X-Git-Url: https://git.distorted.org.uk/u/mdw/catacomb/blobdiff_plain/9f11b970d10c4139e1bfd0be6e817e2dfe982f41..2685767a6125c1620719c7de6234aedf41857b7e:/mp-modsqrt.c

diff --git a/mp-modsqrt.c b/mp-modsqrt.c
index a3a6b1f..6c21dc4 100644
--- a/mp-modsqrt.c
+++ b/mp-modsqrt.c
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: mp-modsqrt.c,v 1.1 2000/06/22 19:01:31 mdw Exp $
+ * $Id: mp-modsqrt.c,v 1.3 2001/02/03 12:00:29 mdw Exp $
  *
  * Compute square roots modulo a prime
  *
@@ -30,6 +30,13 @@
 /*----- Revision history --------------------------------------------------* 
  *
  * $Log: mp-modsqrt.c,v $
+ * Revision 1.3  2001/02/03 12:00:29  mdw
+ * Now @mp_drop@ checks its argument is non-NULL before attempting to free
+ * it.  Note that the macro version @MP_DROP@ doesn't do this.
+ *
+ * Revision 1.2  2000/10/08 12:02:21  mdw
+ * Use @MP_EQ@ instead of @MP_CMP@.
+ *
  * Revision 1.1  2000/06/22 19:01:31  mdw
  * Compute square roots in a prime field.
  *
@@ -75,8 +82,7 @@ mp *mp_modsqrt(mp *d, mp *a, mp *p)
   /* --- Cope if %$a \not\in Q_p$% --- */
 
   if (mp_jacobi(a, p) != 1) {
-    if (d)
-      mp_drop(d);
+    mp_drop(d);
     return (0);
   }
 
@@ -132,7 +138,7 @@ mp *mp_modsqrt(mp *d, mp *a, mp *p)
 
     /* --- Fiddle at the end --- */
 
-    if (MP_CMP(dd, ==, mone))
+    if (MP_EQ(dd, mone))
       r = mpmont_mul(&mm, r, r, c);
     c = mp_sqr(c, c);
     c = mpmont_reduce(&mm, c, c);
@@ -143,8 +149,7 @@ mp *mp_modsqrt(mp *d, mp *a, mp *p)
   d = mpmont_reduce(&mm, d, r);
   mp_drop(ainv);
   mp_drop(r); mp_drop(c);
-  if (dd)
-    mp_drop(dd);
+  mp_drop(dd);
   mp_drop(mone);
   mpmont_destroy(&mm);
 
@@ -167,11 +172,11 @@ static int verify(dstr *v)
 
   if (!r)
     ok = 0;
-  else if (MP_CMP(r, ==, rr))
+  else if (MP_EQ(r, rr))
     ok = 1;
   else {
     r = mp_sub(r, p, r);
-    if (MP_CMP(r, ==, rr))
+    if (MP_EQ(r, rr))
       ok = 1;
   }
 
@@ -191,8 +196,7 @@ static int verify(dstr *v)
 
   mp_drop(a);
   mp_drop(p);
-  if (r)
-    mp_drop(r);
+  mp_drop(r);
   mp_drop(rr);
   assert(mparena_count(MPARENA_GLOBAL) == 0);
   return (ok);