1 files changed, 225 insertions, 26 deletions

diff --git a/src/lib/libcrypto/bn/bn_mod.c b/src/lib/libcrypto/bn/bn_mod.c
index c351aac14f..5cf82480d7 100644
--- a/src/lib/libcrypto/bn/bn_mod.c
+++ b/src/lib/libcrypto/bn/bn_mod.c
@@ -1,4 +1,59 @@
 /* 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.
  *
@@ -56,42 +111,186 @@
  * [including the GNU Public Licence.]
  */
 
-#include <stdio.h>
 #include "cryptlib.h"
 #include "bn_lcl.h"
 
-/* rem != m */
-int BN_mod(rem, m, d,ctx)
-BIGNUM *rem;
-BIGNUM *m;
-BIGNUM *d;
-BN_CTX *ctx;
+
+#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 *r, const BIGNUM *m, const BIGNUM *d, BN_CTX *ctx)
+        {
+        /* like BN_mod, but returns non-negative remainder
+         * (i.e.,  0 <= r < |d|  always holds) */
+
+        if (!(BN_mod(r,m,d,ctx)))
+                return 0;
+        if (!r->neg)
+                return 1;
+        /* now   -|d| < r < 0,  so we have to set  r := r + |d| */
+        return (d->neg ? BN_sub : BN_add)(r, r, d);
+}
+
+
+int BN_mod_add(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, const BIGNUM *m, BN_CTX *ctx)
+        {
+        if (!BN_add(r, a, b)) return 0;
+        return BN_nnmod(r, r, m, ctx);
+        }
+
+
+/* BN_mod_add variant that may be used if both  a  and  b  are non-negative
+ * and less than  m */
+int BN_mod_add_quick(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, const BIGNUM *m)
+        {
+        if (!BN_add(r, a, b)) return 0;
+        if (BN_ucmp(r, m) >= 0)
+                return BN_usub(r, r, m);
+        return 1;
+        }
+
+
+int BN_mod_sub(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, const BIGNUM *m, BN_CTX *ctx)
+        {
+        if (!BN_sub(r, a, b)) return 0;
+        return BN_nnmod(r, r, m, ctx);
+        }
+
+
+/* BN_mod_sub variant that may be used if both  a  and  b  are non-negative
+ * and less than  m */
+int BN_mod_sub_quick(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, const BIGNUM *m)
+        {
+        if (!BN_sub(r, a, b)) return 0;
+        if (r->neg)
+                return BN_add(r, r, m);
+        return 1;
+        }
+
+
+/* slow but works */
+int BN_mod_mul(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, const BIGNUM *m,
+        BN_CTX *ctx)
         {
-#if 0 /* The old slow way */
-        int i,nm,nd;
-        BIGNUM *dv;
+        BIGNUM *t;
+        int ret=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(r,t,m,ctx)) goto err;
+        ret=1;
+err:
+        BN_CTX_end(ctx);
+        return(ret);
+        }
 
-        if (BN_ucmp(m,d) < 0)
-                return((BN_copy(rem,m) == NULL)?0:1);
 
-        dv=ctx->bn[ctx->tos];
+int BN_mod_sqr(BIGNUM *r, const BIGNUM *a, const BIGNUM *m, BN_CTX *ctx)
+        {
+        if (!BN_sqr(r, a, ctx)) return 0;
+        /* r->neg == 0,  thus we don't need BN_nnmod */
+        return BN_mod(r, r, m, ctx);
+        }
 
-        if (!BN_copy(rem,m)) return(0);
 
-        nm=BN_num_bits(rem);
-        nd=BN_num_bits(d);
-        if (!BN_lshift(dv,d,nm-nd)) return(0);
-        for (i=nm-nd; i>=0; i--)
+int BN_mod_lshift1(BIGNUM *r, const BIGNUM *a, const BIGNUM *m, BN_CTX *ctx)
+        {
+        if (!BN_lshift1(r, a)) return 0;
+        return BN_nnmod(r, r, m, ctx);
+        }
+
+
+/* BN_mod_lshift1 variant that may be used if  a  is non-negative
+ * and less than  m */
+int BN_mod_lshift1_quick(BIGNUM *r, const BIGNUM *a, const BIGNUM *m)
+        {
+        if (!BN_lshift1(r, a)) return 0;
+        if (BN_cmp(r, m) >= 0)
+                return BN_sub(r, r, m);
+        return 1;
+        }
+
+
+int BN_mod_lshift(BIGNUM *r, const BIGNUM *a, int n, const BIGNUM *m, BN_CTX *ctx)
+        {
+        BIGNUM *abs_m = NULL;
+        int ret;
+
+        if (!BN_nnmod(r, a, m, ctx)) return 0;
+
+        if (m->neg)
                 {
-                if (BN_cmp(rem,dv) >= 0)
+                abs_m = BN_dup(m);
+                if (abs_m == NULL) return 0;
+                abs_m->neg = 0;
+                }
+        
+        ret = BN_mod_lshift_quick(r, r, n, (abs_m ? abs_m : m));
+
+        if (abs_m)
+                BN_free(abs_m);
+        return ret;
+        }
+
+
+/* BN_mod_lshift variant that may be used if  a  is non-negative
+ * and less than  m */
+int BN_mod_lshift_quick(BIGNUM *r, const BIGNUM *a, int n, const BIGNUM *m)
+        {
+        if (r != a)
+                {
+                if (BN_copy(r, a) == NULL) return 0;
+                }
+
+        while (n > 0)
+                {
+                int max_shift;
+                
+                /* 0 < r < m */
+                max_shift = BN_num_bits(m) - BN_num_bits(r);
+                /* max_shift >= 0 */
+
+                if (max_shift < 0)
+                        {
+                        BNerr(BN_F_BN_MOD_LSHIFT_QUICK, BN_R_INPUT_NOT_REDUCED);
+                        return 0;
+                        }
+
+                if (max_shift > n)
+                        max_shift = n;
+
+                if (max_shift)
+                        {
+                        if (!BN_lshift(r, r, max_shift)) return 0;
+                        n -= max_shift;
+                        }
+                else
+                        {
+                        if (!BN_lshift1(r, r)) return 0;
+                        --n;
+                        }
+
+                /* BN_num_bits(r) <= BN_num_bits(m) */
+
+                if (BN_cmp(r, m) >= 0) 
                         {
-                        if (!BN_sub(rem,rem,dv)) return(0);
+                        if (!BN_sub(r, r, m)) return 0;
                         }
-                if (!BN_rshift1(dv,dv)) return(0);
                 }
-        return(1);
-#else
-        return(BN_div(NULL,rem,m,d,ctx));
-#endif
+        
+        return 1;
         }
-