Simplify BN_cmp() and BN_ucmp().

The only real difference between BN_cmp() and BN_ucmp() is that one has
to respect the sign of the BN (although BN_cmp() also gets to deal with
some insanity from accepting NULLs). Rewrite/cleanup BN_ucmp() and turn
BN_cmp() into code that handles differences in sign, before calling
BN_ucmp().

ok tb@

diff --git a/lib/libcrypto/bn/bn_lib.c b/lib/libcrypto/bn/bn_lib.c
index c47f2fa..eed7377 100644 (file)
--- a/lib/libcrypto/bn/bn_lib.c
+++ b/lib/libcrypto/bn/bn_lib.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: bn_lib.c,v 1.67 2022/12/17 15:56:25 jsing Exp $ */
+/* $OpenBSD: bn_lib.c,v 1.68 2022/12/23 03:15:35 jsing Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -695,69 +695,38 @@ int
 BN_ucmp(const BIGNUM *a, const BIGNUM *b)
 {
        int i;
-       BN_ULONG t1, t2, *ap, *bp;
-
 
        if (a->top < b->top)
                return -1;
        if (a->top > b->top)
                return 1;
 
-       ap = a->d;
-       bp = b->d;
        for (i = a->top - 1; i >= 0; i--) {
-               t1 = ap[i];
-               t2 = bp[i];
-               if (t1 != t2)
-                       return ((t1 > t2) ? 1 : -1);
+               if (a->d[i] != b->d[i])
+                       return (a->d[i] > b->d[i] ? 1 : -1);
        }
-       return (0);
+
+       return 0;
 }
 
 int
 BN_cmp(const BIGNUM *a, const BIGNUM *b)
 {
-       int i;
-       int gt, lt;
-       BN_ULONG t1, t2;
-
-       if ((a == NULL) || (b == NULL)) {
+       if (a == NULL || b == NULL) {
                if (a != NULL)
-                       return (-1);
-               else if (b != NULL)
-                       return (1);
-               else
-                       return (0);
+                       return -1;
+               if (b != NULL)
+                       return 1;
+               return 0;
        }
 
+       if (a->neg != b->neg)
+               return b->neg - a->neg;
 
-       if (a->neg != b->neg) {
-               if (a->neg)
-                       return (-1);
-               else
-                       return (1);
-       }
-       if (a->neg == 0) {
-               gt = 1;
-               lt = -1;
-       } else {
-               gt = -1;
-               lt = 1;
-       }
+       if (a->neg)
+               return BN_ucmp(b, a);
 
-       if (a->top > b->top)
-               return (gt);
-       if (a->top < b->top)
-               return (lt);
-       for (i = a->top - 1; i >= 0; i--) {
-               t1 = a->d[i];
-               t2 = b->d[i];
-               if (t1 > t2)
-                       return (gt);
-               if (t1 < t2)
-                       return (lt);
-       }
-       return (0);
+       return BN_ucmp(a, b);
 }
 
 int