Improved ecc-mod-test with random seeding.

ChangeLog

+2015-12-18  Niels Möller  <nisse@lysator.liu.se>
+
+	* testsuite/ecc-mod-test.c (test_main): Handle random seeding if
+	NETTLE_TEST_SEED is set in the environment.
+
 2015-12-15  Niels Möller  <nisse@lysator.liu.se>
 
 	* x86_64/ecc-384-modp.asm: Fixed carry propagation bug. Problem

testsuite/ecc-mod-test.c

 #include "testutils.h"
 
+#include <errno.h>
+#include <limits.h>
+#include <sys/time.h>
+
 static void
 ref_mod (mp_limb_t *rp, const mp_limb_t *ap, const mp_limb_t *mp, mp_size_t mn)
 {
@@ -16,38 +20,49 @@ ref_mod (mp_limb_t *rp, const mp_limb_t *ap, const mp_limb_t *mp, mp_size_t mn)
 #define COUNT 50000
 
 static void
-test_modulo (gmp_randstate_t rands, const char *name,
-	     const struct ecc_modulo *m)
+test_one(const char *name,
+	 const struct ecc_modulo *m,
+	 const mpz_t r)
 {
   mp_limb_t a[MAX_SIZE];
   mp_limb_t t[MAX_SIZE];
   mp_limb_t ref[MAX_SIZE];
-  mpz_t r;
-  unsigned j;
 
-  mpz_init (r);
-  
-  for (j = 0; j < COUNT; j++)
-    {
-      if (j & 1)
-	mpz_rrandomb (r, rands, 2*m->size * GMP_NUMB_BITS);
-      else
-	mpz_urandomb (r, rands, 2*m->size * GMP_NUMB_BITS);
+  mpz_limbs_copy (a, r, 2*m->size);
 
-      mpz_limbs_copy (a, r, 2*m->size);
+  ref_mod (ref, a, m->m, m->size);
 
-      ref_mod (ref, a, m->m, m->size);
+  mpn_copyi (t, a, 2*m->size);
+  m->mod (m, t);
+  if (mpn_cmp (t, m->m, m->size) >= 0)
+    mpn_sub_n (t, t, m->m, m->size);
 
+  if (mpn_cmp (t, ref, m->size))
+    {
+      fprintf (stderr, "m->mod %s failed: bit_size = %u\n",
+	       name, m->bit_size);
+
+      fprintf (stderr, "a   = ");
+      mpn_out_str (stderr, 16, a, 2*m->size);
+      fprintf (stderr, "\nt   = ");
+      mpn_out_str (stderr, 16, t, m->size);
+      fprintf (stderr, " (bad)\nref = ");
+      mpn_out_str (stderr, 16, ref, m->size);
+      fprintf (stderr, "\n");
+      abort ();
+    }
+
+  if (m->B_size < m->size)
+    {
       mpn_copyi (t, a, 2*m->size);
-      m->mod (m, t);
+      ecc_mod (m, t);
       if (mpn_cmp (t, m->m, m->size) >= 0)
 	mpn_sub_n (t, t, m->m, m->size);
 
       if (mpn_cmp (t, ref, m->size))
 	{
-	  fprintf (stderr, "m->mod %s failed: bit_size = %u\n",
+	  fprintf (stderr, "ecc_mod %s failed: bit_size = %u\n",
 		   name, m->bit_size);
-
 	  fprintf (stderr, "a   = ");
 	  mpn_out_str (stderr, 16, a, 2*m->size);
 	  fprintf (stderr, "\nt   = ");
@@ -57,44 +72,153 @@ test_modulo (gmp_randstate_t rands, const char *name,
 	  fprintf (stderr, "\n");
 	  abort ();
 	}
+    }
+}
 
-      if (m->B_size < m->size)
+static void
+test_modulo (gmp_randstate_t rands, const char *name,
+	     const struct ecc_modulo *m, unsigned count)
+{
+  mpz_t r;
+  unsigned j;
+
+  mpz_init (r);
+
+  for (j = 0; j < count; j++)
+    {
+      if (j & 1)
+	mpz_rrandomb (r, rands, 2*m->size * GMP_NUMB_BITS);
+      else
+	mpz_urandomb (r, rands, 2*m->size * GMP_NUMB_BITS);
+
+      test_one (name, m, r);
+    }
+  mpz_clear (r);
+}
+
+static void
+test_fixed (void)
+{
+  mpz_t r;
+  mpz_init (r);
+
+  /* Triggered a bug reported by Hanno Böck. */
+  mpz_set_str (r, "FFFFFFFF00000001000000000000000000000000FFFFFFFFFFFFFFFF001C2C00", 16);
+  mpz_mul_2exp (r, r, 256);
+  test_one ("p", &nettle_secp_256r1.p, r);
+  test_one ("q", &nettle_secp_256r1.q, r);
+
+  mpz_set_str (r, "ffffffff00000001fffffffeffffffffffffffffffffffffffffffc0000000000007ffffffffffffffffffffffffffff00000000000000000fffffffffffffff", 16);
+  test_one ("p", &nettle_secp_256r1.p, r);
+  test_one ("q", &nettle_secp_256r1.q, r);
+
+  /* Triggered a bug reported by Hanno Böck. */
+  mpz_set_str (r, "4c9000000000000000000000000000000000000000000000004a604db486e000000000000000000000000000000000000000121025be29575adb2c8ffffffffffffffffffffffffffffffffffffffffffffffffffffffff", 16);
+  test_one ("p", &nettle_secp_384r1.p, r);
+  test_one ("q", &nettle_secp_384r1.q, r);
+
+  /* Triggered a carry bug in development version. */
+  mpz_set_str (r, "e64a84643150260640e4677c19ffc4faef06042132b86af6e9ee33fe1850222e57a514d5f1d6d444008bb896a96a43d5629945e57548f5e12f66be132b24110cbb2df6d7d3dd3aaadc98b0bbf29573843ad72e57f59fc5d4f56cc599da18bb99", 16);
+
+  test_one ("p", &nettle_secp_384r1.p, r);
+  test_one ("q", &nettle_secp_384r1.q, r);
+
+  mpz_clear (r);
+}
+
+static void
+test_patterns (const char *name,
+	       const struct ecc_modulo *m)
+{
+  mpz_t r;
+  unsigned j;
+
+  mpz_init (r);
+
+  for (j = m->bit_size; j < 2*m->bit_size; j++)
+    {
+      mpz_set_ui (r, 1);
+      mpz_mul_2exp (r, r, j);
+
+      test_one (name, m, r);
+    }
+  mpz_clear (r);
+}
+
+#if !NETTLE_USE_MINI_GMP
+static void
+get_random_seed(mpz_t seed)
+{
+  struct timeval tv;
+  FILE *f;
+  f = fopen ("/dev/urandom", "rb");
+  if (f)
+    {
+      uint8_t buf[8];
+      size_t res;
+
+      setbuf (f, NULL);
+      res = fread (&buf, sizeof(buf), 1, f);
+      fclose(f);
+      if (res == 1)
 	{
-	  mpn_copyi (t, a, 2*m->size);
-	  ecc_mod (m, t);
-	  if (mpn_cmp (t, m->m, m->size) >= 0)
-	    mpn_sub_n (t, t, m->m, m->size);
-
-	  if (mpn_cmp (t, ref, m->size))
-	    {
-	      fprintf (stderr, "ecc_mod %s failed: bit_size = %u\n",
-		       name, m->bit_size);
-	      fprintf (stderr, "a   = ");
-	      mpn_out_str (stderr, 16, a, 2*m->size);
-	      fprintf (stderr, "\nt   = ");
-	      mpn_out_str (stderr, 16, t, m->size);
-	      fprintf (stderr, " (bad)\nref = ");
-	      mpn_out_str (stderr, 16, ref, m->size);
-	      fprintf (stderr, "\n");
-	      abort ();
-	    }
+	  nettle_mpz_set_str_256_u (seed, sizeof(buf), buf);
+	  return;
 	}
+      fprintf (stderr, "Read of /dev/urandom failed: %s\n",
+	       strerror (errno));
     }
-  mpz_clear (r);
+  gettimeofday(&tv, NULL);
+  mpz_set_ui (seed, tv.tv_sec);
+  mpz_mul_ui (seed, seed, 1000000UL);
+  mpz_add_ui (seed, seed, tv.tv_usec);
 }
+#endif /* !NETTLE_USE_MINI_GMP */
 
 void
 test_main (void)
 {
+  const char *nettle_test_seed;
   gmp_randstate_t rands;
+  unsigned count = COUNT;
   unsigned i;
 
   gmp_randinit_default (rands);
-  
+
+  test_fixed ();
+
+  for (i = 0; ecc_curves[i]; i++)
+    {
+      test_patterns ("p", &ecc_curves[i]->p);
+      test_patterns ("q", &ecc_curves[i]->p);
+    }
+
+#if !NETTLE_USE_MINI_GMP
+  nettle_test_seed = getenv ("NETTLE_TEST_SEED");
+  if (nettle_test_seed && *nettle_test_seed)
+    {
+      mpz_t seed;
+      mpz_init (seed);
+      if (mpz_set_str (seed, nettle_test_seed, 0) < 0
+	  || mpz_sgn (seed) < 0)
+	die ("Invalid NETTLE_TEST_SEED: %s\n",
+	     nettle_test_seed);
+      if (mpz_sgn (seed) == 0)
+	get_random_seed (seed);
+      fprintf (stderr, "Using NETTLE_TEST_SEED=");
+      mpz_out_str (stderr, 10, seed);
+      fprintf (stderr, "\n");
+
+      gmp_randseed (rands, seed);
+      mpz_clear (seed);
+      count *= 20;
+    }
+#endif /* !NETTLE_USE_MINI_GMP */
+
   for (i = 0; ecc_curves[i]; i++)
     {
-      test_modulo (rands, "p", &ecc_curves[i]->p);
-      test_modulo (rands, "q", &ecc_curves[i]->q);
+      test_modulo (rands, "p", &ecc_curves[i]->p, count);
+      test_modulo (rands, "q", &ecc_curves[i]->q, count);
     }
   gmp_randclear (rands);
 }