X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=crypto%2Fbn%2Fbn_word.c;h=ee7b87c45ccd38839db6261ed81c2d87b9e881b5;hb=9b4eab501a52c8bdc19a8a002e1f9d4d7ad6f4c4;hp=b61ddd95cebd836b673b3654028f38f18d29000d;hpb=d02b48c63a58ea4367a0e905979f140b7d090f86;p=oweals%2Fopenssl.git

diff --git a/crypto/bn/bn_word.c b/crypto/bn/bn_word.c
index b61ddd95ce..ee7b87c45c 100644
--- a/crypto/bn/bn_word.c
+++ b/crypto/bn/bn_word.c
@@ -1,5 +1,5 @@
 /* crypto/bn/bn_word.c */
-/* Copyright (C) 1995-1997 Eric Young (eay@cryptsoft.com)
+/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
  * This package is an SSL implementation written
@@ -60,9 +60,7 @@
 #include "cryptlib.h"
 #include "bn_lcl.h"
 
-BN_ULONG BN_mod_word(a, w)
-BIGNUM *a;
-unsigned long w;
+BN_ULONG BN_mod_word(const BIGNUM *a, BN_ULONG w)
 	{
 #ifndef BN_LLONG
 	BN_ULONG ret=0;
@@ -71,11 +69,16 @@ unsigned long w;
 #endif
 	int i;
 
+	if (w == 0)
+		return (BN_ULONG)-1;
+
+	bn_check_top(a);
+	w&=BN_MASK2;
 	for (i=a->top-1; i>=0; i--)
 		{
 #ifndef BN_LLONG
-		ret=((ret<<BN_BITS4)|((a->d[i]>>BN_BITS4)&BN_MASK2l))%(int)w;
-		ret=((ret<<BN_BITS4)|(a->d[i]&BN_MASK2l))%(int)w;
+		ret=((ret<<BN_BITS4)|((a->d[i]>>BN_BITS4)&BN_MASK2l))%w;
+		ret=((ret<<BN_BITS4)|(a->d[i]&BN_MASK2l))%w;
 #else
 		ret=(BN_ULLONG)(((ret<<(BN_ULLONG)BN_BITS2)|a->d[i])%
 			(BN_ULLONG)w);
@@ -84,45 +87,74 @@ unsigned long w;
 	return((BN_ULONG)ret);
 	}
 
-BN_ULONG BN_div_word(a, w)
-BIGNUM *a;
-unsigned long w;
+BN_ULONG BN_div_word(BIGNUM *a, BN_ULONG w)
 	{
-	BN_ULONG ret;
-	int i;
+	BN_ULONG ret = 0;
+	int i, j;
+
+	bn_check_top(a);
+	w &= BN_MASK2;
+
+	if (!w)
+		/* actually this an error (division by zero) */
+		return (BN_ULONG)-1;
+	if (a->top == 0)
+		return 0;
+
+	/* normalize input (so bn_div_words doesn't complain) */
+	j = BN_BITS2 - BN_num_bits_word(w);
+	w <<= j;
+	if (!BN_lshift(a, a, j))
+		return (BN_ULONG)-1;
 
-	if (a->top == 0) return(0);
-	ret=0;
 	for (i=a->top-1; i>=0; i--)
 		{
-#ifndef BN_LLONG
-		ret=((ret<<BN_BITS4)|((a->d[i]>>BN_BITS4)&BN_MASK2l))%(int)w;
-		ret=((ret<<BN_BITS4)|(a->d[i]&BN_MASK2l))%(int)w;
-#else
-		BN_ULLONG ll;
-
-		ll=((BN_ULLONG)ret<<(BN_ULONG)BN_BITS2)|a->d[i];
-		a->d[i]=(BN_ULONG)(ll/w);
-		ret=(BN_ULONG)(ll%w);
-#endif
+		BN_ULONG l,d;
+		
+		l=a->d[i];
+		d=bn_div_words(ret,l,w);
+		ret=(l-((d*w)&BN_MASK2))&BN_MASK2;
+		a->d[i]=d;
 		}
-	if (a->d[a->top-1] == 0)
+	if ((a->top > 0) && (a->d[a->top-1] == 0))
 		a->top--;
+	ret >>= j;
+	bn_check_top(a);
 	return(ret);
 	}
 
-int BN_add_word(a, w)
-BIGNUM *a;
-unsigned long w;
+int BN_add_word(BIGNUM *a, BN_ULONG w)
 	{
 	BN_ULONG l;
 	int i;
 
-	if (bn_expand(a,a->top*BN_BITS2+1) == NULL) return(0);
+	bn_check_top(a);
+	w &= BN_MASK2;
+
+	/* degenerate case: w is zero */
+	if (!w) return 1;
+	/* degenerate case: a is zero */
+	if(BN_is_zero(a)) return BN_set_word(a, w);
+	/* handle 'a' when negative */
+	if (a->neg)
+		{
+		a->neg=0;
+		i=BN_sub_word(a,w);
+		if (!BN_is_zero(a))
+			a->neg=!(a->neg);
+		return(i);
+		}
+	/* Only expand (and risk failing) if it's possibly necessary */
+	if (((BN_ULONG)(a->d[a->top - 1] + 1) == 0) &&
+			(bn_wexpand(a,a->top+1) == NULL))
+		return(0);
 	i=0;
 	for (;;)
 		{
-		l=(a->d[i]+(BN_ULONG)w)&BN_MASK2;
+		if (i >= a->top)
+			l=w;
+		else
+			l=(a->d[i]+w)&BN_MASK2;
 		a->d[i]=l;
 		if (w > l)
 			w=1;
@@ -132,24 +164,84 @@ unsigned long w;
 		}
 	if (i >= a->top)
 		a->top++;
+	bn_check_top(a);
 	return(1);
 	}
 
-#ifdef undef
-BN_ULONG *BN_mod_inverse_word(a)
-BN_ULONG a;
+int BN_sub_word(BIGNUM *a, BN_ULONG w)
 	{
-	BN_ULONG A,B,X,Y,M,D,R,RET,T;
-	int sign,hight=1;
+	int i;
 
-	X=0;
-	Y=1;
-	A=0;
-	B=a;
-	sign=1;
+	bn_check_top(a);
+	w &= BN_MASK2;
 
-	while (B != 0)
+	/* degenerate case: w is zero */
+	if (!w) return 1;
+	/* degenerate case: a is zero */
+	if(BN_is_zero(a))
 		{
+		i = BN_set_word(a,w);
+		if (i != 0)
+			BN_set_negative(a, 1);
+		return i;
+		}
+	/* handle 'a' when negative */
+	if (a->neg)
+		{
+		a->neg=0;
+		i=BN_add_word(a,w);
+		a->neg=1;
+		return(i);
+		}
 
-#endif
+	if ((a->top == 1) && (a->d[0] < w))
+		{
+		a->d[0]=w-a->d[0];
+		a->neg=1;
+		return(1);
+		}
+	i=0;
+	for (;;)
+		{
+		if (a->d[i] >= w)
+			{
+			a->d[i]-=w;
+			break;
+			}
+		else
+			{
+			a->d[i]=(a->d[i]-w)&BN_MASK2;
+			i++;
+			w=1;
+			}
+		}
+	if ((a->d[i] == 0) && (i == (a->top-1)))
+		a->top--;
+	bn_check_top(a);
+	return(1);
+	}
+
+int BN_mul_word(BIGNUM *a, BN_ULONG w)
+	{
+	BN_ULONG ll;
+
+	bn_check_top(a);
+	w&=BN_MASK2;
+	if (a->top)
+		{
+		if (w == 0)
+			BN_zero(a);
+		else
+			{
+			ll=bn_mul_words(a->d,a->d,a->top,w);
+			if (ll)
+				{
+				if (bn_wexpand(a,a->top+1) == NULL) return(0);
+				a->d[a->top++]=ll;
+				}
+			}
+		}
+	bn_check_top(a);
+	return(1);
+	}