X-Git-Url: https://git.distorted.org.uk/u/mdw/catacomb/blobdiff_plain/53cbeae3058cdebd54bf9a6c18d9f46ee52f0595..025c5f4aa5ffbf8948482a4233318db81c2df5d2:/ec-info.c

diff --git a/ec-info.c b/ec-info.c
index cf65584..925ff07 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 ---------------------------------------------------------*/
@@ -163,7 +164,7 @@ fail:
   return (0);
 }
 
-/* --- @getinfo@ --- *
+/* --- @ec_infofromdata@ --- *
  *
  * Arguments:	@ec_info *ei@ = where to write the information
  *		@ecdata *ed@ = raw data
@@ -174,7 +175,7 @@ fail:
  *		curves.
  */
 
-static void getinfo(ec_info *ei, ecdata *ed)
+void ec_infofromdata(ec_info *ei, ecdata *ed)
 {
   field *f;
 
@@ -233,8 +234,12 @@ int ec_infoparse(qd_parse *qd, ec_info *ei)
   const ecentry *ee;
   mp *r = MP_NEW, *h = MP_NEW;
 
-  for (ee = ectab; ee->name; ee++)
-    if (qd_enum(qd, ee->name) >= 0) { getinfo(ei, ee->data); goto found; }
+  for (ee = ectab; ee->name; ee++) {
+    if (qd_enum(qd, ee->name) >= 0) {
+      ec_infofromdata(ei, ee->data);
+      goto found;
+    }
+  }  
 
   if ((c = ec_curveparse(qd)) == 0) goto fail;
   qd_delim(qd, '/'); if (!ec_ptparse(qd, &g)) goto fail;
@@ -325,7 +330,7 @@ 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 +377,6 @@ 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 +421,11 @@ 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 +440,13 @@ 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 +471,6 @@ 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 +512,11 @@ 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);
@@ -551,17 +563,18 @@ int main(int argc, char *argv[])
       }
     }
   } else {
-    fputs("checking standard curves: ", stdout);
+    fputs("checking standard curves:", stdout);
+    fflush(stdout);
     for (ee = ectab; ee->name; ee++) {
       ec_info ei;
-      getinfo(&ei, ee->data);
+      ec_infofromdata(&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("  [%s fails: %s]", ee->name, e);
 	ok = 0;
-      }
-      putchar('.');
+      } else
+	printf(" %s", ee->name);
       fflush(stdout);
     }
     fputs(ok ? " ok\n" : " failed\n", stdout);