using Org.BouncyCastle.Crypto.Utilities; namespace Org.BouncyCastle.Crypto.Engines { public sealed class Cast6Engine : Cast5Engine { private const int ROUNDS = 12; private const int BLOCK_SIZE = 16; private int[] _Kr = new int[48]; private uint[] _Km = new uint[48]; private int[] _Tr = new int[192]; private uint[] _Tm = new uint[192]; private uint[] _workingKey = new uint[8]; public override string AlgorithmName => "CAST6"; public override int GetBlockSize() { return 16; } internal override void SetKey(byte[] key) { uint num = 1518500249; uint num2 = 1859775393; int num3 = 19; int num4 = 17; for (int i = 0; i < 24; i++) { for (int j = 0; j < 8; j++) { _Tm[i * 8 + j] = num; num += num2; _Tr[i * 8 + j] = num3; num3 = ((num3 + num4) & 31); } } byte[] array = new byte[64]; key.CopyTo(array, 0); for (int k = 0; k < 8; k++) { _workingKey[k] = Pack.BE_To_UInt32(array, k * 4); } for (int l = 0; l < 12; l++) { int num5 = l * 2 * 8; _workingKey[6] ^= Cast5Engine.F1(_workingKey[7], _Tm[num5], _Tr[num5]); _workingKey[5] ^= Cast5Engine.F2(_workingKey[6], _Tm[num5 + 1], _Tr[num5 + 1]); _workingKey[4] ^= Cast5Engine.F3(_workingKey[5], _Tm[num5 + 2], _Tr[num5 + 2]); _workingKey[3] ^= Cast5Engine.F1(_workingKey[4], _Tm[num5 + 3], _Tr[num5 + 3]); _workingKey[2] ^= Cast5Engine.F2(_workingKey[3], _Tm[num5 + 4], _Tr[num5 + 4]); _workingKey[1] ^= Cast5Engine.F3(_workingKey[2], _Tm[num5 + 5], _Tr[num5 + 5]); _workingKey[0] ^= Cast5Engine.F1(_workingKey[1], _Tm[num5 + 6], _Tr[num5 + 6]); _workingKey[7] ^= Cast5Engine.F2(_workingKey[0], _Tm[num5 + 7], _Tr[num5 + 7]); num5 = (l * 2 + 1) * 8; _workingKey[6] ^= Cast5Engine.F1(_workingKey[7], _Tm[num5], _Tr[num5]); _workingKey[5] ^= Cast5Engine.F2(_workingKey[6], _Tm[num5 + 1], _Tr[num5 + 1]); _workingKey[4] ^= Cast5Engine.F3(_workingKey[5], _Tm[num5 + 2], _Tr[num5 + 2]); _workingKey[3] ^= Cast5Engine.F1(_workingKey[4], _Tm[num5 + 3], _Tr[num5 + 3]); _workingKey[2] ^= Cast5Engine.F2(_workingKey[3], _Tm[num5 + 4], _Tr[num5 + 4]); _workingKey[1] ^= Cast5Engine.F3(_workingKey[2], _Tm[num5 + 5], _Tr[num5 + 5]); _workingKey[0] ^= Cast5Engine.F1(_workingKey[1], _Tm[num5 + 6], _Tr[num5 + 6]); _workingKey[7] ^= Cast5Engine.F2(_workingKey[0], _Tm[num5 + 7], _Tr[num5 + 7]); _Kr[l * 4] = (int)(_workingKey[0] & 31); _Kr[l * 4 + 1] = (int)(_workingKey[2] & 31); _Kr[l * 4 + 2] = (int)(_workingKey[4] & 31); _Kr[l * 4 + 3] = (int)(_workingKey[6] & 31); _Km[l * 4] = _workingKey[7]; _Km[l * 4 + 1] = _workingKey[5]; _Km[l * 4 + 2] = _workingKey[3]; _Km[l * 4 + 3] = _workingKey[1]; } } internal override int EncryptBlock(byte[] src, int srcIndex, byte[] dst, int dstIndex) { uint a = Pack.BE_To_UInt32(src, srcIndex); uint b = Pack.BE_To_UInt32(src, srcIndex + 4); uint c = Pack.BE_To_UInt32(src, srcIndex + 8); uint d = Pack.BE_To_UInt32(src, srcIndex + 12); uint[] array = new uint[4]; CAST_Encipher(a, b, c, d, array); Pack.UInt32_To_BE(array[0], dst, dstIndex); Pack.UInt32_To_BE(array[1], dst, dstIndex + 4); Pack.UInt32_To_BE(array[2], dst, dstIndex + 8); Pack.UInt32_To_BE(array[3], dst, dstIndex + 12); return 16; } internal override int DecryptBlock(byte[] src, int srcIndex, byte[] dst, int dstIndex) { uint a = Pack.BE_To_UInt32(src, srcIndex); uint b = Pack.BE_To_UInt32(src, srcIndex + 4); uint c = Pack.BE_To_UInt32(src, srcIndex + 8); uint d = Pack.BE_To_UInt32(src, srcIndex + 12); uint[] array = new uint[4]; CAST_Decipher(a, b, c, d, array); Pack.UInt32_To_BE(array[0], dst, dstIndex); Pack.UInt32_To_BE(array[1], dst, dstIndex + 4); Pack.UInt32_To_BE(array[2], dst, dstIndex + 8); Pack.UInt32_To_BE(array[3], dst, dstIndex + 12); return 16; } private void CAST_Encipher(uint A, uint B, uint C, uint D, uint[] result) { for (int i = 0; i < 6; i++) { int num = i * 4; C ^= Cast5Engine.F1(D, _Km[num], _Kr[num]); B ^= Cast5Engine.F2(C, _Km[num + 1], _Kr[num + 1]); A ^= Cast5Engine.F3(B, _Km[num + 2], _Kr[num + 2]); D ^= Cast5Engine.F1(A, _Km[num + 3], _Kr[num + 3]); } for (int j = 6; j < 12; j++) { int num2 = j * 4; D ^= Cast5Engine.F1(A, _Km[num2 + 3], _Kr[num2 + 3]); A ^= Cast5Engine.F3(B, _Km[num2 + 2], _Kr[num2 + 2]); B ^= Cast5Engine.F2(C, _Km[num2 + 1], _Kr[num2 + 1]); C ^= Cast5Engine.F1(D, _Km[num2], _Kr[num2]); } result[0] = A; result[1] = B; result[2] = C; result[3] = D; } private void CAST_Decipher(uint A, uint B, uint C, uint D, uint[] result) { for (int i = 0; i < 6; i++) { int num = (11 - i) * 4; C ^= Cast5Engine.F1(D, _Km[num], _Kr[num]); B ^= Cast5Engine.F2(C, _Km[num + 1], _Kr[num + 1]); A ^= Cast5Engine.F3(B, _Km[num + 2], _Kr[num + 2]); D ^= Cast5Engine.F1(A, _Km[num + 3], _Kr[num + 3]); } for (int j = 6; j < 12; j++) { int num2 = (11 - j) * 4; D ^= Cast5Engine.F1(A, _Km[num2 + 3], _Kr[num2 + 3]); A ^= Cast5Engine.F3(B, _Km[num2 + 2], _Kr[num2 + 2]); B ^= Cast5Engine.F2(C, _Km[num2 + 1], _Kr[num2 + 1]); C ^= Cast5Engine.F1(D, _Km[num2], _Kr[num2]); } result[0] = A; result[1] = B; result[2] = C; result[3] = D; } } }