Fix for BN_mul_word(a, 0).

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

diff --git a/crypto/bn/bn_word.c b/crypto/bn/bn_word.c
index 9c168e4f48a1777986780dfa780a1b10b115463f..cd59baa2c4902910f34a0268627512a24e839f0e 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;
-BN_ULONG w;
+BN_ULONG BN_mod_word(const BIGNUM *a, BN_ULONG w)
        {
 #ifndef BN_LLONG
        BN_ULONG ret=0;
@@ -85,9 +83,7 @@ BN_ULONG w;
        return((BN_ULONG)ret);
        }
 
-BN_ULONG BN_div_word(a, w)
-BIGNUM *a;
-BN_ULONG w;
+BN_ULONG BN_div_word(BIGNUM *a, BN_ULONG w)
        {
        BN_ULONG ret;
        int i;
@@ -109,9 +105,7 @@ BN_ULONG w;
        return(ret);
        }
 
-int BN_add_word(a, w)
-BIGNUM *a;
-BN_ULONG w;
+int BN_add_word(BIGNUM *a, BN_ULONG w)
        {
        BN_ULONG l;
        int i;
@@ -121,7 +115,7 @@ BN_ULONG 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 @@ BN_ULONG w;
        return(1);
        }
 
-int BN_sub_word(a, w)
-BIGNUM *a;
-BN_ULONG 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);
@@ -183,20 +175,23 @@ BN_ULONG w;
        return(1);
        }
 
-int BN_mul_word(a,w)
-BIGNUM *a;
-BN_ULONG w;
+int BN_mul_word(BIGNUM *a, BN_ULONG w)
        {
        BN_ULONG ll;
 
        w&=BN_MASK2;
        if (a->top)
                {
-               ll=bn_mul_words(a->d,a->d,a->top,w);
-               if (ll)
+               if (w == 0)
+                       BN_zero(a);
+               else
                        {
-                       if (bn_wexpand(a,a->top+1) == NULL) return(0);
-                       a->d[a->top++]=ll;
+                       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;
+                               }
                        }
                }
        return(1);