There's a slight possibility that a is 0 in BN_sub_word(), and might

[openssl.git] / crypto / bn / bn_word.c

diff --git a/crypto/bn/bn_word.c b/crypto/bn/bn_word.c
index 4b3d0f011d20e44fa7872421f6422369f1abece3..f3bdde969cc376a9344b9d58c6d8c6a97766bcd6 100644 (file)
--- a/crypto/bn/bn_word.c
+++ b/crypto/bn/bn_word.c
@@ -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;
@@ -75,8 +73,8 @@ unsigned long w;
        for (i=a->top-1; i>=0; i--)
                {
 #ifndef BN_LLONG
-               ret=((ret<<BN_BITS4)|((a->d[i]>>BN_BITS4)&BN_MASK2l))%(unsigned long)w;
-               ret=((ret<<BN_BITS4)|(a->d[i]&BN_MASK2l))%(unsigned long)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);
@@ -85,9 +83,7 @@ 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;
@@ -100,18 +96,16 @@ unsigned long w;
                BN_ULONG l,d;
                
                l=a->d[i];
-               d=bn_div64(ret,l,w);
+               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--;
        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;
@@ -121,7 +115,7 @@ unsigned long w;
                a->neg=0;
                i=BN_sub_word(a,w);
                if (!BN_is_zero(a))
-                       a->neg=1;
+                       a->neg=!(a->neg);
                return(i);
                }
        w&=BN_MASK2;
@@ -142,13 +136,11 @@ unsigned long w;
        return(1);
        }
 
-int BN_sub_word(a, w)
-BIGNUM *a;
-unsigned long w;
+int BN_sub_word(BIGNUM *a, BN_ULONG w)
        {
        int i;
 
-       if (a->neg)
+       if (BN_is_zero(a) || a->neg)
                {
                a->neg=0;
                i=BN_add_word(a,w);
@@ -183,9 +175,7 @@ unsigned long w;
        return(1);
        }
 
-int BN_mul_word(a,w)
-BIGNUM *a;
-unsigned long w;
+int BN_mul_word(BIGNUM *a, BN_ULONG w)
        {
        BN_ULONG ll;
 
@@ -199,6 +189,6 @@ unsigned long w;
                        a->d[a->top++]=ll;
                        }
                }
-       return(0);
+       return(1);
        }