/*

Copyright (c) 2016, Alden Torres
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:

    * Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.
    * 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.
    * Neither the name of the author 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 OWNER 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.

*/

#include "test.hpp"

#ifndef TORRENT_DISABLE_DHT

#include <memory>

#include "libtorrent/kademlia/ed25519.hpp"
#include "libtorrent/hex.hpp"

using namespace lt;
using namespace lt::dht;

namespace
{
	void test_vector(std::string seed, std::string pub, std::string sig_hex, std::string message)
	{
		std::array<char, 32> s;
		secret_key sk;
		public_key pk;
		signature sig;
		std::vector<char> msg(message.size() / 2);

		aux::from_hex(seed, s.data());
		std::tie(pk, sk) = ed25519_create_keypair(s);

		TEST_EQUAL(aux::to_hex(pk.bytes), pub);

		aux::from_hex(message, msg.data());
		sig = ed25519_sign(msg, pk, sk);

		TEST_EQUAL(aux::to_hex(sig.bytes), sig_hex);

		bool r = ed25519_verify(sig, msg, pk);

		TEST_CHECK(r);
	}
}

// https://git.gnupg.org/cgi-bin/gitweb.cgi?p=libgcrypt.git;a=blob;f=tests/t-ed25519.inp;hb=HEAD
TORRENT_TEST(ed25519_test_vec1)
{
	// TST: 2
	test_vector(
		  "4ccd089b28ff96da9db6c346ec114e0f5b8a319f35aba624da8cf6ed4fb8a6fb"
		, "3d4017c3e843895a92b70aa74d1b7ebc9c982ccf2ec4968cc0cd55f12af4660c"
		, "92a009a9f0d4cab8720e820b5f642540a2b27b5416503f8fb3762223ebdb69da"
		  "085ac1e43e15996e458f3613d0f11d8c387b2eaeb4302aeeb00d291612bb0c00"
		, "72"
	);

	// TST: 3
	test_vector(
		  "c5aa8df43f9f837bedb7442f31dcb7b166d38535076f094b85ce3a2e0b4458f7"
		, "fc51cd8e6218a1a38da47ed00230f0580816ed13ba3303ac5deb911548908025"
		, "6291d657deec24024827e69c3abe01a30ce548a284743a445e3680d7db5ac3ac"
		  "18ff9b538d16f290ae67f760984dc6594a7c15e9716ed28dc027beceea1ec40a"
		, "af82"
	);

	// TST: 4
	test_vector(
		  "0d4a05b07352a5436e180356da0ae6efa0345ff7fb1572575772e8005ed978e9"
		, "e61a185bcef2613a6c7cb79763ce945d3b245d76114dd440bcf5f2dc1aa57057"
		, "d9868d52c2bebce5f3fa5a79891970f309cb6591e3e1702a70276fa97c24b3a8"
		  "e58606c38c9758529da50ee31b8219cba45271c689afa60b0ea26c99db19b00c"
		, "cbc77b"
	);

	// TST: 47
	test_vector(
		  "89f0d68299ba0a5a83f248ae0c169f8e3849a9b47bd4549884305c9912b46603"
		, "aba3e795aab2012acceadd7b3bd9daeeed6ff5258bdcd7c93699c2a3836e3832"
		, "2c691fa8d487ce20d5d2fa41559116e0bbf4397cf5240e152556183541d66cf7"
		  "53582401a4388d390339dbef4d384743caa346f55f8daba68ba7b9131a8a6e0b"
		, "4f1846dd7ad50e545d4cfbffbb1dc2ff145dc123754d08af4e44ecc0bc8c9141"
		  "1388bc7653e2d893d1eac2107d05"
	);

	// TST: 48
	test_vector(
		  "0a3c1844e2db070fb24e3c95cb1cc6714ef84e2ccd2b9dd2f1460ebf7ecf13b1"
		, "72e409937e0610eb5c20b326dc6ea1bbbc0406701c5cd67d1fbde09192b07c01"
		, "87f7fdf46095201e877a588fe3e5aaf476bd63138d8a878b89d6ac60631b3458"
		  "b9d41a3c61a588e1db8d29a5968981b018776c588780922f5aa732ba6379dd05"
		, "4c8274d0ed1f74e2c86c08d955bde55b2d54327e82062a1f71f70d536fdc8722"
		  "cdead7d22aaead2bfaa1ad00b82957"
	);

	// TST: 49
	test_vector(
		  "c8d7a8818b98dfdb20839c871cb5c48e9e9470ca3ad35ba2613a5d3199c8ab23"
		, "90d2efbba4d43e6b2b992ca16083dbcfa2b322383907b0ee75f3e95845d3c47f"
		, "fa2e994421aef1d5856674813d05cbd2cf84ef5eb424af6ecd0dc6fdbdc2fe60"
		  "5fe985883312ecf34f59bfb2f1c9149e5b9cc9ecda05b2731130f3ed28ddae0b"
		, "783e33c3acbdbb36e819f544a7781d83fc283d3309f5d3d12c8dcd6b0b3d0e89"
		  "e38cfd3b4d0885661ca547fb9764abff"
	);

	// TST: 50
	test_vector(
		  "b482703612d0c586f76cfcb21cfd2103c957251504a8c0ac4c86c9c6f3e429ff"
		, "fd711dc7dd3b1dfb9df9704be3e6b26f587fe7dd7ba456a91ba43fe51aec09ad"
		, "58832bdeb26feafc31b46277cf3fb5d7a17dfb7ccd9b1f58ecbe6feb97966682"
		  "8f239ba4d75219260ecac0acf40f0e5e2590f4caa16bbbcd8a155d347967a607"
		, "29d77acfd99c7a0070a88feb6247a2bce9984fe3e6fbf19d4045042a21ab26cb"
		  "d771e184a9a75f316b648c6920db92b87b"
	);

	// TST: 51
	test_vector(
		  "84e50dd9a0f197e3893c38dbd91fafc344c1776d3a400e2f0f0ee7aa829eb8a2"
		, "2c50f870ee48b36b0ac2f8a5f336fb090b113050dbcc25e078200a6e16153eea"
		, "69e6a4491a63837316e86a5f4ba7cd0d731ecc58f1d0a264c67c89befdd8d382"
		  "9d8de13b33cc0bf513931715c7809657e2bfb960e5c764c971d733746093e500"
		, "f3992cde6493e671f1e129ddca8038b0abdb77bb9035f9f8be54bd5d68c1aeff"
		  "724ff47d29344391dc536166b8671cbbf123"
	);

	// TST: 52
	test_vector(
		  "b322d46577a2a991a4d1698287832a39c487ef776b4bff037a05c7f1812bdeec"
		, "eb2bcadfd3eec2986baff32b98e7c4dbf03ff95d8ad5ff9aa9506e5472ff845f"
		, "c7b55137317ca21e33489ff6a9bfab97c855dc6f85684a70a9125a261b56d5e6"
		  "f149c5774d734f2d8debfc77b721896a8267c23768e9badb910eef83ec258802"
		, "19f1bf5dcf1750c611f1c4a2865200504d82298edd72671f62a7b1471ac3d4a3"
		  "0f7de9e5da4108c52a4ce70a3e114a52a3b3c5"
	);

	// TST: 53
	test_vector(
		  "960cab5034b9838d098d2dcbf4364bec16d388f6376d73a6273b70f82bbc98c0"
		, "5e3c19f2415acf729f829a4ebd5c40e1a6bc9fbca95703a9376087ed0937e51a"
		, "27d4c3a1811ef9d4360b3bdd133c2ccc30d02c2f248215776cb07ee4177f9b13"
		  "fc42dd70a6c2fed8f225c7663c7f182e7ee8eccff20dc7b0e1d5834ec5b1ea01"
		, "f8b21962447b0a8f2e4279de411bea128e0be44b6915e6cda88341a68a0d8183"
		  "57db938eac73e0af6d31206b3948f8c48a447308"
	);

	// TST: 224
	test_vector(
		  "ae1d2c6b171be24c2e413d364dcda97fa476aaf9123d3366b0be03a142fe6e7d"
		, "d437f57542c681dd543487408ec7a44bd42a5fd545ce2f4c8297d67bb0b3aa7b"
		, "909008f3fcfff43988aee1314b15b1822caaa8dab120bd452af494e08335b44a"
		  "94c313c4b145eadd5166eaac034e29b7e6ac7941d5961fc49d260e1c4820b00e"
		, "9e6c2fc76e30f17cd8b498845da44f22d55bec150c6130b411c6339d14b39969"
		  "ab1033be687569a991a06f70b2a8a6931a777b0e4be6723cd75e5aa7532813ef"
		  "50b3d37271640fa2fb287c0355257641ea935c851c0b6ac68be72c88dfc5856f"
		  "b53543fb377b0dbf64808afcc4274aa456855ad28f61267a419bc72166b9ca73"
		  "cd3bb79bf7dd259baa75911440974b68e8ba95a78cbbe1cb6ad807a33a1cce2f"
		  "406ff7bcbd058b44a311b38ab4d4e61416c4a74d883d6a6a794abd9cf1c03902"
		  "8bf1b20e3d4990aae86f32bf06cd8349a7a884cce0165e36a0640e987b9d51"
	);

	// TST: 225
	test_vector(
		  "0265a7944baccfebf417b87ae1e6df2ff2a544ffb58225a08e092be03f026097"
		, "63d327615ea0139be0740b618aff1acfa818d4b0c2cfeaf0da93cdd5245fb5a9"
		, "b6c445b7eddca5935c61708d44ea5906bd19cc54224eae3c8e46ce99f5cbbd34"
		  "1f26623938f5fe04070b1b02e71fbb7c78a90c0dda66cb143fab02e6a0bae306"
		, "874ed712a2c41c26a2d9527c55233fde0a4ffb86af8e8a1dd0a820502c5a2693"
		  "2bf87ee0de72a8874ef2eebf83384d443f7a5f46a1233b4fb514a24699818248"
		  "94f325bf86aa0fe1217153d40f3556c43a8ea9269444e149fb70e9415ae0766c"
		  "565d93d1d6368f9a23a0ad76f9a09dbf79634aa97178677734d04ef1a5b3f87c"
		  "e1ee9fc5a9ac4e7a72c9d7d31ec89e28a845d2e1103c15d6410ce3c723b0cc22"
		  "09f698aa9fa288bbbecfd9e5f89cdcb09d3c215feb47a58b71ea70e2abead67f"
		  "1b08ea6f561fb93ef05232eedabfc1c7702ab039bc465cf57e207f1093fc8208"
	);
}

TORRENT_TEST(create_seed)
{
	std::array<char, 32> s1 = ed25519_create_seed();
	std::array<char, 32> s2 = ed25519_create_seed();

	TEST_CHECK(s1 != s2); // what are the odds

	int n1 = 0;
	int n2 = 0;
	for (std::size_t i = 0; i < 32; i++)
	{
		if (s1[i] != 0) n1++;
		if (s2[i] != 0) n2++;
	}
	TEST_CHECK(n1 > 0);
	TEST_CHECK(n2 > 0);
}

TORRENT_TEST(add_scalar)
{
	// client
	std::array<char, 32> s1 = ed25519_create_seed();

	public_key pk1;
	secret_key sk1;
	std::tie(pk1, sk1) = ed25519_create_keypair(s1);

	// client sends to server the public key

	// server generates another seed, it could be an scalar
	// n = HMAC(k, pk1) and sends it back to the client
	// see http://crypto.stackexchange.com/a/6215/4697
	std::array<char, 32> n = ed25519_create_seed();

	// now the server knows that the client's public key
	// must be (or assigns) pk1 + n
	pk1 = ed25519_add_scalar(pk1, n);

	// server sends n to the client

	// the client, in order to properly sign messages, must
	// adjust the private key
	sk1 = ed25519_add_scalar(sk1, n);

	// test sign and verification
	std::string msg = "Hello world";
	signature sig = ed25519_sign(msg, pk1, sk1);
	bool r = ed25519_verify(sig, msg, pk1);
	TEST_CHECK(r);
}

TORRENT_TEST(key_exchange)
{
	// user A
	std::array<char, 32> s1 = ed25519_create_seed();

	public_key pk1;
	secret_key sk1;
	std::tie(pk1, sk1) = ed25519_create_keypair(s1);

	// user A sends to user B the public key

	// user B
	std::array<char, 32> s2 = ed25519_create_seed();

	public_key pk2;
	secret_key sk2;
	std::tie(pk2, sk2) = ed25519_create_keypair(s2);

	// user B performs the key exchange
	std::array<char, 32> secretB = ed25519_key_exchange(pk1, sk2);

	// user B sends to user A the public key

	// user A performs the key exchange
	std::array<char, 32> secretA = ed25519_key_exchange(pk2, sk1);

	// now both users A and B must shared the same secret
	TEST_EQUAL(aux::to_hex(secretA), aux::to_hex(secretB));
}

#else
TORRENT_TEST(empty)
{
	TEST_CHECK(true);
}
#endif // TORRENT_DISABLE_DHT