Release 2.1.4.

[u/mdw/catacomb] / pkcs1.c

diff --git a/pkcs1.c b/pkcs1.c
index 3460467..47c135f 100644 (file)
--- a/pkcs1.c
+++ b/pkcs1.c
@@ -7,7 +7,7 @@
  * (c) 2000 Straylight/Edgeware
  */
 
-/*----- Licensing notice --------------------------------------------------* 
+/*----- Licensing notice --------------------------------------------------*
  *
  * This file is part of Catacomb.
  *
@@ -15,12 +15,12 @@
  * 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,
@@ -34,6 +34,7 @@
 #include <mLib/bits.h>
 #include <mLib/dstr.h>
 
+#include "ct.h"
 #include "grand.h"
 #include "rsa.h"
 
@@ -90,7 +91,7 @@ mp *pkcs1_cryptencode(mp *d, const void *m, size_t msz, octet *b, size_t sz,
   assert(q == b + sz);
 
   /* --- Collect the result --- */
-  
+
   return (mp_loadb(d, b, sz));
 }
 
@@ -109,24 +110,13 @@ mp *pkcs1_cryptencode(mp *d, const void *m, size_t msz, octet *b, size_t sz,
  *             in PKCS#1 v. 2.0 (RFC2437).
  */
 
-static int memeq(const void *xx, const void *yy, size_t sz)
-{
-  int eq = 1;
-  const octet *x = xx, *y = yy;
-  while (sz) {                         /* Always check every byte */
-    if (*x++ != *y++) eq = 0;
-    sz--;
-  }
-  return (eq);
-}
-
 int pkcs1_cryptdecode(mp *m, octet *b, size_t sz,
                      unsigned long nbits, void *p)
 {
   pkcs1 *pp = p;
   const octet *q, *qq;
   size_t n, i;
-  int bad = 0;
+  uint32 goodp = 1;
 
   /* --- Check the size of the block looks sane --- */
 
@@ -138,26 +128,29 @@ int pkcs1_cryptdecode(mp *m, octet *b, size_t sz,
 
   /* --- Ensure that the block looks OK --- */
 
-  bad |= (*q++ != 0x00 || *q++ != 0x02);
+  goodp &= ct_inteq(*q++, 0);
+  goodp &= ct_inteq(*q++, 2);
 
   /* --- Check the nonzero padding --- */
 
   i = 0;
   while (*q != 0 && q < qq)
     i++, q++;
-  bad |= (i < 8 || qq - q < pp->epsz + 1);
+  goodp &= ct_intle(8, i);
+  goodp &= ~ct_intle(qq - q, pp->epsz + 1);
   q++;
 
   /* --- Check the encoding parameters --- */
 
-  bad |= (pp->ep && !memeq(bad ? b : q, pp->ep, pp->epsz));
+  if (pp->ep)
+    goodp &= ct_memeq(b + ct_pick(goodp, 0, q - b), pp->ep, pp->epsz);
   q += pp->epsz;
 
   /* --- Done --- */
 
   n = qq - q;
-  memmove(b, bad ? b + 1 : q, n);
-  return (bad ? -1 : n);
+  memmove(b, b + ct_pick(goodp, 1, q - b), n);
+  return (goodp ? n : -1);
 }
 
 /* --- @pkcs1_sigencode@ --- *