X-Git-Url: https://git.distorted.org.uk/u/mdw/catacomb/blobdiff_plain/53cbeae3058cdebd54bf9a6c18d9f46ee52f0595..389d822217b802003674d2085b3b902cbe13cf25:/ec-info.c

diff --git a/ec-info.c b/ec-info.c
index cf65584..bf9607c 100644
--- a/ec-info.c
+++ b/ec-info.c
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: ec-info.c,v 1.6 2004/04/08 16:17:32 mdw Exp $
+ * $Id$
  *
  * Elliptic curve information management
  *
@@ -34,6 +34,7 @@
 #include "gf.h"
 #include "pgen.h"
 #include "mprand.h"
+#include "mpint.h"
 #include "rabin.h"
 
 /*----- Main code ---------------------------------------------------------*/
@@ -325,7 +326,7 @@ void ec_freeinfo(ec_info *ei)
 
 static int primeeltp(mp *x, field *f)
 {
-  return (!MP_ISNEG(x) && MP_CMP(x, <, f->m));
+  return (!MP_NEGP(x) && MP_CMP(x, <, f->m));
 }
 
 static const char *primecheck(const ec_info *ei, grand *gr)
@@ -372,11 +373,6 @@ static const char *primecheck(const ec_info *ei, grand *gr)
 
   if (!pgen_primep(ei->r, gr)) return ("generator order not prime");
 
-  /* --- Check %$0 < h \le 4$% --- */
-
-  if (MP_CMP(ei->h, <, MP_ONE) || MP_CMP(ei->h, >, MP_FOUR))
-    return ("cofactor out of range");
-
   /* --- Check %$h = \lfloor (\sqrt{p} + 1)^2/r \rlfoor$% --- *
    *
    * This seems to work with the approximate-sqrt in the library, but might
@@ -421,6 +417,11 @@ static const char *primecheck(const ec_info *ei, grand *gr)
   MP_DROP(x);
   if (i) return ("curve is weak");
 
+  /* --- Check %$0 < h \le 4$% --- */
+
+  if (MP_CMP(ei->h, <, MP_ONE) || MP_CMP(ei->h, >, MP_FOUR))
+    return ("cofactor out of range");
+
   /* --- Done --- */
 
   return (0);
@@ -435,6 +436,13 @@ static const char *bincheck(const ec_info *ei, grand *gr)
   ec p;
   int rc;
 
+  /* --- Check that %$m$% is prime --- */
+
+  x = mp_fromuint(MP_NEW, f->nbits);
+  rc = pfilt_smallfactor(x);
+  mp_drop(x);
+  if (rc != PGEN_DONE) return ("degree not prime");
+
   /* --- Check that %$p$% is irreducible --- */
 
   if (!gf_irreduciblep(f->m)) return ("p not irreducible");
@@ -459,11 +467,6 @@ static const char *bincheck(const ec_info *ei, grand *gr)
 
   if (!pgen_primep(ei->r, gr)) return ("generator order not prime");
 
-  /* --- Check %$0 < h \le 4$% --- */
-
-  if (MP_CMP(ei->h, <, MP_ONE) || MP_CMP(ei->h, >, MP_FOUR))
-    return ("cofactor out of range");
-
   /* --- Check %$h = \lfloor (\sqrt{2^m} + 1)^2/r \rlfoor$% --- *
    *
    * This seems to work with the approximate-sqrt in the library, but might
@@ -505,6 +508,11 @@ static const char *bincheck(const ec_info *ei, grand *gr)
   MP_DROP(x);
   if (i) return ("curve is weak");
 
+  /* --- Check %$0 < h \le 4$% --- */
+
+  if (MP_CMP(ei->h, <, MP_ONE) || MP_CMP(ei->h, >, MP_FOUR))
+    return ("cofactor out of range");
+
   /* --- Done --- */
 
   return (0);
@@ -551,20 +559,23 @@ int main(int argc, char *argv[])
       }
     }
   } else {
-    fputs("checking standard curves: ", stdout);
+    fputs("checking standard curves...\n", stdout);
     for (ee = ectab; ee->name; ee++) {
       ec_info ei;
+      printf("  %s: ", ee->name);
+      fflush(stdout);
       getinfo(&ei, ee->data);
       e = ec_checkinfo(&ei, gr);
       ec_freeinfo(&ei);
       if (e) {
-	fprintf(stderr, "\n*** curve %s fails: %s\n", ee->name, e);
+	printf("fails: %s\n", e);
 	ok = 0;
-      }
-      putchar('.');
+      } else
+	fputs("ok\n", stdout);
       fflush(stdout);
     }
-    fputs(ok ? " ok\n" : " failed\n", stdout);
+    if (ok)
+      fputs("all ok\n", stdout);
   }
   gr->ops->destroy(gr);
   return (!ok);