Implemented ecc_point_mul and ecc_point_mul_g.

ChangeLog

 2013-04-03  Niels Möller  <nisse@lysator.liu.se>
 
+	* ecc-point-mul-g.c (ecc_point_mul_g): New file and function.
+	* ecc-point-mul.c (ecc_point_mul): New file and function.
+	* ecc.h: Updated declarations and name mangling.
+	* Makefile.in (hogweed_SOURCES): Added ecc-point-mul.c and
+	ecc-point-mul-g.c.
+
 	* testsuite/salsa20-test.c (test_main): Tests for salsa20r12,
 	contributed by Nikos Mavrogiannopoulos.
 

Makefile.in

@@ -133,7 +133,7 @@ hogweed_SOURCES = sexp.c sexp-format.c \
 		  ecc-size.c ecc-j-to-a.c ecc-a-to-j.c \
 		  ecc-dup-jj.c ecc-add-jja.c ecc-add-jjj.c \
 		  ecc-mul-g.c ecc-mul-a.c ecc-hash.c ecc-random.c \
-		  ecc-point.c ecc-scalar.c \
+		  ecc-point.c ecc-scalar.c ecc-point-mul.c ecc-point-mul-g.c \
 		  ecc-ecdsa-sign.c ecdsa-sign.c \
 		  ecc-ecdsa-verify.c ecdsa-verify.c ecdsa-keygen.c
 

ecc-point-mul-g.c

+/* ecc-point-mul-g.c */
+
+/* nettle, low-level cryptographics library
+ *
+ * Copyright (C) 2013 Niels Möller
+ *  
+ * The nettle library is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or (at your
+ * option) any later version.
+ * 
+ * The nettle library 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 Lesser General Public
+ * License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with the nettle library; see the file COPYING.LIB.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02111-1301, USA.
+ */
+
+/* Development of Nettle's ECC support was funded by Internetfonden. */
+
+#if HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <assert.h>
+
+#include "ecc.h"
+#include "ecc-internal.h"
+#include "gmp-glue.h"
+#include "nettle-internal.h"
+
+void
+ecc_point_mul_g (struct ecc_point *r, const struct ecc_scalar *n)
+{
+  TMP_DECL(scratch, mp_limb_t, 3*ECC_MAX_SIZE + ECC_MUL_G_ITCH (ECC_MAX_SIZE));
+  mp_limb_t size = r->ecc->size;
+  mp_size_t itch = 3*size + ECC_MUL_G_ITCH (size);
+
+  assert (r->ecc == n->ecc);
+
+  TMP_ALLOC (scratch, itch);
+
+  ecc_mul_g (r->ecc, scratch, n->p, scratch + 3*size);
+  ecc_j_to_a (r->ecc, 1, r->p, scratch, scratch + 3*size);
+}

ecc-point-mul.c

+/* ecc-point-mul.c */
+
+/* nettle, low-level cryptographics library
+ *
+ * Copyright (C) 2013 Niels Möller
+ *  
+ * The nettle library is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or (at your
+ * option) any later version.
+ * 
+ * The nettle library 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 Lesser General Public
+ * License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with the nettle library; see the file COPYING.LIB.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02111-1301, USA.
+ */
+
+/* Development of Nettle's ECC support was funded by Internetfonden. */
+
+#if HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <assert.h>
+
+#include "ecc.h"
+#include "ecc-internal.h"
+#include "gmp-glue.h"
+
+void
+ecc_point_mul (struct ecc_point *r, const struct ecc_scalar *n,
+	       const struct ecc_point *p)
+{
+  mp_limb_t size = p->ecc->size;
+  mp_size_t itch = 3*size + ECC_MUL_A_ITCH (size);
+  mp_limb_t *scratch = gmp_alloc_limbs (itch);
+
+  assert (n->ecc == p->ecc);
+  assert (r->ecc == p->ecc);
+
+  ecc_mul_a (p->ecc, 1, scratch, n->p, p->p, scratch + 3*size);
+  ecc_j_to_a (r->ecc, 1, r->p, scratch, scratch + 3*size);
+  gmp_free_limbs (scratch, itch);
+}

ecc.h

@@ -38,6 +38,8 @@ extern "C" {
 #define ecc_point_clear nettle_ecc_point_clear
 #define ecc_point_set nettle_ecc_point_set
 #define ecc_point_get nettle_ecc_point_get
+#define ecc_point_mul nettle_ecc_point_mul
+#define ecc_point_mul_g nettle_ecc_point_mul_g
 #define ecc_scalar_init nettle_ecc_scalar_init
 #define ecc_scalar_clear nettle_ecc_scalar_clear
 #define ecc_scalar_set nettle_ecc_scalar_set
@@ -118,6 +120,10 @@ void
 ecc_point_mul (struct ecc_point *r, const struct ecc_scalar *n,
 	       const struct ecc_point *p);
 
+/* Computes r = n g */
+void
+ecc_point_mul_g (struct ecc_point *r, const struct ecc_scalar *n);
+
 
 /* Low-level interface */