X-Git-Url: https://git.openssl.org/?p=openssl.git;a=blobdiff_plain;f=crypto%2Fbn%2Fbn_asm.c;h=c43c91cc09f485fa615eddc61ddb81d20e792bf4;hp=a62fdcf07a2300cb3317ba7d370b37c12fcf6980;hb=55614f89f0beb53ebafbfc680cf7b4d114b44d30;hpb=fb81ac5e6be4041e59df9362cd63880b21e2cafc

diff --git a/crypto/bn/bn_asm.c b/crypto/bn/bn_asm.c
index a62fdcf07a..c43c91cc09 100644
--- a/crypto/bn/bn_asm.c
+++ b/crypto/bn/bn_asm.c
@@ -56,19 +56,26 @@
  * [including the GNU Public Licence.]
  */
 
+#ifndef BN_DEBUG
+# undef NDEBUG /* avoid conflicting definitions */
+# define NDEBUG
+#endif
+
 #include <stdio.h>
+#include <assert.h>
 #include "cryptlib.h"
 #include "bn_lcl.h"
 
 #if defined(BN_LLONG) || defined(BN_UMULT_HIGH)
 
-BN_ULONG bn_mul_add_words(BN_ULONG *rp, BN_ULONG *ap, int num, BN_ULONG w)
+BN_ULONG bn_mul_add_words(BN_ULONG *rp, const BN_ULONG *ap, int num, BN_ULONG w)
 	{
 	BN_ULONG c1=0;
 
-	bn_check_num(num);
+	assert(num >= 0);
 	if (num <= 0) return(c1);
 
+#ifndef OPENSSL_SMALL_FOOTPRINT
 	while (num&~3)
 		{
 		mul_add(rp[0],ap[0],w,c1);
@@ -77,23 +84,24 @@ BN_ULONG bn_mul_add_words(BN_ULONG *rp, BN_ULONG *ap, int num, BN_ULONG w)
 		mul_add(rp[3],ap[3],w,c1);
 		ap+=4; rp+=4; num-=4;
 		}
-	if (num)
+#endif
+	while (num)
 		{
-		mul_add(rp[0],ap[0],w,c1); if (--num==0) return c1;
-		mul_add(rp[1],ap[1],w,c1); if (--num==0) return c1;
-		mul_add(rp[2],ap[2],w,c1); return c1;
+		mul_add(rp[0],ap[0],w,c1);
+		ap++; rp++; num--;
 		}
 	
 	return(c1);
 	} 
 
-BN_ULONG bn_mul_words(BN_ULONG *rp, BN_ULONG *ap, int num, BN_ULONG w)
+BN_ULONG bn_mul_words(BN_ULONG *rp, const BN_ULONG *ap, int num, BN_ULONG w)
 	{
 	BN_ULONG c1=0;
 
-	bn_check_num(num);
+	assert(num >= 0);
 	if (num <= 0) return(c1);
 
+#ifndef OPENSSL_SMALL_FOOTPRINT
 	while (num&~3)
 		{
 		mul(rp[0],ap[0],w,c1);
@@ -102,19 +110,21 @@ BN_ULONG bn_mul_words(BN_ULONG *rp, BN_ULONG *ap, int num, BN_ULONG w)
 		mul(rp[3],ap[3],w,c1);
 		ap+=4; rp+=4; num-=4;
 		}
-	if (num)
+#endif
+	while (num)
 		{
-		mul(rp[0],ap[0],w,c1); if (--num == 0) return c1;
-		mul(rp[1],ap[1],w,c1); if (--num == 0) return c1;
-		mul(rp[2],ap[2],w,c1);
+		mul(rp[0],ap[0],w,c1);
+		ap++; rp++; num--;
 		}
 	return(c1);
 	} 
 
-void bn_sqr_words(BN_ULONG *r, BN_ULONG *a, int n)
+void bn_sqr_words(BN_ULONG *r, const BN_ULONG *a, int n)
         {
-	bn_check_num(n);
+	assert(n >= 0);
 	if (n <= 0) return;
+
+#ifndef OPENSSL_SMALL_FOOTPRINT
 	while (n&~3)
 		{
 		sqr(r[0],r[1],a[0]);
@@ -123,94 +133,97 @@ void bn_sqr_words(BN_ULONG *r, BN_ULONG *a, int n)
 		sqr(r[6],r[7],a[3]);
 		a+=4; r+=8; n-=4;
 		}
-	if (n)
+#endif
+	while (n)
 		{
-		sqr(r[0],r[1],a[0]); if (--n == 0) return;
-		sqr(r[2],r[3],a[1]); if (--n == 0) return;
-		sqr(r[4],r[5],a[2]);
+		sqr(r[0],r[1],a[0]);
+		a++; r+=2; n--;
 		}
 	}
 
-#else
+#else /* !(defined(BN_LLONG) || defined(BN_UMULT_HIGH)) */
 
-BN_ULONG bn_mul_add_words(BN_ULONG *rp, BN_ULONG *ap, int num, BN_ULONG w)
+BN_ULONG bn_mul_add_words(BN_ULONG *rp, const BN_ULONG *ap, int num, BN_ULONG w)
 	{
 	BN_ULONG c=0;
 	BN_ULONG bl,bh;
 
-	bn_check_num(num);
+	assert(num >= 0);
 	if (num <= 0) return((BN_ULONG)0);
 
 	bl=LBITS(w);
 	bh=HBITS(w);
 
-	for (;;)
+#ifndef OPENSSL_SMALL_FOOTPRINT
+	while (num&~3)
 		{
 		mul_add(rp[0],ap[0],bl,bh,c);
-		if (--num == 0) break;
 		mul_add(rp[1],ap[1],bl,bh,c);
-		if (--num == 0) break;
 		mul_add(rp[2],ap[2],bl,bh,c);
-		if (--num == 0) break;
 		mul_add(rp[3],ap[3],bl,bh,c);
-		if (--num == 0) break;
-		ap+=4;
-		rp+=4;
+		ap+=4; rp+=4; num-=4;
+		}
+#endif
+	while (num)
+		{
+		mul_add(rp[0],ap[0],bl,bh,c);
+		ap++; rp++; num--;
 		}
 	return(c);
 	} 
 
-BN_ULONG bn_mul_words(BN_ULONG *rp, BN_ULONG *ap, int num, BN_ULONG w)
+BN_ULONG bn_mul_words(BN_ULONG *rp, const BN_ULONG *ap, int num, BN_ULONG w)
 	{
 	BN_ULONG carry=0;
 	BN_ULONG bl,bh;
 
-	bn_check_num(num);
+	assert(num >= 0);
 	if (num <= 0) return((BN_ULONG)0);
 
 	bl=LBITS(w);
 	bh=HBITS(w);
 
-	for (;;)
+#ifndef OPENSSL_SMALL_FOOTPRINT
+	while (num&~3)
 		{
 		mul(rp[0],ap[0],bl,bh,carry);
-		if (--num == 0) break;
 		mul(rp[1],ap[1],bl,bh,carry);
-		if (--num == 0) break;
 		mul(rp[2],ap[2],bl,bh,carry);
-		if (--num == 0) break;
 		mul(rp[3],ap[3],bl,bh,carry);
-		if (--num == 0) break;
-		ap+=4;
-		rp+=4;
+		ap+=4; rp+=4; num-=4;
+		}
+#endif
+	while (num)
+		{
+		mul(rp[0],ap[0],bl,bh,carry);
+		ap++; rp++; num--;
 		}
 	return(carry);
 	} 
 
-void bn_sqr_words(BN_ULONG *r, BN_ULONG *a, int n)
+void bn_sqr_words(BN_ULONG *r, const BN_ULONG *a, int n)
         {
-	bn_check_num(n);
+	assert(n >= 0);
 	if (n <= 0) return;
-	for (;;)
+
+#ifndef OPENSSL_SMALL_FOOTPRINT
+	while (n&~3)
 		{
 		sqr64(r[0],r[1],a[0]);
-		if (--n == 0) break;
-
 		sqr64(r[2],r[3],a[1]);
-		if (--n == 0) break;
-
 		sqr64(r[4],r[5],a[2]);
-		if (--n == 0) break;
-
 		sqr64(r[6],r[7],a[3]);
-		if (--n == 0) break;
-
-		a+=4;
-		r+=8;
+		a+=4; r+=8; n-=4;
+		}
+#endif
+	while (n)
+		{
+		sqr64(r[0],r[1],a[0]);
+		a++; r+=2; n--;
 		}
 	}
 
-#endif
+#endif /* !(defined(BN_LLONG) || defined(BN_UMULT_HIGH)) */
 
 #if defined(BN_LLONG) && defined(BN_DIV2W)
 
@@ -221,7 +234,7 @@ BN_ULONG bn_div_words(BN_ULONG h, BN_ULONG l, BN_ULONG d)
 
 #else
 
-/* Divide h-l by d and return the result. */
+/* Divide h,l by d and return the result. */
 /* I need to test this some more :-( */
 BN_ULONG bn_div_words(BN_ULONG h, BN_ULONG l, BN_ULONG d)
 	{
@@ -231,13 +244,8 @@ BN_ULONG bn_div_words(BN_ULONG h, BN_ULONG l, BN_ULONG d)
 	if (d == 0) return(BN_MASK2);
 
 	i=BN_num_bits_word(d);
-	if ((i != BN_BITS2) && (h > (BN_ULONG)1<<i))
-		{
-#if !defined(NO_STDIO) && !defined(WIN16)
-		fprintf(stderr,"Division would overflow (%d)\n",i);
-#endif
-		abort();
-		}
+	assert((i == BN_BITS2) || (h <= (BN_ULONG)1<<i));
+
 	i=BN_BITS2-i;
 	if (h >= d) h-=d;
 
@@ -292,54 +300,54 @@ BN_ULONG bn_div_words(BN_ULONG h, BN_ULONG l, BN_ULONG d)
 	ret|=q;
 	return(ret);
 	}
-#endif
+#endif /* !defined(BN_LLONG) && defined(BN_DIV2W) */
 
 #ifdef BN_LLONG
-BN_ULONG bn_add_words(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n)
+BN_ULONG bn_add_words(BN_ULONG *r, const BN_ULONG *a, const BN_ULONG *b, int n)
         {
 	BN_ULLONG ll=0;
 
-	bn_check_num(n);
+	assert(n >= 0);
 	if (n <= 0) return((BN_ULONG)0);
 
-	for (;;)
+#ifndef OPENSSL_SMALL_FOOTPRINT
+	while (n&~3)
 		{
 		ll+=(BN_ULLONG)a[0]+b[0];
 		r[0]=(BN_ULONG)ll&BN_MASK2;
 		ll>>=BN_BITS2;
-		if (--n <= 0) break;
-
 		ll+=(BN_ULLONG)a[1]+b[1];
 		r[1]=(BN_ULONG)ll&BN_MASK2;
 		ll>>=BN_BITS2;
-		if (--n <= 0) break;
-
 		ll+=(BN_ULLONG)a[2]+b[2];
 		r[2]=(BN_ULONG)ll&BN_MASK2;
 		ll>>=BN_BITS2;
-		if (--n <= 0) break;
-
 		ll+=(BN_ULLONG)a[3]+b[3];
 		r[3]=(BN_ULONG)ll&BN_MASK2;
 		ll>>=BN_BITS2;
-		if (--n <= 0) break;
-
-		a+=4;
-		b+=4;
-		r+=4;
+		a+=4; b+=4; r+=4; n-=4;
+		}
+#endif
+	while (n)
+		{
+		ll+=(BN_ULLONG)a[0]+b[0];
+		r[0]=(BN_ULONG)ll&BN_MASK2;
+		ll>>=BN_BITS2;
+		a++; b++; r++; n--;
 		}
 	return((BN_ULONG)ll);
 	}
-#else
-BN_ULONG bn_add_words(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n)
+#else /* !BN_LLONG */
+BN_ULONG bn_add_words(BN_ULONG *r, const BN_ULONG *a, const BN_ULONG *b, int n)
         {
 	BN_ULONG c,l,t;
 
-	bn_check_num(n);
+	assert(n >= 0);
 	if (n <= 0) return((BN_ULONG)0);
 
 	c=0;
-	for (;;)
+#ifndef OPENSSL_SMALL_FOOTPRINT
+	while (n&~3)
 		{
 		t=a[0];
 		t=(t+c)&BN_MASK2;
@@ -347,84 +355,89 @@ BN_ULONG bn_add_words(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n)
 		l=(t+b[0])&BN_MASK2;
 		c+=(l < t);
 		r[0]=l;
-		if (--n <= 0) break;
-
 		t=a[1];
 		t=(t+c)&BN_MASK2;
 		c=(t < c);
 		l=(t+b[1])&BN_MASK2;
 		c+=(l < t);
 		r[1]=l;
-		if (--n <= 0) break;
-
 		t=a[2];
 		t=(t+c)&BN_MASK2;
 		c=(t < c);
 		l=(t+b[2])&BN_MASK2;
 		c+=(l < t);
 		r[2]=l;
-		if (--n <= 0) break;
-
 		t=a[3];
 		t=(t+c)&BN_MASK2;
 		c=(t < c);
 		l=(t+b[3])&BN_MASK2;
 		c+=(l < t);
 		r[3]=l;
-		if (--n <= 0) break;
-
-		a+=4;
-		b+=4;
-		r+=4;
+		a+=4; b+=4; r+=4; n-=4;
+		}
+#endif
+	while(n)
+		{
+		t=a[0];
+		t=(t+c)&BN_MASK2;
+		c=(t < c);
+		l=(t+b[0])&BN_MASK2;
+		c+=(l < t);
+		r[0]=l;
+		a++; b++; r++; n--;
 		}
 	return((BN_ULONG)c);
 	}
-#endif
+#endif /* !BN_LLONG */
 
-BN_ULONG bn_sub_words(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n)
+BN_ULONG bn_sub_words(BN_ULONG *r, const BN_ULONG *a, const BN_ULONG *b, int n)
         {
 	BN_ULONG t1,t2;
 	int c=0;
 
-	bn_check_num(n);
+	assert(n >= 0);
 	if (n <= 0) return((BN_ULONG)0);
 
-	for (;;)
+#ifndef OPENSSL_SMALL_FOOTPRINT
+	while (n&~3)
 		{
 		t1=a[0]; t2=b[0];
 		r[0]=(t1-t2-c)&BN_MASK2;
 		if (t1 != t2) c=(t1 < t2);
-		if (--n <= 0) break;
-
 		t1=a[1]; t2=b[1];
 		r[1]=(t1-t2-c)&BN_MASK2;
 		if (t1 != t2) c=(t1 < t2);
-		if (--n <= 0) break;
-
 		t1=a[2]; t2=b[2];
 		r[2]=(t1-t2-c)&BN_MASK2;
 		if (t1 != t2) c=(t1 < t2);
-		if (--n <= 0) break;
-
 		t1=a[3]; t2=b[3];
 		r[3]=(t1-t2-c)&BN_MASK2;
 		if (t1 != t2) c=(t1 < t2);
-		if (--n <= 0) break;
-
-		a+=4;
-		b+=4;
-		r+=4;
+		a+=4; b+=4; r+=4; n-=4;
+		}
+#endif
+	while (n)
+		{
+		t1=a[0]; t2=b[0];
+		r[0]=(t1-t2-c)&BN_MASK2;
+		if (t1 != t2) c=(t1 < t2);
+		a++; b++; r++; n--;
 		}
 	return(c);
 	}
 
-#ifdef BN_MUL_COMBA
+#if defined(BN_MUL_COMBA) && !defined(OPENSSL_SMALL_FOOTPRINT)
 
 #undef bn_mul_comba8
 #undef bn_mul_comba4
 #undef bn_sqr_comba8
 #undef bn_sqr_comba4
 
+/* mul_add_c(a,b,c0,c1,c2)  -- c+=a*b for three word number c=(c2,c1,c0) */
+/* mul_add_c2(a,b,c0,c1,c2) -- c+=2*a*b for three word number c=(c2,c1,c0) */
+/* sqr_add_c(a,i,c0,c1,c2)  -- c+=a[i]^2 for three word number c=(c2,c1,c0) */
+/* sqr_add_c2(a,i,c0,c1,c2) -- c+=2*a[i]*a[j] for three word number c=(c2,c1,c0) */
+
 #ifdef BN_LLONG
 #define mul_add_c(a,b,c0,c1,c2) \
 	t=(BN_ULLONG)a*b; \
@@ -453,6 +466,34 @@ BN_ULONG bn_sub_words(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n)
 #define sqr_add_c2(a,i,j,c0,c1,c2) \
 	mul_add_c2((a)[i],(a)[j],c0,c1,c2)
 
+#elif defined(BN_UMULT_LOHI)
+
+#define mul_add_c(a,b,c0,c1,c2)	{	\
+	BN_ULONG ta=(a),tb=(b);		\
+	BN_UMULT_LOHI(t1,t2,ta,tb);	\
+	c0 += t1; t2 += (c0<t1)?1:0;	\
+	c1 += t2; c2 += (c1<t2)?1:0;	\
+	}
+
+#define mul_add_c2(a,b,c0,c1,c2) {	\
+	BN_ULONG ta=(a),tb=(b),t0;	\
+	BN_UMULT_LOHI(t0,t1,ta,tb);	\
+	t2 = t1+t1; c2 += (t2<t1)?1:0;	\
+	t1 = t0+t0; t2 += (t1<t0)?1:0;	\
+	c0 += t1; t2 += (c0<t1)?1:0;	\
+	c1 += t2; c2 += (c1<t2)?1:0;	\
+	}
+
+#define sqr_add_c(a,i,c0,c1,c2)	{	\
+	BN_ULONG ta=(a)[i];		\
+	BN_UMULT_LOHI(t1,t2,ta,ta);	\
+	c0 += t1; t2 += (c0<t1)?1:0;	\
+	c1 += t2; c2 += (c1<t2)?1:0;	\
+	}
+
+#define sqr_add_c2(a,i,j,c0,c1,c2)	\
+	mul_add_c2((a)[i],(a)[j],c0,c1,c2)
+
 #elif defined(BN_UMULT_HIGH)
 
 #define mul_add_c(a,b,c0,c1,c2)	{	\
@@ -484,7 +525,7 @@ BN_ULONG bn_sub_words(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n)
 #define sqr_add_c2(a,i,j,c0,c1,c2)	\
 	mul_add_c2((a)[i],(a)[j],c0,c1,c2)
 
-#else
+#else /* !BN_LLONG */
 #define mul_add_c(a,b,c0,c1,c2) \
 	t1=LBITS(a); t2=HBITS(a); \
 	bl=LBITS(b); bh=HBITS(b); \
@@ -511,7 +552,7 @@ BN_ULONG bn_sub_words(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n)
 
 #define sqr_add_c2(a,i,j,c0,c1,c2) \
 	mul_add_c2((a)[i],(a)[j],c0,c1,c2)
-#endif
+#endif /* !BN_LLONG */
 
 void bn_mul_comba8(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b)
 	{
@@ -667,7 +708,7 @@ void bn_mul_comba4(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b)
 	r[7]=c2;
 	}
 
-void bn_sqr_comba8(BN_ULONG *r, BN_ULONG *a)
+void bn_sqr_comba8(BN_ULONG *r, const BN_ULONG *a)
 	{
 #ifdef BN_LLONG
 	BN_ULLONG t,tt;
@@ -748,7 +789,7 @@ void bn_sqr_comba8(BN_ULONG *r, BN_ULONG *a)
 	r[15]=c1;
 	}
 
-void bn_sqr_comba4(BN_ULONG *r, BN_ULONG *a)
+void bn_sqr_comba4(BN_ULONG *r, const BN_ULONG *a)
 	{
 #ifdef BN_LLONG
 	BN_ULLONG t,tt;
@@ -786,18 +827,134 @@ void bn_sqr_comba4(BN_ULONG *r, BN_ULONG *a)
 	r[6]=c1;
 	r[7]=c2;
 	}
+
+#ifdef OPENSSL_NO_ASM
+#ifdef OPENSSL_BN_ASM_MONT
+#include <alloca.h>
+/*
+ * This is essentially reference implementation, which may or may not
+ * result in performance improvement. E.g. on IA-32 this routine was
+ * observed to give 40% faster rsa1024 private key operations and 10%
+ * faster rsa4096 ones, while on AMD64 it improves rsa1024 sign only
+ * by 10% and *worsens* rsa4096 sign by 15%. Once again, it's a
+ * reference implementation, one to be used as starting point for
+ * platform-specific assembler. Mentioned numbers apply to compiler
+ * generated code compiled with and without -DOPENSSL_BN_ASM_MONT and
+ * can vary not only from platform to platform, but even for compiler
+ * versions. Assembler vs. assembler improvement coefficients can
+ * [and are known to] differ and are to be documented elsewhere.
+ */
+int bn_mul_mont(BN_ULONG *rp, const BN_ULONG *ap, const BN_ULONG *bp, const BN_ULONG *np,const BN_ULONG *n0p, int num)
+	{
+	BN_ULONG c0,c1,ml,*tp,n0;
+#ifdef mul64
+	BN_ULONG mh;
+#endif
+	volatile BN_ULONG *vp;
+	int i=0,j;
+
+#if 0	/* template for platform-specific implementation */
+	if (ap==bp)	return bn_sqr_mont(rp,ap,np,n0p,num);
+#endif
+	vp = tp = alloca((num+2)*sizeof(BN_ULONG));
+
+	n0 = *n0p;
+
+	c0 = 0;
+	ml = bp[0];
+#ifdef mul64
+	mh = HBITS(ml);
+	ml = LBITS(ml);
+	for (j=0;j<num;++j)
+		mul(tp[j],ap[j],ml,mh,c0);
+#else
+	for (j=0;j<num;++j)
+		mul(tp[j],ap[j],ml,c0);
+#endif
+
+	tp[num]   = c0;
+	tp[num+1] = 0;
+	goto enter;
+
+	for(i=0;i<num;i++)
+		{
+		c0 = 0;
+		ml = bp[i];
+#ifdef mul64
+		mh = HBITS(ml);
+		ml = LBITS(ml);
+		for (j=0;j<num;++j)
+			mul_add(tp[j],ap[j],ml,mh,c0);
+#else
+		for (j=0;j<num;++j)
+			mul_add(tp[j],ap[j],ml,c0);
+#endif
+		c1 = (tp[num] + c0)&BN_MASK2;
+		tp[num]   = c1;
+		tp[num+1] = (c1<c0?1:0);
+	enter:
+		c1  = tp[0];
+		ml = (c1*n0)&BN_MASK2;
+		c0 = 0;
+#ifdef mul64
+		mh = HBITS(ml);
+		ml = LBITS(ml);
+		mul_add(c1,np[0],ml,mh,c0);
+#else
+		mul_add(c1,ml,np[0],c0);
+#endif
+		for(j=1;j<num;j++)
+			{
+			c1 = tp[j];
+#ifdef mul64
+			mul_add(c1,np[j],ml,mh,c0);
 #else
+			mul_add(c1,ml,np[j],c0);
+#endif
+			tp[j-1] = c1&BN_MASK2;
+			}
+		c1        = (tp[num] + c0)&BN_MASK2;
+		tp[num-1] = c1;
+		tp[num]   = tp[num+1] + (c1<c0?1:0);
+		}
+
+	if (tp[num]!=0 || tp[num-1]>=np[num-1])
+		{
+		c0 = bn_sub_words(rp,tp,np,num);
+		if (tp[num]!=0 || c0==0)
+			{
+			for(i=0;i<num+2;i++)	vp[i] = 0;
+			return 1;
+			}
+		}
+	for(i=0;i<num;i++)	rp[i] = tp[i],	vp[i] = 0;
+	vp[num]   = 0;
+	vp[num+1] = 0;
+	return 1;
+	}
+#else
+/*
+ * Return value of 0 indicates that multiplication/convolution was not
+ * performed to signal the caller to fall down to alternative/original
+ * code-path.
+ */
+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)
+{	return 0;	}
+#endif /* OPENSSL_BN_ASM_MONT */
+#endif
+
+#else /* !BN_MUL_COMBA */
 
 /* hmm... is it faster just to do a multiply? */
 #undef bn_sqr_comba4
-void bn_sqr_comba4(BN_ULONG *r, BN_ULONG *a)
+void bn_sqr_comba4(BN_ULONG *r, const BN_ULONG *a)
 	{
 	BN_ULONG t[8];
 	bn_sqr_normal(r,a,4,t);
 	}
 
 #undef bn_sqr_comba8
-void bn_sqr_comba8(BN_ULONG *r, BN_ULONG *a)
+void bn_sqr_comba8(BN_ULONG *r, const BN_ULONG *a)
 	{
 	BN_ULONG t[16];
 	bn_sqr_normal(r,a,8,t);
@@ -823,4 +980,51 @@ void bn_mul_comba8(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b)
 	r[15]=bn_mul_add_words(&(r[7]),a,8,b[7]);
 	}
 
-#endif /* BN_COMBA */
+#ifdef OPENSSL_NO_ASM
+#ifdef OPENSSL_BN_ASM_MONT
+#include <alloca.h>
+int bn_mul_mont(BN_ULONG *rp, const BN_ULONG *ap, const BN_ULONG *bp, const BN_ULONG *np,const BN_ULONG *n0p, int num)
+	{
+	BN_ULONG c0,c1,*tp,n0=*n0p;
+	volatile BN_ULONG *vp;
+	int i=0,j;
+
+	vp = tp = alloca((num+2)*sizeof(BN_ULONG));
+
+	for(i=0;i<=num;i++)	tp[i]=0;
+
+	for(i=0;i<num;i++)
+		{
+		c0         = bn_mul_add_words(tp,ap,num,bp[i]);
+		c1         = (tp[num] + c0)&BN_MASK2;
+		tp[num]    = c1;
+		tp[num+1]  = (c1<c0?1:0);
+
+		c0         = bn_mul_add_words(tp,np,num,tp[0]*n0);
+		c1         = (tp[num] + c0)&BN_MASK2;
+		tp[num]    = c1;
+		tp[num+1] += (c1<c0?1:0);
+		for(j=0;j<=num;j++)	tp[j]=tp[j+1];
+		}
+
+	if (tp[num]!=0 || tp[num-1]>=np[num-1])
+		{
+		c0 = bn_sub_words(rp,tp,np,num);
+		if (tp[num]!=0 || c0==0)
+			{
+			for(i=0;i<num+2;i++)	vp[i] = 0;
+			return 1;
+			}
+		}
+	for(i=0;i<num;i++)	rp[i] = tp[i],	vp[i] = 0;
+	vp[num]   = 0;
+	vp[num+1] = 0;
+	return 1;
+	}
+#else
+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)
+{	return 0;	}
+#endif /* OPENSSL_BN_ASM_MONT */
+#endif
+
+#endif /* !BN_MUL_COMBA */