// <copyright file="UnixCrypt.cs" company="Cédric Belin"> // This sourcecode is a port from Java to C#. // The original (Java) version was made by John Dumas and can be found at: http://www.dynamic.net.au/christos/crypt/UnixCrypt.txt // </copyright> // <summary> // Implémentation de la classe <c>DigiWar.Security.Cryptography.UnixCrypt</c>. // </summary> // <author>$Author: cedx $</author> // <date>$Date: 2009-09-10 19:44:34 +0200 (jeu. 10 sept. 2009) $</date> // <version>$Revision: 1827 $</version> using System; using System.Linq; using System.Text; //// /// <summary> /// Provides the Unix crypt() encryption algorithm. /// </summary> /// <remarks> /// This class is a port from Java source. I do not understand the underlying algorithms, I just converted it to C# and it works. /// Because I do not understand the underlying algorithms I cannot give most of the variables useful names. I have no clue what their /// significance is. I tried to give the variable names as much meaning as possible, but the original source just called them a, b, c , etc... /// /// A very important thing to note is that all ints in this code are UNSIGNED ints! Do not change this, ever!!! It will seriously fuckup the working /// of this class. It uses major bitshifting and while Java gives you the >>> operator to signify a right bitshift WITHOUT setting the MSB for /// a signed int, C# does not have this operator and will just set the new MSB for you if it happened to be set the moment you bitshifted it. /// This is undesirable for most bitshifts and in the cases it did matter, I casted the variable back to an int. This was only required where /// a variable was on the right-side of a bitshift operator. /// </remarks> internal static class UnixCrypt { /// <value> /// The list with characters allowed in a Unix encrypted password. /// It is used to randomly chose two characters for use in the encryption. /// </value> private const string m_encryptionSaltCharacters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789./"; /// <value> /// A lookup-table, presumably filled with some sort of encryption key. /// It is used to calculate the index to the m_SPTranslationTable lookup-table. /// </value> private static readonly uint[] m_saltTranslation = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, 0x3E, 0x3F, 0x00, 0x00, 0x00, 0x00, 0x00, }; /// <value> /// A lookup-table. /// It is used to calculate the index to the m_skb lookup-table. /// </value> private static readonly bool[] m_shifts = { false, false, true, true, true, true, true, true, false, true, true, true, true, true, true, false }; /// <value> /// A lookup-table. /// It is used the dynamically create the schedule lookup-table. /// </value> private static readonly uint[,] m_skb = { { /* for C bits (numbered as per FIPS 46) 1 2 3 4 5 6 */ 0x00000000, 0x00000010, 0x20000000, 0x20000010, 0x00010000, 0x00010010, 0x20010000, 0x20010010, 0x00000800, 0x00000810, 0x20000800, 0x20000810, 0x00010800, 0x00010810, 0x20010800, 0x20010810, 0x00000020, 0x00000030, 0x20000020, 0x20000030, 0x00010020, 0x00010030, 0x20010020, 0x20010030, 0x00000820, 0x00000830, 0x20000820, 0x20000830, 0x00010820, 0x00010830, 0x20010820, 0x20010830, 0x00080000, 0x00080010, 0x20080000, 0x20080010, 0x00090000, 0x00090010, 0x20090000, 0x20090010, 0x00080800, 0x00080810, 0x20080800, 0x20080810, 0x00090800, 0x00090810, 0x20090800, 0x20090810, 0x00080020, 0x00080030, 0x20080020, 0x20080030, 0x00090020, 0x00090030, 0x20090020, 0x20090030, 0x00080820, 0x00080830, 0x20080820, 0x20080830, 0x00090820, 0x00090830, 0x20090820, 0x20090830, }, { /* for C bits (numbered as per FIPS 46) 7 8 10 11 12 13 */ 0x00000000, 0x02000000, 0x00002000, 0x02002000, 0x00200000, 0x02200000, 0x00202000, 0x02202000, 0x00000004, 0x02000004, 0x00002004, 0x02002004, 0x00200004, 0x02200004, 0x00202004, 0x02202004, 0x00000400, 0x02000400, 0x00002400, 0x02002400, 0x00200400, 0x02200400, 0x00202400, 0x02202400, 0x00000404, 0x02000404, 0x00002404, 0x02002404, 0x00200404, 0x02200404, 0x00202404, 0x02202404, 0x10000000, 0x12000000, 0x10002000, 0x12002000, 0x10200000, 0x12200000, 0x10202000, 0x12202000, 0x10000004, 0x12000004, 0x10002004, 0x12002004, 0x10200004, 0x12200004, 0x10202004, 0x12202004, 0x10000400, 0x12000400, 0x10002400, 0x12002400, 0x10200400, 0x12200400, 0x10202400, 0x12202400, 0x10000404, 0x12000404, 0x10002404, 0x12002404, 0x10200404, 0x12200404, 0x10202404, 0x12202404, }, { /* for C bits (numbered as per FIPS 46) 14 15 16 17 19 20 */ 0x00000000, 0x00000001, 0x00040000, 0x00040001, 0x01000000, 0x01000001, 0x01040000, 0x01040001, 0x00000002, 0x00000003, 0x00040002, 0x00040003, 0x01000002, 0x01000003, 0x01040002, 0x01040003, 0x00000200, 0x00000201, 0x00040200, 0x00040201, 0x01000200, 0x01000201, 0x01040200, 0x01040201, 0x00000202, 0x00000203, 0x00040202, 0x00040203, 0x01000202, 0x01000203, 0x01040202, 0x01040203, 0x08000000, 0x08000001, 0x08040000, 0x08040001, 0x09000000, 0x09000001, 0x09040000, 0x09040001, 0x08000002, 0x08000003, 0x08040002, 0x08040003, 0x09000002, 0x09000003, 0x09040002, 0x09040003, 0x08000200, 0x08000201, 0x08040200, 0x08040201, 0x09000200, 0x09000201, 0x09040200, 0x09040201, 0x08000202, 0x08000203, 0x08040202, 0x08040203, 0x09000202, 0x09000203, 0x09040202, 0x09040203, }, { /* for C bits (numbered as per FIPS 46) 21 23 24 26 27 28 */ 0x00000000, 0x00100000, 0x00000100, 0x00100100, 0x00000008, 0x00100008, 0x00000108, 0x00100108, 0x00001000, 0x00101000, 0x00001100, 0x00101100, 0x00001008, 0x00101008, 0x00001108, 0x00101108, 0x04000000, 0x04100000, 0x04000100, 0x04100100, 0x04000008, 0x04100008, 0x04000108, 0x04100108, 0x04001000, 0x04101000, 0x04001100, 0x04101100, 0x04001008, 0x04101008, 0x04001108, 0x04101108, 0x00020000, 0x00120000, 0x00020100, 0x00120100, 0x00020008, 0x00120008, 0x00020108, 0x00120108, 0x00021000, 0x00121000, 0x00021100, 0x00121100, 0x00021008, 0x00121008, 0x00021108, 0x00121108, 0x04020000, 0x04120000, 0x04020100, 0x04120100, 0x04020008, 0x04120008, 0x04020108, 0x04120108, 0x04021000, 0x04121000, 0x04021100, 0x04121100, 0x04021008, 0x04121008, 0x04021108, 0x04121108, }, { /* for D bits (numbered as per FIPS 46) 1 2 3 4 5 6 */ 0x00000000, 0x10000000, 0x00010000, 0x10010000, 0x00000004, 0x10000004, 0x00010004, 0x10010004, 0x20000000, 0x30000000, 0x20010000, 0x30010000, 0x20000004, 0x30000004, 0x20010004, 0x30010004, 0x00100000, 0x10100000, 0x00110000, 0x10110000, 0x00100004, 0x10100004, 0x00110004, 0x10110004, 0x20100000, 0x30100000, 0x20110000, 0x30110000, 0x20100004, 0x30100004, 0x20110004, 0x30110004, 0x00001000, 0x10001000, 0x00011000, 0x10011000, 0x00001004, 0x10001004, 0x00011004, 0x10011004, 0x20001000, 0x30001000, 0x20011000, 0x30011000, 0x20001004, 0x30001004, 0x20011004, 0x30011004, 0x00101000, 0x10101000, 0x00111000, 0x10111000, 0x00101004, 0x10101004, 0x00111004, 0x10111004, 0x20101000, 0x30101000, 0x20111000, 0x30111000, 0x20101004, 0x30101004, 0x20111004, 0x30111004, }, { /* for D bits (numbered as per FIPS 46) 8 9 11 12 13 14 */ 0x00000000, 0x08000000, 0x00000008, 0x08000008, 0x00000400, 0x08000400, 0x00000408, 0x08000408, 0x00020000, 0x08020000, 0x00020008, 0x08020008, 0x00020400, 0x08020400, 0x00020408, 0x08020408, 0x00000001, 0x08000001, 0x00000009, 0x08000009, 0x00000401, 0x08000401, 0x00000409, 0x08000409, 0x00020001, 0x08020001, 0x00020009, 0x08020009, 0x00020401, 0x08020401, 0x00020409, 0x08020409, 0x02000000, 0x0A000000, 0x02000008, 0x0A000008, 0x02000400, 0x0A000400, 0x02000408, 0x0A000408, 0x02020000, 0x0A020000, 0x02020008, 0x0A020008, 0x02020400, 0x0A020400, 0x02020408, 0x0A020408, 0x02000001, 0x0A000001, 0x02000009, 0x0A000009, 0x02000401, 0x0A000401, 0x02000409, 0x0A000409, 0x02020001, 0x0A020001, 0x02020009, 0x0A020009, 0x02020401, 0x0A020401, 0x02020409, 0x0A020409, }, { /* for D bits (numbered as per FIPS 46) 16 17 18 19 20 21 */ 0x00000000, 0x00000100, 0x00080000, 0x00080100, 0x01000000, 0x01000100, 0x01080000, 0x01080100, 0x00000010, 0x00000110, 0x00080010, 0x00080110, 0x01000010, 0x01000110, 0x01080010, 0x01080110, 0x00200000, 0x00200100, 0x00280000, 0x00280100, 0x01200000, 0x01200100, 0x01280000, 0x01280100, 0x00200010, 0x00200110, 0x00280010, 0x00280110, 0x01200010, 0x01200110, 0x01280010, 0x01280110, 0x00000200, 0x00000300, 0x00080200, 0x00080300, 0x01000200, 0x01000300, 0x01080200, 0x01080300, 0x00000210, 0x00000310, 0x00080210, 0x00080310, 0x01000210, 0x01000310, 0x01080210, 0x01080310, 0x00200200, 0x00200300, 0x00280200, 0x00280300, 0x01200200, 0x01200300, 0x01280200, 0x01280300, 0x00200210, 0x00200310, 0x00280210, 0x00280310, 0x01200210, 0x01200310, 0x01280210, 0x01280310, }, { /* for D bits (numbered as per FIPS 46) 22 23 24 25 27 28 */ 0x00000000, 0x04000000, 0x00040000, 0x04040000, 0x00000002, 0x04000002, 0x00040002, 0x04040002, 0x00002000, 0x04002000, 0x00042000, 0x04042000, 0x00002002, 0x04002002, 0x00042002, 0x04042002, 0x00000020, 0x04000020, 0x00040020, 0x04040020, 0x00000022, 0x04000022, 0x00040022, 0x04040022, 0x00002020, 0x04002020, 0x00042020, 0x04042020, 0x00002022, 0x04002022, 0x00042022, 0x04042022, 0x00000800, 0x04000800, 0x00040800, 0x04040800, 0x00000802, 0x04000802, 0x00040802, 0x04040802, 0x00002800, 0x04002800, 0x00042800, 0x04042800, 0x00002802, 0x04002802, 0x00042802, 0x04042802, 0x00000820, 0x04000820, 0x00040820, 0x04040820, 0x00000822, 0x04000822, 0x00040822, 0x04040822, 0x00002820, 0x04002820, 0x00042820, 0x04042820, 0x00002822, 0x04002822, 0x00042822, 0x04042822, } }; /// <value> /// A lookup-table. /// It is used to calculate two ints that are used to encrypt the password. /// </value> private static readonly uint[,] m_SPTranslationTable = { { /* nibble 0 */ 0x00820200, 0x00020000, 0x80800000, 0x80820200, 0x00800000, 0x80020200, 0x80020000, 0x80800000, 0x80020200, 0x00820200, 0x00820000, 0x80000200, 0x80800200, 0x00800000, 0x00000000, 0x80020000, 0x00020000, 0x80000000, 0x00800200, 0x00020200, 0x80820200, 0x00820000, 0x80000200, 0x00800200, 0x80000000, 0x00000200, 0x00020200, 0x80820000, 0x00000200, 0x80800200, 0x80820000, 0x00000000, 0x00000000, 0x80820200, 0x00800200, 0x80020000, 0x00820200, 0x00020000, 0x80000200, 0x00800200, 0x80820000, 0x00000200, 0x00020200, 0x80800000, 0x80020200, 0x80000000, 0x80800000, 0x00820000, 0x80820200, 0x00020200, 0x00820000, 0x80800200, 0x00800000, 0x80000200, 0x80020000, 0x00000000, 0x00020000, 0x00800000, 0x80800200, 0x00820200, 0x80000000, 0x80820000, 0x00000200, 0x80020200, }, { /* nibble 1 */ 0x10042004, 0x00000000, 0x00042000, 0x10040000, 0x10000004, 0x00002004, 0x10002000, 0x00042000, 0x00002000, 0x10040004, 0x00000004, 0x10002000, 0x00040004, 0x10042000, 0x10040000, 0x00000004, 0x00040000, 0x10002004, 0x10040004, 0x00002000, 0x00042004, 0x10000000, 0x00000000, 0x00040004, 0x10002004, 0x00042004, 0x10042000, 0x10000004, 0x10000000, 0x00040000, 0x00002004, 0x10042004, 0x00040004, 0x10042000, 0x10002000, 0x00042004, 0x10042004, 0x00040004, 0x10000004, 0x00000000, 0x10000000, 0x00002004, 0x00040000, 0x10040004, 0x00002000, 0x10000000, 0x00042004, 0x10002004, 0x10042000, 0x00002000, 0x00000000, 0x10000004, 0x00000004, 0x10042004, 0x00042000, 0x10040000, 0x10040004, 0x00040000, 0x00002004, 0x10002000, 0x10002004, 0x00000004, 0x10040000, 0x00042000, }, { /* nibble 2 */ 0x41000000, 0x01010040, 0x00000040, 0x41000040, 0x40010000, 0x01000000, 0x41000040, 0x00010040, 0x01000040, 0x00010000, 0x01010000, 0x40000000, 0x41010040, 0x40000040, 0x40000000, 0x41010000, 0x00000000, 0x40010000, 0x01010040, 0x00000040, 0x40000040, 0x41010040, 0x00010000, 0x41000000, 0x41010000, 0x01000040, 0x40010040, 0x01010000, 0x00010040, 0x00000000, 0x01000000, 0x40010040, 0x01010040, 0x00000040, 0x40000000, 0x00010000, 0x40000040, 0x40010000, 0x01010000, 0x41000040, 0x00000000, 0x01010040, 0x00010040, 0x41010000, 0x40010000, 0x01000000, 0x41010040, 0x40000000, 0x40010040, 0x41000000, 0x01000000, 0x41010040, 0x00010000, 0x01000040, 0x41000040, 0x00010040, 0x01000040, 0x00000000, 0x41010000, 0x40000040, 0x41000000, 0x40010040, 0x00000040, 0x01010000, }, { /* nibble 3 */ 0x00100402, 0x04000400, 0x00000002, 0x04100402, 0x00000000, 0x04100000, 0x04000402, 0x00100002, 0x04100400, 0x04000002, 0x04000000, 0x00000402, 0x04000002, 0x00100402, 0x00100000, 0x04000000, 0x04100002, 0x00100400, 0x00000400, 0x00000002, 0x00100400, 0x04000402, 0x04100000, 0x00000400, 0x00000402, 0x00000000, 0x00100002, 0x04100400, 0x04000400, 0x04100002, 0x04100402, 0x00100000, 0x04100002, 0x00000402, 0x00100000, 0x04000002, 0x00100400, 0x04000400, 0x00000002, 0x04100000, 0x04000402, 0x00000000, 0x00000400, 0x00100002, 0x00000000, 0x04100002, 0x04100400, 0x00000400, 0x04000000, 0x04100402, 0x00100402, 0x00100000, 0x04100402, 0x00000002, 0x04000400, 0x00100402, 0x00100002, 0x00100400, 0x04100000, 0x04000402, 0x00000402, 0x04000000, 0x04000002, 0x04100400, }, { /* nibble 4 */ 0x02000000, 0x00004000, 0x00000100, 0x02004108, 0x02004008, 0x02000100, 0x00004108, 0x02004000, 0x00004000, 0x00000008, 0x02000008, 0x00004100, 0x02000108, 0x02004008, 0x02004100, 0x00000000, 0x00004100, 0x02000000, 0x00004008, 0x00000108, 0x02000100, 0x00004108, 0x00000000, 0x02000008, 0x00000008, 0x02000108, 0x02004108, 0x00004008, 0x02004000, 0x00000100, 0x00000108, 0x02004100, 0x02004100, 0x02000108, 0x00004008, 0x02004000, 0x00004000, 0x00000008, 0x02000008, 0x02000100, 0x02000000, 0x00004100, 0x02004108, 0x00000000, 0x00004108, 0x02000000, 0x00000100, 0x00004008, 0x02000108, 0x00000100, 0x00000000, 0x02004108, 0x02004008, 0x02004100, 0x00000108, 0x00004000, 0x00004100, 0x02004008, 0x02000100, 0x00000108, 0x00000008, 0x00004108, 0x02004000, 0x02000008, }, { /* nibble 5 */ 0x20000010, 0x00080010, 0x00000000, 0x20080800, 0x00080010, 0x00000800, 0x20000810, 0x00080000, 0x00000810, 0x20080810, 0x00080800, 0x20000000, 0x20000800, 0x20000010, 0x20080000, 0x00080810, 0x00080000, 0x20000810, 0x20080010, 0x00000000, 0x00000800, 0x00000010, 0x20080800, 0x20080010, 0x20080810, 0x20080000, 0x20000000, 0x00000810, 0x00000010, 0x00080800, 0x00080810, 0x20000800, 0x00000810, 0x20000000, 0x20000800, 0x00080810, 0x20080800, 0x00080010, 0x00000000, 0x20000800, 0x20000000, 0x00000800, 0x20080010, 0x00080000, 0x00080010, 0x20080810, 0x00080800, 0x00000010, 0x20080810, 0x00080800, 0x00080000, 0x20000810, 0x20000010, 0x20080000, 0x00080810, 0x00000000, 0x00000800, 0x20000010, 0x20000810, 0x20080800, 0x20080000, 0x00000810, 0x00000010, 0x20080010, }, { /* nibble 6 */ 0x00001000, 0x00000080, 0x00400080, 0x00400001, 0x00401081, 0x00001001, 0x00001080, 0x00000000, 0x00400000, 0x00400081, 0x00000081, 0x00401000, 0x00000001, 0x00401080, 0x00401000, 0x00000081, 0x00400081, 0x00001000, 0x00001001, 0x00401081, 0x00000000, 0x00400080, 0x00400001, 0x00001080, 0x00401001, 0x00001081, 0x00401080, 0x00000001, 0x00001081, 0x00401001, 0x00000080, 0x00400000, 0x00001081, 0x00401000, 0x00401001, 0x00000081, 0x00001000, 0x00000080, 0x00400000, 0x00401001, 0x00400081, 0x00001081, 0x00001080, 0x00000000, 0x00000080, 0x00400001, 0x00000001, 0x00400080, 0x00000000, 0x00400081, 0x00400080, 0x00001080, 0x00000081, 0x00001000, 0x00401081, 0x00400000, 0x00401080, 0x00000001, 0x00001001, 0x00401081, 0x00400001, 0x00401080, 0x00401000, 0x00001001, }, { /* nibble 7 */ 0x08200020, 0x08208000, 0x00008020, 0x00000000, 0x08008000, 0x00200020, 0x08200000, 0x08208020, 0x00000020, 0x08000000, 0x00208000, 0x00008020, 0x00208020, 0x08008020, 0x08000020, 0x08200000, 0x00008000, 0x00208020, 0x00200020, 0x08008000, 0x08208020, 0x08000020, 0x00000000, 0x00208000, 0x08000000, 0x00200000, 0x08008020, 0x08200020, 0x00200000, 0x00008000, 0x08208000, 0x00000020, 0x00200000, 0x00008000, 0x08000020, 0x08208020, 0x00008020, 0x08000000, 0x00000000, 0x00208000, 0x08200020, 0x08008020, 0x08008000, 0x00200020, 0x08208000, 0x00000020, 0x00200020, 0x08008000, 0x08208020, 0x00200000, 0x08200000, 0x08000020, 0x00208000, 0x00008020, 0x08008020, 0x08200000, 0x00000020, 0x08208000, 0x00208020, 0x00000000, 0x08000000, 0x08200020, 0x00008000, 0x00208020 } }; /// <value> /// A lookup-table filled with printable characters. /// It is used to make sure the encrypted password contains only printable characters. It is filled with /// ASCII characters 46 - 122 (from the dot (.) untill (including) the lowercase 'z'). /// </value> private static readonly uint[] m_characterConversionTable = { 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5A, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7A }; /// <value> /// Marks the size of the dynamically created schedule lookup-table. /// </value> private const int m_desIterations = 16; /// <summary> /// Converts four seperate bytes into one uint. /// </summary> /// <param name="inputBytes">The bytes to use for the conversion.</param> /// <param name="offset">The offset at which to start in the inputBytes buffer.</param> /// <returns></returns> private static uint FourBytesToInt(byte[] inputBytes, uint offset) { // I used an int here because the compiler would complain the stuff below would require a cast from int to uint. // To keep the code cleaner I opted to use an int and cast it when I returned it. int resultValue = 0; resultValue = (inputBytes[offset++] & 0xFF); resultValue |= (inputBytes[offset++] & 0xFF) << 8; resultValue |= (inputBytes[offset++] & 0xFF) << 16; resultValue |= (inputBytes[offset++]& 0xFF) << 24; return (uint)resultValue; } /// <summary> /// Converts an uint into 4 seperate bytes. /// </summary> /// <param name="inputInt">The uint to convert.</param> /// <param name="outputBytes">The byte buffer into which to store the result.</param> /// <param name="offset">The offset to start storing at in the outputBytes buffer.</param> private static void IntToFourBytes(uint inputInt, byte[] outputBytes, uint offset) { outputBytes[offset++] = (byte)(inputInt & 0xFF); outputBytes[offset++] = (byte)((inputInt >> 8) & 0xFF); outputBytes[offset++] = (byte)((inputInt >> 16) & 0xFF); outputBytes[offset++] = (byte)((inputInt >> 24) & 0xFF); } /// <summary> /// Performs some operation on 4 uints. It's labeled PERM_OP in the original source. /// </summary> /// <param name="firstInt">The first uint to use.</param> /// <param name="secondInt">The second uint to use.</param> /// <param name="thirdInt">The third uint to use.</param> /// <param name="fourthInt">The fourth uint to use.</param> /// <param name="operationResults">An array of 2 uints that are the result of this operation.</param> private static void PermOperation(uint firstInt, uint secondInt, uint thirdInt, uint fourthInt, uint[] operationResults) { // Because here an uint variable is at the right side of a bitshift, I needed to cast it to int. See the remarks of the class itself // for more details. uint tempInt = ((firstInt >> (int)thirdInt) ^ secondInt) & fourthInt; firstInt ^= tempInt << (int)thirdInt; secondInt ^= tempInt; operationResults[0] = firstInt; operationResults[1] = secondInt; } /// <summary> /// Performs some operation on 3 uints. It's labeled HPERM_OP in the original source. /// </summary> /// <param name="firstInt">The first uint to use.</param> /// <param name="secondInt">The second int to use.</param> /// <param name="thirdInt">The third uint to use.</param> /// <returns>An int that is the result of this operation.</returns> private static uint HPermOperation(uint firstInt, int secondInt, uint thirdInt) { // The variable secondInt is always used to calculate the number at the right side of a // bitshift. It is not used anywhere else, so I made the method parameter an int, to avoid // unnecessary casting. uint tempInt = ((firstInt << (16 - secondInt)) ^ firstInt) & thirdInt; uint returnInt = firstInt ^ tempInt ^ (tempInt >> (16 - secondInt)); return returnInt; } /// <summary> /// This method does some very complex bit manipulations. /// </summary> /// <param name="encryptionKey">The input data to use for the bit manipulations.</param> /// <returns>m_desIterations * 2 number of uints that are the result of the manipulations.</returns> private static uint[] SetDESKey(byte[] encryptionKey) { uint[] schedule = new uint[m_desIterations * 2]; uint firstInt = FourBytesToInt(encryptionKey, 0); uint secondInt = FourBytesToInt(encryptionKey, 4); uint[] operationResults = new uint[2]; PermOperation(secondInt, firstInt, 4, 0x0F0F0F0F, operationResults); secondInt = operationResults[0]; firstInt = operationResults[1]; firstInt = HPermOperation(firstInt, -2, 0xCCCC0000); secondInt = HPermOperation(secondInt, -2, 0xCCCC0000); PermOperation(secondInt, firstInt, 1, 0x55555555, operationResults); secondInt = operationResults[0]; firstInt = operationResults[1]; PermOperation(firstInt, secondInt, 8, 0x00FF00FF, operationResults); firstInt = operationResults[0]; secondInt = operationResults[1]; PermOperation(secondInt, firstInt, 1, 0x55555555, operationResults); secondInt = operationResults[0]; firstInt = operationResults[1]; secondInt = (((secondInt & 0xFF) << 16) | (secondInt & 0xFF00) | ((secondInt & 0xFF0000) >> 16) | ((firstInt & 0xF0000000) >> 4)); firstInt &= 0x0FFFFFFF; bool needToShift; uint firstSkbValue, secondSkbValue; uint scheduleIndex = 0; for(int index = 0; index < m_desIterations; index++) { needToShift = m_shifts[index]; if(needToShift) { firstInt = (firstInt >> 2) | (firstInt << 26); secondInt = (secondInt >> 2) | (secondInt << 26); } else { firstInt = (firstInt >> 1) | (firstInt << 27); secondInt = (secondInt >> 1) | (secondInt << 27); } firstInt &= 0x0FFFFFFF; secondInt &= 0xFFFFFFF; firstSkbValue = m_skb[0, firstInt & 0x3F] | m_skb[1, ((firstInt >> 6) & 0x03) | ((firstInt >> 7) & 0x3C)] | m_skb[2, ((firstInt >> 13) & 0x0F) | ((firstInt >> 14) & 0x30)] | m_skb[3, ((firstInt >> 20) & 0x01) | ((firstInt >> 21) & 0x06) | ((firstInt >> 22) & 0x38)]; secondSkbValue = m_skb[4, secondInt & 0x3F] | m_skb[5, ((secondInt >> 7) & 0x03) | ((secondInt >> 8) & 0x3C)] | m_skb[6, (secondInt >> 15) & 0x3F] | m_skb[7, ((secondInt >> 21) & 0x0F) | ((secondInt >> 22) & 0x30)]; schedule[scheduleIndex++] = ((secondSkbValue << 16) | (firstSkbValue & 0xFFFF)) & 0xFFFFFFFF; firstSkbValue = ((firstSkbValue >> 16) | (secondSkbValue & 0xFFFF0000)); firstSkbValue = (firstSkbValue << 4) | (firstSkbValue >> 28); schedule[scheduleIndex++] = firstSkbValue & 0xFFFFFFFF; } return schedule; } /// <summary> /// This method does some bit manipulations. /// </summary> /// <param name="left">An input that is manipulated and then used for output.</param> /// <param name="right">This is used for the bit manipulation.</param> /// <param name="scheduleIndex">The index of an uint to use from the schedule array.</param> /// <param name="firstSaltTranslator">The translated salt for the first salt character.</param> /// <param name="secondSaltTranslator">The translated salt for the second salt character.</param> /// <param name="schedule">The schedule arrray calculated before.</param> /// <returns>The result of these manipulations.</returns> private static uint DEncrypt(uint left, uint right, uint scheduleIndex, uint firstSaltTranslator, uint secondSaltTranslator, uint[] schedule) { uint firstInt, secondInt, thirdInt; thirdInt = right ^ (right >> 16); secondInt = thirdInt & firstSaltTranslator; thirdInt = thirdInt & secondSaltTranslator; secondInt = (secondInt ^ (secondInt << 16)) ^ right ^ schedule[scheduleIndex]; firstInt = (thirdInt ^ (thirdInt << 16)) ^ right ^ schedule[scheduleIndex+1]; firstInt = (firstInt >> 4) | (firstInt << 28); left ^= (m_SPTranslationTable[1, firstInt & 0x3F] | m_SPTranslationTable[3, (firstInt >> 8) & 0x3F] | m_SPTranslationTable[5, (firstInt >> 16) & 0x3F] | m_SPTranslationTable[7, (firstInt >> 24) & 0x3F] | m_SPTranslationTable[0, secondInt & 0x3F] | m_SPTranslationTable[2, (secondInt >> 8) & 0x3F] | m_SPTranslationTable[4, (secondInt >> 16) & 0x3F] | m_SPTranslationTable[6, (secondInt >> 24) & 0x3F]); return left; } /// <summary> /// Calculates two uints that are used to encrypt the password. /// </summary> /// <param name="schedule">The schedule table calculated earlier.</param> /// <param name="firstSaltTranslator">The first translated salt character.</param> /// <param name="secondSaltTranslator">The second translated salt character.</param> /// <returns>2 uints in an array.</returns> private static uint[] Body(uint[] schedule, uint firstSaltTranslator, uint secondSaltTranslator) { uint left = 0; uint right = 0; uint tempInt; for(int index = 0; index < 25; index++) { for(uint secondIndex = 0; secondIndex < m_desIterations * 2; secondIndex += 4) { left = DEncrypt(left, right, secondIndex, firstSaltTranslator, secondSaltTranslator, schedule); right = DEncrypt(right, left, secondIndex + 2, firstSaltTranslator, secondSaltTranslator, schedule); } tempInt = left; left = right; right = tempInt; } tempInt = right; right = (left >> 1) | (left << 31); left = (tempInt >> 1) | (tempInt << 31); left &= 0xFFFFFFFF; right &= 0xFFFFFFFF; uint[] operationResults = new uint[2]; PermOperation(right, left, 1, 0x55555555, operationResults); right = operationResults[0]; left = operationResults[1]; PermOperation(left, right, 8, 0x00FF00FF, operationResults); left = operationResults[0]; right = operationResults[1]; PermOperation(right, left, 2, 0x33333333, operationResults); right = operationResults[0]; left = operationResults[1]; PermOperation(left, right, 16, 0xFFFF, operationResults); left = operationResults[0]; right = operationResults[1]; PermOperation(right, left, 4, 0x0F0F0F0F, operationResults); right = operationResults[0]; left = operationResults[1]; uint[] singleOutputKey = new uint[2]; singleOutputKey[0] = left; singleOutputKey[1] = right; return singleOutputKey; } /// <summary> /// Automatically generate the encryption salt (2 random printable characters for use in the encryption) and call the Crypt() method. /// </summary> /// <param name="textToEncrypt">The text that must be encrypted.</param> /// <returns>The encrypted text.</returns> public static string Crypt(string textToEncrypt) { Random randomGenerator = new Random(); int maxGeneratedNumber = m_encryptionSaltCharacters.Length; int randomIndex; StringBuilder encryptionSaltBuilder = new StringBuilder(); for(int index = 0; index < 2; index++) { randomIndex = randomGenerator.Next(maxGeneratedNumber); encryptionSaltBuilder.Append(m_encryptionSaltCharacters[randomIndex]); } string encryptionSalt = encryptionSaltBuilder.ToString(); string encryptedString = Crypt(encryptionSalt, textToEncrypt); return encryptedString; } /// <summary> /// Encrypts the specified string using the Unix crypt algorithm. /// </summary> /// <param name="encryptionSalt">2 random printable characters that are used to randomize the encryption.</param> /// <param name="textToEncrypt">The text that must be encrypted.</param> /// <returns>The encrypted text.</returns> public static string Crypt(string encryptionSalt, string textToEncrypt) { if(encryptionSalt==null) throw new ArgumentNullException("encryptionSalt"); if(textToEncrypt==null) throw new ArgumentNullException("textToEncrypt"); bool isSaltTooSmall = (encryptionSalt.Length < 2); if(isSaltTooSmall) { throw new ArgumentException("The encryptionSalt must be 2 characters big."); } char firstSaltCharacter = encryptionSalt[0]; char secondSaltCharacter = encryptionSalt[1]; // Make sure the string builder is big enough AND filled with 13 characters (the length of the encrypted password). // We will use the index operator to set them, but when the characters are not present, even though the string builder // has enough capacity, it will throw an exception. StringBuilder encryptionBuffer = new StringBuilder("*************"); encryptionBuffer[0] = firstSaltCharacter; encryptionBuffer[1] = secondSaltCharacter; // Use the ASCII value of the salt characters to lookup a number in the salt translation table. uint firstSaltTranslator = m_saltTranslation[Convert.ToUInt32(firstSaltCharacter)]; uint secondSaltTranslator = m_saltTranslation[Convert.ToUInt32(secondSaltCharacter)] << 4; // Build the first encryption key table by taking the ASCII value of every character in the text to encrypt and // multiplying it by two. Note how the cast will not lose any information. The highest possible ASCII character // in a password is the tilde (~), which has ASCII value 126, so the highest possible value after the // multiplication would be 252. byte[] encryptionKey = new byte[8]; for(int index = 0; index < encryptionKey.Length && index < textToEncrypt.Length; index++) { int shiftedCharacter = Convert.ToInt32(textToEncrypt[index]); encryptionKey[index] = (byte)(shiftedCharacter << 1); } uint[] schedule = SetDESKey(encryptionKey); uint[] singleOutputKey = Body(schedule, firstSaltTranslator, secondSaltTranslator); byte[] binaryBuffer = new byte[9]; IntToFourBytes(singleOutputKey[0], binaryBuffer, 0); IntToFourBytes(singleOutputKey[1], binaryBuffer, 4); binaryBuffer[8] = 0; uint binaryBufferIndex = 0; uint passwordCharacter; uint bitChecker = 0x80; bool isAnyBitSet, bitCheckerOverflow; for(int index = 2; index < 13; index++) { passwordCharacter = 0; for(int secondIndex = 0; secondIndex < 6; secondIndex++) { passwordCharacter <<= 1; isAnyBitSet = ((binaryBuffer[binaryBufferIndex] & bitChecker) != 0); if(isAnyBitSet) { passwordCharacter |= 1; } bitChecker >>= 1; bitCheckerOverflow = (bitChecker == 0); if(bitCheckerOverflow) { binaryBufferIndex++; bitChecker = 0x80; } // The original source had the line below, I moved it outside the compound signs, because it will overwrite the value // a few times before incrementing the index. Where it is now it will be written only once. // Just to be on the safe side, I keep the original line here, so I know where it originally was. //encryptionBuffer[index] = Convert.ToChar(m_characterConversionTable[passwordCharacter]); } encryptionBuffer[index] = Convert.ToChar(m_characterConversionTable[passwordCharacter]); } return encryptionBuffer.ToString(); } }
Author: coder
Decrypt Utils
/////////////////////////////////////////////////////////////////////////////////////////////// // // This File is Part of the CallButler Open Source PBX (http://www.codeplex.com/callbutler // // Copyright (c) 2005-2008, Jim Heising // All rights reserved. // // Redistribution and use in source and binary forms, with or without modification, // are permitted provided that the following conditions are met: // // * Redistributions of source code must retain the above copyright notice, // this list of conditions and the following disclaimer. // // * Redistributions in binary form must reproduce the above copyright notice, // this list of conditions and the following disclaimer in the documentation and/or // other materials provided with the distribution. // // * Neither the name of Jim Heising nor the names of its contributors may be // used to endorse or promote products derived from this software without specific prior // written permission. // // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND // ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED // WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. // IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, // INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT // NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR // PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, // WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) // ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE // POSSIBILITY OF SUCH DAMAGE. // /////////////////////////////////////////////////////////////////////////////////////////////// using System; using System.Security.Cryptography; using System.Text; using System.Globalization; using System.IO; namespace WOSI.Utilities { /// <summary> /// Summary description for CryptoUtils. /// </summary> public class CryptoUtils { private CryptoUtils() { // // TODO: Add constructor logic here // } // Decrypt a byte array into a byte array using a key and an IV public static byte[] Decrypt(byte[] cipherData, byte[] Key, byte[] IV) { try { // Create a MemoryStream that is going to accept the // decrypted bytes MemoryStream ms = new MemoryStream(); // Create a symmetric algorithm. // We are going to use Rijndael because it is strong and // available on all platforms. // You can use other algorithms, to do so substitute the next // line with something like // TripleDES alg = TripleDES.Create(); Rijndael alg = Rijndael.Create(); // Now set the key and the IV. // We need the IV (Initialization Vector) because the algorithm // is operating in its default // mode called CBC (Cipher Block Chaining). The IV is XORed with // the first block (8 byte) // of the data after it is decrypted, and then each decrypted // block is XORed with the previous // cipher block. This is done to make encryption more secure. // There is also a mode called ECB which does not need an IV, // but it is much less secure. alg.Key = Key; alg.IV = IV; // Create a CryptoStream through which we are going to be // pumping our data. // CryptoStreamMode.Write means that we are going to be // writing data to the stream // and the output will be written in the MemoryStream // we have provided. CryptoStream cs = new CryptoStream(ms, alg.CreateDecryptor(), CryptoStreamMode.Write); // Write the data and make it do the decryption cs.Write(cipherData, 0, cipherData.Length); // Close the crypto stream (or do FlushFinalBlock). // This will tell it that we have done our decryption // and there is no more data coming in, // and it is now a good time to remove the padding // and finalize the decryption process. cs.Close(); // Now get the decrypted data from the MemoryStream. // Some people make a mistake of using GetBuffer() here, // which is not the right way. byte[] decryptedData = ms.ToArray(); return decryptedData; } catch { return null; } } // Decrypt a string into a string using a password // Uses Decrypt(byte[], byte[], byte[]) public static string Decrypt(string cipherText, string Password) { try { // First we need to turn the input string into a byte array. // We presume that Base64 encoding was used byte[] cipherBytes = Convert.FromBase64String(cipherText); // Then, we need to turn the password into Key and IV // We are using salt to make it harder to guess our key // using a dictionary attack - // trying to guess a password by enumerating all possible words. PasswordDeriveBytes pdb = new PasswordDeriveBytes(Password, new byte[] {0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76}); // Now get the key/IV and do the decryption using // the function that accepts byte arrays. // Using PasswordDeriveBytes object we are first // getting 32 bytes for the Key // (the default Rijndael key length is 256bit = 32bytes) // and then 16 bytes for the IV. // IV should always be the block size, which is by // default 16 bytes (128 bit) for Rijndael. // If you are using DES/TripleDES/RC2 the block size is // 8 bytes and so should be the IV size. // You can also read KeySize/BlockSize properties off // the algorithm to find out the sizes. byte[] decryptedData = Decrypt(cipherBytes, pdb.GetBytes(32), pdb.GetBytes(16)); // Now we need to turn the resulting byte array into a string. // A common mistake would be to use an Encoding class for that. // It does not work // because not all byte values can be represented by characters. // We are going to be using Base64 encoding that is // designed exactly for what we are trying to do. return System.Text.Encoding.Unicode.GetString(decryptedData); } catch { return null; } } // Decrypt bytes into bytes using a password // Uses Decrypt(byte[], byte[], byte[]) public static byte[] Decrypt(byte[] cipherData, string Password) { // We need to turn the password into Key and IV. // We are using salt to make it harder to guess our key // using a dictionary attack - // trying to guess a password by enumerating all possible words. PasswordDeriveBytes pdb = new PasswordDeriveBytes(Password, new byte[] {0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76}); // Now get the key/IV and do the Decryption using the //function that accepts byte arrays. // Using PasswordDeriveBytes object we are first getting // 32 bytes for the Key // (the default Rijndael key length is 256bit = 32bytes) // and then 16 bytes for the IV. // IV should always be the block size, which is by default // 16 bytes (128 bit) for Rijndael. // If you are using DES/TripleDES/RC2 the block size is // 8 bytes and so should be the IV size. // You can also read KeySize/BlockSize properties off the // algorithm to find out the sizes. return Decrypt(cipherData, pdb.GetBytes(32), pdb.GetBytes(16)); } // Decrypt a file into another file using a password public static void Decrypt(string fileIn, string fileOut, string Password) { try { // First we are going to open the file streams FileStream fsIn = new FileStream(fileIn, FileMode.Open, FileAccess.Read); FileStream fsOut = new FileStream(fileOut, FileMode.OpenOrCreate, FileAccess.Write); // Then we are going to derive a Key and an IV from // the Password and create an algorithm PasswordDeriveBytes pdb = new PasswordDeriveBytes(Password, new byte[] {0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76}); Rijndael alg = Rijndael.Create(); alg.Key = pdb.GetBytes(32); alg.IV = pdb.GetBytes(16); // Now create a crypto stream through which we are going // to be pumping data. // Our fileOut is going to be receiving the Decrypted bytes. CryptoStream cs = new CryptoStream(fsOut, alg.CreateDecryptor(), CryptoStreamMode.Write); // Now will will initialize a buffer and will be // processing the input file in chunks. // This is done to avoid reading the whole file (which can be // huge) into memory. int bufferLen = 4096; byte[] buffer = new byte[bufferLen]; int bytesRead; do { // read a chunk of data from the input file bytesRead = fsIn.Read(buffer, 0, bufferLen); // Decrypt it cs.Write(buffer, 0, bytesRead); } while (bytesRead != 0); // close everything cs.Close(); // this will also close the unrelying fsOut stream fsIn.Close(); } catch { } } } }
Encrypt Utils
/////////////////////////////////////////////////////////////////////////////////////////////// // // This File is Part of the CallButler Open Source PBX (http://www.codeplex.com/callbutler // // Copyright (c) 2005-2008, Jim Heising // All rights reserved. // // Redistribution and use in source and binary forms, with or without modification, // are permitted provided that the following conditions are met: // // * Redistributions of source code must retain the above copyright notice, // this list of conditions and the following disclaimer. // // * Redistributions in binary form must reproduce the above copyright notice, // this list of conditions and the following disclaimer in the documentation and/or // other materials provided with the distribution. // // * Neither the name of Jim Heising nor the names of its contributors may be // used to endorse or promote products derived from this software without specific prior // written permission. // // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND // ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED // WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. // IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, // INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT // NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR // PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, // WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) // ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE // POSSIBILITY OF SUCH DAMAGE. // /////////////////////////////////////////////////////////////////////////////////////////////// using System; using System.Security.Cryptography; using System.Text; using System.Globalization; using System.IO; namespace WOSI.Utilities { /// <summary> /// Summary description for CryptoUtils. /// </summary> public class CryptoUtils { public static byte[] Encrypt(byte[] clearData, byte[] Key, byte[] IV) { // Create a MemoryStream to accept the encrypted bytes MemoryStream ms = new MemoryStream(); // Create a symmetric algorithm. // We are going to use Rijndael because it is strong and // available on all platforms. // You can use other algorithms, to do so substitute the // next line with something like // TripleDES alg = TripleDES.Create(); Rijndael alg = Rijndael.Create(); // Now set the key and the IV. // We need the IV (Initialization Vector) because // the algorithm is operating in its default // mode called CBC (Cipher Block Chaining). // The IV is XORed with the first block (8 byte) // of the data before it is encrypted, and then each // encrypted block is XORed with the // following block of plaintext. // This is done to make encryption more secure. // There is also a mode called ECB which does not need an IV, // but it is much less secure. alg.Key = Key; alg.IV = IV; // Create a CryptoStream through which we are going to be // pumping our data. // CryptoStreamMode.Write means that we are going to be // writing data to the stream and the output will be written // in the MemoryStream we have provided. CryptoStream cs = new CryptoStream(ms, alg.CreateEncryptor(), CryptoStreamMode.Write); // Write the data and make it do the encryption cs.Write(clearData, 0, clearData.Length); // Close the crypto stream (or do FlushFinalBlock). // This will tell it that we have done our encryption and // there is no more data coming in, // and it is now a good time to apply the padding and // finalize the encryption process. cs.Close(); // Now get the encrypted data from the MemoryStream. // Some people make a mistake of using GetBuffer() here, // which is not the right way. byte[] encryptedData = ms.ToArray(); return encryptedData; } // Encrypt a string into a string using a password // Uses Encrypt(byte[], byte[], byte[]) public static string Encrypt(string clearText, string Password) { // First we need to turn the input string into a byte array. byte[] clearBytes = System.Text.Encoding.Unicode.GetBytes(clearText); // Then, we need to turn the password into Key and IV // We are using salt to make it harder to guess our key // using a dictionary attack - // trying to guess a password by enumerating all possible words. PasswordDeriveBytes pdb = new PasswordDeriveBytes(Password, new byte[] {0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76}); // Now get the key/IV and do the encryption using the // function that accepts byte arrays. // Using PasswordDeriveBytes object we are first getting // 32 bytes for the Key // (the default Rijndael key length is 256bit = 32bytes) // and then 16 bytes for the IV. // IV should always be the block size, which is by default // 16 bytes (128 bit) for Rijndael. // If you are using DES/TripleDES/RC2 the block size is // 8 bytes and so should be the IV size. // You can also read KeySize/BlockSize properties off // the algorithm to find out the sizes. byte[] encryptedData = Encrypt(clearBytes, pdb.GetBytes(32), pdb.GetBytes(16)); // Now we need to turn the resulting byte array into a string. // A common mistake would be to use an Encoding class for that. //It does not work because not all byte values can be // represented by characters. // We are going to be using Base64 encoding that is designed //exactly for what we are trying to do. return Convert.ToBase64String(encryptedData); } // Encrypt bytes into bytes using a password // Uses Encrypt(byte[], byte[], byte[]) public static byte[] Encrypt(byte[] clearData, string Password) { // We need to turn the password into Key and IV. // We are using salt to make it harder to guess our key // using a dictionary attack - // trying to guess a password by enumerating all possible words. PasswordDeriveBytes pdb = new PasswordDeriveBytes(Password, new byte[] {0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76}); // Now get the key/IV and do the encryption using the function // that accepts byte arrays. // Using PasswordDeriveBytes object we are first getting // 32 bytes for the Key // (the default Rijndael key length is 256bit = 32bytes) // and then 16 bytes for the IV. // IV should always be the block size, which is by default // 16 bytes (128 bit) for Rijndael. // If you are using DES/TripleDES/RC2 the block size is 8 // bytes and so should be the IV size. // You can also read KeySize/BlockSize properties off the // algorithm to find out the sizes. return Encrypt(clearData, pdb.GetBytes(32), pdb.GetBytes(16)); } // Encrypt a file into another file using a password public static void Encrypt(string fileIn, string fileOut, string Password) { // First we are going to open the file streams FileStream fsIn = new FileStream(fileIn, FileMode.Open, FileAccess.Read); FileStream fsOut = new FileStream(fileOut, FileMode.OpenOrCreate, FileAccess.Write); // Then we are going to derive a Key and an IV from the // Password and create an algorithm PasswordDeriveBytes pdb = new PasswordDeriveBytes(Password, new byte[] {0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76}); Rijndael alg = Rijndael.Create(); alg.Key = pdb.GetBytes(32); alg.IV = pdb.GetBytes(16); // Now create a crypto stream through which we are going // to be pumping data. // Our fileOut is going to be receiving the encrypted bytes. CryptoStream cs = new CryptoStream(fsOut, alg.CreateEncryptor(), CryptoStreamMode.Write); // Now will will initialize a buffer and will be processing // the input file in chunks. // This is done to avoid reading the whole file (which can // be huge) into memory. int bufferLen = 4096; byte[] buffer = new byte[bufferLen]; int bytesRead; do { // read a chunk of data from the input file bytesRead = fsIn.Read(buffer, 0, bufferLen); // encrypt it cs.Write(buffer, 0, bytesRead); } while(bytesRead != 0); // close everything // this will also close the unrelying fsOut stream cs.Close(); fsIn.Close(); } } }
Do CRC32 hashing.
/* -------------------------------------------------------------------------- * * License * * The contents of this file are subject to the Jabber Open Source License * Version 1.0 (the "License"). You may not copy or use this file, in either * source code or executable form, except in compliance with the License. You * may obtain a copy of the License at http://www.jabber.com/license/ or at * http://www.opensource.org/. * * Software distributed under the License is distributed on an "AS IS" basis, * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License * for the specific language governing rights and limitations under the * License. * * Copyrights * * Portions created by or assigned to Cursive Systems, Inc. are * Copyright (c) 2002 Cursive Systems, Inc. All Rights Reserved. Contact * information for Cursive Systems, Inc. is available at http://www.cursive.net/. * * Portions Copyright (c) 2002 Joe Hildebrand. * * Acknowledgements * * Special thanks to the Jabber Open Source Contributors for their * suggestions and support of Jabber. * * --------------------------------------------------------------------------*/ using System; using System.Security.Cryptography; namespace bedrock.util { /// <summary> /// Do CRC32 hashing. Note: just use SHA1, or MD5, from System.Security.Cryptography. /// </summary> public class CRC32 { private const int WIDTH = 32; private const ulong POLY = 0x04C11DB7; private const ulong INIT = 0xFFFFFFFF; private const ulong XOROUT = 0xFFFFFFFF; private static readonly uint[] crctable = { 0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA, 0x076DC419, 0x706AF48F, 0xE963A535, 0x9E6495A3, 0x0EDB8832, 0x79DCB8A4, 0xE0D5E91E, 0x97D2D988, 0x09B64C2B, 0x7EB17CBD, 0xE7B82D07, 0x90BF1D91, 0x1DB71064, 0x6AB020F2, 0xF3B97148, 0x84BE41DE, 0x1ADAD47D, 0x6DDDE4EB, 0xF4D4B551, 0x83D385C7, 0x136C9856, 0x646BA8C0, 0xFD62F97A, 0x8A65C9EC, 0x14015C4F, 0x63066CD9, 0xFA0F3D63, 0x8D080DF5, 0x3B6E20C8, 0x4C69105E, 0xD56041E4, 0xA2677172, 0x3C03E4D1, 0x4B04D447, 0xD20D85FD, 0xA50AB56B, 0x35B5A8FA, 0x42B2986C, 0xDBBBC9D6, 0xACBCF940, 0x32D86CE3, 0x45DF5C75, 0xDCD60DCF, 0xABD13D59, 0x26D930AC, 0x51DE003A, 0xC8D75180, 0xBFD06116, 0x21B4F4B5, 0x56B3C423, 0xCFBA9599, 0xB8BDA50F, 0x2802B89E, 0x5F058808, 0xC60CD9B2, 0xB10BE924, 0x2F6F7C87, 0x58684C11, 0xC1611DAB, 0xB6662D3D, 0x76DC4190, 0x01DB7106, 0x98D220BC, 0xEFD5102A, 0x71B18589, 0x06B6B51F, 0x9FBFE4A5, 0xE8B8D433, 0x7807C9A2, 0x0F00F934, 0x9609A88E, 0xE10E9818, 0x7F6A0DBB, 0x086D3D2D, 0x91646C97, 0xE6635C01, 0x6B6B51F4, 0x1C6C6162, 0x856530D8, 0xF262004E, 0x6C0695ED, 0x1B01A57B, 0x8208F4C1, 0xF50FC457, 0x65B0D9C6, 0x12B7E950, 0x8BBEB8EA, 0xFCB9887C, 0x62DD1DDF, 0x15DA2D49, 0x8CD37CF3, 0xFBD44C65, 0x4DB26158, 0x3AB551CE, 0xA3BC0074, 0xD4BB30E2, 0x4ADFA541, 0x3DD895D7, 0xA4D1C46D, 0xD3D6F4FB, 0x4369E96A, 0x346ED9FC, 0xAD678846, 0xDA60B8D0, 0x44042D73, 0x33031DE5, 0xAA0A4C5F, 0xDD0D7CC9, 0x5005713C, 0x270241AA, 0xBE0B1010, 0xC90C2086, 0x5768B525, 0x206F85B3, 0xB966D409, 0xCE61E49F, 0x5EDEF90E, 0x29D9C998, 0xB0D09822, 0xC7D7A8B4, 0x59B33D17, 0x2EB40D81, 0xB7BD5C3B, 0xC0BA6CAD, 0xEDB88320, 0x9ABFB3B6, 0x03B6E20C, 0x74B1D29A, 0xEAD54739, 0x9DD277AF, 0x04DB2615, 0x73DC1683, 0xE3630B12, 0x94643B84, 0x0D6D6A3E, 0x7A6A5AA8, 0xE40ECF0B, 0x9309FF9D, 0x0A00AE27, 0x7D079EB1, 0xF00F9344, 0x8708A3D2, 0x1E01F268, 0x6906C2FE, 0xF762575D, 0x806567CB, 0x196C3671, 0x6E6B06E7, 0xFED41B76, 0x89D32BE0, 0x10DA7A5A, 0x67DD4ACC, 0xF9B9DF6F, 0x8EBEEFF9, 0x17B7BE43, 0x60B08ED5, 0xD6D6A3E8, 0xA1D1937E, 0x38D8C2C4, 0x4FDFF252, 0xD1BB67F1, 0xA6BC5767, 0x3FB506DD, 0x48B2364B, 0xD80D2BDA, 0xAF0A1B4C, 0x36034AF6, 0x41047A60, 0xDF60EFC3, 0xA867DF55, 0x316E8EEF, 0x4669BE79, 0xCB61B38C, 0xBC66831A, 0x256FD2A0, 0x5268E236, 0xCC0C7795, 0xBB0B4703, 0x220216B9, 0x5505262F, 0xC5BA3BBE, 0xB2BD0B28, 0x2BB45A92, 0x5CB36A04, 0xC2D7FFA7, 0xB5D0CF31, 0x2CD99E8B, 0x5BDEAE1D, 0x9B64C2B0, 0xEC63F226, 0x756AA39C, 0x026D930A, 0x9C0906A9, 0xEB0E363F, 0x72076785, 0x05005713, 0x95BF4A82, 0xE2B87A14, 0x7BB12BAE, 0x0CB61B38, 0x92D28E9B, 0xE5D5BE0D, 0x7CDCEFB7, 0x0BDBDF21, 0x86D3D2D4, 0xF1D4E242, 0x68DDB3F8, 0x1FDA836E, 0x81BE16CD, 0xF6B9265B, 0x6FB077E1, 0x18B74777, 0x88085AE6, 0xFF0F6A70, 0x66063BCA, 0x11010B5C, 0x8F659EFF, 0xF862AE69, 0x616BFFD3, 0x166CCF45, 0xA00AE278, 0xD70DD2EE, 0x4E048354, 0x3903B3C2, 0xA7672661, 0xD06016F7, 0x4969474D, 0x3E6E77DB, 0xAED16A4A, 0xD9D65ADC, 0x40DF0B66, 0x37D83BF0, 0xA9BCAE53, 0xDEBB9EC5, 0x47B2CF7F, 0x30B5FFE9, 0xBDBDF21C, 0xCABAC28A, 0x53B39330, 0x24B4A3A6, 0xBAD03605, 0xCDD70693, 0x54DE5729, 0x23D967BF, 0xB3667A2E, 0xC4614AB8, 0x5D681B02, 0x2A6F2B94, 0xB40BBE37, 0xC30C8EA1, 0x5A05DF1B, 0x2D02EF8D }; /// <summary> /// Hash a block of bytes. /// </summary> /// <param name="block"></param> /// <returns></returns> public static uint compute(byte[] block) { ulong c = INIT; int len = block.Length; int i = 0; while (len-- > 0) { c = crctable[(c ^ block[i++]) & 0xFFL] ^ (c >> 8); } return (uint)(c ^ XOROUT); } /// <summary> /// Hash a string /// </summary> /// <param name="s"></param> /// <returns></returns> public static uint compute(string s) { return compute(System.Text.Encoding.ASCII.GetBytes(s)); } } }
Calculates a 32 bit Cyclic Redundancy Checksum (CRC) using the same polynomial used by Zip.
// Crc32.cs // // Implements the CRC algorithm, which is used in zip files. The zip format calls for // the zipfile to contain a CRC for the unencrypted byte stream of each file. // // It is based on example source code published at // http://www.vbaccelerator.com/home/net/code/libraries/CRC32/Crc32_zip_CRC32_CRC32_cs.asp // // This implementation adds a tweak of that code for use within zip creation. While // computing the CRC we also compress the byte stream, in the same read loop. This // avoids the need to read through the uncompressed stream twice - once to computer CRC // and another time to compress. // // // Thu, 30 Mar 2006 13:58 // using System; namespace ionic.utils.zip { /// <summary> /// Calculates a 32bit Cyclic Redundancy Checksum (CRC) using the /// same polynomial used by Zip. /// </summary> public class CRC32 { private UInt32[] crc32Table; private const int BUFFER_SIZE = 8192; private Int32 _TotalBytesRead = 0; public Int32 TotalBytesRead { get { return _TotalBytesRead; } } /// <summary> /// Returns the CRC32 for the specified stream. /// </summary> /// <param name="input">The stream over which to calculate the CRC32</param> /// <returns>the CRC32 calculation</returns> public UInt32 GetCrc32(System.IO.Stream input) { return GetCrc32AndCopy(input, null); } /// <summary> /// Returns the CRC32 for the specified stream, and writes the input into the output stream. /// </summary> /// <param name="input">The stream over which to calculate the CRC32</param> /// <param name="output">The stream into which to deflate the input</param> /// <returns>the CRC32 calculation</returns> public UInt32 GetCrc32AndCopy(System.IO.Stream input, System.IO.Stream output) { unchecked { UInt32 crc32Result; crc32Result = 0xFFFFFFFF; byte[] buffer = new byte[BUFFER_SIZE]; int readSize = BUFFER_SIZE; _TotalBytesRead = 0; int count = input.Read(buffer, 0, readSize); if (output != null) output.Write(buffer, 0, count); _TotalBytesRead += count; while (count > 0) { for (int i = 0; i < count; i++) { crc32Result = ((crc32Result) >> 8) ^ crc32Table[(buffer[i]) ^ ((crc32Result) & 0x000000FF)]; } count = input.Read(buffer, 0, readSize); if (output != null) output.Write(buffer, 0, count); _TotalBytesRead += count; } return ~crc32Result; } } /// <summary> /// Construct an instance of the CRC32 class, pre-initialising the table /// for speed of lookup. /// </summary> public CRC32() { unchecked { // This is the official polynomial used by CRC32 in PKZip. // Often the polynomial is shown reversed as 0x04C11DB7. UInt32 dwPolynomial = 0xEDB88320; UInt32 i, j; crc32Table = new UInt32[256]; UInt32 dwCrc; for (i = 0; i < 256; i++) { dwCrc = i; for (j = 8; j > 0; j--) { if ((dwCrc & 1) == 1) { dwCrc = (dwCrc >> 1) ^ dwPolynomial; } else { dwCrc >>= 1; } } crc32Table[i] = dwCrc; } } } } }
Generate a table for a byte-wise 32-bit CRC calculation on the polynomial: x^32+x^26+x^23+x^22+x^16+x^12+x^11+x^10+x^8+x^7+x^5+x^4+x^2+x+1.
// CRC32.cs - Computes CRC32 data checksum of a data stream // Copyright (C) 2001 Mike Krueger // // This file was translated from java, it was part of the GNU Classpath // Copyright (C) 1999, 2000, 2001 Free Software Foundation, Inc. // // 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 2 // 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, write to the Free Software // Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. // // Linking this library statically or dynamically with other modules is // making a combined work based on this library. Thus, the terms and // conditions of the GNU General Public License cover the whole // combination. // // As a special exception, the copyright holders of this library give you // permission to link this library with independent modules to produce an // executable, regardless of the license terms of these independent // modules, and to copy and distribute the resulting executable under // terms of your choice, provided that you also meet, for each linked // independent module, the terms and conditions of the license of that // module. An independent module is a module which is not derived from // or based on this library. If you modify this library, you may extend // this exception to your version of the library, but you are not // obligated to do so. If you do not wish to do so, delete this // exception statement from your version. using System; namespace ICSharpCode.SharpZipLib.Checksums { /// <summary> /// Generate a table for a byte-wise 32-bit CRC calculation on the polynomial: /// x^32+x^26+x^23+x^22+x^16+x^12+x^11+x^10+x^8+x^7+x^5+x^4+x^2+x+1. /// /// Polynomials over GF(2) are represented in binary, one bit per coefficient, /// with the lowest powers in the most significant bit. Then adding polynomials /// is just exclusive-or, and multiplying a polynomial by x is a right shift by /// one. If we call the above polynomial p, and represent a byte as the /// polynomial q, also with the lowest power in the most significant bit (so the /// byte 0xb1 is the polynomial x^7+x^3+x+1), then the CRC is (q*x^32) mod p, /// where a mod b means the remainder after dividing a by b. /// /// This calculation is done using the shift-register method of multiplying and /// taking the remainder. The register is initialized to zero, and for each /// incoming bit, x^32 is added mod p to the register if the bit is a one (where /// x^32 mod p is p+x^32 = x^26+...+1), and the register is multiplied mod p by /// x (which is shifting right by one and adding x^32 mod p if the bit shifted /// out is a one). We start with the highest power (least significant bit) of /// q and repeat for all eight bits of q. /// /// The table is simply the CRC of all possible eight bit values. This is all /// the information needed to generate CRC's on data a byte at a time for all /// combinations of CRC register values and incoming bytes. /// </summary> public sealed class Crc32 { const uint CrcSeed = 0xFFFFFFFF; readonly static uint[] CrcTable = new uint[] { 0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA, 0x076DC419, 0x706AF48F, 0xE963A535, 0x9E6495A3, 0x0EDB8832, 0x79DCB8A4, 0xE0D5E91E, 0x97D2D988, 0x09B64C2B, 0x7EB17CBD, 0xE7B82D07, 0x90BF1D91, 0x1DB71064, 0x6AB020F2, 0xF3B97148, 0x84BE41DE, 0x1ADAD47D, 0x6DDDE4EB, 0xF4D4B551, 0x83D385C7, 0x136C9856, 0x646BA8C0, 0xFD62F97A, 0x8A65C9EC, 0x14015C4F, 0x63066CD9, 0xFA0F3D63, 0x8D080DF5, 0x3B6E20C8, 0x4C69105E, 0xD56041E4, 0xA2677172, 0x3C03E4D1, 0x4B04D447, 0xD20D85FD, 0xA50AB56B, 0x35B5A8FA, 0x42B2986C, 0xDBBBC9D6, 0xACBCF940, 0x32D86CE3, 0x45DF5C75, 0xDCD60DCF, 0xABD13D59, 0x26D930AC, 0x51DE003A, 0xC8D75180, 0xBFD06116, 0x21B4F4B5, 0x56B3C423, 0xCFBA9599, 0xB8BDA50F, 0x2802B89E, 0x5F058808, 0xC60CD9B2, 0xB10BE924, 0x2F6F7C87, 0x58684C11, 0xC1611DAB, 0xB6662D3D, 0x76DC4190, 0x01DB7106, 0x98D220BC, 0xEFD5102A, 0x71B18589, 0x06B6B51F, 0x9FBFE4A5, 0xE8B8D433, 0x7807C9A2, 0x0F00F934, 0x9609A88E, 0xE10E9818, 0x7F6A0DBB, 0x086D3D2D, 0x91646C97, 0xE6635C01, 0x6B6B51F4, 0x1C6C6162, 0x856530D8, 0xF262004E, 0x6C0695ED, 0x1B01A57B, 0x8208F4C1, 0xF50FC457, 0x65B0D9C6, 0x12B7E950, 0x8BBEB8EA, 0xFCB9887C, 0x62DD1DDF, 0x15DA2D49, 0x8CD37CF3, 0xFBD44C65, 0x4DB26158, 0x3AB551CE, 0xA3BC0074, 0xD4BB30E2, 0x4ADFA541, 0x3DD895D7, 0xA4D1C46D, 0xD3D6F4FB, 0x4369E96A, 0x346ED9FC, 0xAD678846, 0xDA60B8D0, 0x44042D73, 0x33031DE5, 0xAA0A4C5F, 0xDD0D7CC9, 0x5005713C, 0x270241AA, 0xBE0B1010, 0xC90C2086, 0x5768B525, 0x206F85B3, 0xB966D409, 0xCE61E49F, 0x5EDEF90E, 0x29D9C998, 0xB0D09822, 0xC7D7A8B4, 0x59B33D17, 0x2EB40D81, 0xB7BD5C3B, 0xC0BA6CAD, 0xEDB88320, 0x9ABFB3B6, 0x03B6E20C, 0x74B1D29A, 0xEAD54739, 0x9DD277AF, 0x04DB2615, 0x73DC1683, 0xE3630B12, 0x94643B84, 0x0D6D6A3E, 0x7A6A5AA8, 0xE40ECF0B, 0x9309FF9D, 0x0A00AE27, 0x7D079EB1, 0xF00F9344, 0x8708A3D2, 0x1E01F268, 0x6906C2FE, 0xF762575D, 0x806567CB, 0x196C3671, 0x6E6B06E7, 0xFED41B76, 0x89D32BE0, 0x10DA7A5A, 0x67DD4ACC, 0xF9B9DF6F, 0x8EBEEFF9, 0x17B7BE43, 0x60B08ED5, 0xD6D6A3E8, 0xA1D1937E, 0x38D8C2C4, 0x4FDFF252, 0xD1BB67F1, 0xA6BC5767, 0x3FB506DD, 0x48B2364B, 0xD80D2BDA, 0xAF0A1B4C, 0x36034AF6, 0x41047A60, 0xDF60EFC3, 0xA867DF55, 0x316E8EEF, 0x4669BE79, 0xCB61B38C, 0xBC66831A, 0x256FD2A0, 0x5268E236, 0xCC0C7795, 0xBB0B4703, 0x220216B9, 0x5505262F, 0xC5BA3BBE, 0xB2BD0B28, 0x2BB45A92, 0x5CB36A04, 0xC2D7FFA7, 0xB5D0CF31, 0x2CD99E8B, 0x5BDEAE1D, 0x9B64C2B0, 0xEC63F226, 0x756AA39C, 0x026D930A, 0x9C0906A9, 0xEB0E363F, 0x72076785, 0x05005713, 0x95BF4A82, 0xE2B87A14, 0x7BB12BAE, 0x0CB61B38, 0x92D28E9B, 0xE5D5BE0D, 0x7CDCEFB7, 0x0BDBDF21, 0x86D3D2D4, 0xF1D4E242, 0x68DDB3F8, 0x1FDA836E, 0x81BE16CD, 0xF6B9265B, 0x6FB077E1, 0x18B74777, 0x88085AE6, 0xFF0F6A70, 0x66063BCA, 0x11010B5C, 0x8F659EFF, 0xF862AE69, 0x616BFFD3, 0x166CCF45, 0xA00AE278, 0xD70DD2EE, 0x4E048354, 0x3903B3C2, 0xA7672661, 0xD06016F7, 0x4969474D, 0x3E6E77DB, 0xAED16A4A, 0xD9D65ADC, 0x40DF0B66, 0x37D83BF0, 0xA9BCAE53, 0xDEBB9EC5, 0x47B2CF7F, 0x30B5FFE9, 0xBDBDF21C, 0xCABAC28A, 0x53B39330, 0x24B4A3A6, 0xBAD03605, 0xCDD70693, 0x54DE5729, 0x23D967BF, 0xB3667A2E, 0xC4614AB8, 0x5D681B02, 0x2A6F2B94, 0xB40BBE37, 0xC30C8EA1, 0x5A05DF1B, 0x2D02EF8D }; internal static uint ComputeCrc32(uint oldCrc, byte value) { return (uint)(Crc32.CrcTable[(oldCrc ^ value) & 0xFF] ^ (oldCrc >> 8)); } /// <summary> /// The crc data checksum so far. /// </summary> uint crc; /// <summary> /// Returns the CRC32 data checksum computed so far. /// </summary> public long Value { get { return (long)crc; } set { crc = (uint)value; } } /// <summary> /// Resets the CRC32 data checksum as if no update was ever called. /// </summary> public void Reset() { crc = 0; } /// <summary> /// Updates the checksum with the int bval. /// </summary> /// <param name = "value"> /// the byte is taken as the lower 8 bits of value /// </param> public void Update(int value) { crc ^= CrcSeed; crc = CrcTable[(crc ^ value) & 0xFF] ^ (crc >> 8); crc ^= CrcSeed; } /// <summary> /// Updates the checksum with the bytes taken from the array. /// </summary> /// <param name="buffer"> /// buffer an array of bytes /// </param> public void Update(byte[] buffer) { if (buffer == null) { throw new ArgumentNullException("buffer"); } Update(buffer, 0, buffer.Length); } /// <summary> /// Adds the byte array to the data checksum. /// </summary> /// <param name = "buffer"> /// The buffer which contains the data /// </param> /// <param name = "offset"> /// The offset in the buffer where the data starts /// </param> /// <param name = "count"> /// The number of data bytes to update the CRC with. /// </param> public void Update(byte[] buffer, int offset, int count) { if (buffer == null) { throw new ArgumentNullException("buffer"); } if ( count < 0 ) { #if NETCF_1_0 throw new ArgumentOutOfRangeException("count"); #else throw new ArgumentOutOfRangeException("count", "Count cannot be less than zero"); #endif } if (offset < 0 || offset + count > buffer.Length) { throw new ArgumentOutOfRangeException("offset"); } crc ^= CrcSeed; while (--count >= 0) { crc = CrcTable[(crc ^ buffer[offset++]) & 0xFF] ^ (crc >> 8); } crc ^= CrcSeed; } } }
A utility class to compute CRC32
// HtmlAgilityPack V1.0 - Simon Mourier <simon underscore mourier at hotmail dot com> using System; using System.IO; namespace HtmlAgilityPack { /// <summary> /// A utility class to compute CRC32. /// </summary> public class Crc32 { private uint _crc32 = 0; static private uint[] crc_32_tab = // CRC polynomial 0xedb88320 { 0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59, 0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433, 0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01, 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65, 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f, 0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, 0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b, 0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713, 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777, 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, 0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9, 0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693, 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d }; static private uint UPDC32(byte octet, uint crc) { return (crc_32_tab[((crc)^((byte)octet)) & 0xff] ^ ((crc) >> 8)); } internal uint CheckSum { get { return _crc32; } set { _crc32 = value; } } internal uint AddToCRC32(int c) { return AddToCRC32((ushort)c); } internal uint AddToCRC32(ushort c) { byte lowByte, hiByte; lowByte = (byte)(c & 0x00ff); hiByte = (byte)(c >> 8); _crc32 = UPDC32(hiByte, _crc32); _crc32 = UPDC32(lowByte, _crc32); return ~_crc32; } /// <summary> /// Compute a checksum for a given string. /// </summary> /// <param name="text">The string to compute the checksum for.</param> /// <returns>The computed checksum.</returns> static public uint CRC32String(string text) { uint oldcrc32; oldcrc32 = 0xFFFFFFFF; int len = text.Length; ushort uCharVal; byte lowByte, hiByte; for ( int i=0; len>0; i++) { --len; uCharVal = text[len]; unchecked { lowByte = (byte)(uCharVal & 0x00ff); hiByte = (byte)(uCharVal >> 8); } oldcrc32 = UPDC32(hiByte, oldcrc32); oldcrc32 = UPDC32(lowByte, oldcrc32); } return ~oldcrc32; } /// <summary> /// Compute a checksum for a given array of bytes. /// </summary> /// <param name="bytes">The array of bytes to compute the checksum for.</param> /// <returns>The computed checksum.</returns> static public uint CRC32Bytes(byte[] bytes) { uint oldcrc32; oldcrc32 = 0xFFFFFFFF; int len = bytes.Length; for ( int i=0; len>0; i++) { --len; oldcrc32 = UPDC32(bytes[len], oldcrc32); } return ~oldcrc32; } } }