/*
	This file is part of cpp-ethereum.

	cpp-ethereum is free software: you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation, either version 3 of the License, or
	(at your option) any later version.

	cpp-ethereum 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 a copy of the GNU General Public License
	along with cpp-ethereum.  If not, see <http://www.gnu.org/licenses/>.
*/
/** @file crypto.cpp
 * @author Gav Wood <i@gavwood.com>
 * @date 2014
 * Crypto test functions.
 */

#include <random>
#include <secp256k1/secp256k1.h>
#include <libdevcore/Common.h>
#include <libdevcore/RLP.h>
#include <libdevcore/Log.h>
#include <libethereum/Transaction.h>
#include <boost/test/unit_test.hpp>
#include <libdevcrypto/EC.h>
#include <libdevcrypto/ECIES.h>
#include "TestHelperCrypto.h"

using namespace std;
using namespace dev;
using namespace dev::crypto;
using namespace CryptoPP;

BOOST_AUTO_TEST_SUITE(devcrypto)

BOOST_AUTO_TEST_CASE(ecies)
{
	ECKeyPair k = ECKeyPair::create();

	string message("Now is the time for all good men to come to the aide of humanity.");
	bytes b = bytesRef(message).toBytes();
	ECIESEncryptor(&k).encrypt(b);

	bytesConstRef br(&b);
	bytes plain = ECIESDecryptor(&k).decrypt(br);

	// ideally, decryptor will go a step further, accept a bytesRef and zero input.
	assert(plain != b);
	
	// plaintext is same as output
	assert(plain == bytesConstRef(message).toBytes());
}

BOOST_AUTO_TEST_CASE(ecdhe_aes128_ctr_sha3mac)
{
	// New connections require new ECDH keypairs
	// Every new connection requires a new EC keypair
	// Every new trust requires a new EC keypair
	// All connections should share seed for PRF (or PRNG) for nonces
	
	
	
	
	
}

BOOST_AUTO_TEST_CASE(cryptopp_ecies_message)
{
	cnote << "Testing cryptopp_ecies_message...";

	string const message("Now is the time for all good men to come to the aide of humanity.");

	ECIES<ECP>::Decryptor localDecryptor(crypto::PRNG(), crypto::secp256k1());
	SavePrivateKey(localDecryptor.GetPrivateKey());
	
	ECIES<ECP>::Encryptor localEncryptor(localDecryptor);
	SavePublicKey(localEncryptor.GetPublicKey());

	ECIES<ECP>::Decryptor futureDecryptor;
	LoadPrivateKey(futureDecryptor.AccessPrivateKey());
	futureDecryptor.GetPrivateKey().ThrowIfInvalid(crypto::PRNG(), 3);
	
	ECIES<ECP>::Encryptor futureEncryptor;
	LoadPublicKey(futureEncryptor.AccessPublicKey());
	futureEncryptor.GetPublicKey().ThrowIfInvalid(crypto::PRNG(), 3);

	// encrypt/decrypt with local
	string cipherLocal;
	StringSource ss1 (message, true, new PK_EncryptorFilter(crypto::PRNG(), localEncryptor, new StringSink(cipherLocal) ) );
	string plainLocal;
	StringSource ss2 (cipherLocal, true, new PK_DecryptorFilter(crypto::PRNG(), localDecryptor, new StringSink(plainLocal) ) );

	// encrypt/decrypt with future
	string cipherFuture;
	StringSource ss3 (message, true, new PK_EncryptorFilter(crypto::PRNG(), futureEncryptor, new StringSink(cipherFuture) ) );
	string plainFuture;
	StringSource ss4 (cipherFuture, true, new PK_DecryptorFilter(crypto::PRNG(), futureDecryptor, new StringSink(plainFuture) ) );
	
	// decrypt local w/future
	string plainFutureFromLocal;
	StringSource ss5 (cipherLocal, true, new PK_DecryptorFilter(crypto::PRNG(), futureDecryptor, new StringSink(plainFutureFromLocal) ) );
	
	// decrypt future w/local
	string plainLocalFromFuture;
	StringSource ss6 (cipherFuture, true, new PK_DecryptorFilter(crypto::PRNG(), localDecryptor, new StringSink(plainLocalFromFuture) ) );
	
	
	assert(plainLocal == message);
	assert(plainFuture == plainLocal);
	assert(plainFutureFromLocal == plainLocal);
	assert(plainLocalFromFuture == plainLocal);
}

BOOST_AUTO_TEST_CASE(cryptopp_ecdh_prime)
{
	cnote << "Testing cryptopp_ecdh_prime...";
	
	using namespace CryptoPP;
	OID curve = ASN1::secp256k1();

	ECDH<ECP>::Domain dhLocal(curve);
	SecByteBlock privLocal(dhLocal.PrivateKeyLength());
	SecByteBlock pubLocal(dhLocal.PublicKeyLength());
	dhLocal.GenerateKeyPair(dev::crypto::PRNG(), privLocal, pubLocal);
	
	ECDH<ECP>::Domain dhRemote(curve);
	SecByteBlock privRemote(dhRemote.PrivateKeyLength());
	SecByteBlock pubRemote(dhRemote.PublicKeyLength());
	dhRemote.GenerateKeyPair(dev::crypto::PRNG(), privRemote, pubRemote);
	
	assert(dhLocal.AgreedValueLength() == dhRemote.AgreedValueLength());
	
	// local: send public to remote; remote: send public to local
	
	// Local
	SecByteBlock sharedLocal(dhLocal.AgreedValueLength());
	assert(dhLocal.Agree(sharedLocal, privLocal, pubRemote));
	
	// Remote
	SecByteBlock sharedRemote(dhRemote.AgreedValueLength());
	assert(dhRemote.Agree(sharedRemote, privRemote, pubLocal));
	
	// Test
	Integer ssLocal, ssRemote;
	ssLocal.Decode(sharedLocal.BytePtr(), sharedLocal.SizeInBytes());
	ssRemote.Decode(sharedRemote.BytePtr(), sharedRemote.SizeInBytes());
	
	assert(ssLocal != 0);
	assert(ssLocal == ssRemote);
}

BOOST_AUTO_TEST_CASE(cryptopp_aes128_ctr)
{
	const int aesKeyLen = 16;
	assert(sizeof(char) == sizeof(byte));
	
	// generate test key
	AutoSeededRandomPool rng;
	SecByteBlock key(0x00, aesKeyLen);
	rng.GenerateBlock(key, key.size());
	
	// cryptopp uses IV as nonce/counter which is same as using nonce w/0 ctr
	byte ctr[ AES::BLOCKSIZE ];
	rng.GenerateBlock( ctr, sizeof(ctr) );
	
	string text = "Now is the time for all good men to come to the aide of humanity.";
	// c++11 ftw
	unsigned char const* in = (unsigned char*)&text[0];
	unsigned char* out = (unsigned char*)&text[0];
	string original = text;
	
	string cipherCopy;
	try
	{
		CTR_Mode< AES >::Encryption e;
		e.SetKeyWithIV( key, key.size(), ctr );
		e.ProcessData(out, in, text.size());
		assert(text!=original);
		cipherCopy = text;
	}
	catch( CryptoPP::Exception& e )
	{
		cerr << e.what() << endl;
	}
	
	try
	{
		CTR_Mode< AES >::Decryption d;
		d.SetKeyWithIV( key, key.size(), ctr );
		d.ProcessData(out, in, text.size());
		assert(text==original);
	}
	catch( CryptoPP::Exception& e )
	{
		cerr << e.what() << endl;
	}
	
	
	// reencrypt ciphertext...
	try
	{
		assert(cipherCopy!=text);
		in = (unsigned char*)&cipherCopy[0];
		out = (unsigned char*)&cipherCopy[0];
		
		CTR_Mode< AES >::Encryption e;
		e.SetKeyWithIV( key, key.size(), ctr );
		e.ProcessData(out, in, text.size());
		
		// yep, ctr mode.
		assert(cipherCopy==original);
	}
	catch( CryptoPP::Exception& e )
	{
		cerr << e.what() << endl;
	}
	
}

BOOST_AUTO_TEST_CASE(cryptopp_aes128_cbc)
{
	const int aesKeyLen = 16;
	assert(sizeof(char) == sizeof(byte));
	
	AutoSeededRandomPool rng;
	SecByteBlock key(0x00, aesKeyLen);
	rng.GenerateBlock(key, key.size());
	
	// Generate random IV
	byte iv[AES::BLOCKSIZE];
	rng.GenerateBlock(iv, AES::BLOCKSIZE);
	
	string string128("AAAAAAAAAAAAAAAA");
	string plainOriginal = string128;
	
	CryptoPP::CBC_Mode<Rijndael>::Encryption cbcEncryption(key, key.size(), iv);
	cbcEncryption.ProcessData((byte*)&string128[0], (byte*)&string128[0], string128.size());
	assert(string128 != plainOriginal);
	
	CBC_Mode<Rijndael>::Decryption cbcDecryption(key, key.size(), iv);
	cbcDecryption.ProcessData((byte*)&string128[0], (byte*)&string128[0], string128.size());
	assert(plainOriginal == string128);
	
	
	// plaintext whose size isn't divisible by block size must use stream filter for padding
	string string192("AAAAAAAAAAAAAAAABBBBBBBB");
	plainOriginal = string192;

	string cipher;
	StreamTransformationFilter* aesStream = new StreamTransformationFilter(cbcEncryption, new StringSink(cipher));
	StringSource source(string192, true, aesStream);
	assert(cipher.size() == 32);

	cbcDecryption.ProcessData((byte*)&cipher[0], (byte*)&string192[0], cipher.size());
	assert(string192 == plainOriginal);
}

BOOST_AUTO_TEST_CASE(eth_keypairs)
{
	cnote << "Testing Crypto...";
	secp256k1_start();

	KeyPair p(Secret(fromHex("3ecb44df2159c26e0f995712d4f39b6f6e499b40749b1cf1246c37f9516cb6a4")));
	BOOST_REQUIRE(p.pub() == Public(fromHex("97466f2b32bc3bb76d4741ae51cd1d8578b48d3f1e68da206d47321aec267ce78549b514e4453d74ef11b0cd5e4e4c364effddac8b51bcfc8de80682f952896f")));
	BOOST_REQUIRE(p.address() == Address(fromHex("8a40bfaa73256b60764c1bf40675a99083efb075")));
	{
		eth::Transaction t;
		t.nonce = 0;
		t.receiveAddress = h160(fromHex("944400f4b88ac9589a0f17ed4671da26bddb668b"));
		t.value = 1000;
		auto rlp = t.rlp(false);
		cnote << RLP(rlp);
		cnote << toHex(rlp);
		cnote << t.sha3(false);
		t.sign(p.secret());
		rlp = t.rlp(true);
		cnote << RLP(rlp);
		cnote << toHex(rlp);
		cnote << t.sha3(true);
		BOOST_REQUIRE(t.sender() == p.address());
	}

} 
 

int cryptoTest()
{
	cnote << "Testing Crypto...";
	secp256k1_start();

	KeyPair p(Secret(fromHex("3ecb44df2159c26e0f995712d4f39b6f6e499b40749b1cf1246c37f9516cb6a4")));
	assert(p.pub() == Public(fromHex("97466f2b32bc3bb76d4741ae51cd1d8578b48d3f1e68da206d47321aec267ce78549b514e4453d74ef11b0cd5e4e4c364effddac8b51bcfc8de80682f952896f")));
	assert(p.address() == Address(fromHex("8a40bfaa73256b60764c1bf40675a99083efb075")));
	{
		eth::Transaction t;
		t.nonce = 0;
		t.receiveAddress = h160(fromHex("944400f4b88ac9589a0f17ed4671da26bddb668b"));
		t.value = 1000;
		auto rlp = t.rlp(false);
		cnote << RLP(rlp);
		cnote << toHex(rlp);
		cnote << t.sha3(false);
		t.sign(p.secret());
		rlp = t.rlp(true);
		cnote << RLP(rlp);
		cnote << toHex(rlp);
		cnote << t.sha3(true);
		assert(t.sender() == p.address());
	}


#if 0
	// Test transaction.
	bytes tx = fromHex("88005401010101010101010101010101010101010101011f0de0b6b3a76400001ce8d4a5100080181c373130a009ba1f10285d4e659568bfcfec85067855c5a3c150100815dad4ef98fd37cf0593828c89db94bd6c64e210a32ef8956eaa81ea9307194996a3b879441f5d");
	cout << "TX: " << RLP(tx) << endl;

	Transaction t2(tx);
	cout << "SENDER: " << hex << t2.sender() << dec << endl;

	secp256k1_start();

	Transaction t;
	t.nonce = 0;
	t.value = 1;			// 1 wei.
	t.receiveAddress = toAddress(sha3("123"));

	bytes sig64 = toBigEndian(t.vrs.r) + toBigEndian(t.vrs.s);
	cout << "SIG: " << sig64.size() << " " << toHex(sig64) << " " << t.vrs.v << endl;

	auto msg = t.rlp(false);
	cout << "TX w/o SIG: " << RLP(msg) << endl;
	cout << "RLP(TX w/o SIG): " << toHex(t.rlpString(false)) << endl;
	std::string hmsg = sha3(t.rlpString(false), false);
	cout << "SHA256(RLP(TX w/o SIG)): 0x" << toHex(hmsg) << endl;

	bytes privkey = sha3Bytes("123");

	{
		bytes pubkey(65);
		int pubkeylen = 65;

		int ret = secp256k1_ecdsa_seckey_verify(privkey.data());
		cout << "SEC: " << dec << ret << " " << toHex(privkey) << endl;

		ret = secp256k1_ecdsa_pubkey_create(pubkey.data(), &pubkeylen, privkey.data(), 1);
		pubkey.resize(pubkeylen);
		int good = secp256k1_ecdsa_pubkey_verify(pubkey.data(), (int)pubkey.size());
		cout << "PUB: " << dec << ret << " " << pubkeylen << " " << toHex(pubkey) << (good ? " GOOD" : " BAD") << endl;
	}

	// Test roundtrip...
	{
		bytes sig(64);
		u256 nonce = 0;
		int v = 0;
		cout << toHex(hmsg) << endl;
		cout << toHex(privkey) << endl;
		cout << hex << nonce << dec << endl;
		int ret = secp256k1_ecdsa_sign_compact((byte const*)hmsg.data(), (int)hmsg.size(), sig.data(), privkey.data(), (byte const*)&nonce, &v);
		cout << "MYSIG: " << dec << ret << " " << sig.size() << " " << toHex(sig) << " " << v << endl;

		bytes pubkey(65);
		int pubkeylen = 65;
		ret = secp256k1_ecdsa_recover_compact((byte const*)hmsg.data(), (int)hmsg.size(), (byte const*)sig.data(), pubkey.data(), &pubkeylen, 0, v);
		pubkey.resize(pubkeylen);
		cout << "MYREC: " << dec << ret << " " << pubkeylen << " " << toHex(pubkey) << endl;
	}

	{
		bytes pubkey(65);
		int pubkeylen = 65;
		int ret = secp256k1_ecdsa_recover_compact((byte const*)hmsg.data(), (int)hmsg.size(), (byte const*)sig64.data(), pubkey.data(), &pubkeylen, 0, (int)t.vrs.v - 27);
		pubkey.resize(pubkeylen);
		cout << "RECPUB: " << dec << ret << " " << pubkeylen << " " << toHex(pubkey) << endl;
		cout << "SENDER: " << hex << toAddress(dev::sha3(bytesConstRef(&pubkey).cropped(1))) << dec << endl;
	}
#endif
	return 0;
}

BOOST_AUTO_TEST_SUITE_END()