Tests for eddsa compression and decompression.

ChangeLog

 2014-10-02  Niels Möller  <nisse@lysator.liu.se>
 
+	* testsuite/eddsa-compress-test.c: New testcase.
+	* testsuite/Makefile.in (TS_HOGWEED_SOURCES): Added
+	eddsa-compress-test.c.
+
 	* eddsa-decompress.c (_eddsa_decompress): New file, new function.
 	* eddsa-compress.c (_eddsa_compress): New file, new function.
 	* eddsa.h: New file.

testsuite/.test-rules.make

@@ -226,6 +226,9 @@ ecdsa-keygen-test$(EXEEXT): ecdsa-keygen-test.$(OBJEXT)
 ecdh-test$(EXEEXT): ecdh-test.$(OBJEXT)
 	$(LINK) ecdh-test.$(OBJEXT) $(TEST_OBJS) -o ecdh-test$(EXEEXT)
 
+eddsa-compress-test$(EXEEXT): eddsa-compress-test.$(OBJEXT)
+	$(LINK) eddsa-compress-test.$(OBJEXT) $(TEST_OBJS) -o eddsa-compress-test$(EXEEXT)
+
 sha1-huge-test$(EXEEXT): sha1-huge-test.$(OBJEXT)
 	$(LINK) sha1-huge-test.$(OBJEXT) $(TEST_OBJS) -o sha1-huge-test$(EXEEXT)
 

testsuite/Makefile.in

@@ -44,7 +44,8 @@ TS_HOGWEED_SOURCES = sexp-test.c sexp-format-test.c \
 		     ecc-dup-test.c ecc-add-test.c \
 		     ecc-mul-g-test.c ecc-mul-a-test.c \
 		     ecdsa-sign-test.c ecdsa-verify-test.c \
-		     ecdsa-keygen-test.c ecdh-test.c
+		     ecdsa-keygen-test.c ecdh-test.c \
+		     eddsa-compress-test.c
 
 TS_SOURCES = $(TS_NETTLE_SOURCES) $(TS_HOGWEED_SOURCES)
 CXX_SOURCES = cxx-test.cxx

testsuite/eddsa-compress-test.c

+/* eddsa-compress-test.c
+
+   Copyright (C) 2014 Niels Möller
+
+   This file is part of GNU Nettle.
+
+   GNU Nettle is free software: you can redistribute it and/or
+   modify it under the terms of either:
+
+     * the GNU Lesser General Public License as published by the Free
+       Software Foundation; either version 3 of the License, or (at your
+       option) any later version.
+
+   or
+
+     * the GNU General Public License as published by the Free
+       Software Foundation; either version 2 of the License, or (at your
+       option) any later version.
+
+   or both in parallel, as here.
+
+   GNU Nettle 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
+   General Public License for more details.
+
+   You should have received copies of the GNU General Public License and
+   the GNU Lesser General Public License along with this program.  If
+   not, see http://www.gnu.org/licenses/.
+*/
+
+#include "testutils.h"
+
+#include "eddsa.h"
+
+#define COUNT 1000
+
+void test_main (void)
+{
+  const struct ecc_curve *ecc = &nettle_curve25519;
+  gmp_randstate_t rands;
+  mp_size_t size, itch;
+  mpz_t zp, t;
+  mp_limb_t *s;
+  mp_limb_t *p;
+  mp_limb_t *pa1;
+  mp_limb_t *pa2;
+  mp_limb_t *scratch;
+  size_t clen;
+  uint8_t *c;
+  unsigned j;
+
+  gmp_randinit_default (rands);
+
+  size = ecc_size (ecc);
+  clen = 1 + ecc->p.bit_size / 8;
+
+  mpz_roinit_n (zp, ecc->p.m, size);
+
+  mpz_init (t);
+  s = xalloc_limbs (size);
+  p = xalloc_limbs (ecc_size_j (ecc));
+  pa1 = xalloc_limbs (ecc_size_a (ecc));
+  pa2 = xalloc_limbs (ecc_size_a (ecc));
+  c = xalloc (clen);
+
+  itch = _eddsa_decompress_itch (ecc);
+  if (itch < ecc->mul_g_itch)
+    itch = ecc->mul_g_itch;
+
+  scratch = xalloc_limbs (itch);
+
+  for (j = 0; j < COUNT; j++)
+    {
+      mpz_t x1, y1, x2, y2;
+
+      mpz_urandomb (t, rands, ecc->q.bit_size);
+      mpz_limbs_copy (s, t, ecc->q.size);
+      ecc->mul_g (ecc, p, s, scratch);
+      _eddsa_compress (ecc, c, p, scratch);
+      ecc->h_to_a (ecc, 0, pa1, p, scratch);
+      _eddsa_decompress (ecc, pa2, c, scratch);
+      mpz_roinit_n (x1, pa1, size);
+      mpz_roinit_n (y1, pa1 + size, size);
+      mpz_roinit_n (x2, pa2, size);
+      mpz_roinit_n (y2, pa2 + size, size);
+      if (!(mpz_congruent_p (x1, x2, zp)
+	    && mpz_congruent_p (y1, y2, zp)))
+	{
+	  fprintf (stderr, "eddsa compression failed:\nc = ");
+	  print_hex (clen, c);
+	  fprintf (stderr, "\np1 = 0x");
+	  mpz_out_str (stderr, 16, x1);
+	  fprintf (stderr, ",\n     0x");
+	  mpz_out_str (stderr, 16, y1);
+	  fprintf (stderr, "\np2 = 0x");
+	  mpz_out_str (stderr, 16, x2);
+	  fprintf (stderr, ",\n     0x");
+	  mpz_out_str (stderr, 16, y2);
+	  fprintf (stderr, "\n");
+	  abort ();
+	}
+    }
+  mpz_clear (t);
+  free (s);
+  free (p);
+  free (c);
+  free (pa1);
+  free (pa2);
+  free (scratch);
+  gmp_randclear (rands);
+}