ecc: add new ECC library

Adding a new ECC library which will be used to implement
TLS_ECDHE_ECDSA_WITH_AES_128_CCM_8. This library was developed in the
GOBI project: http://gobi.tzi.de and extended by me for ECDSA support.

Signed-off-by: Hauke Mehrtens <[email protected]>

Makefile.contiki

@@ -23,7 +23,7 @@ LDFLAGS += -Wl,--gc-sections,--undefined=_reset_vector__,--undefined=InterruptVe
 
 CFLAGS += -DUIP_CONF_TCP=0 -DSHA2_USE_INTTYPES_H
 
-APPS += tinydtls/aes tinydtls/sha2 tinydtls
+APPS += tinydtls/aes tinydtls/sha2 tinydtls/ecc tinydtls
 
 ccm-test: tests/ccm-test
 

Makefile.in

@@ -37,12 +37,12 @@ package = @PACKAGE_TARNAME@-@PACKAGE_VERSION@
 
 # files and flags
 SOURCES:= dtls.c crypto.c ccm.c hmac.c debug.c netq.c
-OBJECTS:= $(patsubst %.c, %.o, $(SOURCES)) aes/rijndael.o @OPT_OBJS@
+OBJECTS:= $(patsubst %.c, %.o, $(SOURCES)) aes/rijndael.o ecc/ecc.o @OPT_OBJS@
 HEADERS:=dtls.h hmac.h debug.h config.h uthash.h numeric.h crypto.h global.h ccm.h \
  netq.h t_list.h alert.h utlist.h prng.h
 CFLAGS:=-Wall -pedantic -std=c99 @CFLAGS@
 CPPFLAGS:=@CPPFLAGS@ -DDTLS_CHECK_CONTENTTYPE
-SUBDIRS:=tests doc sha2 aes
+SUBDIRS:=tests doc sha2 aes ecc
 DISTDIR=$(top_builddir)/$(package)
 FILES:=Makefile.in configure configure.in config.h.in $(SOURCES) $(HEADERS)
 LIB:=libtinydtls.a

configure.in

@@ -88,5 +88,6 @@ AC_CONFIG_FILES([Makefile
                  doc/Doxyfile
                  tests/Makefile
 		 sha2/Makefile
-		 aes/Makefile])
+		 aes/Makefile
+		 ecc/Makefile])
 AC_OUTPUT

crypto.c

@@ -1,6 +1,7 @@
 /* dtls -- a very basic DTLS implementation
  *
  * Copyright (C) 2011--2012 Olaf Bergmann <[email protected]>
+ * Copyright (C) 2013 Hauke Mehrtens <[email protected]>
  *
  * Permission is hereby granted, free of charge, to any person
  * obtaining a copy of this software and associated documentation
@@ -34,6 +35,7 @@
 #include "dtls.h"
 #include "crypto.h"
 #include "ccm.h"
+#include "ecc/ecc.h"
 
 #ifndef WITH_CONTIKI
 #include <stdlib.h>
@@ -240,6 +242,151 @@ dtls_psk_pre_master_secret(unsigned char *key, size_t keylen,
   return (sizeof(uint16) + keylen) << 1;
 }
 
+static void dtls_ec_key_to_uint32(const unsigned char *key, size_t key_size,
+				  uint32_t *result) {
+  int i;
+
+  for (i = (key_size / sizeof(uint32_t)) - 1; i >= 0 ; i--) {
+    *result = ntohl(((uint32_t *)key)[i]);
+    result++;
+  }
+}
+
+static void dtls_ec_key_from_uint32(const uint32_t *key, size_t key_size,
+				    unsigned char *result) {
+  int i;
+  uint32_t *result32 = (uint32_t *)result;
+
+  for (i = (key_size / sizeof(uint32_t)) - 1; i >= 0 ; i--) {
+    *result32 = htonl(key[i]);
+    result32++;
+  }
+}
+
+size_t dtls_ecdh_pre_master_secret(unsigned char *priv_key,
+				   unsigned char *pub_key_x,
+                                   unsigned char *pub_key_y,
+                                   size_t key_size,
+                                   unsigned char *result) {
+  uint32_t priv[8];
+  uint32_t pub_x[8];
+  uint32_t pub_y[8];
+  uint32_t result_x[8];
+  uint32_t result_y[8];
+
+  dtls_ec_key_to_uint32(priv_key, key_size, priv);
+  dtls_ec_key_to_uint32(pub_key_x, key_size, pub_x);
+  dtls_ec_key_to_uint32(pub_key_y, key_size, pub_y);
+
+  ecc_ecdh(pub_x, pub_y, priv, result_x, result_y);
+
+  dtls_ec_key_from_uint32(result_x, key_size, result);
+  return key_size;
+}
+
+void
+dtls_ecdsa_generate_key(unsigned char *priv_key,
+			unsigned char *pub_key_x,
+			unsigned char *pub_key_y,
+			size_t key_size) {
+  uint32_t priv[8];
+  uint32_t pub_x[8];
+  uint32_t pub_y[8];
+
+  do {
+    prng((unsigned char *)priv, key_size);
+  } while (!ecc_is_valid_key(priv));
+
+  ecc_gen_pub_key(priv, pub_x, pub_y);
+
+  dtls_ec_key_from_uint32(priv, key_size, priv_key);
+  dtls_ec_key_from_uint32(pub_x, key_size, pub_key_x);
+  dtls_ec_key_from_uint32(pub_y, key_size, pub_key_y);
+}
+
+/* rfc4492#section-5.4 */
+void
+dtls_ecdsa_create_sig_hash(const unsigned char *priv_key, size_t key_size,
+			   const unsigned char *sign_hash, size_t sign_hash_size,
+			   unsigned char *result_r, unsigned char *result_s) {
+  int ret;
+  uint32_t priv[8];
+  uint32_t hash[8];
+  uint32_t rand[8];
+  uint32_t point_r[9];
+  uint32_t point_s[9];
+
+  dtls_ec_key_to_uint32(priv_key, key_size, priv);
+  dtls_ec_key_to_uint32(sign_hash, sign_hash_size, hash);
+  do {
+    prng((unsigned char *)rand, key_size);
+    ret = ecc_ecdsa_sign(priv, hash, rand, point_r, point_s);
+  } while (ret);
+
+  dtls_ec_key_from_uint32(point_r, key_size, result_r);
+  dtls_ec_key_from_uint32(point_s, key_size, result_s);
+}
+
+void
+dtls_ecdsa_create_sig(const unsigned char *priv_key, size_t key_size,
+		      const unsigned char *client_random, size_t client_random_size,
+		      const unsigned char *server_random, size_t server_random_size,
+		      const unsigned char *keyx_params, size_t keyx_params_size,
+		      unsigned char *result_r, unsigned char *result_s) {
+  dtls_hash_ctx data;
+  unsigned char sha256hash[DTLS_HMAC_DIGEST_SIZE];
+
+  dtls_hash_init(&data);
+  dtls_hash_update(&data, client_random, client_random_size);
+  dtls_hash_update(&data, server_random, server_random_size);
+  dtls_hash_update(&data, keyx_params, keyx_params_size);
+  dtls_hash_finalize(sha256hash, &data);
+
+  dtls_ecdsa_create_sig_hash(priv_key, key_size, sha256hash,
+			     sizeof(sha256hash), result_r, result_s);
+}
+
+/* rfc4492#section-5.4 */
+int
+dtls_ecdsa_verify_sig_hash(const unsigned char *pub_key_x,
+			   const unsigned char *pub_key_y, size_t key_size,
+			   const unsigned char *sign_hash, size_t sign_hash_size,
+			   unsigned char *result_r, unsigned char *result_s) {
+  uint32_t pub_x[8];
+  uint32_t pub_y[8];
+  uint32_t hash[8];
+  uint32_t point_r[8];
+  uint32_t point_s[8];
+
+  dtls_ec_key_to_uint32(pub_key_x, key_size, pub_x);
+  dtls_ec_key_to_uint32(pub_key_y, key_size, pub_y);
+  dtls_ec_key_to_uint32(result_r, key_size, point_r);
+  dtls_ec_key_to_uint32(result_s, key_size, point_s);
+  dtls_ec_key_to_uint32(sign_hash, sign_hash_size, hash);
+
+  return ecc_ecdsa_validate(pub_x, pub_y, hash, point_r, point_s);
+}
+
+int
+dtls_ecdsa_verify_sig(const unsigned char *pub_key_x,
+		      const unsigned char *pub_key_y, size_t key_size,
+		      const unsigned char *client_random, size_t client_random_size,
+		      const unsigned char *server_random, size_t server_random_size,
+		      const unsigned char *keyx_params, size_t keyx_params_size,
+		      unsigned char *result_r, unsigned char *result_s) {
+  dtls_hash_ctx data;
+  unsigned char sha256hash[DTLS_HMAC_DIGEST_SIZE];
+
+  dtls_hash_init(&data);
+  dtls_hash_update(&data, client_random, client_random_size);
+  dtls_hash_update(&data, server_random, server_random_size);
+  dtls_hash_update(&data, keyx_params, keyx_params_size);
+  dtls_hash_finalize(sha256hash, &data);
+
+  return dtls_ecdsa_verify_sig_hash(pub_key_x, pub_key_y, key_size, sha256hash,
+				    sizeof(sha256hash), result_r, result_s);
+}
+
 void 
 dtls_cipher_set_iv(dtls_cipher_context_t *ctx,
 		   unsigned char *iv, size_t length) {

crypto.h

@@ -1,6 +1,7 @@
 /* dtls -- a very basic DTLS implementation
  *
  * Copyright (C) 2011--2012 Olaf Bergmann <[email protected]>
+ * Copyright (C) 2013 Hauke Mehrtens <[email protected]>
  *
  * Permission is hereby granted, free of charge, to any person
  * obtaining a copy of this software and associated documentation
@@ -267,6 +268,39 @@ int dtls_decrypt(dtls_cipher_context_t *ctx,
 size_t dtls_psk_pre_master_secret(unsigned char *key, size_t keylen,
 				  unsigned char *result);
 
+size_t dtls_ecdh_pre_master_secret(unsigned char *priv_key,
+				   unsigned char *pub_key_x,
+                                   unsigned char *pub_key_y,
+                                   size_t key_size,
+                                   unsigned char *result);
+
+void dtls_ecdsa_generate_key(unsigned char *priv_key,
+			     unsigned char *pub_key_x,
+			     unsigned char *pub_key_y,
+			     size_t key_size);
+
+void dtls_ecdsa_create_sig_hash(const unsigned char *priv_key, size_t key_size,
+				const unsigned char *sign_hash, size_t sign_hash_size,
+				unsigned char *result_r, unsigned char *result_s);
+
+void dtls_ecdsa_create_sig(const unsigned char *priv_key, size_t key_size,
+			   const unsigned char *client_random, size_t client_random_size,
+			   const unsigned char *server_random, size_t server_random_size,
+			   const unsigned char *keyx_params, size_t keyx_params_size,
+			   unsigned char *result_r, unsigned char *result_s);
+
+int dtls_ecdsa_verify_sig_hash(const unsigned char *pub_key_x,
+			       const unsigned char *pub_key_y, size_t key_size,
+			       const unsigned char *sign_hash, size_t sign_hash_size,
+			       unsigned char *result_r, unsigned char *result_s);
+
+int dtls_ecdsa_verify_sig(const unsigned char *pub_key_x,
+			  const unsigned char *pub_key_y, size_t key_size,
+			  const unsigned char *client_random, size_t client_random_size,
+			  const unsigned char *server_random, size_t server_random_size,
+			  const unsigned char *keyx_params, size_t keyx_params_size,
+			  unsigned char *result_r, unsigned char *result_s);
+
 /**
  * Creates a new dtls_cipher_context_t object for given @c cipher.
  * The storage allocated for this object must be released using 

ecc/Makefile.in

@@ -0,0 +1,73 @@
+# Makefile for tinydtls
+#
+# Copyright (C) 2011 Olaf Bergmann <[email protected]>
+# Copyright (C) 2013 Hauke Mehrtens <[email protected]>
+#
+# Permission is hereby granted, free of charge, to any person
+# obtaining a copy of this software and associated documentation
+# files (the "Software"), to deal in the Software without
+# restriction, including without limitation the rights to use, copy,
+# modify, merge, publish, distribute, sublicense, and/or sell copies
+# of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be
+# included in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+# BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+# ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+
+# the library's version
+VERSION:=@PACKAGE_VERSION@
+
+# tools
+@SET_MAKE@
+SHELL = /bin/sh
+MKDIR = mkdir
+
+abs_builddir = @abs_builddir@
+top_builddir = @top_builddir@
+top_srcdir:= @top_srcdir@
+
+SOURCES:= ecc.c
+HEADERS:= ecc.h
+OBJECTS:= $(patsubst %.c, %.o, $(SOURCES))
+CPPFLAGS=@CPPFLAGS@
+CFLAGS=-Wall -std=c99 -pedantic @CFLAGS@
+LDLIBS=@LIBS@
+FILES:=Makefile.in $(SOURCES) $(HEADERS) 
+DISTDIR=$(top_builddir)/@PACKAGE_TARNAME@-@PACKAGE_VERSION@
+
+.PHONY: all dirs clean distclean .gitignore doc
+
+.SUFFIXES:
+.SUFFIXES:      .c .o
+
+all:
+
+check:	
+	echo DISTDIR: $(DISTDIR)
+	echo top_builddir: $(top_builddir)
+
+clean:
+	@rm -f $(PROGRAMS) main.o $(LIB) $(OBJECTS)
+	for dir in $(SUBDIRS); do \
+		$(MAKE) -C $$dir clean ; \
+	done
+
+distclean:	clean
+	@rm -rf $(DISTDIR)
+	@rm -f *~ $(DISTDIR).tar.gz
+
+dist:	$(FILES)
+	test -d $(DISTDIR)/ecc || mkdir $(DISTDIR)/ecc
+	cp -p $(FILES) $(DISTDIR)/ecc
+
+.gitignore:
+	echo "core\n*~\n*.[oa]\n*.gz\n*.cap\n$(PROGRAM)\n$(DISTDIR)\n.gitignore" >$@