Import of old SSLeay release: SSLeay 0.8.1b

1 files changed, 389 insertions, 0 deletions

diff --git a/crypto/bn/bn_prime.c b/crypto/bn/bn_prime.c
new file mode 100644
index 0000000..07a8289
--- /dev/null
+++ b/crypto/bn/bn_prime.c
@@ -0,0 +1,389 @@
+/* crypto/bn/bn_prime.c */
+/* Copyright (C) 1995-1997 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 <time.h>
+#include "cryptlib.h"
+#include "bn_lcl.h"
+#include "rand.h"
+
+/* The quick seive algorithm approach to weeding out primes is
+ * Philip Zimmermann's, as implemented in PGP.  I have had a read of
+ * his comments and implemented my own version.
+ */
+#include "bn_prime.h"
+
+#ifndef NOPROTO
+static int witness(BIGNUM *a, BIGNUM *n, BN_CTX *ctx);
+static int probable_prime(BIGNUM *rnd, int bits);
+static int probable_prime_dh(BIGNUM *rnd, int bits,
+	BIGNUM *add, BIGNUM *rem, BN_CTX *ctx);
+static int probable_prime_dh_strong(BIGNUM *rnd, int bits,
+	BIGNUM *add, BIGNUM *rem, BN_CTX *ctx);
+#else
+static int witness();
+static int probable_prime();
+static int probable_prime_dh();
+static int probable_prime_dh_strong();
+#endif
+
+BIGNUM *BN_generate_prime(bits,strong,add,rem,callback)
+int bits;
+int strong;
+BIGNUM *add;
+BIGNUM *rem;
+void (*callback)(P_I_I); 
+	{
+	BIGNUM *rnd=NULL;
+	BIGNUM *ret=NULL;
+	BIGNUM *t=NULL;
+	int i,j,c1=0;
+	BN_CTX *ctx;
+
+	ctx=BN_CTX_new();
+	if (ctx == NULL) goto err;
+	if ((rnd=BN_new()) == NULL) goto err;
+	if (strong)
+		if ((t=BN_new()) == NULL) goto err;
+loop: 
+	/* make a random number and set the top and bottom bits */
+	if (add == NULL)
+		{
+		if (!probable_prime(rnd,bits)) goto err;
+		}
+	else
+		{
+		if (strong)
+			{
+			if (!probable_prime_dh_strong(rnd,bits,add,rem,ctx))
+				 goto err;
+			}
+		else
+			{
+			if (!probable_prime_dh(rnd,bits,add,rem,ctx))
+				goto err;
+			}
+		}
+	/* if (BN_mod_word(rnd,(BN_ULONG)3) == 1) goto loop; */
+	if (callback != NULL) callback(0,c1++);
+
+	if (!strong)
+		{
+		i=BN_is_prime(rnd,BN_prime_checks,callback,ctx);
+		if (i == -1) goto err;
+		if (i == 0) goto loop;
+		}
+	else
+		{
+		/* for a strong prime generation,
+		 * check that (p-1)/2 is prime.
+		 * Since a prime is odd, We just
+		 * need to divide by 2 */
+		if (!BN_rshift1(t,rnd)) goto err;
+
+		for (i=0; i<BN_prime_checks; i++)
+			{
+			j=BN_is_prime(rnd,1,callback,ctx);
+			if (j == -1) goto err;
+			if (j == 0) goto loop;
+
+			j=BN_is_prime(t,1,callback,ctx);
+			if (j == -1) goto err;
+			if (j == 0) goto loop;
+
+			if (callback != NULL) callback(2,c1-1);
+			/* We have a strong prime test pass */
+			}
+		}
+	/* we have a prime :-) */
+	ret=rnd;
+err:
+	if ((ret == NULL) && (rnd != NULL)) BN_free(rnd);
+	if (t != NULL) BN_free(t);
+	if (ctx != NULL) BN_CTX_free(ctx);
+	return(ret);
+	}
+
+int BN_is_prime(a,checks,callback,ctx_passed)
+BIGNUM *a;
+int checks;
+void (*callback)(P_I_I);
+BN_CTX *ctx_passed;
+	{
+	int i,j,c2=0,ret= -1;
+	BIGNUM *check;
+	BN_CTX *ctx;
+
+	if (ctx_passed != NULL)
+		ctx=ctx_passed;
+	else
+		if ((ctx=BN_CTX_new()) == NULL) goto err;
+
+	check=ctx->bn[ctx->tos++];
+	for (i=0; i<checks; i++)
+		{
+		if (!BN_rand(check,BN_num_bits(a)-1,0,0)) goto err;
+		j=witness(check,a,ctx);
+		if (j == -1) goto err;
+		if (j)
+			{
+			ret=0;
+			goto err;
+			}
+		if (callback != NULL) callback(1,c2++);
+		}
+	ret=1;
+err:
+	ctx->tos--;
+	if ((ctx_passed == NULL) && (ctx != NULL))
+		BN_CTX_free(ctx);
+		
+	return(ret);
+	}
+
+#define RECP_MUL_MOD
+
+static int witness(a, n,ctx)
+BIGNUM *a;
+BIGNUM *n;
+BN_CTX *ctx;
+	{
+	int k,i,nb,ret= -1;
+	BIGNUM *d,*dd,*tmp;
+	BIGNUM *d1,*d2,*x,*n1,*inv;
+
+	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;
+
+	d=d1;
+	dd=d2;
+	if (!BN_one(d)) goto err;
+	if (!BN_sub(n1,n,d)) goto err; /* n1=n-1; */
+	k=BN_num_bits(n1);
+
+	/* i=BN_num_bits(n); */
+#ifdef RECP_MUL_MOD
+	nb=BN_reciprocal(inv,n,ctx); /**/
+	if (nb == -1) goto err;
+#endif
+
+	for (i=k-1; i>=0; i--)
+		{
+		if (BN_copy(x,d) == NULL) goto err;
+#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;
+#endif
+		if (	BN_is_one(dd) &&
+			!BN_is_one(x) &&
+			(BN_cmp(x,n1) != 0))
+			{
+			ret=1;
+			goto err;
+			}
+		if (BN_is_bit_set(n1,i))
+			{
+#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; 
+#endif
+			}
+		else
+			{
+			tmp=d;
+			d=dd;
+			dd=tmp;
+			}
+		}
+	if (BN_is_one(d))
+		i=0;
+	else	i=1;
+	ret=i;
+err:
+	ctx->tos-=5;
+	return(ret);
+	}
+
+static int probable_prime(rnd, bits)
+BIGNUM *rnd;
+int bits;
+	{
+	int i;
+	MS_STATIC BN_ULONG mods[NUMPRIMES];
+	BN_ULONG delta;
+
+	if (!BN_rand(rnd,bits,1,1)) return(0);
+	/* we now have a random number 'rand' to test. */
+	for (i=1; i<NUMPRIMES; i++)
+		mods[i]=BN_mod_word(rnd,(BN_ULONG)primes[i]);
+	delta=0;
+	loop: for (i=1; i<NUMPRIMES; i++)
+		{
+		/* check that rnd is not a prime and also
+		 * that gcd(rnd-1,primes) == 1 (except for 2) */
+		if (((mods[i]+delta)%primes[i]) <= 1)
+			{
+			delta+=2;
+			/* perhaps need to check for overflow of
+			 * delta (but delta can be upto 2^32) */
+			goto loop;
+			}
+		}
+	if (!BN_add_word(rnd,delta)) return(0);
+	return(1);
+	}
+
+static int probable_prime_dh(rnd, bits, add, rem,ctx)
+BIGNUM *rnd;
+int bits;
+BIGNUM *add;
+BIGNUM *rem;
+BN_CTX *ctx;
+	{
+	int i,ret=0;
+	BIGNUM *t1;
+
+	t1=ctx->bn[ctx->tos++];
+
+	if (!BN_rand(rnd,bits,0,1)) goto err;
+
+	/* we need ((rnd-rem) % add) == 0 */
+
+	if (!BN_mod(t1,rnd,add,ctx)) goto err;
+	if (!BN_sub(rnd,rnd,t1)) goto err;
+	if (rem == NULL)
+		{ if (!BN_add_word(rnd,1)) goto err; }
+	else
+		{ if (!BN_add(rnd,rnd,rem)) goto err; }
+
+	/* we now have a random number 'rand' to test. */
+
+	loop: for (i=1; i<NUMPRIMES; i++)
+		{
+		/* check that rnd is a prime */
+		if (BN_mod_word(rnd,(BN_LONG)primes[i]) <= 1)
+			{
+			if (!BN_add(rnd,rnd,add)) goto err;
+			goto loop;
+			}
+		}
+	ret=1;
+err:
+	ctx->tos--;
+	return(ret);
+	}
+
+static int probable_prime_dh_strong(p, bits, padd, rem,ctx)
+BIGNUM *p;
+int bits;
+BIGNUM *padd;
+BIGNUM *rem;
+BN_CTX *ctx;
+	{
+	int i,ret=0;
+	BIGNUM *t1,*qadd=NULL,*q=NULL;
+
+	bits--;
+	t1=ctx->bn[ctx->tos++];
+	q=ctx->bn[ctx->tos++];
+	qadd=ctx->bn[ctx->tos++];
+
+	if (!BN_rshift1(qadd,padd)) goto err;
+		
+	if (!BN_rand(q,bits,0,1)) goto err;
+
+	/* we need ((rnd-rem) % add) == 0 */
+	if (!BN_mod(t1,q,qadd,ctx)) goto err;
+	if (!BN_sub(q,q,t1)) goto err;
+	if (rem == NULL)
+		{ if (!BN_add_word(q,1)) goto err; }
+	else
+		{
+		if (!BN_rshift1(t1,rem)) goto err;
+		if (!BN_add(q,q,t1)) goto err;
+		}
+
+	/* we now have a random number 'rand' to test. */
+	if (!BN_lshift1(p,q)) goto err;
+	if (!BN_add_word(p,1)) goto err;
+
+	loop: for (i=1; i<NUMPRIMES; i++)
+		{
+		/* check that p and q are prime */
+		/* check that for p and q
+		 * gcd(p-1,primes) == 1 (except for 2) */
+		if (	(BN_mod_word(p,(BN_LONG)primes[i]) == 0) ||
+			(BN_mod_word(q,(BN_LONG)primes[i]) == 0))
+			{
+			if (!BN_add(p,p,padd)) goto err;
+			if (!BN_add(q,q,qadd)) goto err;
+			goto loop;
+			}
+		}
+	ret=1;
+err:
+	ctx->tos-=3;
+	return(ret);
+	}
+