Merge pull request #817 from SmallLars/econotag-ecc

Addet ECC functions on elliptic curve secp256r1.

examples/econotag-ecc-test/Makefile

@@ -0,0 +1,8 @@
+CONTIKI = ../..
+TARGET = econotag
+
+all: econotag-ecc-test
+
+APPS += ecc
+
+include $(CONTIKI)/Makefile.include

platform/econotag/apps/ecc/Makefile.ecc

@@ -0,0 +1 @@
+ecc_src = ecc.c

platform/econotag/apps/ecc/ecc.h

@@ -0,0 +1,103 @@
+/*
+ * Copyright (c) 2015, Lars Schmertmann <SmallLars@t-online.de>,
+ * Jens Trillmann <jtrillma@informatik.uni-bremen.de>.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
+ * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * This file is part of the Contiki operating system.
+ *
+ */
+
+/**
+ * \file
+ *      Calculations on elliptic curve secp256r1
+ *
+ *      This is a efficient ECC implementation on the secp256r1 curve for
+ *      32 Bit CPU architectures. It provides basic operations on the
+ *      secp256r1 curve and support for ECDH and ECDSA.
+ *
+ * \author
+ *      Lars Schmertmann <SmallLars@t-online.de>
+ *      Jens Trillmann <jtrillma@informatik.uni-bremen.de>
+ */
+
+#ifndef ECC_H_
+#define ECC_H_
+
+#include <stdint.h>
+
+/**
+ * \brief  Checks if a (random) number is valid as scalar on elliptic curve secp256r1
+ *
+ *         A (random) number is only usable as scalar on elliptic curve secp256r1 if
+ *         it is lower than the order of the curve. For the check, you need to provide
+ *         the order of elliptic curve secp256r1.
+ *
+ *         uint32_t order[8] = {0xFC632551, 0xF3B9CAC2, 0xA7179E84, 0xBCE6FAAD, 0xFFFFFFFF, 0xFFFFFFFF, 0x00000000, 0xFFFFFFFF};
+ *
+ * \param  key    The (random) number to check for usability
+ * \param  order  The order of elliptic curve secp256r1
+ *
+ * \return 1 if key is valid
+ */
+#define ecc_is_valid_key(key, order) (ecc_compare(order, key) == 1)
+
+/**
+ * \brief  Compares the value of a with the value of b
+ *
+ *         This function is only public because its needed for the macro ecc_is_valid_key.
+ *         It does a comparison of two 256 bit numbers. The return values are 1, 0 or -1.
+ *
+ * \param  a  First number
+ * \param  b  Second number
+ *
+ * \return  1 if a is greater than b
+            0 if a is equal to b
+           -1 if a is less than b
+ */
+int32_t ecc_compare(const uint32_t *a, const uint32_t *b);
+
+/**
+ * \brief  ECC scalar multiplication on elliptic curve secp256r1
+ *
+ *         This function does a scalar multiplication on elliptic curve secp256r1.
+ *         For an Elliptic curve Diffie–Hellman you need two multiplications. First one
+ *         with the base point of elliptic curve secp256r1 you need to provide.
+ *
+ *         uint32_t base_x[8] = {0xd898c296, 0xf4a13945, 0x2deb33a0, 0x77037d81, 0x63a440f2, 0xf8bce6e5, 0xe12c4247, 0x6b17d1f2};
+ *         uint32_t base_y[8] = {0x37bf51f5, 0xcbb64068, 0x6b315ece, 0x2bce3357, 0x7c0f9e16, 0x8ee7eb4a, 0xfe1a7f9b, 0x4fe342e2};
+ *
+ * \param  resultx  Pointer to memory to store the x-coordinate of the result
+ * \param  resulty  Pointer to memory to store the y-coordinate of the result
+ * \param  px       x-coordinate of the point to multiply with scalar
+ * \param  py       y-coordinate of the point to multiply with scalar
+ * \param  secret   Scalar for multiplication with elliptic curve point
+ */
+void ecc_ec_mult(uint32_t *resultx, uint32_t *resulty, const uint32_t *px, const uint32_t *py, const uint32_t *secret);
+
+#endif /* ECC_H_ */

regression-tests/15-compile-arm-apcs-ports/Makefile

@@ -9,6 +9,7 @@ er-rest-example/econotag \
 webserver-ipv6/econotag \
 ipv6/multicast/econotag \
 econotag-flash-test/econotag \
+econotag-ecc-test/econotag \
 
 TOOLS=