bntest.c

/* crypto/bn/bntest.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 <stdlib.h>
#include <string.h>

#include "openssl/e_os.h"

#include <openssl/bio.h>
#include <openssl/bn.h>
#include <openssl/rand.h>
#include <openssl/x509.h>
#include <openssl/err.h>

#ifdef WINDOWS
#include "../bio/bss_file.c"
#endif

const int num0 = 100; /* number of tests */
const int num1 = 50;  /* additional tests for some functions */
const int num2 = 5;   /* number of tests for slow functions */

int test_add(BIO *bp);
int test_sub(BIO *bp);
int test_lshift1(BIO *bp);
int test_lshift(BIO *bp,BN_CTX *ctx,BIGNUM *a_);
int test_rshift1(BIO *bp);
int test_rshift(BIO *bp,BN_CTX *ctx);
int test_div(BIO *bp,BN_CTX *ctx);
int test_div_recp(BIO *bp,BN_CTX *ctx);
int test_mul(BIO *bp);
int test_sqr(BIO *bp,BN_CTX *ctx);
int test_mont(BIO *bp,BN_CTX *ctx);
int test_mod(BIO *bp,BN_CTX *ctx);
int test_mod_mul(BIO *bp,BN_CTX *ctx);
int test_mod_exp(BIO *bp,BN_CTX *ctx);
int test_exp(BIO *bp,BN_CTX *ctx);
int test_kron(BIO *bp,BN_CTX *ctx);
int test_sqrt(BIO *bp,BN_CTX *ctx);
int rand_neg(void);
static int results=0;

#ifdef NO_STDIO
#define APPS_WIN16
#include "bss_file.c"
#endif

static unsigned char lst[]="\xC6\x4F\x43\x04\x2A\xEA\xCA\x6E\x58\x36\x80\x5B\xE8\xC9"
"\x9B\x04\x5D\x48\x36\xC2\xFD\x16\xC9\x64\xF0";

static const char rnd_seed[] = "string to make the random number generator think it has entropy";

static void message(BIO *out, char *m)
	{
	fprintf(stderr, "test %s\n", m);
#if defined(linux) || defined(__FreeBSD__) /* can we use GNU bc features? */
	BIO_puts(out, "print \"test ");
	BIO_puts(out, m);
	BIO_puts(out, "\\n\"\n");
#endif
	}

int main(int argc, char *argv[])
	{
	BN_CTX *ctx;
	BIO *out;
	char *outfile=NULL;

	results = 0;

	RAND_seed(rnd_seed, sizeof rnd_seed); /* or BN_rand may fail, and we don't
	                                       * even check its return value
	                                       * (which we should) */

	argc--;
	argv++;
	while (argc >= 1)
		{
		if (strcmp(*argv,"-results") == 0)
			results=1;
		else if (strcmp(*argv,"-out") == 0)
			{
			if (--argc < 1) break;
			outfile= *(++argv);
			}
		argc--;
		argv++;
		}


	ctx=BN_CTX_new();
	if (ctx == NULL) exit(1);

	out=BIO_new(BIO_s_file());
	if (out == NULL) exit(1);
	if (outfile == NULL)
		{
		BIO_set_fp(out,stdout,BIO_NOCLOSE);
		}
	else
		{
		if (!BIO_write_filename(out,outfile))
			{
			perror(outfile);
			exit(1);
			}
		}

	if (!results)
		BIO_puts(out,"obase=16\nibase=16\n");

	message(out,"BN_add");
	if (!test_add(out)) goto err;
	BIO_flush(out);

	message(out,"BN_sub");
	if (!test_sub(out)) goto err;
	BIO_flush(out);

	message(out,"BN_lshift1");
	if (!test_lshift1(out)) goto err;
	BIO_flush(out);

	message(out,"BN_lshift (fixed)");
	if (!test_lshift(out,ctx,BN_bin2bn(lst,sizeof(lst)-1,NULL)))
	    goto err;
	BIO_flush(out);

	message(out,"BN_lshift");
	if (!test_lshift(out,ctx,NULL)) goto err;
	BIO_flush(out);

	message(out,"BN_rshift1");
	if (!test_rshift1(out)) goto err;
	BIO_flush(out);

	message(out,"BN_rshift");
	if (!test_rshift(out,ctx)) goto err;
	BIO_flush(out);

	message(out,"BN_sqr");
	if (!test_sqr(out,ctx)) goto err;
	BIO_flush(out);

	message(out,"BN_mul");
	if (!test_mul(out)) goto err;
	BIO_flush(out);

	message(out,"BN_div");
	if (!test_div(out,ctx)) goto err;
	BIO_flush(out);

	message(out,"BN_div_recp");
	if (!test_div_recp(out,ctx)) goto err;
	BIO_flush(out);

	message(out,"BN_mod");
	if (!test_mod(out,ctx)) goto err;
	BIO_flush(out);

	message(out,"BN_mod_mul");
	if (!test_mod_mul(out,ctx)) goto err;
	BIO_flush(out);

	message(out,"BN_mont");
	if (!test_mont(out,ctx)) goto err;
	BIO_flush(out);

	message(out,"BN_mod_exp");
	if (!test_mod_exp(out,ctx)) goto err;
	BIO_flush(out);

	message(out,"BN_exp");
	if (!test_exp(out,ctx)) goto err;
	BIO_flush(out);

	message(out,"BN_kronecker");
	if (!test_kron(out,ctx)) goto err;
	BIO_flush(out);

	message(out,"BN_mod_sqrt");
	if (!test_sqrt(out,ctx)) goto err;
	BIO_flush(out);

	BN_CTX_free(ctx);
	BIO_free(out);

/**/
	exit(0);
err:
	BIO_puts(out,"1\n"); /* make sure the Perl script fed by bc notices
	                      * the failure, see test_bn in test/Makefile.ssl*/
	BIO_flush(out);
	ERR_load_crypto_strings();
	ERR_print_errors_fp(stderr);
	exit(1);
	return(1);
	}

int test_add(BIO *bp)
	{
	BIGNUM a,b,c;
	int i;
	int j;

	BN_init(&a);
	BN_init(&b);
	BN_init(&c);

	BN_rand(&a,512,0,0);
	for (i=0; i<num0; i++)
		{
		BN_rand(&b,450+i,0,0);
		a.neg=rand_neg();
		b.neg=rand_neg();
		if (bp == NULL)
			for (j=0; j<10000; j++)
				BN_add(&c,&a,&b);
		BN_add(&c,&a,&b);
		if (bp != NULL)
			{
			if (!results)
				{
				BN_print(bp,&a);
				BIO_puts(bp," + ");
				BN_print(bp,&b);
				BIO_puts(bp," - ");
				}
			BN_print(bp,&c);
			BIO_puts(bp,"\n");
			}
		a.neg=!a.neg;
		b.neg=!b.neg;
		BN_add(&c,&c,&b);
		BN_add(&c,&c,&a);
		if(!BN_is_zero(&c))
		    {
		    fprintf(stderr,"Add test failed!\n");
		    return 0;
		    }
		}
	BN_free(&a);
	BN_free(&b);
	BN_free(&c);
	return(1);
	}

int test_sub(BIO *bp)
	{
	BIGNUM a,b,c;
	int i;
	int j;

	BN_init(&a);
	BN_init(&b);
	BN_init(&c);

	for (i=0; i<num0+num1; i++)
		{
		if (i < num1)
			{
			BN_rand(&a,512,0,0);
			BN_copy(&b,&a);
			if (BN_set_bit(&a,i)==0) return(0);
			BN_add_word(&b,i);
			}
		else
			{
			BN_rand(&b,400+i-num1,0,0);
			a.neg=rand_neg();
			b.neg=rand_neg();
			}
		if (bp == NULL)
			for (j=0; j<10000; j++)
				BN_sub(&c,&a,&b);
		BN_sub(&c,&a,&b);
		if (bp != NULL)
			{
			if (!results)
				{
				BN_print(bp,&a);
				BIO_puts(bp," - ");
				BN_print(bp,&b);
				BIO_puts(bp," - ");
				}
			BN_print(bp,&c);
			BIO_puts(bp,"\n");
			}
		BN_add(&c,&c,&b);
		BN_sub(&c,&c,&a);
		if(!BN_is_zero(&c))
		    {
		    fprintf(stderr,"Subtract test failed!\n");
		    return 0;
		    }
		}
	BN_free(&a);
	BN_free(&b);
	BN_free(&c);
	return(1);
	}

int test_div(BIO *bp, BN_CTX *ctx)
	{
	BIGNUM a,b,c,d,e;
	int i;
	int j;

	BN_init(&a);
	BN_init(&b);
	BN_init(&c);
	BN_init(&d);
	BN_init(&e);

	for (i=0; i<num0+num1; i++)
		{
		if (i < num1)
			{
			BN_rand(&a,400,0,0);
			BN_copy(&b,&a);
			BN_lshift(&a,&a,i);
			BN_add_word(&a,i);
			}
		else
			BN_rand(&b,50+3*(i-num1),0,0);
		a.neg=rand_neg();
		b.neg=rand_neg();
		if (bp == NULL)
			for (j=0; j<100; j++)
				BN_div(&d,&c,&a,&b,ctx);
		BN_div(&d,&c,&a,&b,ctx);
		if (bp != NULL)
			{
			if (!results)
				{
				BN_print(bp,&a);
				BIO_puts(bp," / ");
				BN_print(bp,&b);
				BIO_puts(bp," - ");
				}
			BN_print(bp,&d);
			BIO_puts(bp,"\n");

			if (!results)
				{
				BN_print(bp,&a);
				BIO_puts(bp," % ");
				BN_print(bp,&b);
				BIO_puts(bp," - ");
				}
			BN_print(bp,&c);
			BIO_puts(bp,"\n");
			}
		BN_mul(&e,&d,&b,ctx);
		BN_add(&d,&e,&c);
		BN_sub(&d,&d,&a);
		if(!BN_is_zero(&d))
		    {
		    fprintf(stderr,"Division test failed!\n");
		    return 0;
		    }
		}
	BN_free(&a);
	BN_free(&b);
	BN_free(&c);
	BN_free(&d);
	BN_free(&e);
	return(1);
	}

int test_div_recp(BIO *bp, BN_CTX *ctx)
	{
	BIGNUM a,b,c,d,e;
	BN_RECP_CTX recp;
	int i;
	int j;

	BN_RECP_CTX_init(&recp);
	BN_init(&a);
	BN_init(&b);
	BN_init(&c);
	BN_init(&d);
	BN_init(&e);

	for (i=0; i<num0+num1; i++)
		{
		if (i < num1)
			{
			BN_rand(&a,400,0,0);
			BN_copy(&b,&a);
			BN_lshift(&a,&a,i);
			BN_add_word(&a,i);
			}
		else
			BN_rand(&b,50+3*(i-num1),0,0);
		a.neg=rand_neg();
		b.neg=rand_neg();
		BN_RECP_CTX_set(&recp,&b,ctx);
		if (bp == NULL)
			for (j=0; j<100; j++)
				BN_div_recp(&d,&c,&a,&recp,ctx);
		BN_div_recp(&d,&c,&a,&recp,ctx);
		if (bp != NULL)
			{
			if (!results)
				{
				BN_print(bp,&a);
				BIO_puts(bp," / ");
				BN_print(bp,&b);
				BIO_puts(bp," - ");
				}
			BN_print(bp,&d);
			BIO_puts(bp,"\n");

			if (!results)
				{
				BN_print(bp,&a);
				BIO_puts(bp," % ");
				BN_print(bp,&b);
				BIO_puts(bp," - ");
				}
			BN_print(bp,&c);
			BIO_puts(bp,"\n");
			}
		BN_mul(&e,&d,&b,ctx);
		BN_add(&d,&e,&c);
		BN_sub(&d,&d,&a);
		if(!BN_is_zero(&d))
		    {
		    fprintf(stderr,"Reciprocal division test failed!\n");
		    fprintf(stderr,"a=");
		    BN_print_fp(stderr,&a);
		    fprintf(stderr,"\nb=");
		    BN_print_fp(stderr,&b);
		    fprintf(stderr,"\n");
		    return 0;
		    }
		}
	BN_free(&a);
	BN_free(&b);
	BN_free(&c);
	BN_free(&d);
	BN_free(&e);
	BN_RECP_CTX_free(&recp);
	return(1);
	}

int test_mul(BIO *bp)
	{
	BIGNUM a,b,c,d,e;
	int i;
	int j;
	BN_CTX ctx;

	BN_CTX_init(&ctx);
	BN_init(&a);
	BN_init(&b);
	BN_init(&c);
	BN_init(&d);
	BN_init(&e);

	for (i=0; i<num0+num1; i++)
		{
		if (i <= num1)
			{
			BN_rand(&a,100,0,0);
			BN_rand(&b,100,0,0);
			}
		else
			BN_rand(&b,i-num1,0,0);
		a.neg=rand_neg();
		b.neg=rand_neg();
		if (bp == NULL)
			for (j=0; j<100; j++)
				BN_mul(&c,&a,&b,&ctx);
		BN_mul(&c,&a,&b,&ctx);
		if (bp != NULL)
			{
			if (!results)
				{
				BN_print(bp,&a);
				BIO_puts(bp," * ");
				BN_print(bp,&b);
				BIO_puts(bp," - ");
				}
			BN_print(bp,&c);
			BIO_puts(bp,"\n");
			}
		BN_div(&d,&e,&c,&a,&ctx);
		BN_sub(&d,&d,&b);
		if(!BN_is_zero(&d) || !BN_is_zero(&e))
		    {
		    fprintf(stderr,"Multiplication test failed!\n");
		    return 0;
		    }
		}
	BN_free(&a);
	BN_free(&b);
	BN_free(&c);
	BN_free(&d);
	BN_free(&e);
	BN_CTX_free(&ctx);
	return(1);
	}

int test_sqr(BIO *bp, BN_CTX *ctx)
	{
	BIGNUM a,c,d,e;
	int i;
	int j;

	BN_init(&a);
	BN_init(&c);
	BN_init(&d);
	BN_init(&e);

	for (i=0; i<num0; i++)
		{
		BN_rand(&a,40+i*10,0,0);
		a.neg=rand_neg();
		if (bp == NULL)
			for (j=0; j<100; j++)
				BN_sqr(&c,&a,ctx);
		BN_sqr(&c,&a,ctx);
		if (bp != NULL)
			{
			if (!results)
				{
				BN_print(bp,&a);
				BIO_puts(bp," * ");
				BN_print(bp,&a);
				BIO_puts(bp," - ");
				}
			BN_print(bp,&c);
			BIO_puts(bp,"\n");
			}
		BN_div(&d,&e,&c,&a,ctx);
		BN_sub(&d,&d,&a);
		if(!BN_is_zero(&d) || !BN_is_zero(&e))
		    {
		    fprintf(stderr,"Square test failed!\n");
		    return 0;
		    }
		}
	BN_free(&a);
	BN_free(&c);
	BN_free(&d);
	BN_free(&e);
	return(1);
	}

int test_mont(BIO *bp, BN_CTX *ctx)
	{
	BIGNUM a,b,c,d,A,B;
	BIGNUM n;
	int i;
	int j;
	BN_MONT_CTX *mont;

	BN_init(&a);
	BN_init(&b);
	BN_init(&c);
	BN_init(&d);
	BN_init(&A);
	BN_init(&B);
	BN_init(&n);

	mont=BN_MONT_CTX_new();

	BN_rand(&a,100,0,0); /**/
	BN_rand(&b,100,0,0); /**/
	for (i=0; i<num2; i++)
		{
		int bits = (200*(i+1))/num2;

		if (bits == 0)
			continue;
		BN_rand(&n,bits,0,1);
		BN_MONT_CTX_set(mont,&n,ctx);

		BN_nnmod(&a,&a,&n,ctx);
		BN_nnmod(&b,&b,&n,ctx);

		BN_to_montgomery(&A,&a,mont,ctx);
		BN_to_montgomery(&B,&b,mont,ctx);

		if (bp == NULL)
			for (j=0; j<100; j++)
				BN_mod_mul_montgomery(&c,&A,&B,mont,ctx);/**/
		BN_mod_mul_montgomery(&c,&A,&B,mont,ctx);/**/
		BN_from_montgomery(&A,&c,mont,ctx);/**/
		if (bp != NULL)
			{
			if (!results)
				{
#ifdef undef
fprintf(stderr,"%d * %d %% %d\n",
BN_num_bits(&a),
BN_num_bits(&b),
BN_num_bits(mont->N));
#endif
				BN_print(bp,&a);
				BIO_puts(bp," * ");
				BN_print(bp,&b);
				BIO_puts(bp," % ");
				BN_print(bp,&(mont->N));
				BIO_puts(bp," - ");
				}
			BN_print(bp,&A);
			BIO_puts(bp,"\n");
			}
		BN_mod_mul(&d,&a,&b,&n,ctx);
		BN_sub(&d,&d,&A);
		if(!BN_is_zero(&d))
		    {
		    fprintf(stderr,"Montgomery multiplication test failed!\n");
		    return 0;
		    }
		}
	BN_MONT_CTX_free(mont);
	BN_free(&a);
	BN_free(&b);
	BN_free(&c);
	BN_free(&d);
	BN_free(&A);
	BN_free(&B);
	BN_free(&n);
	return(1);
	}

int test_mod(BIO *bp, BN_CTX *ctx)
	{
	BIGNUM *a,*b,*c,*d,*e;
	int i;
	int j;

	a=BN_new();
	b=BN_new();
	c=BN_new();
	d=BN_new();
	e=BN_new();

	BN_rand(a,1024,0,0); /**/
	for (i=0; i<num0; i++)
		{
		BN_rand(b,450+i*10,0,0); /**/
		a->neg=rand_neg();
		b->neg=rand_neg();
		if (bp == NULL)
			for (j=0; j<100; j++)
				BN_mod(c,a,b,ctx);/**/
		BN_mod(c,a,b,ctx);/**/
		if (bp != NULL)
			{
			if (!results)
				{
				BN_print(bp,a);
				BIO_puts(bp," % ");
				BN_print(bp,b);
				BIO_puts(bp," - ");
				}
			BN_print(bp,c);
			BIO_puts(bp,"\n");
			}
		BN_div(d,e,a,b,ctx);
		BN_sub(e,e,c);
		if(!BN_is_zero(e))
		    {
		    fprintf(stderr,"Modulo test failed!\n");
		    return 0;
		    }
		}
	BN_free(a);
	BN_free(b);
	BN_free(c);
	BN_free(d);
	BN_free(e);
	return(1);
	}

int test_mod_mul(BIO *bp, BN_CTX *ctx)
	{
	BIGNUM *a,*b,*c,*d,*e;
	int i;

	a=BN_new();
	b=BN_new();
	c=BN_new();
	d=BN_new();
	e=BN_new();

	BN_rand(c,1024,0,0); /**/
	for (i=0; i<num0; i++)
		{
		BN_rand(a,475+i*10,0,0); /**/
		BN_rand(b,425+i*11,0,0); /**/
		a->neg=rand_neg();
		b->neg=rand_neg();
	/*	if (bp == NULL)
			for (j=0; j<100; j++)
				BN_mod_mul(d,a,b,c,ctx);*/ /**/

		if (!BN_mod_mul(e,a,b,c,ctx))
			{
			unsigned long l;

			while ((l=ERR_get_error()))
				fprintf(stderr,"ERROR:%s\n",
					ERR_error_string(l,NULL));
			exit(1);
			}
		if (bp != NULL)
			{
			if (!results)
				{
				BN_print(bp,a);
				BIO_puts(bp," * ");
				BN_print(bp,b);
				BIO_puts(bp," % ");
				BN_print(bp,c);
				if ((a->neg ^ b->neg) && !BN_is_zero(e))
					{
					/* If  (a*b) % c  is negative,  c  must be added
					 * in order to obtain the normalized remainder
					 * (new with OpenSSL 0.9.7, previous versions of
					 * BN_mod_mul could generate negative results)
					 */
					BIO_puts(bp," + ");
					BN_print(bp,c);
					}
				BIO_puts(bp," - ");
				}
			BN_print(bp,e);
			BIO_puts(bp,"\n");
			}
		BN_mul(d,a,b,ctx);
		BN_sub(d,d,e);
		BN_div(a,b,d,c,ctx);
		if(!BN_is_zero(b))
		    {
		    fprintf(stderr,"Modulo multiply test failed!\n");
		    ERR_print_errors_fp(stderr);
		    return 0;
		    }
		}
	BN_free(a);
	BN_free(b);
	BN_free(c);
	BN_free(d);
	BN_free(e);
	return(1);
	}

int test_mod_exp(BIO *bp, BN_CTX *ctx)
	{
	BIGNUM *a,*b,*c,*d,*e;
	int i;

	a=BN_new();
	b=BN_new();
	c=BN_new();
	d=BN_new();
	e=BN_new();

	BN_rand(c,30,0,1); /* must be odd for montgomery */
	for (i=0; i<num2; i++)
		{
		BN_rand(a,20+i*5,0,0); /**/
		BN_rand(b,2+i,0,0); /**/

		if (!BN_mod_exp(d,a,b,c,ctx))
			return(00);

		if (bp != NULL)
			{
			if (!results)
				{
				BN_print(bp,a);
				BIO_puts(bp," ^ ");
				BN_print(bp,b);
				BIO_puts(bp," % ");
				BN_print(bp,c);
				BIO_puts(bp," - ");
				}
			BN_print(bp,d);
			BIO_puts(bp,"\n");
			}
		BN_exp(e,a,b,ctx);
		BN_sub(e,e,d);
		BN_div(a,b,e,c,ctx);
		if(!BN_is_zero(b))
		    {
		    fprintf(stderr,"Modulo exponentiation test failed!\n");
		    return 0;
		    }
		}
	BN_free(a);
	BN_free(b);
	BN_free(c);
	BN_free(d);
	BN_free(e);
	return(1);
	}

int test_exp(BIO *bp, BN_CTX *ctx)
	{
	BIGNUM *a,*b,*d,*e,*one;
	int i;

	a=BN_new();
	b=BN_new();
	d=BN_new();
	e=BN_new();
	one=BN_new();
	BN_one(one);

	for (i=0; i<num2; i++)
		{
		BN_rand(a,20+i*5,0,0); /**/
		BN_rand(b,2+i,0,0); /**/

		if (!BN_exp(d,a,b,ctx))
			return(00);

		if (bp != NULL)
			{
			if (!results)
				{
				BN_print(bp,a);
				BIO_puts(bp," ^ ");
				BN_print(bp,b);
				BIO_puts(bp," - ");
				}
			BN_print(bp,d);
			BIO_puts(bp,"\n");
			}
		BN_one(e);
		for( ; !BN_is_zero(b) ; BN_sub(b,b,one))
		    BN_mul(e,e,a,ctx);
		BN_sub(e,e,d);
		if(!BN_is_zero(e))
		    {
		    fprintf(stderr,"Exponentiation test failed!\n");
		    return 0;
		    }
		}
	BN_free(a);
	BN_free(b);
	BN_free(d);
	BN_free(e);
	BN_free(one);
	return(1);
	}

static void genprime_cb(int p, int n, void *arg)
	{
	char c='*';

	if (p == 0) c='.';
	if (p == 1) c='+';
	if (p == 2) c='*';
	if (p == 3) c='\n';
	putc(c, stderr);
	fflush(stderr);
	(void)n;
	(void)arg;
	}

int test_kron(BIO *bp, BN_CTX *ctx)
	{
	BIGNUM *a,*b,*r,*t;
	int i;
	int legendre, kronecker;
	int ret = 0;

	a = BN_new();
	b = BN_new();
	r = BN_new();
	t = BN_new();
	if (a == NULL || b == NULL || r == NULL || t == NULL) goto err;
	
	/* We test BN_kronecker(a, b, ctx) just for  b  odd (Jacobi symbol).
	 * In this case we know that if  b  is prime, then BN_kronecker(a, b, ctx)
	 * is congruent to $a^{(b-1)/2}$, modulo $b$ (Legendre symbol).
	 * So we generate a random prime  b  and compare these values
	 * for a number of random  a's.  (That is, we run the Solovay-Strassen
	 * primality test to confirm that  b  is prime, except that we
	 * don't want to test whether  b  is prime but whether BN_kronecker
	 * works.) */

	if (!BN_generate_prime(b, 512, 0, NULL, NULL, genprime_cb, NULL)) goto err;
	putc('\n', stderr);

	for (i = 0; i < num0; i++)
		{
		if (!BN_rand(a, 512, 0, 0)) goto err;
		a->neg = rand_neg();

		/* t := (b-1)/2  (note that b is odd) */
		if (!BN_copy(t, b)) goto err;
		if (!BN_sub_word(t, 1)) goto err;
		if (!BN_rshift1(t, t)) goto err;
		/* r := a^t mod b */
		if (!BN_mod_exp(r, a, t, b, ctx)) goto err;

		if (BN_is_word(r, 1))
			legendre = 1;
		else if (BN_is_zero(r))
			legendre = 0;
		else
			{
			if (!BN_add_word(r, 1)) goto err;
			if (0 != BN_cmp(r, b))
				{
				fprintf(stderr, "Legendre symbol computation failed\n");
				goto err;
				}
			legendre = -1;
			}
		
		kronecker = BN_kronecker(a, b, ctx);
		if (kronecker < -1) goto err;
		
		if (legendre != kronecker)
			{
			fprintf(stderr, "legendre != kronecker; a = ");
			BN_print_fp(stderr, a);
			fprintf(stderr, ", b = ");
			BN_print_fp(stderr, b);
			fprintf(stderr, "\n");
			goto err;
			}

		putc('.', stderr);
		fflush(stderr);
		}

	putc('\n', stderr);
	fflush(stderr);
	ret = 1;
 err:
	if (a != NULL) BN_free(a);
	if (b != NULL) BN_free(b);
	if (r != NULL) BN_free(r);
	if (t != NULL) BN_free(t);
	return ret;
	}

int test_sqrt(BIO *bp, BN_CTX *ctx)
	{
	BIGNUM *a,*p,*r;
	int i, j;
	int ret = 0;

	a = BN_new();
	p = BN_new();
	r = BN_new();
	if (a == NULL || p == NULL || r == NULL) goto err;
	
	for (i = 0; i < 16; i++)
		{
		if (i < 8)
			{
			unsigned primes[8] = { 2, 3, 5, 7, 11, 13, 17, 19 };
			
			if (!BN_set_word(p, primes[i])) goto err;
			}
		else
			{
			if (!BN_set_word(a, 32)) goto err;
			if (!BN_set_word(r, 2*i + 1)) goto err;
		
			if (!BN_generate_prime(p, 256, 0, a, r, genprime_cb, NULL)) goto err;
			putc('\n', stderr);
			}

		for (j = 0; j < num2; j++)
			{
			/* construct 'a' such that it is a square modulo p,
			 * but in general not a proper square and not reduced modulo p */
			if (!BN_rand(r, 256, 0, 3)) goto err;
			if (!BN_nnmod(r, r, p, ctx)) goto err;
			if (!BN_mod_sqr(r, r, p, ctx)) goto err;
			if (!BN_rand(a, 256, 0, 3)) goto err;
			if (!BN_nnmod(a, a, p, ctx)) goto err;
			if (!BN_mod_sqr(a, a, p, ctx)) goto err;
			if (!BN_mul(a, a, r, ctx)) goto err;

			if (!BN_mod_sqrt(r, a, p, ctx)) goto err;
			if (!BN_mod_sqr(r, r, p, ctx)) goto err;

			if (!BN_nnmod(a, a, p, ctx)) goto err;

			if (BN_cmp(a, r) != 0)
				{
				fprintf(stderr, "BN_mod_sqrt failed: a = ");
				BN_print_fp(stderr, a);
				fprintf(stderr, ", r = ");
				BN_print_fp(stderr, r);
				fprintf(stderr, ", p = ");
				BN_print_fp(stderr, p);
				fprintf(stderr, "\n");
				goto err;
				}

			putc('.', stderr);
			fflush(stderr);
			}
		
		putc('\n', stderr);
		fflush(stderr);
		}
	ret = 1;
 err:
	if (a != NULL) BN_free(a);
	if (p != NULL) BN_free(p);
	if (r != NULL) BN_free(r);
	return ret;
	}

int test_lshift(BIO *bp,BN_CTX *ctx,BIGNUM *a_)
	{
	BIGNUM *a,*b,*c,*d;
	int i;

	b=BN_new();
	c=BN_new();
	d=BN_new();
	BN_one(c);

	if(a_)
	    a=a_;
	else
	    {
	    a=BN_new();
	    BN_rand(a,200,0,0); /**/
	    a->neg=rand_neg();
	    }
	for (i=0; i<num0; i++)
		{
		BN_lshift(b,a,i+1);
		BN_add(c,c,c);
		if (bp != NULL)
			{
			if (!results)
				{
				BN_print(bp,a);
				BIO_puts(bp," * ");
				BN_print(bp,c);
				BIO_puts(bp," - ");
				}
			BN_print(bp,b);
			BIO_puts(bp,"\n");
			}
		BN_mul(d,a,c,ctx);
		BN_sub(d,d,b);
		if(!BN_is_zero(d))
		    {
		    fprintf(stderr,"Left shift test failed!\n");
		    fprintf(stderr,"a=");
		    BN_print_fp(stderr,a);
		    fprintf(stderr,"\nb=");
		    BN_print_fp(stderr,b);
		    fprintf(stderr,"\nc=");
		    BN_print_fp(stderr,c);
		    fprintf(stderr,"\nd=");
		    BN_print_fp(stderr,d);
		    fprintf(stderr,"\n");
		    return 0;
		    }
		}
	BN_free(a);
	BN_free(b);
	BN_free(c);
	BN_free(d);
	return(1);
	}

int test_lshift1(BIO *bp)
	{
	BIGNUM *a,*b,*c;
	int i;

	a=BN_new();
	b=BN_new();
	c=BN_new();

	BN_rand(a,200,0,0); /**/
	a->neg=rand_neg();
	for (i=0; i<num0; i++)
		{
		BN_lshift1(b,a);
		if (bp != NULL)
			{
			if (!results)
				{
				BN_print(bp,a);
				BIO_puts(bp," * 2");
				BIO_puts(bp," - ");
				}
			BN_print(bp,b);
			BIO_puts(bp,"\n");
			}
		BN_add(c,a,a);
		BN_sub(a,b,c);
		if(!BN_is_zero(a))
		    {
		    fprintf(stderr,"Left shift one test failed!\n");
		    return 0;
		    }
		
		BN_copy(a,b);
		}
	BN_free(a);
	BN_free(b);
	BN_free(c);
	return(1);
	}

int test_rshift(BIO *bp,BN_CTX *ctx)
	{
	BIGNUM *a,*b,*c,*d,*e;
	int i;

	a=BN_new();
	b=BN_new();
	c=BN_new();
	d=BN_new();
	e=BN_new();
	BN_one(c);

	BN_rand(a,200,0,0); /**/
	a->neg=rand_neg();
	for (i=0; i<num0; i++)
		{
		BN_rshift(b,a,i+1);
		BN_add(c,c,c);
		if (bp != NULL)
			{
			if (!results)
				{
				BN_print(bp,a);
				BIO_puts(bp," / ");
				BN_print(bp,c);
				BIO_puts(bp," - ");
				}
			BN_print(bp,b);
			BIO_puts(bp,"\n");
			}
		BN_div(d,e,a,c,ctx);
		BN_sub(d,d,b);
		if(!BN_is_zero(d))
		    {
		    fprintf(stderr,"Right shift test failed!\n");
		    return 0;
		    }
		}
	BN_free(a);
	BN_free(b);
	BN_free(c);
	BN_free(d);
	BN_free(e);
	return(1);
	}

int test_rshift1(BIO *bp)
	{
	BIGNUM *a,*b,*c;
	int i;

	a=BN_new();
	b=BN_new();
	c=BN_new();

	BN_rand(a,200,0,0); /**/
	a->neg=rand_neg();
	for (i=0; i<num0; i++)
		{
		BN_rshift1(b,a);
		if (bp != NULL)
			{
			if (!results)
				{
				BN_print(bp,a);
				BIO_puts(bp," / 2");
				BIO_puts(bp," - ");
				}
			BN_print(bp,b);
			BIO_puts(bp,"\n");
			}
		BN_sub(c,a,b);
		BN_sub(c,c,b);
		if(!BN_is_zero(c) && !BN_is_one(c))
		    {
		    fprintf(stderr,"Right shift one test failed!\n");
		    return 0;
		    }
		BN_copy(a,b);
		}
	BN_free(a);
	BN_free(b);
	BN_free(c);
	return(1);
	}

int rand_neg(void)
	{
	static unsigned int neg=0;
	static int sign[8]={0,0,0,1,1,0,1,1};

	return(sign[(neg++)%8]);
	}