X-Git-Url: https://git.distorted.org.uk/u/mdw/catacomb/blobdiff_plain/ba6e6b64033b1f9de49feccb5c9cd438354481f7..0f00dc4c8eb47e67bc0f148c2dd109f73a451e0a:/dh-check.c

diff --git a/dh-check.c b/dh-check.c
deleted file mode 100644
index ef07e66..0000000
--- a/dh-check.c
+++ /dev/null
@@ -1,172 +0,0 @@
-/* -*-c-*-
- *
- * $Id: dh-check.c,v 1.3 2004/04/08 01:36:15 mdw Exp $
- *
- * Checks Diffie-Hellman group parameters
- *
- * (c) 2001 Straylight/Edgeware
- */
-
-/*----- Licensing notice --------------------------------------------------*
- *
- * This file is part of Catacomb.
- *
- * Catacomb is free software; you can redistribute it and/or modify
- * it under the terms of the GNU Library General Public License as
- * published by the Free Software Foundation; either version 2 of the
- * License, or (at your option) any later version.
- *
- * Catacomb is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU Library General Public License for more details.
- *
- * You should have received a copy of the GNU Library General Public
- * License along with Catacomb; if not, write to the Free
- * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
- * MA 02111-1307, USA.
- */
-
-/*----- Header files ------------------------------------------------------*/
-
-#include <mLib/dstr.h>
-
-#include "dh.h"
-#include "keycheck.h"
-#include "mp.h"
-#include "mpmont.h"
-#include "mpmul.h"
-
-/*----- Main code ---------------------------------------------------------*/
-
-/* --- @dh_checkparam@ --- *
- *
- * Arguments:	@keycheck *kc@ = keycheck state
- *		@const dh_param *dp@ = pointer to the parameter set
- *		@mp **v@ = optional vector of factors
- *		@size_t n@ = size of vector
- *
- * Returns:	Zero if all OK, or return status from function.
- *
- * Use:		Checks a set of Diffie-Hellman parameters for consistency and
- *		security.
- */
-
-int dh_checkparam(keycheck *kc, const dh_param *dp, mp **v, size_t n)
-{
-  int rc = 0;
-  mpmont mm;
-  mp *pm1 = MP_NEW;
-  mp *q = MP_NEW;
-  mp *x;
-  mpmul mu;
-  size_t i;
-
-  /* --- Check that the numbers which are supposed to be prime are --- */
-
-  if ((!v && keycheck_prime(kc, KCSEV_WARN, dp->q, "q")) ||
-      keycheck_prime(kc, KCSEV_ERR, dp->p, "p"))
-    goto fail;
-
-  /* --- Ensure that %$q$% is a sensible choice of number --- */
-
-  pm1 = mp_sub(pm1, dp->p, MP_ONE);
-  mp_div(0, &q, pm1, dp->q);
-  if (!mp_eq(q, MP_ZERO) &&
-      keycheck_report(kc, KCSEV_ERR, "q not a factor of p - 1"))
-    goto fail;
-
-  /* --- Check that %$g$% is actually right --- *
-   *
-   * This isn't perfect.  If %$q$% is composite and we don't have the factors
-   * of %$p - 1$% then the order of %$g$% may be some factor of %$q$% which
-   * we can't find.  (If we do have the factors, we check them all lower
-   * down.)  We do strip out powers of two from %$q$% before testing, though.
-   */
-
-  if ((mp_eq(dp->g, MP_ONE) || mp_eq(dp->g, pm1)) &&
-      keycheck_report(kc, KCSEV_ERR, "g is degenerate (+/-1 mod p)"))
-    goto fail;
-  q = mp_odd(q, dp->q, &i);
-  mpmont_create(&mm, dp->p);
-  x = mpmont_mul(&mm, MP_NEW, dp->g, mm.r2);
-  q = mpmont_expr(&mm, q, x, q);
-  mp_drop(x);
-  do {
-    if (mp_eq(q, mm.r) != !i) {
-      if (keycheck_report(kc, KCSEV_ERR, "order of g != q")) {
-	mpmont_destroy(&mm);
-	goto fail;
-      }
-      break;
-    }
-    if (i) {
-      q = mp_sqr(q, q);
-      q = mpmont_reduce(&mm, q, q);
-    }
-  } while (i--);
-
-  /* --- Check Lim-Lee primes more carefully --- *
-   *
-   * In this case, we really can be sure whether the order of %$g$% is
-   * actually %$q$% as advertised.  Also ensure that the individual primes
-   * are really prime, and that their product is correct.
-   */
-
-  if (!v)
-    mpmont_destroy(&mm);
-  else {
-    dstr d = DSTR_INIT;
-    mp *r = MP_NEW;
-
-    mpmul_init(&mu);
-    for (i = 0; i < n; i++) {
-      DRESET(&d);
-      dstr_putf(&d, "factor f_%lu of p", (unsigned long)i);
-      if ((rc = keycheck_prime(kc, KCSEV_ERR, v[i], d.buf)) != 0)
-	break;
-      mp_div(&q, &r, dp->q, v[i]);
-      if (mp_eq(r, MP_ZERO) && !mp_eq(q, MP_ONE)) {
-	q = mpmont_exp(&mm, q, dp->g, q);
-	if (mp_eq(q, MP_ONE) &&
-	    (rc = keycheck_report(kc, KCSEV_ERR,
-				  "order of g is proper divisor of q")) != 0)
-	  break;
-      }
-      mpmul_add(&mu, v[i]);
-    }
-    mp_drop(q);
-    mp_drop(r);
-    q = mpmul_done(&mu);
-    mpmont_destroy(&mm);
-    dstr_destroy(&d);
-    if (rc)
-      goto fail;
-    q = mp_lsl(q, q, 1);
-    if (!mp_eq(q, pm1) &&
-	keycheck_report(kc, KCSEV_ERR, "product of f_i != (p - 1)/2"))
-      goto fail;
-  }
-
-  /* --- Finally, check the key sizes --- */
-
-  if ((mp_bits(dp->p) < 1024 &&
-       keycheck_report(kc, KCSEV_WARN,
-		       "p too small to resist index calculus attacks")) ||
-      (mp_bits(dp->q) < 160 &&
-       keycheck_report(kc, KCSEV_WARN,
-		       "q too small to resist collision-finding attacks")))
-    goto fail;
-
-  /* --- Done --- */
-
-tidy:
-  mp_drop(q);
-  mp_drop(pm1);
-  return (rc);
-fail:
-  rc = -1;
-  goto tidy;
-}
-
-/*----- That's all, folks -------------------------------------------------*/