stuff

[oweals/gnunet.git] / src / util / crypto_ksk.c

diff --git a/src/util/crypto_ksk.c b/src/util/crypto_ksk.c
index 3c4830b76d56d7392de5df940015f57f217f4106..b44c8e992beed5a97809a3a49fb2e387297d1f67 100644 (file)
--- a/src/util/crypto_ksk.c
+++ b/src/util/crypto_ksk.c
@@ -87,14 +87,17 @@ mpz_randomize (gcry_mpi_t n, unsigned int nbits, GNUNET_HashCode * rnd)
 
       if (i > 0)
        GNUNET_CRYPTO_hash (&hc, sizeof (GNUNET_HashCode), &tmp);
-      for (j = sizeof(GNUNET_HashCode) / sizeof(unsigned int); j > 0; j--)
+      fprintf (stderr, "H: %s\n", GNUNET_h2s (&tmp));
+
+      for (j=0;j<sizeof(GNUNET_HashCode) / sizeof(uint32_t); j++)
         {
-#if HAVE_GCRY_MPI_LSHIFT
-          gcry_mpi_lshift (n, n, sizeof(unsigned int));
+#if HAVE_GCRY_MPI_LSHIFT 
+          gcry_mpi_lshift (n, n, sizeof(uint32_t)*8);
 #else
-          gcry_mpi_mul_ui(n, n, pow (2, sizeof(unsigned int)));
+         gcry_mpi_mul_ui(n, n, 1 << (sizeof(uint32_t)*4));
+         gcry_mpi_mul_ui(n, n, 1 << (sizeof(uint32_t)*4));
 #endif
-          gcry_mpi_add_ui(n, n, ((unsigned int *) &tmp)[j]);
+          gcry_mpi_add_ui(n, n, ntohl (((uint32_t *) &tmp)[j]));
         }
       hc = tmp;
     }
@@ -198,6 +201,22 @@ leave:
   return rc;
 }
 
+/**
+ * If target != size, move target bytes to the
+ * end of the size-sized buffer and zero out the
+ * first target-size bytes.
+ */
+static void
+adjust (unsigned char *buf, size_t size, size_t target)
+{
+  if (size < target)
+    {
+      memmove (&buf[target - size], buf, size);
+      memset (buf, 0, target - size);
+    }
+}
+
+
 static void
 gen_prime (gcry_mpi_t *ptest, unsigned int nbits, GNUNET_HashCode * hc)
 {
@@ -289,22 +308,23 @@ gen_prime (gcry_mpi_t *ptest, unsigned int nbits, GNUNET_HashCode * hc)
   static int no_of_small_prime_numbers = DIM (small_prime_numbers) - 1;
 
   gcry_mpi_t prime, pminus1, val_2, val_3, result;
-  int i;
-  unsigned x, step;
-  unsigned int *mods;
+  unsigned int i;
+  unsigned int step;
+  unsigned int mods[no_of_small_prime_numbers];
   gcry_mpi_t tmp;
   gcry_mpi_t sp;
 
   GNUNET_assert (nbits >= 16);
 
-  mods = GNUNET_malloc (no_of_small_prime_numbers * sizeof (*mods));
   /* Make nbits fit into mpz_t implementation. */
   val_2 = gcry_mpi_set_ui (NULL, 2);
   val_3 = gcry_mpi_set_ui (NULL, 3);
-  prime = gcry_mpi_new(0);
+  prime = gcry_mpi_snew(0);
   result = gcry_mpi_new(0);
   pminus1 = gcry_mpi_new(0);
   *ptest = gcry_mpi_new(0);
+  tmp = gcry_mpi_new (0);
+  sp = gcry_mpi_new (0);
   while (1)
     {
       /* generate a random number */
@@ -318,31 +338,34 @@ gen_prime (gcry_mpi_t *ptest, unsigned int nbits, GNUNET_HashCode * hc)
       gcry_mpi_set_bit (prime, 0);
 
       /* Calculate all remainders. */
-      tmp = gcry_mpi_new (0);
-      sp = gcry_mpi_new (0);
-      for (i = 0; (x = small_prime_numbers[i]); i++)
+      for (i = 0; i < no_of_small_prime_numbers; i++)
         {
           size_t written;
 
-          gcry_mpi_set_ui(sp, x);
+          gcry_mpi_set_ui(sp, small_prime_numbers[i]);
           gcry_mpi_div (NULL, tmp, prime, sp, -1);
          mods[i] = 0;
-          gcry_mpi_print (GCRYMPI_FMT_USG, (unsigned char *) &mods[i], sizeof(*mods), &written, tmp);
-        }
-      gcry_mpi_release (sp);
-      gcry_mpi_release (tmp);
+         written = sizeof (unsigned int);
+          GNUNET_assert (0 ==
+                        gcry_mpi_print (GCRYMPI_FMT_USG, 
+                                        (unsigned char*) &mods[i], written, &written, 
+                                        tmp));
+         adjust ( (unsigned char*) &mods[i], written, sizeof (unsigned int));
+         mods[i] = ntohl (mods[i]);
+       }
       /* Now try some primes starting with prime. */
       for (step = 0; step < 20000; step += 2)
         {
           /* Check against all the small primes we have in mods. */
-          for (i = 0; (x = small_prime_numbers[i]); i++)
+          for (i = 0; i < no_of_small_prime_numbers; i++)
             {
+             uint16_t x = small_prime_numbers[i];
               while (mods[i] + step >= x)
                 mods[i] -= x;
               if (!(mods[i] + step))
                 break;
             }
-          if (x)
+          if (i < no_of_small_prime_numbers)
             continue;           /* Found a multiple of an already known prime. */
 
           gcry_mpi_add_ui (*ptest, prime, step);
@@ -355,12 +378,13 @@ gen_prime (gcry_mpi_t *ptest, unsigned int nbits, GNUNET_HashCode * hc)
           if ((!gcry_mpi_cmp_ui (result, 1)) && (is_prime (*ptest, 5, hc)))
             {
               /* Got it. */
+             gcry_mpi_release (sp);
+             gcry_mpi_release (tmp);
               gcry_mpi_release (val_2);
               gcry_mpi_release (val_3);
               gcry_mpi_release (result);
               gcry_mpi_release (pminus1);
               gcry_mpi_release (prime);
-              GNUNET_free (mods);
               return;
             }
         }