From e5128d369037291e2e4e1e87c362b36a70ad736d Mon Sep 17 00:00:00 2001 From: morkt Date: Thu, 29 Sep 2016 11:30:54 +0400 Subject: [PATCH] (Emic): encrypted archive variation. --- ArcFormats/Emic/ArcPACK.cs | 144 +++++++++++++++++++------------------ 1 file changed, 74 insertions(+), 70 deletions(-) diff --git a/ArcFormats/Emic/ArcPACK.cs b/ArcFormats/Emic/ArcPACK.cs index 8542b50a..fd4c277b 100644 --- a/ArcFormats/Emic/ArcPACK.cs +++ b/ArcFormats/Emic/ArcPACK.cs @@ -2,7 +2,7 @@ //! \date Sun Aug 30 01:11:18 2015 //! \brief Emic engine archive implementation. // -// Copyright (C) 2015 by morkt +// Copyright (C) 2015-2016 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 @@ -23,7 +23,6 @@ // IN THE SOFTWARE. // -using System; using System.Collections.Generic; using System.ComponentModel.Composition; using System.IO; @@ -47,7 +46,7 @@ namespace GameRes.Formats.Emic { public override string Tag { get { return "PAC/EMIC"; } } public override string Description { get { return "Emic engine resource archive"; } } - public override uint Signature { get { return 0x4B434150; } } + public override uint Signature { get { return 0x4B434150; } } // 'PACK' public override bool IsHierarchic { get { return true; } } public override bool CanCreate { get { return false; } } @@ -58,95 +57,100 @@ namespace GameRes.Formats.Emic public override ArcFile TryOpen (ArcView file) { + byte[] key; int count = file.View.ReadInt32 (0x28); - if (!IsSaneCount (count)) - return null; - - var reader = new PacReader (file, count); - var dir = reader.ReadIndex(); - if (null == dir) - return null; - if (reader.Encrypted) - return new EmicArchive (file, this, dir, reader.Key); + uint is_encrypted = file.View.ReadUInt32 (4); + if (IsSaneCount (count) && is_encrypted <= 1) + { + key = file.View.ReadBytes (8, 0x20); + for (int i = 0; i < key.Length; ++i) + key[i] ^= 0xAA; + } else - return new ArcFile (file, this, dir); + { + count = file.View.ReadInt32 (4); + is_encrypted = file.View.ReadUInt32 (8); + if (!IsSaneCount (count) || is_encrypted > 1) + return null; + key = file.View.ReadBytes (0xC, 0x20); + for (int i = 0; i < key.Length; ++i) + key[i] ^= 0xAB; + } + Stream input = file.CreateStream(); + if (1 == is_encrypted) + input = new ByteStringEncryptedStream (input, 0, key); + using (var reader = new BinaryReader (input)) + { + input.Position = 0x2C; + var index_buf = new byte[0x108]; + var dir = new List (count); + for (int i = 0; i < count; ++i) + { + int name_len = reader.ReadInt32(); + if (name_len <= 0 || name_len > index_buf.Length) // file name is too long + return null; + if (name_len != reader.Read (index_buf, 0, name_len)) + return null; + string name = Binary.GetCString (index_buf, 0, name_len); + var entry = FormatCatalog.Instance.Create (name); + entry.Size = reader.ReadUInt32(); + entry.Offset = reader.ReadUInt32(); + if (!entry.CheckPlacement (file.MaxOffset)) + return null; + dir.Add (entry); + } + if (1 == is_encrypted) + return new EmicArchive (file, this, dir, key); + else + return new ArcFile (file, this, dir); + } } public override Stream OpenEntry (ArcFile arc, Entry entry) { var emic = arc as EmicArchive; - if (null == emic) - return arc.File.CreateStream (entry.Offset, entry.Size); - var reader = new PacReader (emic.File, emic.Key); - var data = new byte[entry.Size]; - reader.Read (entry.Offset, data, 0, data.Length); - return new MemoryStream (data); + Stream input = arc.File.CreateStream (entry.Offset, entry.Size); + if (null != emic) + input = new ByteStringEncryptedStream (input, entry.Offset, emic.Key); + return input; } } - internal class PacReader + internal class ByteStringEncryptedStream : InputProxyStream { - ArcView m_file; - int m_count; + byte[] m_key; + int m_base_pos; - public bool Encrypted { get; private set; } - public byte[] Key { get; private set; } - - public PacReader (ArcView file, int count) + public ByteStringEncryptedStream (Stream main, long start_pos, byte[] key, bool leave_open = false) + : base (main, leave_open) { - m_file = file; - m_count = count; - Key = new byte[0x20]; - Encrypted = 1 == m_file.View.ReadInt32 (4); - file.View.Read (8, Key, 0, (uint)Key.Length); - for (int i = 0; i < Key.Length; ++i) - Key[i] ^= 0xAA; + m_key = key; + m_base_pos = (int)(start_pos % m_key.Length); } - public PacReader (ArcView file, byte[] key) + public override int Read (byte[] buffer, int offset, int count) { - m_file = file; - Encrypted = true; - Key = key; - } - - public List ReadIndex () - { - var index_buf = new byte[0x110]; - var dir = new List (m_count); - uint index_offset = 0x2C; - for (int i = 0; i < m_count; ++i) + int start_pos = (int)((m_base_pos + BaseStream.Position) % m_key.Length); + int read = BaseStream.Read (buffer, offset, count); + if (read > 0) { - Read (index_offset, index_buf, 0, 4); - int name_len = LittleEndian.ToInt32 (index_buf, 0); - if (name_len > index_buf.Length-8) // file name is too long - return null; - index_offset += 4; - Read (index_offset, index_buf, 0, name_len+8); - string name = Binary.GetCString (index_buf, 0, name_len); - var entry = FormatCatalog.Instance.Create (name); - entry.Offset = LittleEndian.ToUInt32 (index_buf, name_len+4); - entry.Size = LittleEndian.ToUInt32 (index_buf, name_len); - if (!entry.CheckPlacement (m_file.MaxOffset)) - return null; - dir.Add (entry); - index_offset += (uint)name_len + 8; - } - return dir; - } - - public int Read (long offset, byte[] buf, int index, int count) - { - int read = m_file.View.Read (offset, buf, index, (uint)count); - if (Encrypted) - { - int key_offset = (int)offset; for (int i = 0; i < read; ++i) { - buf[i] ^= Key[key_offset++ & 0x1F]; + buffer[offset+i] ^= m_key[(start_pos + i) % m_key.Length]; } } return read; } + + public override int ReadByte () + { + long pos = BaseStream.Position; + int b = BaseStream.ReadByte(); + if (-1 != b) + { + b ^= m_key[(m_base_pos + pos) % m_key.Length]; + } + return b; + } } }