//! \file YuzCrypt.cs //! \date 2018 Apr 01 //! \brief YuzuSoft KiriKiri encryption schemes. // // Copyright (C) 2018 by morkt // // Permission is hereby granted, free of charge, to any person obtaining a copy // of this software and associated documentation files (the "Software"), to // deal in the Software without restriction, including without limitation the // rights to use, copy, modify, merge, publish, distribute, sublicense, and/or // sell copies of the Software, and to permit persons to whom the Software is // furnished to do so, subject to the following conditions: // // The above copyright notice and this permission notice shall be included in // all copies or substantial portions of the Software. // // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING // FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS // IN THE SOFTWARE. // using System; using System.IO; using System.Text; using GameRes.Compression; using GameRes.Utility; namespace GameRes.Formats.KiriKiri { [Serializable] public class RiddleCxCrypt : CxEncryption { uint m_random_seed; public uint[] YuzKey; public RiddleCxCrypt (CxScheme scheme, uint seed) : base (scheme) { m_random_seed = seed; } internal override CxProgram NewProgram (uint seed) { return new CxProgramNana (seed, m_random_seed, ControlBlock); } public override void Decrypt (Xp3Entry entry, long offset, byte[] buffer, int pos, int count) { ProcessFirstBytes (entry, offset, buffer, pos, count); base.Decrypt (entry, offset, buffer, pos, count); } public override void Encrypt (Xp3Entry entry, long offset, byte[] buffer, int pos, int count) { base.Encrypt (entry, offset, buffer, pos, count); ProcessFirstBytes (entry, offset, buffer, pos, count); } internal void ProcessFirstBytes (Xp3Entry entry, long offset, byte[] buffer, int pos, int count) { if (offset < 8 && count > 0) { ulong key = GetKeyFromHash (entry.Hash); key >>= (int)offset << 3; int first_chunk = Math.Min (count, 8); for (int i = 0; i < first_chunk; ++i) { buffer[pos+i] ^= (byte)key; key >>= 8; } } } internal ulong GetKeyFromHash (uint hash) { uint lo = hash ^ 0x55555555; uint hi = (hash << 13) ^ hash; hi = (hi >> 17) ^ hi; hi = hi ^ (hi << 5) ^ 0xAAAAAAAA; return (ulong)hi << 32 | lo; } internal void ReadYuzNames (byte[] yuz, FilenameMap filename_map) { if (null == YuzKey) throw new InvalidEncryptionScheme(); var decryptor = new YuzDecryptor (ControlBlock, YuzKey, YuzKey[4], YuzKey[5]); decryptor.Decrypt (yuz, Math.Min (yuz.Length, 0x100)); using (var ystream = new MemoryStream (yuz)) using (var zstream = ZLibCompressor.DeCompress (ystream)) using (var input = new BinaryReader (zstream, Encoding.Unicode)) { long dir_offset = 0; while (-1 != input.PeekChar()) { uint entry_signature = input.ReadUInt32(); long entry_size = input.ReadInt64(); if (entry_size < 0) return; dir_offset += 12 + entry_size; uint hash = input.ReadUInt32(); int name_size = input.ReadInt16(); if (name_size > 0) { entry_size -= 6; if (name_size * 2 <= entry_size) { var filename = new string (input.ReadChars (name_size)); filename_map.Add (hash, filename); } } input.BaseStream.Position = dir_offset; } filename_map.AddShortcut ("$", "startup.tjs"); } } } internal class YuzDecryptor { byte[] m_state; public YuzDecryptor (uint[] key1, uint[] key2, uint seed1, uint seed2) { m_state = new byte[64]; Buffer.BlockCopy (key2, 0, m_state, 0, 16); Buffer.BlockCopy (key1, 0, m_state, 16, 32); LittleEndian.Pack (~0, m_state, 48); LittleEndian.Pack (~0, m_state, 52); LittleEndian.Pack (~seed1, m_state, 56); LittleEndian.Pack (~seed2, m_state, 60); } public void Decrypt (byte[] data, int length) { var state1 = new byte[64]; var state2 = new byte[64]; int i = 0; ulong offset = 0; while (length > 0) { Buffer.BlockCopy (m_state, 0, state1, 0, 64); LittleEndian.Pack (~offset++, state1, 48); TransformState (state1, state2, 8); int count = Math.Min (0x40, length); for (int j = 0; j < count; ++j) { data[i++] ^= state2[j]; } length -= count; } } uint[] tmp = new uint[16]; void TransformState (byte[] state1, byte[] target, int length) { for (int i = 0; i < 16; ++i) { tmp[i] = ~LittleEndian.ToUInt32 (state1, i * 4); } if (length > 0) { for (int count = ((length - 1) >> 1) + 1; count > 0; --count) { uint t1 = tmp[4] + tmp[0]; uint t2 = Binary.RotL (t1 ^ tmp[12], 16); uint t3 = t2 + tmp[8]; uint t4 = Binary.RotL (tmp[4] ^ t3, 12); uint t5 = t4 + t1; uint t6 = Binary.RotL (t5 ^ t2, 8); tmp[12] = t6; t6 += t3; tmp[4] = Binary.RotL (t4 ^ t6, 7); t4 = Binary.RotL ((tmp[5] + tmp[1]) ^ tmp[13], 16); t3 = Binary.RotL (tmp[5] ^ (t4 + tmp[9]), 12); t2 = t3 + tmp[5] + tmp[1]; tmp[13] = Binary.RotL (t2 ^ t4, 8); tmp[9] += tmp[13] + t4; tmp[5] = Binary.RotL (t3 ^ tmp[9], 7); t4 = Binary.RotL ((tmp[6] + tmp[2]) ^ tmp[14], 16); tmp[10] += t4; t1 = Binary.RotL (tmp[6] ^ tmp[10], 12); t3 = t1 + tmp[6] + tmp[2]; tmp[14] = Binary.RotL (t3 ^ t4, 8); tmp[6] = Binary.RotL (t1 ^ (tmp[14] + tmp[10]), 7); tmp[10] += tmp[14]; t4 = (tmp[7] + tmp[3]) ^ tmp[15]; tmp[3] += tmp[7]; t4 = Binary.RotL (t4, 16); tmp[11] += t4; t1 = Binary.RotL (tmp[7] ^ tmp[11], 12); t4 ^= t1 + tmp[3]; tmp[3] += t1; t4 = Binary.RotL (t4, 8); tmp[11] += t4; t1 = Binary.RotL (t1 ^ tmp[11], 7); t5 += tmp[5]; t2 += tmp[6]; t4 = Binary.RotL (t5 ^ t4, 16); tmp[10] += t4; tmp[5] = Binary.RotL (tmp[5] ^ tmp[10], 12); tmp[0] = tmp[5] + t5; t4 = Binary.RotL (tmp[0] ^ t4, 8); tmp[15] = t4; tmp[10] += t4; tmp[5] = Binary.RotL (tmp[5] ^ tmp[10], 7); tmp[12] = Binary.RotL (tmp[12] ^ t2, 16); tmp[11] += tmp[12]; t4 = Binary.RotL (tmp[11] ^ tmp[6], 12); tmp[1] = t4 + t2; tmp[12] = Binary.RotL (tmp[12] ^ tmp[1], 8); tmp[11] += tmp[12]; tmp[6] = Binary.RotL (t4 ^ tmp[11], 7); t3 += t1; t4 = Binary.RotL (tmp[13] ^ t3, 16); t2 = t4 + t6; t1 = Binary.RotL (t2 ^ t1, 12); tmp[2] = t1 + t3; tmp[13] = Binary.RotL (t4 ^ tmp[2], 8); tmp[8] = tmp[13] + t2; tmp[7] = Binary.RotL (tmp[8] ^ t1, 7); t6 = Binary.RotL (tmp[14] ^ (tmp[4] + tmp[3]), 16); t1 = Binary.RotL (tmp[4] ^ (t6 + tmp[9]), 12); tmp[3] += t1 + tmp[4]; t3 = Binary.RotL (t6 ^ tmp[3], 8); tmp[9] += t3 + t6; tmp[4] = Binary.RotL (t1 ^ tmp[9], 7); tmp[14] = t3; } } int pos = 0; for (int i = 0; i < 16; ++i) { uint x = tmp[i] + ~LittleEndian.ToUInt32 (state1, pos); LittleEndian.Pack (x, target, pos); pos += 4; } } } }