Mercurial > projects > dcrypt
view dcrypt/crypto/ciphers/XTEA.d @ 28:ad687db713a4
Further reworked the code for hash padding. Replaced all instances of 'char[]' with 'string' and removed a few 'const' modifiers as per Glenn Haecker's patch for D2 compatibility. Updated CONTRIBUTORS file.
author | Thomas Dixon <reikon@reikon.us> |
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date | Sun, 10 May 2009 22:38:48 -0400 |
parents | 8b5eaf3c2979 |
children |
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/** * This file is part of the dcrypt project. * * Copyright: Copyright (C) dcrypt contributors 2008. All rights reserved. * License: MIT * Authors: Thomas Dixon */ module dcrypt.crypto.ciphers.XTEA; import dcrypt.misc.ByteConverter; import dcrypt.crypto.BlockCipher; /** Implementation of the XTEA cipher designed by David Wheeler and Roger Needham. */ class XTEA : BlockCipher { private { static const uint ROUNDS = 32, KEY_SIZE = 16, BLOCK_SIZE = 8, DELTA = 0x9e3779b9u; uint[] subkeys, sum0, sum1; } void reset(){} string name() { return "XTEA"; } uint blockSize() { return BLOCK_SIZE; } void init(bool encrypt, CipherParameters params) { SymmetricKey keyParams = cast(SymmetricKey)params; if (!keyParams) throw new InvalidParameterError( name()~": Invalid parameter passed to init"); _encrypt = encrypt; if (keyParams.key.length != KEY_SIZE) throw new InvalidKeyError( name()~": Invalid key length (requires 16 bytes)"); subkeys = new uint[4]; sum0 = new uint[32]; sum1 = new uint[32]; int i, j; for (i = j = 0; i < 4; i++, j+=int.sizeof) subkeys[i] = ByteConverter.BigEndian.to!(uint)(keyParams.key[j..j+int.sizeof]); // Precompute the values of sum + k[] to speed up encryption for (i = j = 0; i < ROUNDS; i++) { sum0[i] = (j + subkeys[j & 3]); j += DELTA; sum1[i] = (j + subkeys[j >> 11 & 3]); } _initialized = true; } uint update(void[] input_, void[] output_) { if (!_initialized) throw new NotInitializedError(name()~": Cipher not initialized"); ubyte[] input = cast(ubyte[]) input_, output = cast(ubyte[]) output_; if (input.length < BLOCK_SIZE) throw new ShortBufferError(name()~": Input buffer too short"); if (output.length < BLOCK_SIZE) throw new ShortBufferError(name()~": Output buffer too short"); uint v0 = ByteConverter.BigEndian.to!(uint)(input[0..4]), v1 = ByteConverter.BigEndian.to!(uint)(input[4..8]); if (_encrypt) { for (int i = 0; i < ROUNDS; i++) { v0 += ((v1 << 4 ^ v1 >> 5) + v1) ^ sum0[i]; v1 += ((v0 << 4 ^ v0 >> 5) + v0) ^ sum1[i]; } } else { for (int i = ROUNDS-1; i >= 0; i--) { v1 -= (((v0 << 4) ^ (v0 >> 5)) + v0) ^ sum1[i]; v0 -= (((v1 << 4) ^ (v1 >> 5)) + v1) ^ sum0[i]; } } output[0..4] = ByteConverter.BigEndian.from!(uint)(v0); output[4..8] = ByteConverter.BigEndian.from!(uint)(v1); return BLOCK_SIZE; } /** Some XTEA test vectors. */ debug (UnitTest) { unittest { static string[] test_keys = [ "00000000000000000000000000000000", "00000000000000000000000000000000", "0123456712345678234567893456789a", "0123456712345678234567893456789a", "00000000000000000000000000000001", "01010101010101010101010101010101", "0123456789abcdef0123456789abcdef", "0123456789abcdef0123456789abcdef", "00000000000000000000000000000000", "00000000000000000000000000000000" ]; static string[] test_plaintexts = [ "0000000000000000", "0102030405060708", "0000000000000000", "0102030405060708", "0000000000000001", "0101010101010101", "0123456789abcdef", "0000000000000000", "0123456789abcdef", "4141414141414141" ]; static string[] test_ciphertexts = [ "dee9d4d8f7131ed9", "065c1b8975c6a816", "1ff9a0261ac64264", "8c67155b2ef91ead", "9f25fa5b0f86b758", "c2eca7cec9b7f992", "27e795e076b2b537", "5c8eddc60a95b3e1", "7e66c71c88897221", "ed23375a821a8c2d" ]; XTEA t = new XTEA(); foreach (uint i, string test_key; test_keys) { ubyte[] buffer = new ubyte[t.blockSize]; string result; SymmetricKey key = new SymmetricKey(ByteConverter.hexDecode(test_key)); // Encryption t.init(true, key); t.update(ByteConverter.hexDecode(test_plaintexts[i]), buffer); result = ByteConverter.hexEncode(buffer); assert(result == test_ciphertexts[i], t.name~": ("~result~") != ("~test_ciphertexts[i]~")"); // Decryption t.init(false, key); t.update(ByteConverter.hexDecode(test_ciphertexts[i]), buffer); result = ByteConverter.hexEncode(buffer); assert(result == test_plaintexts[i], t.name~": ("~result~") != ("~test_plaintexts[i]~")"); } } } }