From aec330d8a56af8bd782f34e7459e4091fff08eb0 Mon Sep 17 00:00:00 2001 From: morkt Date: Tue, 21 Nov 2017 12:10:18 +0400 Subject: [PATCH] (RPM): moved archive index interpreter logic to separate class. --- ArcFormats/RPM/ArcARC.cs | 161 ++++++++++++++++++++++----------------- 1 file changed, 92 insertions(+), 69 deletions(-) diff --git a/ArcFormats/RPM/ArcARC.cs b/ArcFormats/RPM/ArcARC.cs index b0bb8c1b..ddbd66b8 100644 --- a/ArcFormats/RPM/ArcARC.cs +++ b/ArcFormats/RPM/ArcARC.cs @@ -92,7 +92,9 @@ namespace GameRes.Formats.Rpm uint is_compressed = file.View.ReadUInt32 (4); if (is_compressed > 1) // should be either 0 or 1 return null; - var scheme = GuessScheme (file, count); + + var index_reader = new ArcIndexReader (file, count, is_compressed != 0); + var scheme = index_reader.GuessScheme (8, new int[] { 0x20, 0x18 }); // additional filename extension check avoids dialog popup on false positives if (null == scheme && KnownSchemes.Count > 0 && file.Name.HasExtension (".arc")) scheme = QueryScheme(); @@ -104,35 +106,9 @@ namespace GameRes.Formats.Rpm && VFS.IsPathEqualsToFileName (file.Name, "instdata.arc")) scheme = new EncryptionScheme ("inst", scheme.NameLength); - int index_size = count * (scheme.NameLength + 12); - var index = new byte[index_size]; - if (index_size != file.View.Read (8, index, 0, (uint)index_size)) + var dir = index_reader.ReadIndex (8, scheme); + if (null == dir) return null; - DecryptIndex (index, scheme.Keyword); - - uint data_offset = LittleEndian.ToUInt32 (index, scheme.NameLength + 8); - if (data_offset != 8 + index_size) - return null; - - int index_offset = 0; - var dir = new List (count); - for (int i = 0; i < count; ++i) - { - var name = Binary.GetCString (index, index_offset, scheme.NameLength); - index_offset += scheme.NameLength; - var entry = FormatCatalog.Instance.Create (name); - entry.UnpackedSize = LittleEndian.ToUInt32 (index, index_offset); - entry.Size = LittleEndian.ToUInt32 (index, index_offset+4); - entry.Offset = LittleEndian.ToUInt32 (index, index_offset+8); - entry.IsPacked = is_compressed != 0; - if (0 != entry.Size) - { - if (entry.Offset < data_offset || !entry.CheckPlacement (file.MaxOffset)) - return null; - } - dir.Add (entry); - index_offset += 12; - } return new ArcFile (file, this, dir); } @@ -147,18 +123,98 @@ namespace GameRes.Formats.Rpm return new LzssStream (input); } - EncryptionScheme GuessScheme (ArcView file, int count) + public override ResourceOptions GetDefaultOptions () { - int[] possible_sizes = { 0x20, 0x18 }; - byte[] first_entry = new byte[possible_sizes[0] + 12]; - if (first_entry.Length != file.View.Read (8, first_entry, 0, (uint)first_entry.Length)) + return new RpmOptions { + Scheme = GetScheme (Settings.Default.RPMScheme), + }; + } + + public override object GetAccessWidget () + { + return new WidgetARC(); + } + + EncryptionScheme QueryScheme () + { + var options = Query (arcStrings.RPMEncryptedNotice); + return options.Scheme; + } + + static EncryptionScheme GetScheme (string title) + { + EncryptionScheme scheme = null; + KnownSchemes.TryGetValue (title, out scheme); + return scheme; + } + } + + internal sealed class ArcIndexReader + { + ArcView m_file; + int m_count; + bool m_is_compressed; + + public ArcIndexReader (ArcView file, int count, bool is_compressed) + { + m_file = file; + m_count = count; + m_is_compressed = is_compressed; + } + + public List ReadIndex (long offset, EncryptionScheme scheme) + { + int index_size = m_count * (scheme.NameLength + 12); + var index = m_file.View.ReadBytes (offset, (uint)index_size); + if (index.Length != index_size) + return null; + DecryptIndex (index, scheme.Keyword); + + uint data_offset = LittleEndian.ToUInt32 (index, scheme.NameLength + 8); + if (data_offset != offset + index_size) + return null; + + int index_offset = 0; + var dir = new List (m_count); + for (int i = 0; i < m_count; ++i) + { + var name = Binary.GetCString (index, index_offset, scheme.NameLength); + index_offset += scheme.NameLength; + var entry = FormatCatalog.Instance.Create (name); + entry.UnpackedSize = LittleEndian.ToUInt32 (index, index_offset); + entry.Size = LittleEndian.ToUInt32 (index, index_offset+4); + entry.Offset = LittleEndian.ToUInt32 (index, index_offset+8); + entry.IsPacked = m_is_compressed; + if (0 != entry.Size) + { + if (entry.Offset < data_offset || !entry.CheckPlacement (m_file.MaxOffset)) + return null; + } + dir.Add (entry); + index_offset += 12; + } + return dir; + } + + internal static void DecryptIndex (byte[] data, string key) + { + for (int i = 0; i < data.Length; ++i) + { + data[i] += (byte)key[i % key.Length]; + } + } + + public EncryptionScheme GuessScheme (int index_offset, int[] possible_name_sizes) + { + byte[] first_entry = new byte[possible_name_sizes[0] + 12]; + if (first_entry.Length != m_file.View.Read (index_offset, first_entry, 0, (uint)first_entry.Length)) return null; byte[] key_bits = new byte[4]; byte[] actual_offset = new byte[4]; - foreach (var name_length in possible_sizes) + foreach (var name_length in possible_name_sizes) { - int first_offset = 8 + count * (name_length + 12); - if (first_offset >= file.MaxOffset) + int first_offset = index_offset + m_count * (name_length + 12); + if (first_offset >= m_file.MaxOffset) continue; LittleEndian.Pack (first_offset, actual_offset, 0); int i; @@ -208,38 +264,5 @@ namespace GameRes.Formats.Rpm } return -1; } - - private void DecryptIndex (byte[] data, string key) - { - for (int i = 0; i < data.Length; ++i) - { - data[i] += (byte)key[i % key.Length]; - } - } - - public override ResourceOptions GetDefaultOptions () - { - return new RpmOptions { - Scheme = GetScheme (Settings.Default.RPMScheme), - }; - } - - public override object GetAccessWidget () - { - return new WidgetARC(); - } - - EncryptionScheme QueryScheme () - { - var options = Query (arcStrings.RPMEncryptedNotice); - return options.Scheme; - } - - static EncryptionScheme GetScheme (string title) - { - EncryptionScheme scheme = null; - KnownSchemes.TryGetValue (title, out scheme); - return scheme; - } } }