From fd60149c373662906002089b11b5df288c249d81 Mon Sep 17 00:00:00 2001 From: Natalia Portillo Date: Mon, 25 Aug 2014 04:54:45 +0100 Subject: [PATCH] * DiscImageChef/Checksums/CDChecksums.cs: Implement CD EDC and ECC checks. * DiscImageChef/Checksums/CRC16Context.cs: Implements CRC16. * DiscImageChef/Checksums/CRC32Context.cs: * DiscImageChef/Checksums/CRC64Context.cs: Adds support to calculate custom CRCs on specified buffer. * DiscImageChef/DiscImageChef.csproj: DiscImageChef/Checksums/CDChecksums.cs --- DiscImageChef/Checksums/CDChecksums.cs | 501 ++++++++++++++++++++++++ DiscImageChef/Checksums/CRC16Context.cs | 235 +++++++++++ DiscImageChef/Checksums/CRC32Context.cs | 25 +- DiscImageChef/Checksums/CRC64Context.cs | 17 +- DiscImageChef/DiscImageChef.csproj | 2 + 5 files changed, 774 insertions(+), 6 deletions(-) create mode 100644 DiscImageChef/Checksums/CDChecksums.cs create mode 100644 DiscImageChef/Checksums/CRC16Context.cs diff --git a/DiscImageChef/Checksums/CDChecksums.cs b/DiscImageChef/Checksums/CDChecksums.cs new file mode 100644 index 00000000..14744fc3 --- /dev/null +++ b/DiscImageChef/Checksums/CDChecksums.cs @@ -0,0 +1,501 @@ +/*************************************************************************** +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; + } + } +} + diff --git a/DiscImageChef/Checksums/CRC16Context.cs b/DiscImageChef/Checksums/CRC16Context.cs new file mode 100644 index 00000000..1dcdaed2 --- /dev/null +++ b/DiscImageChef/Checksums/CRC16Context.cs @@ -0,0 +1,235 @@ +/*************************************************************************** +The Disc Image Chef +---------------------------------------------------------------------------- + +Filename : CRC16Context.cs +Version : 1.0 +Author(s) : Natalia Portillo + +Component : Checksums. + +Revision : $Revision$ +Last change by : $Author$ +Date : $Date$ + +--[ Description ] ---------------------------------------------------------- + +Implements a CRC16-CCITT algorithm. + +--[ 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 +****************************************************************************/ +//$Id$ +using System.Text; +using System.IO; +using System; + +namespace DiscImageChef.Checksums +{ + /// + /// Provides a UNIX similar API to calculate CRC16. + /// + public class CRC16Context + { + const UInt16 crc16Poly = 0x8408; + const UInt16 crc16Seed = 0xFFFF; + + UInt16[] table; + UInt16 hashInt; + + /// + /// Initializes the CRC16 table and seed + /// + public void Init() + { + hashInt = crc16Seed; + + table = new UInt16[256]; + for (int i = 0; i < 256; i++) + { + UInt16 entry = (UInt16)i; + for (int j = 0; j < 8; j++) + if ((entry & 1) == 1) + entry = (ushort)((entry >> 1) ^ crc16Poly); + else + entry = (ushort)(entry >> 1); + table[i] = entry; + } + } + + /// + /// Updates the hash with data. + /// + /// Data buffer. + /// Length of buffer to hash. + public void Update(byte[] data, uint len) + { + for (int i = 0; i < len; i++) + hashInt = (ushort)((hashInt >> 8) ^ table[data[i] ^ hashInt & 0xff]); + } + + /// + /// Updates the hash with data. + /// + /// Data buffer. + public void Update(byte[] data) + { + Update(data, (uint)data.Length); + } + + /// + /// Returns a byte array of the hash value. + /// + public byte[] Final() + { + hashInt ^= crc16Seed; + return BigEndianBitConverter.GetBytes(hashInt); + } + + /// + /// Returns a hexadecimal representation of the hash value. + /// + public string End() + { + hashInt ^= crc16Seed; + StringBuilder crc16Output = new StringBuilder(); + + for (int i = 0; i < BigEndianBitConverter.GetBytes(hashInt).Length; i++) + { + crc16Output.Append(BigEndianBitConverter.GetBytes(hashInt)[i].ToString("x2")); + } + + return crc16Output.ToString(); + } + + /// + /// Gets the hash of a file + /// + /// File path. + public static byte[] File(string filename) + { + byte[] hash; + File(filename, out hash); + return hash; + } + + /// + /// Gets the hash of a file in hexadecimal and as a byte array. + /// + /// File path. + /// Byte array of the hash value. + public static string File(string filename, out byte[] hash) + { + FileStream fileStream = new FileStream(filename, FileMode.Open); + UInt16[] localTable; + UInt16 localhashInt; + + localhashInt = crc16Seed; + + localTable = new UInt16[256]; + for (int i = 0; i < 256; i++) + { + UInt16 entry = (UInt16)i; + for (int j = 0; j < 8; j++) + if ((entry & 1) == 1) + entry = (ushort)((entry >> 1) ^ crc16Poly); + else + entry = (ushort)(entry >> 1); + localTable[i] = entry; + } + + for (int i = 0; i < fileStream.Length; i++) + localhashInt = (ushort)((localhashInt >> 8) ^ localTable[fileStream.ReadByte() ^ localhashInt & 0xff]); + + hash = BitConverter.GetBytes(localhashInt); + + StringBuilder crc16Output = new StringBuilder(); + + for (int i = 0; i < hash.Length; i++) + { + crc16Output.Append(hash[i].ToString("x2")); + } + + return crc16Output.ToString(); + } + + /// + /// Gets the hash of the specified data buffer. + /// + /// Data buffer. + /// Length of the data buffer to hash. + /// Byte array of the hash value. + public static string Data(byte[] data, uint len, out byte[] hash) + { + return Data(data, len, out hash, crc16Poly, crc16Seed); + } + + /// + /// Gets the hash of the specified data buffer. + /// + /// Data buffer. + /// Length of the data buffer to hash. + /// Byte array of the hash value. + /// CRC polynomial + /// CRC seed + public static string Data(byte[] data, uint len, out byte[] hash, UInt16 polynomial, UInt16 seed) + { + UInt16[] localTable; + UInt16 localhashInt; + + localhashInt = seed; + + localTable = new UInt16[256]; + for (int i = 0; i < 256; i++) + { + UInt16 entry = (UInt16)i; + for (int j = 0; j < 8; j++) + if ((entry & 1) == 1) + entry = (ushort)((entry >> 1) ^ polynomial); + else + entry = (ushort)(entry >> 1); + localTable[i] = entry; + } + + for (int i = 0; i < len; i++) + localhashInt = (ushort)((localhashInt >> 8) ^ localTable[data[i] ^ localhashInt & 0xff]); + + hash = BitConverter.GetBytes(localhashInt); + + StringBuilder crc16Output = new StringBuilder(); + + for (int i = 0; i < hash.Length; i++) + { + crc16Output.Append(hash[i].ToString("x2")); + } + + return crc16Output.ToString(); + } + + /// + /// Gets the hash of the specified data buffer. + /// + /// Data buffer. + /// Byte array of the hash value. + public static string Data(byte[] data, out byte[] hash) + { + return Data(data, (uint)data.Length, out hash); + } + } +} + diff --git a/DiscImageChef/Checksums/CRC32Context.cs b/DiscImageChef/Checksums/CRC32Context.cs index a3b8a2a5..5efef0d5 100644 --- a/DiscImageChef/Checksums/CRC32Context.cs +++ b/DiscImageChef/Checksums/CRC32Context.cs @@ -46,8 +46,12 @@ namespace DiscImageChef.Checksums /// public class CRC32Context { - const UInt32 crc32Poly = 0xEDB88320; - const UInt32 crc32Seed = 0xFFFFFFFF; + //const UInt32 crc32Poly = 0xEDB88320; + //const UInt32 crc32Seed = 0xFFFFFFFF; + + const UInt32 crc32Poly = 0xD8018001; + const UInt32 crc32Seed = 0x00000000; + UInt32[] table; UInt32 hashInt; @@ -175,11 +179,24 @@ namespace DiscImageChef.Checksums /// Length of the data buffer to hash. /// Byte array of the hash value. public static string Data(byte[] data, uint len, out byte[] hash) + { + return Data(data, len, out hash, crc32Poly, crc32Seed); + } + + /// + /// Gets the hash of the specified data buffer. + /// + /// Data buffer. + /// Length of the data buffer to hash. + /// Byte array of the hash value. + /// CRC polynomial + /// CRC seed + public static string Data(byte[] data, uint len, out byte[] hash, UInt32 polynomial, UInt32 seed) { UInt32[] localTable; UInt32 localhashInt; - localhashInt = crc32Seed; + localhashInt = seed; localTable = new UInt32[256]; for (int i = 0; i < 256; i++) @@ -187,7 +204,7 @@ namespace DiscImageChef.Checksums UInt32 entry = (UInt32)i; for (int j = 0; j < 8; j++) if ((entry & 1) == 1) - entry = (entry >> 1) ^ crc32Poly; + entry = (entry >> 1) ^ polynomial; else entry = entry >> 1; localTable[i] = entry; diff --git a/DiscImageChef/Checksums/CRC64Context.cs b/DiscImageChef/Checksums/CRC64Context.cs index 33d4f25d..6fb6ebb5 100644 --- a/DiscImageChef/Checksums/CRC64Context.cs +++ b/DiscImageChef/Checksums/CRC64Context.cs @@ -174,11 +174,24 @@ namespace DiscImageChef.Checksums /// Length of the data buffer to hash. /// Byte array of the hash value. public static string Data(byte[] data, uint len, out byte[] hash) + { + return Data(data, len, out hash, crc64Poly, crc64Seed); + } + + /// + /// Gets the hash of the specified data buffer. + /// + /// Data buffer. + /// Length of the data buffer to hash. + /// Byte array of the hash value. + /// CRC polynomial + /// CRC seed + public static string Data(byte[] data, uint len, out byte[] hash, UInt64 polynomial, UInt64 seed) { UInt64[] localTable; UInt64 localhashInt; - localhashInt = crc64Seed; + localhashInt = seed; localTable = new UInt64[256]; for (int i = 0; i < 256; i++) @@ -186,7 +199,7 @@ namespace DiscImageChef.Checksums UInt64 entry = (UInt64)i; for (int j = 0; j < 8; j++) if ((entry & 1) == 1) - entry = (entry >> 1) ^ crc64Poly; + entry = (entry >> 1) ^ polynomial; else entry = entry >> 1; localTable[i] = entry; diff --git a/DiscImageChef/DiscImageChef.csproj b/DiscImageChef/DiscImageChef.csproj index 43927254..9bcb3938 100644 --- a/DiscImageChef/DiscImageChef.csproj +++ b/DiscImageChef/DiscImageChef.csproj @@ -95,6 +95,8 @@ + +