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.]
*/
#include <stdio.h>
#include "cryptlib.h"
#include "bn_lcl.h"
char *BN_version="Big Number part of SSLeay 0.9.0b 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)
{
#if !defined(NO_STDIO) && !defined(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, words)
BIGNUM *b;
int words;
{
BN_ULONG *p;
if (words > b->max)
{
p=(BN_ULONG *)Realloc(b->d,sizeof(BN_ULONG)*(words+1));
if (p == NULL)
{
BNerr(BN_F_BN_EXPAND2,ERR_R_MALLOC_FAILURE);
return(NULL);
}
b->d=p;
memset(&(p[b->max]),0,((words+1)-b->max)*sizeof(BN_ULONG));
b->max=words;
}
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;
{
int i;
BN_ULONG *A,*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&(~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];
}
#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[0]=0;
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)
{
if (bn_expand(a,n) == NULL) return(0);
a->top=i+1;
}
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);
}
