openssl/crypto/bn/bn_lib.c
Richard Levitte 26a3a48d65 There have been a number of complaints from a number of sources that names
like Malloc, Realloc and especially Free conflict with already existing names
on some operating systems or other packages.  That is reason enough to change
the names of the OpenSSL memory allocation macros to something that has a
better chance of being unique, like prepending them with OPENSSL_.

This change includes all the name changes needed throughout all C files.
2000-06-01 22:19:21 +00:00

755 lines
16 KiB
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"
const char *BN_version="Big Number" OPENSSL_VERSION_PTEXT;
/* For a 32 bit machine
* 2 - 4 == 128
* 3 - 8 == 256
* 4 - 16 == 512
* 5 - 32 == 1024
* 6 - 64 == 2048
* 7 - 128 == 4096
* 8 - 256 == 8192
*/
static int bn_limit_bits=0;
static int bn_limit_num=8; /* (1<<bn_limit_bits) */
static int bn_limit_bits_low=0;
static int bn_limit_num_low=8; /* (1<<bn_limit_bits_low) */
static int bn_limit_bits_high=0;
static int bn_limit_num_high=8; /* (1<<bn_limit_bits_high) */
static int bn_limit_bits_mont=0;
static int bn_limit_num_mont=8; /* (1<<bn_limit_bits_mont) */
void BN_set_params(int mult, int high, int low, int mont)
{
if (mult >= 0)
{
if (mult > (sizeof(int)*8)-1)
mult=sizeof(int)*8-1;
bn_limit_bits=mult;
bn_limit_num=1<<mult;
}
if (high >= 0)
{
if (high > (sizeof(int)*8)-1)
high=sizeof(int)*8-1;
bn_limit_bits_high=high;
bn_limit_num_high=1<<high;
}
if (low >= 0)
{
if (low > (sizeof(int)*8)-1)
low=sizeof(int)*8-1;
bn_limit_bits_low=low;
bn_limit_num_low=1<<low;
}
if (mont >= 0)
{
if (mont > (sizeof(int)*8)-1)
mont=sizeof(int)*8-1;
bn_limit_bits_mont=mont;
bn_limit_num_mont=1<<mont;
}
}
int BN_get_params(int which)
{
if (which == 0) return(bn_limit_bits);
else if (which == 1) return(bn_limit_bits_high);
else if (which == 2) return(bn_limit_bits_low);
else if (which == 3) return(bn_limit_bits_mont);
else return(0);
}
BIGNUM *BN_value_one(void)
{
static BN_ULONG data_one=1L;
static BIGNUM const_one={&data_one,1,1,0};
return(&const_one);
}
char *BN_options(void)
{
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(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];
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(BIGNUM *a)
{
int i;
if (a == NULL) return;
if (a->d != NULL)
{
memset(a->d,0,a->max*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));
}
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->max=0;
ret->d=NULL;
return(ret);
}
/* 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->max)
{
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->max=words;
/* Now need to zero any data between b->top and b->max */
A= &(b->d[b->top]);
for (i=(b->max - 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->max - 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);
}
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));
}
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);
}
void BN_clear(BIGNUM *a)
{
if (a->d != NULL)
memset(a->d,0,a->max*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);
}
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 (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(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);
}
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);
}
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);
}
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);
}