Add bn_mod.c (should have happend in the previous commit ...).

BN_swap manual page.

1 files changed, 185 insertions, 0 deletions

diff --git a/crypto/bn/bn_mod.c b/crypto/bn/bn_mod.c
new file mode 100644
index 0000000000..72f09c2c2f
--- /dev/null
+++ b/crypto/bn/bn_mod.c
@@ -0,0 +1,185 @@
+/* crypto/bn/bn_mod.c */
+/* Includes code written by Lenka Fibikova <fibikova@exp-math.uni-essen.de>
+ * for the OpenSSL project. */
+/* ====================================================================
+ * Copyright (c) 1998-2000 The OpenSSL Project.  All rights reserved.
+ *
+ * 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 above 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 acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
+ *
+ * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
+ *    endorse or promote products derived from this software without
+ *    prior written permission. For written permission, please contact
+ *    openssl-core@openssl.org.
+ *
+ * 5. Products derived from this software may not be called "OpenSSL"
+ *    nor may "OpenSSL" appear in their names without prior written
+ *    permission of the OpenSSL Project.
+ *
+ * 6. Redistributions of any form whatsoever must retain the following
+ *    acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
+ * EXPRESSED 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 OpenSSL PROJECT OR
+ * ITS 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.
+ * ====================================================================
+ *
+ * This product includes cryptographic software written by Eric Young
+ * (eay@cryptsoft.com).  This product includes software written by Tim
+ * Hudson (tjh@cryptsoft.com).
+ *
+ */
+/* 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 "cryptlib.h"
+#include "bn_lcl.h"
+
+
+#if 0 /* now just a #define */
+int BN_mod(BIGNUM *rem, const BIGNUM *m, const BIGNUM *d, BN_CTX *ctx)
+	{
+	return(BN_div(NULL,rem,m,d,ctx));
+	/* note that  rem->neg == m->neg  (unless the remainder is zero) */
+	}
+#endif
+
+
+int BN_nnmod(BIGNUM *rem, const BIGNUM *m, const BIGNUM *d, BN_CTX *ctx)
+	{
+	/* like BN_mod, but returns non-negative remainder
+	 * (i.e.,  0 <= rem < |d|  always holds) */
+
+	if (!(BN_mod(rem,m,d,ctx)))
+		return 0;
+	if (!rem->neg)
+		return 1;
+	/* now   -|d| < rem < 0,  so we have to set  rem := rem + |d| */
+	return (d->neg ? BN_sub : BN_add)(rem, rem, d);
+}
+
+
+int BN_mod_add(BIGNUM *ret, const BIGNUM *a, const BIGNUM *b, const BIGNUM *m, BN_CTX *ctx) 
+	{
+	if (!BN_add(ret, a, b)) return 0;
+	return BN_nnmod(ret, ret, m, ctx);
+	}
+
+
+int BN_mod_sub(BIGNUM *ret, const BIGNUM *a, const BIGNUM *b, const BIGNUM *m, BN_CTX *ctx) 
+	{
+	if (!BN_sub(ret, a, b)) return 0;
+	return BN_nnmod(ret, ret, m, ctx);
+	}
+
+
+/* slow but works */
+int BN_mod_mul(BIGNUM *ret, const BIGNUM *a, const BIGNUM *b, const BIGNUM *m,
+	BN_CTX *ctx)
+	{
+	BIGNUM *t;
+	int r=0;
+
+	bn_check_top(a);
+	bn_check_top(b);
+	bn_check_top(m);
+
+	BN_CTX_start(ctx);
+	if ((t = BN_CTX_get(ctx)) == NULL) goto err;
+	if (a == b)
+		{ if (!BN_sqr(t,a,ctx)) goto err; }
+	else
+		{ if (!BN_mul(t,a,b,ctx)) goto err; }
+	if (!BN_nnmod(ret,t,m,ctx)) goto err;
+	r=1;
+err:
+	BN_CTX_end(ctx);
+	return(r);
+	}
+
+
+int BN_mod_sqr(BIGNUM *ret, const BIGNUM *a, const BIGNUM *m, BN_CTX *ctx)
+	{
+	if (!BN_sqr(ret, a, ctx)) return 0;
+	/* ret->neg == 0,  thus we don't need BN_nnmod */
+	return BN_mod(ret, ret, m, ctx);
+	}