];
                if (aa != bb) return((aa > bb)?1:-1);
                }
        return(0);
        }
#endif
1	matty	32	/* crypto/bn/bn_lib.c */
2			/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3			* All rights reserved.
4			*
5			* This package is an SSL implementation written
6			* by Eric Young (eay@cryptsoft.com).
7			* The implementation was written so as to conform with Netscapes SSL.
8			*
9			* This library is free for commercial and non-commercial use as long as
10			* the following conditions are aheared to. The following conditions
11			* apply to all code found in this distribution, be it the RC4, RSA,
12			* lhash, DES, etc., code; not just the SSL code. The SSL documentation
13			* included with this distribution is covered by the same copyright terms
14			* except that the holder is Tim Hudson (tjh@cryptsoft.com).
15			*
16			* Copyright remains Eric Young's, and as such any Copyright notices in
17			* the code are not to be removed.
18			* If this package is used in a product, Eric Young should be given attribution
19			* as the author of the parts of the library used.
20			* This can be in the form of a textual message at program startup or
21			* in documentation (online or textual) provided with the package.
22			*
23			* Redistribution and use in source and binary forms, with or without
24			* modification, are permitted provided that the following conditions
25			* are met:
26			* 1. Redistributions of source code must retain the copyright
27			* notice, this list of conditions and the following disclaimer.
28			* 2. Redistributions in binary form must reproduce the above copyright
29			* notice, this list of conditions and the following disclaimer in the
30			* documentation and/or other materials provided with the distribution.
31			* 3. All advertising materials mentioning features or use of this software
32			* must display the following acknowledgement:
33			* "This product includes cryptographic software written by
34			* Eric Young (eay@cryptsoft.com)"
35			* The word 'cryptographic' can be left out if the rouines from the library
36			* being used are not cryptographic related :-).
37			* 4. If you include any Windows specific code (or a derivative thereof) from
38			* the apps directory (application code) you must include an acknowledgement:
39			* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
40			*
41			* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42			* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43			* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44			* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45			* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46			* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47			* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48			* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49			* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50			* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
51			* SUCH DAMAGE.
52			*
53			* The licence and distribution terms for any publically available version or
54			* derivative of this code cannot be changed. i.e. this code cannot simply be
55			* copied and put under another distribution licence
56			* [including the GNU Public Licence.]
57			*/
58
59			#ifndef BN_DEBUG
60			# undef NDEBUG /* avoid conflicting definitions */
61			# define NDEBUG
62			#endif
63
64			#include <assert.h>
65			#include <limits.h>
66			#include <stdio.h>
67			#include "bn_lcl.h"
68
69			#if 0
70			BIGNUM *BN_value_one(void)
71			{
72			static BN_ULONG data_one=1L;
73			static BIGNUM const_one={&data_one,1,1,0};
74
75			return(&const_one);
76			}
77			#endif
78
79			int BN_num_bits_word(BN_ULONG l)
80			{
81			static const char bits[256]={
82			0,1,2,2,3,3,3,3,4,4,4,4,4,4,4,4,
83			5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
84			6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
85			6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
86			7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
87			7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
88			7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
89			7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
90			8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
91			8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
92			8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
93			8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
94			8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
95			8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
96			8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
97			8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
98			};
99
100			#if defined(SIXTY_FOUR_BIT_LONG)
101			if (l & 0xffffffff00000000L)
102			{
103			if (l & 0xffff000000000000L)
104			{
105			if (l & 0xff00000000000000L)
106			{
107			return(bits[(int)(l>>56)]+56);
108			}
109			else return(bits[(int)(l>>48)]+48);
110			}
111			else
112			{
113			if (l & 0x0000ff0000000000L)
114			{
115			return(bits[(int)(l>>40)]+40);
116			}
117			else return(bits[(int)(l>>32)]+32);
118			}
119			}
120			else
121			#else
122			#ifdef SIXTY_FOUR_BIT
123			if (l & 0xffffffff00000000LL)
124			{
125			if (l & 0xffff000000000000LL)
126			{
127			if (l & 0xff00000000000000LL)
128			{
129			return(bits[(int)(l>>56)]+56);
130			}
131			else return(bits[(int)(l>>48)]+48);
132			}
133			else
134			{
135			if (l & 0x0000ff0000000000LL)
136			{
137			return(bits[(int)(l>>40)]+40);
138			}
139			else return(bits[(int)(l>>32)]+32);
140			}
141			}
142			else
143			#endif
144			#endif
145			{
146			#if defined(THIRTY_TWO_BIT) \|\| defined(SIXTY_FOUR_BIT) \|\| defined(SIXTY_FOUR_BIT_LONG)
147			if (l & 0xffff0000L)
148			{
149			if (l & 0xff000000L)
150			return(bits[(int)(l>>24L)]+24);
151			else return(bits[(int)(l>>16L)]+16);
152			}
153			else
154			#endif
155			{
156			#if defined(SIXTEEN_BIT) \|\| defined(THIRTY_TWO_BIT) \|\| defined(SIXTY_FOUR_BIT) \|\| defined(SIXTY_FOUR_BIT_LONG)
157			if (l & 0xff00L)
158			return(bits[(int)(l>>8)]+8);
159			else
160			#endif
161			return(bits[(int)(l )] );
162			}
163			}
164			}
165
166			int BN_num_bits(const BIGNUM *a)
167			{
168			BN_ULONG l;
169			int i;
170
171			bn_check_top(a);
172
173			if (a->top == 0) return(0);
174			l=a->d[a->top-1];
175			assert(l != 0);
176			i=(a->top-1)*BN_BITS2;
177			return(i+BN_num_bits_word(l));
178			}
179
180			void BN_clear_free(BIGNUM *a)
181			{
182			int i;
183
184			if (a == NULL) return;
185			if (a->d != NULL)
186			{
187			memset(a->d,0,a->dmax*sizeof(a->d[0]));
188			if (!(BN_get_flags(a,BN_FLG_STATIC_DATA)))
189			OPENSSL_free(a->d);
190			}
191			i=BN_get_flags(a,BN_FLG_MALLOCED);
192			memset(a,0,sizeof(BIGNUM));
193			if (i)
194			OPENSSL_free(a);
195			}
196
197			void BN_free(BIGNUM *a)
198			{
199			if (a == NULL) return;
200			if ((a->d != NULL) && !(BN_get_flags(a,BN_FLG_STATIC_DATA)))
201			OPENSSL_free(a->d);
202			a->flags\|=BN_FLG_FREE; /* REMOVE? */
203			if (a->flags & BN_FLG_MALLOCED)
204			OPENSSL_free(a);
205			}
206
207			void BN_init(BIGNUM *a)
208			{
209			memset(a,0,sizeof(BIGNUM));
210			}
211
212			#if 0
213			BIGNUM *BN_new(void)
214			{
215			BIGNUM *ret;
216
217			if ((ret=(BIGNUM *)OPENSSL_malloc(sizeof(BIGNUM))) == NULL)
218			{
219			BNerr(BN_F_BN_NEW,ERR_R_MALLOC_FAILURE);
220			return(NULL);
221			}
222			ret->flags=BN_FLG_MALLOCED;
223			ret->top=0;
224			ret->neg=0;
225			ret->dmax=0;
226			ret->d=NULL;
227			return(ret);
228			}
229			#endif
230
231			/* This is an internal function that should not be used in applications.
232			* It ensures that 'b' has enough room for a 'words' word number number.
233			* It is mostly used by the various BIGNUM routines. If there is an error,
234			* NULL is returned. If not, 'b' is returned. */
235
236			BIGNUM bn_expand2(BIGNUM b, int words)
237			{
238			BN_ULONG A,a;
239			const BN_ULONG *B;
240			int i;
241
242			bn_check_top(b);
243
244			if (words > b->dmax)
245			{
246			if (words > (INT_MAX/(4*BN_BITS2)))
247			{
248			BNerr(BN_F_BN_EXPAND2,BN_R_BIGNUM_TOO_LONG);
249			return NULL;
250			}
251
252			bn_check_top(b);
253			if (BN_get_flags(b,BN_FLG_STATIC_DATA))
254			{
255			BNerr(BN_F_BN_EXPAND2,BN_R_EXPAND_ON_STATIC_BIGNUM_DATA);
256			return(NULL);
257			}
258			a=A=(BN_ULONG )OPENSSL_malloc(sizeof(BN_ULONG)(words+1));
259			if (A == NULL)
260			{
261			BNerr(BN_F_BN_EXPAND2,ERR_R_MALLOC_FAILURE);
262			return(NULL);
263			}
264			#if 1
265			B=b->d;
266			/* Check if the previous number needs to be copied */
267			if (B != NULL)
268			{
269			#if 0
270			/* This lot is an unrolled loop to copy b->top
271			* BN_ULONGs from B to A
272			*/
273			/*
274			* I have nothing against unrolling but it's usually done for
275			* several reasons, namely:
276			* - minimize percentage of decision making code, i.e. branches;
277			* - avoid cache trashing;
278			* - make it possible to schedule loads earlier;
279			* Now let's examine the code below. The cornerstone of C is
280			* "programmer is always right" and that's what we love it for:-)
281			* For this very reason C compilers have to be paranoid when it
282			* comes to data aliasing and assume the worst. Yeah, but what
283			* does it mean in real life? This means that loop body below will
284			* be compiled to sequence of loads immediately followed by stores
285			* as compiler assumes the worst, something in A==B+1 style. As a
286			* result CPU pipeline is going to starve for incoming data. Secondly
287			* if A and B happen to share same cache line such code is going to
288			* cause severe cache trashing. Both factors have severe impact on
289			* performance of modern CPUs and this is the reason why this
290			* particular piece of code is #ifdefed away and replaced by more
291			* "friendly" version found in #else section below. This comment
292			* also applies to BN_copy function.
293			*
294			* <appro@fy.chalmers.se>
295			*/
296			for (i=b->top&(~7); i>0; i-=8)
297			{
298			A[0]=B[0]; A[1]=B[1]; A[2]=B[2]; A[3]=B[3];
299			A[4]=B[4]; A[5]=B[5]; A[6]=B[6]; A[7]=B[7];
300			A+=8;
301			B+=8;
302			}
303			switch (b->top&7)
304			{
305			case 7:
306			A[6]=B[6];
307			case 6:
308			A[5]=B[5];
309			case 5:
310			A[4]=B[4];
311			case 4:
312			A[3]=B[3];
313			case 3:
314			A[2]=B[2];
315			case 2:
316			A[1]=B[1];
317			case 1:
318			A[0]=B[0];
319			case 0:
320			/* I need the 'case 0' entry for utrix cc.
321			* If the optimizer is turned on, it does the
322			* switch table by doing
323			* a=top&7
324			* a--;
325			* goto jump_table[a];
326			* If top is 0, this makes us jump to 0xffffffc
327			* which is rather bad :-(.
328			* eric 23-Apr-1998
329			*/
330			;
331			}
332			#else
333			for (i=b->top>>2; i>0; i--,A+=4,B+=4)
334			{
335			/*
336			* The fact that the loop is unrolled
337			* 4-wise is a tribute to Intel. It's
338			* the one that doesn't have enough
339			* registers to accomodate more data.
340			* I'd unroll it 8-wise otherwise:-)
341			*
342			* <appro@fy.chalmers.se>
343			*/
344			BN_ULONG a0,a1,a2,a3;
345			a0=B[0]; a1=B[1]; a2=B[2]; a3=B[3];
346			A[0]=a0; A[1]=a1; A[2]=a2; A[3]=a3;
347			}
348			switch (b->top&3)
349			{
350			case 3: A[2]=B[2];
351			case 2: A[1]=B[1];
352			case 1: A[0]=B[0];
353			case 0: ; /* ultrix cc workaround, see above */
354			}
355			#endif
356			OPENSSL_free(b->d);
357			}
358
359			b->d=a;
360			b->dmax=words;
361
362			/* Now need to zero any data between b->top and b->max */
363
364			A= &(b->d[b->top]);
365			for (i=(b->dmax - b->top)>>3; i>0; i--,A+=8)
366			{
367			A[0]=0; A[1]=0; A[2]=0; A[3]=0;
368			A[4]=0; A[5]=0; A[6]=0; A[7]=0;
369			}
370			for (i=(b->dmax - b->top)&7; i>0; i--,A++)
371			A[0]=0;
372			#else
373			memset(A,0,sizeof(BN_ULONG)*(words+1));
374			memcpy(A,b->d,sizeof(b->d[0])*b->top);
375			b->d=a;
376			b->max=words;
377			#endif
378
379			/* memset(&(p[b->max]),0,((words+1)-b->max)sizeof(BN_ULONG)); /
380			/* { int i; for (i=b->max; i<words+1; i++) p[i]=i;} */
381
382			}
383			return(b);
384			}
385
386			#if 0
387			BIGNUM BN_dup(const BIGNUM a)
388			{
389			BIGNUM *r;
390
391			if (a == NULL) return NULL;
392
393			bn_check_top(a);
394
395			r=BN_new();
396			if (r == NULL) return(NULL);
397			return((BIGNUM *)BN_copy(r,a));
398			}
399			#endif
400
401			BIGNUM BN_copy(BIGNUM a, const BIGNUM *b)
402			{
403			int i;
404			BN_ULONG *A;
405			const BN_ULONG *B;
406
407			bn_check_top(b);
408
409			if (a == b) return(a);
410			if (bn_wexpand(a,b->top) == NULL) return(NULL);
411
412			#if 1
413			A=a->d;
414			B=b->d;
415			for (i=b->top>>2; i>0; i--,A+=4,B+=4)
416			{
417			BN_ULONG a0,a1,a2,a3;
418			a0=B[0]; a1=B[1]; a2=B[2]; a3=B[3];
419			A[0]=a0; A[1]=a1; A[2]=a2; A[3]=a3;
420			}
421			switch (b->top&3)
422			{
423			case 3: A[2]=B[2];
424			case 2: A[1]=B[1];
425			case 1: A[0]=B[0];
426			case 0: ; /* ultrix cc workaround, see comments in bn_expand2 */
427			}
428			#else
429			memcpy(a->d,b->d,sizeof(b->d[0])*b->top);
430			#endif
431
432			/* memset(&(a->d[b->top]),0,sizeof(a->d[0])(a->max-b->top));/
433			a->top=b->top;
434			if ((a->top == 0) && (a->d != NULL))
435			a->d[0]=0;
436			a->neg=b->neg;
437			return(a);
438			}
439
440			#if 0
441			void BN_clear(BIGNUM *a)
442			{
443			if (a->d != NULL)
444			memset(a->d,0,a->dmax*sizeof(a->d[0]));
445			a->top=0;
446			a->neg=0;
447			}
448
449			BN_ULONG BN_get_word(BIGNUM *a)
450			{
451			int i,n;
452			BN_ULONG ret=0;
453
454			n=BN_num_bytes(a);
455			if (n > sizeof(BN_ULONG))
456			return(BN_MASK2);
457			for (i=a->top-1; i>=0; i--)
458			{
459			#ifndef SIXTY_FOUR_BIT /* the data item > unsigned long */
460			ret<<=BN_BITS4; /* stops the compiler complaining */
461			ret<<=BN_BITS4;
462			#else
463			ret=0;
464			#endif
465			ret\|=a->d[i];
466			}
467			return(ret);
468			}
469			#endif
470
471			int BN_set_word(BIGNUM *a, BN_ULONG w)
472			{
473			int i,n;
474			if (bn_expand(a,sizeof(BN_ULONG)*8) == NULL) return(0);
475
476			n=sizeof(BN_ULONG)/BN_BYTES;
477			a->neg=0;
478			a->top=0;
479			a->d[0]=(BN_ULONG)w&BN_MASK2;
480			if (a->d[0] != 0) a->top=1;
481			for (i=1; i<n; i++)
482			{
483			/* the following is done instead of
484			* w>>=BN_BITS2 so compilers don't complain
485			* on builds where sizeof(long) == BN_TYPES */
486			#ifndef SIXTY_FOUR_BIT /* the data item > unsigned long */
487			w>>=BN_BITS4;
488			w>>=BN_BITS4;
489			#else
490			w=0;
491			#endif
492			a->d[i]=(BN_ULONG)w&BN_MASK2;
493			if (a->d[i] != 0) a->top=i+1;
494			}
495			return(1);
496			}
497
498			/* ignore negative */
499			BIGNUM BN_bin2bn(const unsigned char s, int len, BIGNUM *ret)
500			{
501			unsigned int i,m;
502			unsigned int n;
503			BN_ULONG l;
504
505			#if 0
506			if (ret == NULL) ret=BN_new();
507			#endif
508			if (ret == NULL) return(NULL);
509			l=0;
510			n=len;
511			if (n == 0)
512			{
513			ret->top=0;
514			return(ret);
515			}
516			if (bn_expand(ret,(int)(n+2)*8) == NULL)
517			return(NULL);
518			i=((n-1)/BN_BYTES)+1;
519			m=((n-1)%(BN_BYTES));
520			ret->top=i;
521			while (n-- > 0)
522			{
523			l=(l<<8L)\| *(s++);
524			if (m-- == 0)
525			{
526			ret->d[--i]=l;
527			l=0;
528			m=BN_BYTES-1;
529			}
530			}
531			/* need to call this due to clear byte at top if avoiding
532			* having the top bit set (-ve number) */
533			bn_fix_top(ret);
534			return(ret);
535			}
536
537			/* ignore negative */
538			int BN_bn2bin(const BIGNUM a, unsigned char to)
539			{
540			int n,i;
541			BN_ULONG l;
542
543			n=i=BN_num_bytes(a);
544			while (i-- > 0)
545			{
546			l=a->d[i/BN_BYTES];
547			(to++)=(unsigned char)(l>>(8(i%BN_BYTES)))&0xff;
548			}
549			return(n);
550			}
551
552			int BN_ucmp(const BIGNUM a, const BIGNUM b)
553			{
554			int i;
555			BN_ULONG t1,t2,ap,bp;
556
557			bn_check_top(a);
558			bn_check_top(b);
559
560			i=a->top-b->top;
561			if (i != 0) return(i);
562			ap=a->d;
563			bp=b->d;
564			for (i=a->top-1; i>=0; i--)
565			{
566			t1= ap[i];
567			t2= bp[i];
568			if (t1 != t2)
569			return(t1 > t2?1:-1);
570			}
571			return(0);
572			}
573
574			#if 0
575			int BN_cmp(const BIGNUM a, const BIGNUM b)
576			{
577			int i;
578			int gt,lt;
579			BN_ULONG t1,t2;
580
581			if ((a == NULL) \|\| (b == NULL))
582			{
583			if (a != NULL)
584			return(-1);
585			else if (b != NULL)
586			return(1);
587			else
588			return(0);
589			}
590
591			bn_check_top(a);
592			bn_check_top(b);
593
594			if (a->neg != b->neg)
595			{
596			if (a->neg)
597			return(-1);
598			else return(1);
599			}
600			if (a->neg == 0)
601			{ gt=1; lt= -1; }
602			else { gt= -1; lt=1; }
603
604			if (a->top > b->top) return(gt);
605			if (a->top < b->top) return(lt);
606			for (i=a->top-1; i>=0; i--)
607			{
608			t1=a->d[i];
609			t2=b->d[i];
610			if (t1 > t2) return(gt);
611			if (t1 < t2) return(lt);
612			}
613			return(0);
614			}
615
616			int BN_set_bit(BIGNUM *a, int n)
617			{
618			int i,j,k;
619
620			i=n/BN_BITS2;
621			j=n%BN_BITS2;
622			if (a->top <= i)
623			{
624			if (bn_wexpand(a,i+1) == NULL) return(0);
625			for(k=a->top; k<i+1; k++)
626			a->d[k]=0;
627			a->top=i+1;
628			}
629
630			a->d[i]\|=(((BN_ULONG)1)<<j);
631			return(1);
632			}
633
634			int BN_clear_bit(BIGNUM *a, int n)
635			{
636			int i,j;
637
638			i=n/BN_BITS2;
639			j=n%BN_BITS2;
640			if (a->top <= i) return(0);
641
642			a->d[i]&=(~(((BN_ULONG)1)<<j));
643			bn_fix_top(a);
644			return(1);
645			}
646			#endif
647
648			int BN_is_bit_set(const BIGNUM *a, int n)
649			{
650			int i,j;
651
652			if (n < 0) return(0);
653			i=n/BN_BITS2;
654			j=n%BN_BITS2;
655			if (a->top <= i) return(0);
656			return((a->d[i]&(((BN_ULONG)1)<<j))?1:0);
657			}
658
659			#if 0
660			int BN_mask_bits(BIGNUM *a, int n)
661			{
662			int b,w;
663
664			w=n/BN_BITS2;
665			b=n%BN_BITS2;
666			if (w >= a->top) return(0);
667			if (b == 0)
668			a->top=w;
669			else
670			{
671			a->top=w+1;
672			a->d[w]&= ~(BN_MASK2<<b);
673			}
674			bn_fix_top(a);
675			return(1);
676			}
677
678			int bn_cmp_words(BN_ULONG a, BN_ULONG b, int n)
679			{
680			int i;
681			BN_ULONG aa,bb;
682
683			aa=a[n-1];
684			bb=b[n-1];
685			if (aa != bb) return((aa > bb)?1:-1);
686			for (i=n-2; i>=0; i--)
687			{
688			aa=a[i];
689			bb=b[i];
690			if (aa != bb) return((aa > bb)?1:-1);
691			}
692			return(0);
693			}
694			#endif