Commit dd8dec69 authored by Ulf Möller's avatar Ulf Möller
Browse files

Document the BN library.

parent ce052b6c

crypto/bn/bn.h

+2 −2
Original line number Diff line number Diff line
@@ -330,7 +330,7 @@ int BN_bn2mpi(const BIGNUM *a, unsigned char *to); 
int	BN_sub(BIGNUM *r, const BIGNUM *a, const BIGNUM *b);

int	BN_usub(BIGNUM *r, const BIGNUM *a, const BIGNUM *b);

int	BN_uadd(BIGNUM *r, const BIGNUM *a, const BIGNUM *b);

int	BN_add(BIGNUM *r, BIGNUM *a, BIGNUM *b);

int	BN_add(BIGNUM *r, const BIGNUM *a, const BIGNUM *b);

int	BN_mod(BIGNUM *rem, const BIGNUM *m, const BIGNUM *d, BN_CTX *ctx);

int	BN_div(BIGNUM *dv, BIGNUM *rem, const BIGNUM *m, const BIGNUM *d,

	       BN_CTX *ctx);

crypto/bn/bn_add.c

+2 −2
Original line number Diff line number Diff line
@@ -61,9 +61,9 @@ 
#include "bn_lcl.h"



/* r can == a or b */

int BN_add(BIGNUM *r, BIGNUM *a, BIGNUM *b)

int BN_add(BIGNUM *r, const BIGNUM *a, const BIGNUM *b)

	{

	BIGNUM *tmp;

	const BIGNUM *tmp;



	bn_check_top(a);

	bn_check_top(b);

crypto/bn/bn_lib.c

+5 −0
Original line number Diff line number Diff line
@@ -341,6 +341,11 @@ void BN_CTX_free(BN_CTX *c) 
		Free(c);

	}



/* This is an internal function that should not be used in applications.

 * It ensures that 'b' has enough room for a 'bits' bit 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;

crypto/bn/bn_prime.c

+17 −12
Original line number Diff line number Diff line
@@ -225,8 +225,6 @@ err: 
	return(ret);

	}



#define RECP_MUL_MOD



static int witness(BIGNUM *a, BIGNUM *n, BN_CTX *ctx, BN_CTX *ctx2,

	     BN_MONT_CTX *mont)

	{
@@ -408,18 +406,22 @@ err: 
	}



#if 0

static int witness(BIGNUM *a, BIGNUM *n, BN_CTX *ctx)



#define RECP_MUL_MOD



static int witness(BIGNUM *a, BIGNUM *n, BN_CTX *ctx,

		   BN_CTX *unused, BN_MONT_CTX *unused2)

	{

	int k,i,nb,ret= -1;

	int k,i,ret= -1;

	BIGNUM *d,*dd,*tmp;

	BIGNUM *d1,*d2,*x,*n1,*inv;

	BIGNUM *d1,*d2,*x,*n1;

	BN_RECP_CTX recp;



	d1= &(ctx->bn[ctx->tos]);

	d2= &(ctx->bn[ctx->tos+1]);

	x=  &(ctx->bn[ctx->tos+2]);

	n1= &(ctx->bn[ctx->tos+3]);

	inv=&(ctx->bn[ctx->tos+4]);

	ctx->tos+=5;

	ctx->tos+=4;



	d=d1;

	dd=d2;
@@ -429,8 +431,8 @@ static int witness(BIGNUM *a, BIGNUM *n, BN_CTX *ctx) 


	/* i=BN_num_bits(n); */

#ifdef RECP_MUL_MOD

	nb=BN_reciprocal(inv,n,ctx); /**/

	if (nb == -1) goto err;

	BN_RECP_CTX_init(&recp);

	if (BN_RECP_CTX_set(&recp,n,ctx) <= 0) goto err;

#endif



	for (i=k-1; i>=0; i--)
@@ -439,7 +441,7 @@ static int witness(BIGNUM *a, BIGNUM *n, BN_CTX *ctx) 
#ifndef RECP_MUL_MOD

		if (!BN_mod_mul(dd,d,d,n,ctx)) goto err;

#else

		if (!BN_mod_mul_reciprocal(dd,d,d,n,inv,nb,ctx)) goto err;

		if (!BN_mod_mul_reciprocal(dd,d,d,&recp,ctx)) goto err;

#endif

		if (	BN_is_one(dd) &&

			!BN_is_one(x) &&
@@ -453,7 +455,7 @@ static int witness(BIGNUM *a, BIGNUM *n, BN_CTX *ctx) 
#ifndef RECP_MUL_MOD

			if (!BN_mod_mul(d,dd,a,n,ctx)) goto err;

#else

			if (!BN_mod_mul_reciprocal(d,dd,a,n,inv,nb,ctx)) goto err; 

			if (!BN_mod_mul_reciprocal(d,dd,a,&recp,ctx)) goto err; 

#endif

			}

		else
@@ -468,7 +470,10 @@ static int witness(BIGNUM *a, BIGNUM *n, BN_CTX *ctx) 
	else	i=1;

	ret=i;

err:

	ctx->tos-=5;

	ctx->tos-=4;

#ifdef RECP_MUL_MOD

	BN_RECP_CTX_free(&recp);

#endif

	return(ret);

	}

#endif

doc/crypto/BN_CTX_new.pod

0 → 100644
+48 −0
Original line number Diff line number Diff line 
=pod



=head1 NAME



BN_CTX_new, BN_CTX_init, BN_CTX_free - allocate and free BN_CTX structures



=head1 SYNOPSIS



 #include <openssl/bn.h>



 BN_CTX *BN_CTX_new(void);



 void BN_CTX_init(BN_CTX *c);



 void BN_CTX_free(BN_CTX *c);



=head1 DESCRIPTION



A B<BN_CTX> is a structure that holds temporary variables used by

library functions. Thus, it can be avoided to create and destroy

the temporary B<BIGNUM> objects whenever a library function is

called.



BN_CTX_new() allocated and initializes a B<BN_CTX>

structure. BN_CTX_init() initializes an existing uninitialized

B<BN_CTX>.



BN_CTX_free() frees the components of the B<BN_CTX>, and if it was

created by BN_CTX_new(), also the structure itself.



=head1 RETURN VALUES



BN_CTX_new() returns a pointer to the B<BN_CTX>. If the allocation fails,

it returns B<NULL> and sets an error code that can be obtained by

ERR_get_error(3).



BN_CTX_init() and BN_CTX_free() have no return values.



=head1 SEE ALSO



bn(3), err(3), BN_add(3)



=head1 HISTORY



BN_CTX_new() and BN_CTX_free() are availabe in all versions on SSLeay

and OpenSSL. BN_CTX_init() was added in SSLeay 0.9.1b.



=cut