/*************************************************************************** The Disc Image Chef ---------------------------------------------------------------------------- Filename : CDChecksums.cs Version : 1.0 Author(s) : Natalia Portillo Component : Checksums. Revision : $Revision$ Last change by : $Author$ Date : $Date$ --[ Description ] ---------------------------------------------------------- Checks a CD checksum --[ License ] -------------------------------------------------------------- This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see . ---------------------------------------------------------------------------- Copyright (C) 2011-2014 Claunia.com ECC algorithm from ECM (C) 2002-2011 Neill Corlett ****************************************************************************/ //$Id$ using System; namespace DiscImageChef.Checksums { public static class CDChecksums { static byte[] ECC_F_Table; static byte[] ECC_B_Table; const UInt32 CDCRC32Poly = 0xD8018001; const UInt32 CDCRC32Seed = 0x00000000; public static bool? CheckCDSector(byte[] buffer) { switch (buffer.Length) { case 2448: { byte[] subchannel = new byte[96]; byte[] channel = new byte[2352]; Array.Copy(buffer, 0, channel, 0, 2352); Array.Copy(buffer, 2352, subchannel, 0, 96); bool? channelStatus = CheckCDSectorChannel(channel); bool? subchannelStatus = CheckCDSectorSubChannel(subchannel); if (channelStatus == null || subchannelStatus == null) return null; if (channelStatus == false || subchannelStatus == false) return false; if (channelStatus == true && subchannelStatus == true) return true; return null; } case 2352: return CheckCDSectorChannel(buffer); default: return null; } } static void ECCInit() { ECC_F_Table = new byte[256]; ECC_B_Table = new byte[256]; for (UInt32 i = 0; i < 256; i++) { UInt32 j = (uint)((i << 1) ^ ((i & 0x80) == 0x80 ? 0x11D : 0)); ECC_F_Table[i] = (byte)j; ECC_B_Table[i ^ j] = (byte)i; } } static bool CheckECC( byte[] address, byte[] data, UInt32 major_count, UInt32 minor_count, UInt32 major_mult, UInt32 minor_inc, byte[] ecc ) { UInt32 size = major_count * minor_count; UInt32 major; for (major = 0; major < major_count; major++) { UInt32 index = (major >> 1) * major_mult + (major & 1); byte ecc_a = 0; byte ecc_b = 0; UInt32 minor; for (minor = 0; minor < minor_count; minor++) { byte temp; if (index < 4) { temp = address[index]; } else { temp = data[index - 4]; } index += minor_inc; if (index >= size) { index -= size; } ecc_a ^= temp; ecc_b ^= temp; ecc_a = ECC_F_Table[ecc_a]; } ecc_a = ECC_B_Table[ECC_F_Table[ecc_a] ^ ecc_b]; if ( ecc[major] != (ecc_a) || ecc[major + major_count] != (ecc_a ^ ecc_b)) { return false; } } return true; } static bool? CheckCDSectorChannel(byte[] channel) { ECCInit(); if ( channel[0x000] == 0x00 && // sync (12 bytes) channel[0x001] == 0xFF && channel[0x002] == 0xFF && channel[0x003] == 0xFF && channel[0x004] == 0xFF && channel[0x005] == 0xFF && channel[0x006] == 0xFF && channel[0x007] == 0xFF && channel[0x008] == 0xFF && channel[0x009] == 0xFF && channel[0x00A] == 0xFF && channel[0x00B] == 0x00) { if (MainClass.isDebug) Console.WriteLine("DEBUG (CDChecksums): Data sector, address {0:X2}:{1:X2}:{2:X2}", channel[0x00C], channel[0x00D], channel[0x00E]); if (channel[0x00F] == 0x00) // mode (1 byte) { if (MainClass.isDebug) Console.WriteLine("DEBUG (CDChecksums): Mode 0 sector at address {0:X2}:{1:X2}:{2:X2}", channel[0x00C], channel[0x00D], channel[0x00E]); for (int i = 0x010; i < 0x930; i++) { if (channel[i] != 0x00) { if (MainClass.isDebug) Console.WriteLine("DEBUG (CDChecksums): Mode 0 sector with error at address: {0:X2}:{1:X2}:{2:X2}", channel[0x00C], channel[0x00D], channel[0x00E]); return false; } } return true; } else if (channel[0x00F] == 0x01) // mode (1 byte) { if (MainClass.isDebug) Console.WriteLine("DEBUG (CDChecksums): Mode 1 sector at address {0:X2}:{1:X2}:{2:X2}", channel[0x00C], channel[0x00D], channel[0x00E]); if (channel[0x814] != 0x00 || // reserved (8 bytes) channel[0x815] != 0x00 || channel[0x816] != 0x00 || channel[0x817] != 0x00 || channel[0x818] != 0x00 || channel[0x819] != 0x00 || channel[0x81A] != 0x00 || channel[0x81B] != 0x00) { if (MainClass.isDebug) Console.WriteLine("DEBUG (CDChecksums): Mode 1 sector with data in reserved bytes at address: {0:X2}:{1:X2}:{2:X2}", channel[0x00C], channel[0x00D], channel[0x00E]); return false; } byte[] address = new byte[4]; byte[] data = new byte[2060]; byte[] data2 = new byte[2232]; byte[] ecc_p = new byte[172]; byte[] ecc_q = new byte[104]; Array.Copy(channel, 0x0C, address, 0, 4); Array.Copy(channel, 0x0C, data, 0, 2060); Array.Copy(channel, 0x0C, data2, 0, 2232); Array.Copy(channel, 0x81C, ecc_p, 0, 172); Array.Copy(channel, 0x8C8, ecc_q, 0, 104); bool FailedECC_P = CheckECC(address, data, 86, 24, 2, 86, ecc_p); bool FailedECC_Q = CheckECC(address, data2, 52, 43, 86, 88, ecc_q); if (FailedECC_P) if (MainClass.isDebug) Console.WriteLine("DEBUG (CDChecksums): Mode 1 sector at address: {0:X2}:{1:X2}:{2:X2}, fails ECC P check", channel[0x00C], channel[0x00D], channel[0x00E]); if (FailedECC_Q) if (MainClass.isDebug) Console.WriteLine("DEBUG (CDChecksums): Mode 1 sector at address: {0:X2}:{1:X2}:{2:X2}, fails ECC Q check", channel[0x00C], channel[0x00D], channel[0x00E]); if (FailedECC_P || FailedECC_Q) return false; byte[] SectorForCheck = new byte[0x810]; UInt32 StoredEDC = BitConverter.ToUInt32(channel, 0x810); byte[] CalculatedEDCBytes; Array.Copy(channel, 0, SectorForCheck, 0, 0x810); CRC32Context.Data(SectorForCheck, 0x810, out CalculatedEDCBytes, CDCRC32Poly, CDCRC32Seed); UInt32 CalculatedEDC = BitConverter.ToUInt32(CalculatedEDCBytes, 0); if (CalculatedEDC != StoredEDC) { if (MainClass.isDebug) Console.WriteLine("DEBUG (CDChecksums): Mode 1 sector at address: {0:X2}:{1:X2}:{2:X2}, got CRC 0x{3:X8} expected 0x{4:X8}", channel[0x00C], channel[0x00D], channel[0x00E], CalculatedEDC, StoredEDC); return false; } return true; } else if (channel[0x00F] == 0x02) // mode (1 byte) { if (MainClass.isDebug) Console.WriteLine("DEBUG (CDChecksums): Mode 2 sector at address {0:X2}:{1:X2}:{2:X2}", channel[0x00C], channel[0x00D], channel[0x00E]); if ((channel[0x012] & 0x20) == 0x20) // mode 2 form 2 { if (channel[0x010] != channel[0x014] || channel[0x011] != channel[0x015] || channel[0x012] != channel[0x016] || channel[0x013] != channel[0x017]) { if (MainClass.isDebug) Console.WriteLine("DEBUG (CDChecksums): Subheader copies differ in mode 2 form 2 sector at address: {0:X2}:{1:X2}:{2:X2}", channel[0x00C], channel[0x00D], channel[0x00E]); } byte[] SectorForCheck = new byte[0x91C]; UInt32 StoredEDC = BitConverter.ToUInt32(channel, 0x92C); byte[] CalculatedEDCBytes; Array.Copy(channel, 0x10, SectorForCheck, 0, 0x91C); CRC32Context.Data(SectorForCheck, 0x91C, out CalculatedEDCBytes, CDCRC32Poly, CDCRC32Seed); UInt32 CalculatedEDC = BitConverter.ToUInt32(CalculatedEDCBytes, 0); if (CalculatedEDC != StoredEDC && StoredEDC != 0x00000000) { if (MainClass.isDebug) Console.WriteLine("DEBUG (CDChecksums): Mode 2 form 2 sector at address: {0:X2}:{1:X2}:{2:X2}, got CRC 0x{3:X8} expected 0x{4:X8}", channel[0x00C], channel[0x00D], channel[0x00E], CalculatedEDC, StoredEDC); return false; } } else { if (channel[0x010] != channel[0x014] || channel[0x011] != channel[0x015] || channel[0x012] != channel[0x016] || channel[0x013] != channel[0x017]) { if (MainClass.isDebug) Console.WriteLine("DEBUG (CDChecksums): Subheader copies differ in mode 2 form 1 sector at address: {0:X2}:{1:X2}:{2:X2}", channel[0x00C], channel[0x00D], channel[0x00E]); } byte[] address = new byte[4]; byte[] data = new byte[2060]; byte[] data2 = new byte[2232]; byte[] ecc_p = new byte[172]; byte[] ecc_q = new byte[104]; address[0] = 0; address[1] = 0; address[2] = 0; address[3] = 0; Array.Copy(channel, 0x0C, data, 0, 2060); Array.Copy(channel, 0x0C, data2, 0, 2232); Array.Copy(channel, 0x80C, ecc_p, 0, 172); Array.Copy(channel, 0x8B8, ecc_q, 0, 104); bool FailedECC_P = CheckECC(address, data, 86, 24, 2, 86, ecc_p); bool FailedECC_Q = CheckECC(address, data2, 52, 43, 86, 88, ecc_q); if (FailedECC_P) if (MainClass.isDebug) Console.WriteLine("DEBUG (CDChecksums): Mode 2 form 1 sector at address: {0:X2}:{1:X2}:{2:X2}, fails ECC P check", channel[0x00C], channel[0x00D], channel[0x00E]); if (FailedECC_Q) if (MainClass.isDebug) Console.WriteLine("DEBUG (CDChecksums): Mode 2 form 1 sector at address: {0:X2}:{1:X2}:{2:X2}, fails ECC Q check", channel[0x00F], channel[0x00C], channel[0x00D], channel[0x00E]); if (FailedECC_P || FailedECC_Q) return false; byte[] SectorForCheck = new byte[0x808]; UInt32 StoredEDC = BitConverter.ToUInt32(channel, 0x818); byte[] CalculatedEDCBytes; Array.Copy(channel, 0x10, SectorForCheck, 0, 0x808); CRC32Context.Data(SectorForCheck, 0x808, out CalculatedEDCBytes, CDCRC32Poly, CDCRC32Seed); UInt32 CalculatedEDC = BitConverter.ToUInt32(CalculatedEDCBytes, 0); if (CalculatedEDC != StoredEDC) { if (MainClass.isDebug) Console.WriteLine("DEBUG (CDChecksums): Mode 2 form 1 sector at address: {0:X2}:{1:X2}:{2:X2}, got CRC 0x{3:X8} expected 0x{4:X8}", channel[0x00C], channel[0x00D], channel[0x00E], CalculatedEDC, StoredEDC); return false; } } return true; } else { if (MainClass.isDebug) Console.WriteLine("DEBUG (CDChecksums): Unknown mode {0} sector at address: {1:X2}:{2:X2}:{3:X2}", channel[0x00F], channel[0x00C], channel[0x00D], channel[0x00E]); return null; } } else return null; } static bool? CheckCDSectorSubChannel(byte[] subchannel) { bool? status = true; byte[] QSubChannel = new byte[12]; byte[] CDTextPack1 = new byte[18]; byte[] CDTextPack2 = new byte[18]; byte[] CDTextPack3 = new byte[18]; byte[] CDTextPack4 = new byte[18]; int i = 0; for (int j = 0; j < 12; j++) QSubChannel[j] = 0; for (int j = 0; j < 18; j++) { CDTextPack1[j] = 0; CDTextPack2[j] = 0; CDTextPack3[j] = 0; CDTextPack4[j] = 0; } for (int j = 0; j < 12; j++) { QSubChannel[j] = (byte)(QSubChannel[j] | ((subchannel[i++] & 0x40) << 1)); QSubChannel[j] = (byte)(QSubChannel[j] | (subchannel[i++] & 0x40)); QSubChannel[j] = (byte)(QSubChannel[j] | ((subchannel[i++] & 0x40) >> 1)); QSubChannel[j] = (byte)(QSubChannel[j] | ((subchannel[i++] & 0x40) >> 2)); QSubChannel[j] = (byte)(QSubChannel[j] | ((subchannel[i++] & 0x40) >> 3)); QSubChannel[j] = (byte)(QSubChannel[j] | ((subchannel[i++] & 0x40) >> 4)); QSubChannel[j] = (byte)(QSubChannel[j] | ((subchannel[i++] & 0x40) >> 5)); QSubChannel[j] = (byte)(QSubChannel[j] | ((subchannel[i++] & 0x40) >> 6)); } i = 0; for (int j = 0; j < 18; j++) { if (j < 18) CDTextPack1[j] = (byte)(CDTextPack1[j] | ((subchannel[i++] & 0x3F) << 2)); if (j < 18) CDTextPack1[j] = (byte)(CDTextPack1[j++] | ((subchannel[i] & 0xC0) >> 4)); if (j < 18) CDTextPack1[j] = (byte)(CDTextPack1[j] | ((subchannel[i++] & 0x0F) << 4)); if (j < 18) CDTextPack1[j] = (byte)(CDTextPack1[j++] | ((subchannel[i] & 0x3C) >> 2)); if (j < 18) CDTextPack1[j] = (byte)(CDTextPack1[j] | ((subchannel[i++] & 0x03) << 6)); if (j < 18) CDTextPack1[j] = (byte)(CDTextPack1[j] | (subchannel[i++] & 0x3F)); } for (int j = 0; j < 18; j++) { if (j < 18) CDTextPack2[j] = (byte)(CDTextPack2[j] | ((subchannel[i++] & 0x3F) << 2)); if (j < 18) CDTextPack2[j] = (byte)(CDTextPack2[j++] | ((subchannel[i] & 0xC0) >> 4)); if (j < 18) CDTextPack2[j] = (byte)(CDTextPack2[j] | ((subchannel[i++] & 0x0F) << 4)); if (j < 18) CDTextPack2[j] = (byte)(CDTextPack2[j++] | ((subchannel[i] & 0x3C) >> 2)); if (j < 18) CDTextPack2[j] = (byte)(CDTextPack2[j] | ((subchannel[i++] & 0x03) << 6)); if (j < 18) CDTextPack2[j] = (byte)(CDTextPack2[j] | (subchannel[i++] & 0x3F)); } for (int j = 0; j < 18; j++) { if (j < 18) CDTextPack3[j] = (byte)(CDTextPack3[j] | ((subchannel[i++] & 0x3F) << 2)); if (j < 18) CDTextPack3[j] = (byte)(CDTextPack3[j++] | ((subchannel[i] & 0xC0) >> 4)); if (j < 18) CDTextPack3[j] = (byte)(CDTextPack3[j] | ((subchannel[i++] & 0x0F) << 4)); if (j < 18) CDTextPack3[j] = (byte)(CDTextPack3[j++] | ((subchannel[i] & 0x3C) >> 2)); if (j < 18) CDTextPack3[j] = (byte)(CDTextPack3[j] | ((subchannel[i++] & 0x03) << 6)); if (j < 18) CDTextPack3[j] = (byte)(CDTextPack3[j] | (subchannel[i++] & 0x3F)); } for (int j = 0; j < 18; j++) { if (j < 18) CDTextPack4[j] = (byte)(CDTextPack4[j] | ((subchannel[i++] & 0x3F) << 2)); if (j < 18) CDTextPack4[j] = (byte)(CDTextPack4[j++] | ((subchannel[i] & 0xC0) >> 4)); if (j < 18) CDTextPack4[j] = (byte)(CDTextPack4[j] | ((subchannel[i++] & 0x0F) << 4)); if (j < 18) CDTextPack4[j] = (byte)(CDTextPack4[j++] | ((subchannel[i] & 0x3C) >> 2)); if (j < 18) CDTextPack4[j] = (byte)(CDTextPack4[j] | ((subchannel[i++] & 0x03) << 6)); if (j < 18) CDTextPack4[j] = (byte)(CDTextPack4[j] | (subchannel[i++] & 0x3F)); } UInt16 QSubChannelCRC = BitConverter.ToUInt16(QSubChannel, 10); byte[] QSubChannelForCRC = new byte[10]; Array.Copy(QSubChannel, 0, QSubChannelForCRC, 0, 10); byte[] CalculatedQCRCBytes = new byte[2]; CRC16Context.Data(QSubChannelForCRC, out CalculatedQCRCBytes); UInt16 CalculatedQCRC = BitConverter.ToUInt16(CalculatedQCRCBytes, 0); if (QSubChannelCRC != CalculatedQCRC) { if (MainClass.isDebug) // Console.WriteLine("DEBUG (CDChecksums): Q subchannel CRC 0x{0:X4}, expected 0x{1:X4}", CalculatedQCRC, QSubChannelCRC); status = false; } UInt16 CDTextPack1CRC = BitConverter.ToUInt16(CDTextPack1, 16); byte[] CDTextPack1ForCRC = new byte[16]; Array.Copy(CDTextPack1, 0, CDTextPack1ForCRC, 0, 16); byte[] CalculatedCDTP1CRCBytes = new byte[2]; CRC16Context.Data(CDTextPack1ForCRC, out CalculatedCDTP1CRCBytes); UInt16 CalculatedCDTP1CRC = BitConverter.ToUInt16(CalculatedCDTP1CRCBytes, 0); if (CDTextPack1CRC != CalculatedCDTP1CRC && CDTextPack1CRC != 0) { if (MainClass.isDebug) // Console.WriteLine("DEBUG (CDChecksums): CD-Text Pack 1 CRC 0x{0:X4}, expected 0x{1:X4}", CDTextPack1CRC, CalculatedCDTP1CRC); status = false; } UInt16 CDTextPack2CRC = BitConverter.ToUInt16(CDTextPack2, 16); byte[] CDTextPack2ForCRC = new byte[16]; Array.Copy(CDTextPack2, 0, CDTextPack2ForCRC, 0, 16); byte[] CalculatedCDTP2CRCBytes = new byte[2]; CRC16Context.Data(CDTextPack2ForCRC, out CalculatedCDTP2CRCBytes); UInt16 CalculatedCDTP2CRC = BitConverter.ToUInt16(CalculatedCDTP2CRCBytes, 0); if (CDTextPack2CRC != CalculatedCDTP2CRC && CDTextPack2CRC != 0) { if (MainClass.isDebug) // Console.WriteLine("DEBUG (CDChecksums): CD-Text Pack 2 CRC 0x{0:X4}, expected 0x{1:X4}", CDTextPack2CRC, CalculatedCDTP2CRC); status = false; } UInt16 CDTextPack3CRC = BitConverter.ToUInt16(CDTextPack3, 16); byte[] CDTextPack3ForCRC = new byte[16]; Array.Copy(CDTextPack3, 0, CDTextPack3ForCRC, 0, 16); byte[] CalculatedCDTP3CRCBytes = new byte[2]; CRC16Context.Data(CDTextPack3ForCRC, out CalculatedCDTP3CRCBytes); UInt16 CalculatedCDTP3CRC = BitConverter.ToUInt16(CalculatedCDTP3CRCBytes, 0); if (CDTextPack3CRC != CalculatedCDTP3CRC && CDTextPack3CRC != 0) { if (MainClass.isDebug) // Console.WriteLine("DEBUG (CDChecksums): CD-Text Pack 3 CRC 0x{0:X4}, expected 0x{1:X4}", CDTextPack3CRC, CalculatedCDTP3CRC); status = false; } UInt16 CDTextPack4CRC = BitConverter.ToUInt16(CDTextPack4, 16); byte[] CDTextPack4ForCRC = new byte[16]; Array.Copy(CDTextPack4, 0, CDTextPack4ForCRC, 0, 16); byte[] CalculatedCDTP4CRCBytes = new byte[2]; CRC16Context.Data(CDTextPack4ForCRC, out CalculatedCDTP4CRCBytes); UInt16 CalculatedCDTP4CRC = BitConverter.ToUInt16(CalculatedCDTP4CRCBytes, 0); if (CDTextPack4CRC != CalculatedCDTP4CRC && CDTextPack4CRC != 0) { if (MainClass.isDebug) // Console.WriteLine("DEBUG (CDChecksums): CD-Text Pack 4 CRC 0x{0:X4}, expected 0x{1:X4}", CDTextPack4CRC, CalculatedCDTP4CRC); status = false; } // return status; // TODO: Correct CRC poly and seed // TODO: Detect CD-Text vs CD+G packets return null; } } }