From 18fb9d807ede04cf7dd52d27e6d94b13e3df1d9a Mon Sep 17 00:00:00 2001
From: Andy Polyakov <appro@openssl.org>
Date: Sun, 11 Nov 2007 20:43:23 +0000
Subject: [PATCH] Add framework for bn_mul_mont [from 098-fips].

---
 Configure           |  1 +
 crypto/bn/bn_lcl.h  |  1 +
 crypto/bn/bn_mont.c | 15 +++++++++++++++
 3 files changed, 17 insertions(+)

diff --git a/Configure b/Configure
index 0a74446c33..bad6c93dd2 100755
--- a/Configure
+++ b/Configure
@@ -1227,6 +1227,7 @@ $bn_obj = $bn_asm unless $bn_obj ne "";
 # bn86* is the only one implementing bn_*_part_words
 $cflags.=" -DOPENSSL_BN_ASM_PART_WORDS" if ($bn_obj =~ /bn86/);
 $cflags.=" -DOPENSSL_IA32_SSE2" if (!$no_sse2 && $bn_obj =~ /bn86/);
+$cflags.=" -DOPENSSL_BN_ASM_MONT" if ($bn_obj =~ /\-mont|mo86\-/);
 
 $des_obj=$des_enc	unless ($des_obj =~ /\.o$/);
 $bf_obj=$bf_enc		unless ($bf_obj =~ /\.o$/);
diff --git a/crypto/bn/bn_lcl.h b/crypto/bn/bn_lcl.h
index ad4ca7ff30..27ac4397a1 100644
--- a/crypto/bn/bn_lcl.h
+++ b/crypto/bn/bn_lcl.h
@@ -481,6 +481,7 @@ BN_ULONG bn_add_part_words(BN_ULONG *r, const BN_ULONG *a, const BN_ULONG *b,
 	int cl, int dl);
 BN_ULONG bn_sub_part_words(BN_ULONG *r, const BN_ULONG *a, const BN_ULONG *b,
 	int cl, int dl);
+int bn_mul_mont(BN_ULONG *rp, const BN_ULONG *ap, const BN_ULONG *bp, const BN_ULONG *np,const BN_ULONG *n0, int num);
 
 #ifdef  __cplusplus
 }
diff --git a/crypto/bn/bn_mont.c b/crypto/bn/bn_mont.c
index b5d35d10be..46b6eddf45 100644
--- a/crypto/bn/bn_mont.c
+++ b/crypto/bn/bn_mont.c
@@ -127,6 +127,21 @@ int BN_mod_mul_montgomery(BIGNUM *r, const BIGNUM *a, const BIGNUM *b,
 	{
 	BIGNUM *tmp;
 	int ret=0;
+#if defined(OPENSSL_BN_ASM_MONT) && defined(MONT_WORD)
+	int num = mont->N.top;
+
+	if (num>1 && a->top==num && b->top==num)
+		{
+		if (bn_wexpand(r,num) == NULL) return(0);
+		if (bn_mul_mont(r->d,a->d,b->d,mont->N.d,&mont->n0,num))
+			{
+			r->neg = a->neg^b->neg;
+			r->top = num;
+			bn_correct_top(r);
+			return(1);
+			}
+		}
+#endif
 
 	BN_CTX_start(ctx);
 	tmp = BN_CTX_get(ctx);
-- 
2.25.1