/* -*-c-*-
*
- * $Id: ec-info.c,v 1.4 2004/04/03 03:32:05 mdw Exp $
+ * $Id$
*
* Elliptic curve information management
*
* MA 02111-1307, USA.
*/
-/*----- Revision history --------------------------------------------------*
- *
- * $Log: ec-info.c,v $
- * Revision 1.4 2004/04/03 03:32:05 mdw
- * General robustification.
- *
- * Revision 1.3 2004/04/01 21:28:41 mdw
- * Normal basis support (translates to poly basis internally). Rewrite
- * EC and prime group table generators in awk, so that they can reuse data
- * for repeated constants.
- *
- * Revision 1.2 2004/04/01 12:50:09 mdw
- * Add cyclic group abstraction, with test code. Separate off exponentation
- * functions for better static linking. Fix a buttload of bugs on the way.
- * Generally ensure that negative exponents do inversion correctly. Add
- * table of standard prime-field subgroups. (Binary field subgroups are
- * currently unimplemented but easy to add if anyone ever finds a good one.)
- *
- * Revision 1.1 2004/03/27 17:54:11 mdw
- * Standard curves and curve checking.
- *
- */
-
/*----- Header files ------------------------------------------------------*/
#include "ec.h"
#include "gf.h"
#include "pgen.h"
#include "mprand.h"
+#include "mpint.h"
#include "rabin.h"
/*----- Main code ---------------------------------------------------------*/
return (0);
}
-/* --- @getinfo@ --- *
+/* --- @ec_infofromdata@ --- *
*
* Arguments: @ec_info *ei@ = where to write the information
* @ecdata *ed@ = raw data
* curves.
*/
-static void getinfo(ec_info *ei, ecdata *ed)
+void ec_infofromdata(ec_info *ei, ecdata *ed)
{
field *f;
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;
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)
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
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);
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");
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
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);
#include "fibrand.h"
-int main(void)
+int main(int argc, char *argv[])
{
const ecentry *ee;
const char *e;
int ok = 1;
+ int i;
grand *gr;
gr = fibrand_create(0);
- fputs("checking standard curves: ", stdout);
- for (ee = ectab; ee->name; ee++) {
- ec_info ei;
- 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);
- ok = 0;
+ if (argc > 1) {
+ for (i = 1; i < argc; i++) {
+ ec_info ei;
+ if ((e = ec_getinfo(&ei, argv[i])) != 0)
+ fprintf(stderr, "bad curve spec `%s': %s", argv[i], e);
+ else {
+ e = ec_checkinfo(&ei, gr);
+ ec_freeinfo(&ei);
+ if (!e)
+ printf("OK %s\n", argv[i]);
+ else {
+ printf("BAD %s: %s\n", argv[i], e);
+ ok = 0;
+ }
+ }
}
- putchar('.');
+ } else {
+ fputs("checking standard curves:", stdout);
fflush(stdout);
+ for (ee = ectab; ee->name; ee++) {
+ ec_info ei;
+ ec_infofromdata(&ei, ee->data);
+ e = ec_checkinfo(&ei, gr);
+ ec_freeinfo(&ei);
+ if (e) {
+ printf(" [%s fails: %s]", ee->name, e);
+ ok = 0;
+ } else
+ printf(" %s", ee->name);
+ fflush(stdout);
+ }
+ fputs(ok ? " ok\n" : " failed\n", stdout);
}
gr->ops->destroy(gr);
- fputs(ok ? " ok\n" : " failed\n", stdout);
return (!ok);
}