using System; using System.Collections.Generic; using System.Linq; // This is an implementation of // http://csrc.nist.gov/publications/fips/fips180-4/fips-180-4.pdf namespace Tiobon.Core.Common.Helper { using Word32 = System.UInt32; using Word64 = System.UInt64; public static class ShaHelper { // Constants K static Word32[] K1; static Word32[] K256; static Word64[] K512; // Initial hash values H0 static Word32[] H0Sha1; static Word32[] H0Sha224; static Word32[] H0Sha256; static Word64[] H0Sha384; static Word64[] H0Sha512; static Word64[] H0Sha512_224; static Word64[] H0Sha512_256; static ShaHelper() { DefineK1(); DefineK256(); DefineK512(); DefineH0Sha1(); DefineH0Sha224(); DefineH0Sha256(); DefineH0Sha384(); DefineH0Sha512(); DefineH0Sha512_224(); DefineH0Sha512_256(); } #region Public Functions public static byte[] Sha1(byte[] plaintext) { DefineH0Sha1(); return Sha1Algorithm(plaintext); } public static string Sha1(string plaintext) { return ShaUtilities.ByteArrayToHexString(Sha1(ShaUtilities.StringToByteArray(plaintext))); } public static byte[] Sha224(byte[] plaintext) { DefineH0Sha224(); return Sha256Algorithm(plaintext, H0Sha224, 224); } public static string Sha224(string plaintext) { return ShaUtilities.ByteArrayToHexString(Sha224(ShaUtilities.StringToByteArray(plaintext))); } public static byte[] Sha256(byte[] plaintext) { DefineH0Sha256(); return Sha256Algorithm(plaintext, H0Sha256, 256); } public static string Sha256(string plaintext) { return ShaUtilities.ByteArrayToHexString(Sha256(ShaUtilities.StringToByteArray(plaintext))); } public static byte[] Sha512(byte[] plaintext) { DefineH0Sha512(); return Sha512Algorithm(plaintext, H0Sha512, 512); } public static string Sha512(string plaintext) { return ShaUtilities.ByteArrayToHexString(Sha512(ShaUtilities.StringToByteArray(plaintext))); } public static byte[] Sha384(byte[] plaintext) { DefineH0Sha384(); return Sha512Algorithm(plaintext, H0Sha384, 384); } public static string Sha384(string plaintext) { return ShaUtilities.ByteArrayToHexString(Sha384(ShaUtilities.StringToByteArray(plaintext))); } public static byte[] Sha512_224(byte[] plaintext) { DefineH0Sha512_224(); return Sha512Algorithm(plaintext, H0Sha512_224, 224); } public static string Sha512_224(string plaintext) { return ShaUtilities.ByteArrayToHexString(Sha512_224(ShaUtilities.StringToByteArray(plaintext))); } public static byte[] Sha512_256(byte[] plaintext) { DefineH0Sha512_256(); return Sha512Algorithm(plaintext, H0Sha512_256, 256); } public static string Sha512_256(string plaintext) { return ShaUtilities.ByteArrayToHexString(Sha512_256(ShaUtilities.StringToByteArray(plaintext))); } #endregion #region Hash Algorithms static Word32[] CreateMessageScheduleSha1(Block512 block) { // The message schedule. Word32[] W = new Word32[80]; // Prepare the message schedule W. // The first 16 words in W are the same as the words of the block. // The remaining 80-16 = 64 words in W are functions of the previously defined words. for (int t = 0; t < 80; t++) { if (t < 16) { W[t] = block.words[t]; } else { W[t] = RotL(1, W[t - 3] ^ W[t - 8] ^ W[t - 14] ^ W[t - 16]); } } return W; } static Word32[] CreateMessageScheduleSha256(Block512 block) { // The message schedule. Word32[] W = new Word32[64]; // Prepare the message schedule W. // The first 16 words in W are the same as the words of the block. // The remaining 64-16 = 48 words in W are functions of the previously defined words. for (int t = 0; t < 64; t++) { if (t < 16) { W[t] = block.words[t]; } else { W[t] = sigma1_256(W[t - 2]) + W[t - 7] + sigma0_256(W[t - 15]) + W[t - 16]; } } return W; } static Word64[] CreateMessageScheduleSha512(Block1024 block) { // The message schedule. Word64[] W = new Word64[80]; // Prepare the message schedule W. // The first 16 words in W are the same as the words of the block. // The remaining 80-16 =64 words in W are functions of the previously defined words. for (int t = 0; t < 80; t++) { if (t < 16) { W[t] = block.words[t]; } else { W[t] = sigma1_512(W[t - 2]) + W[t - 7] + sigma0_512(W[t - 15]) + W[t - 16]; } } return W; } static byte[] Sha1Algorithm(byte[] plaintext) { Block512[] blocks = ConvertPaddedTextToBlock512Array(PadPlainText512(plaintext)); // Define the hash variable and set its initial values. Word32[] H = new Word32[5]; H0Sha1.CopyTo(H, 0); for (int i = 0; i < blocks.Length; i++) { Word32[] W = CreateMessageScheduleSha1(blocks[i]); // Set the working variables a,...,e to the current hash values. Word32 a = H[0]; Word32 b = H[1]; Word32 c = H[2]; Word32 d = H[3]; Word32 e = H[4]; for (int t = 0; t < 80; t++) { Word32 T = RotL(5, a) + f(t, b, c, d) + e + K1[t] + W[t]; e = d; d = c; c = RotL(30, b); b = a; a = T; } // Update the current value of the hash H after processing block i. H[0] += a; H[1] += b; H[2] += c; H[3] += d; H[4] += e; } // Concatenating the final 5 hash words H[0],...,H[4] gives the digest. // Since each H[i] is 4 bytes, the digest is 5 * 4 = 20 bytes = 160 bits. return ShaUtilities.Word32ArrayToByteArray(H); } static byte[] Sha256Algorithm(byte[] plaintext, Word32[] H0, int numberBits) { Block512[] blocks = ConvertPaddedTextToBlock512Array(PadPlainText512(plaintext)); // Define the hash variables and set their initial values. Word32[] H = H0; for (int i = 0; i < blocks.Length; i++) { Word32[] W = CreateMessageScheduleSha256(blocks[i]); // Set the working variables a,...,h to the current hash values. Word32 a = H[0]; Word32 b = H[1]; Word32 c = H[2]; Word32 d = H[3]; Word32 e = H[4]; Word32 f = H[5]; Word32 g = H[6]; Word32 h = H[7]; for (int t = 0; t < 64; t++) { Word32 T1 = h + Sigma1_256(e) + Ch(e, f, g) + K256[t] + W[t]; Word32 T2 = Sigma0_256(a) + Maj(a, b, c); h = g; g = f; f = e; e = d + T1; d = c; c = b; b = a; a = T1 + T2; } // Update the current value of the hash H after processing block i. H[0] += a; H[1] += b; H[2] += c; H[3] += d; H[4] += e; H[5] += f; H[6] += g; H[7] += h; } // Concatenate all the Word32 Hash Values byte[] hash = ShaUtilities.Word32ArrayToByteArray(H); // The number of bytes in the final output hash int numberBytes = numberBits / 8; byte[] truncatedHash = new byte[numberBytes]; Array.Copy(hash, truncatedHash, numberBytes); return truncatedHash; } static byte[] Sha512Algorithm(byte[] plaintext, Word64[] H0, int numberBits) { Block1024[] blocks = ConvertPaddedMessageToBlock1024Array(PadPlainText1024(plaintext)); // Define the hash variable and set its initial values. Word64[] H = H0; for (int i = 0; i < blocks.Length; i++) { Word64[] W = CreateMessageScheduleSha512(blocks[i]); // Set the working variables a,...,h to the current hash values. Word64 a = H[0]; Word64 b = H[1]; Word64 c = H[2]; Word64 d = H[3]; Word64 e = H[4]; Word64 f = H[5]; Word64 g = H[6]; Word64 h = H[7]; for (int t = 0; t < 80; t++) { Word64 T1 = h + Sigma1_512(e) + Ch(e, f, g) + K512[t] + W[t]; Word64 T2 = Sigma0_512(a) + Maj(a, b, c); h = g; g = f; f = e; e = d + T1; d = c; c = b; b = a; a = T1 + T2; } // Update the current value of the hash H after processing block i. H[0] += a; H[1] += b; H[2] += c; H[3] += d; H[4] += e; H[5] += f; H[6] += g; H[7] += h; } // Concatenate all the Word64 Hash Values byte[] hash = ShaUtilities.Word64ArrayToByteArray(H); // The number of bytes in the final output hash int numberBytes = numberBits / 8; byte[] truncatedHash = new byte[numberBytes]; Array.Copy(hash, truncatedHash, numberBytes); return truncatedHash; } #endregion #region Plaintext preprocessing functions static byte[] PadPlainText512(byte[] plaintext) { // After padding the total bits of the output will be divisible by 512. int numberBits = plaintext.Length * 8; int t = (numberBits + 8 + 64) / 512; // Note that 512 * (t + 1) is the least multiple of 512 greater than (numberBits + 8 + 64) // Therefore the number of zero bits we need to add is int k = 512 * (t + 1) - (numberBits + 8 + 64); // Since numberBits % 8 = 0, we know k % 8 = 0. So n = k / 8 is the number of zero bytes to add. int n = k / 8; List paddedtext = plaintext.ToList(); // Start the padding by concatenating 1000_0000 = 0x80 = 128 paddedtext.Add(0x80); // Next add n zero bytes for (int i = 0; i < n; i++) { paddedtext.Add(0); } // Now add 8 bytes (64 bits) to represent the length of the message in bits byte[] B = BitConverter.GetBytes((ulong)numberBits); Array.Reverse(B); for (int i = 0; i < B.Length; i++) { paddedtext.Add(B[i]); } return paddedtext.ToArray(); } static byte[] PadPlainText1024(byte[] plaintext) { // After padding the total bits of the output will be divisible by 1024. int numberBits = plaintext.Length * 8; int t = (numberBits + 8 + 128) / 1024; // Note that 1024 * (t + 1) is the least multiple of 1024 greater than (numberBits + 8 + 128) // Therefore the number of zero bits we need to add is int k = 1024 * (t + 1) - (numberBits + 8 + 128); // Since numberBits % 8 = 0, we know k % 8 = 0. So n = k / 8 is the number of zero bytes to add. int n = k / 8; List paddedtext = plaintext.ToList(); // Start the padding by concatenating 1000_0000 = 0x80 = 128 paddedtext.Add(0x80); // Next add n zero bytes for (int i = 0; i < n; i++) { paddedtext.Add(0); } // Now add 16 bytes (128 bits) to represent the length of the message in bits. // C# does not have 128 bit integer. // For now just add 8 zero bytes and then 8 bytes to represent the int for (int i = 0; i < 8; i++) { paddedtext.Add(0); } byte[] B = BitConverter.GetBytes((ulong)numberBits); Array.Reverse(B); for (int i = 0; i < B.Length; i++) { paddedtext.Add(B[i]); } return paddedtext.ToArray(); } static Block512[] ConvertPaddedTextToBlock512Array(byte[] paddedtext) { // We are assuming M has been padded, so the number of bits in M is divisible by 512 int numberBlocks = (paddedtext.Length * 8) / 512; // same as: paddedtext.Length / 64 Block512[] blocks = new Block512[numberBlocks]; for (int i = 0; i < numberBlocks; i++) { // First extract the relavant subarray from paddedtext byte[] B = new byte[64]; // 64 * 8 = 512 for (int j = 0; j < 64; j++) { B[j] = paddedtext[i * 64 + j]; } Word32[] words = ShaUtilities.ByteArrayToWord32Array(B); blocks[i] = new Block512(words); } return blocks; } static Block1024[] ConvertPaddedMessageToBlock1024Array(byte[] M) { // We are assuming M is padded, so the number of bits in M is divisible by 1024 int numberBlocks = (M.Length * 8) / 1024; // same as: M.Length / 128 Block1024[] blocks = new Block1024[numberBlocks]; for (int i = 0; i < numberBlocks; i++) { // First extract the relavant subarray from M byte[] B = new byte[128]; // 128 * 8 = 1024 for (int j = 0; j < 128; j++) { B[j] = M[i * 128 + j]; } Word64[] words = ShaUtilities.ByteArrayToWord64Array(B); blocks[i] = new Block1024(words); } return blocks; } #endregion #region Functions used in the hashing process. // Most of these functions have a Word32 version and a Word64 version. // Sometimes they are the same (Ch, Maj,..) but sometimes different (Sigma0_256, Sigma0_512). // We do not need a RotL or Parity function for Word64 since they are only used in Sha-1. static Word32 ShR(int n, Word32 x) { // should have 0 <= n < 32 return (x >> n); } static Word64 ShR(int n, Word64 x) { // should have 0 <= n < 64 return (x >> n); } static Word32 RotR(int n, Word32 x) { // should have 0 <= n < 32 return (x >> n) | (x << 32 - n); } static Word64 RotR(int n, Word64 x) { // should have 0 <= n < 64 return (x >> n) | (x << 64 - n); } static Word32 RotL(int n, Word32 x) { // should have 0 <= n < 32 return (x << n) | (x >> 32 - n); } static Word32 Ch(Word32 x, Word32 y, Word32 z) { return (x & y) ^ (~x & z); } static Word64 Ch(Word64 x, Word64 y, Word64 z) { return (x & y) ^ (~x & z); } static Word32 Maj(Word32 x, Word32 y, Word32 z) { return (x & y) ^ (x & z) ^ (y & z); } static Word64 Maj(Word64 x, Word64 y, Word64 z) { return (x & y) ^ (x & z) ^ (y & z); } static Word32 Parity(Word32 x, Word32 y, Word32 z) { return x ^ y ^ z; } static Word32 f(int t, Word32 x, Word32 y, Word32 z) { // This function is used in Sha-1 // should have 0 <= t <= 79 if (t >= 0 && t <= 19) { return Ch(x, y, z); } else if (t >= 20 && t <= 39) { return Parity(x, y, z); } else if (t >= 40 && t <= 59) { return Maj(x, y, z); } else if (t >= 60 && t <= 79) { return Parity(x, y, z); } else { throw new ArgumentException("ERROR: t is out of bounds"); } } static Word32 Sigma0_256(Word32 x) { return RotR(2, x) ^ RotR(13, x) ^ RotR(22, x); } static Word32 Sigma1_256(Word32 x) { return RotR(6, x) ^ RotR(11, x) ^ RotR(25, x); } static Word32 sigma0_256(Word32 x) { return RotR(7, x) ^ RotR(18, x) ^ ShR(3, x); } static Word32 sigma1_256(Word32 x) { return RotR(17, x) ^ RotR(19, x) ^ ShR(10, x); } static Word64 Sigma0_512(Word64 x) { return RotR(28, x) ^ RotR(34, x) ^ RotR(39, x); } static Word64 Sigma1_512(Word64 x) { return RotR(14, x) ^ RotR(18, x) ^ RotR(41, x); } static Word64 sigma0_512(Word64 x) { return RotR(1, x) ^ RotR(8, x) ^ ShR(7, x); } static Word64 sigma1_512(Word64 x) { return RotR(19, x) ^ RotR(61, x) ^ ShR(6, x); } #endregion #region Functions to define the constants K and the initial hashes H0. static void DefineK1() { // The eighty 32-bit words in the array K1 are used in Sha-1. K1 = new Word32[80]; for (int i = 0; i < 80; i++) { if (i <= 19) { K1[i] = 0x5a827999; } else if (i <= 39) { K1[i] = 0x6ed9eba1; } else if (i <= 59) { K1[i] = 0x8f1bbcdc; } else { K1[i] = 0xca62c1d6; } } } static void DefineK256() { // The sixty four 32-bit words in the array K256 are used in Sha-224 and Sha-256. // They are obtained by taking the first 32 bits of the fractional // parts of the cube roots of the first sixty four primes. // ------------------------------------------------------- // NOTE: To find the first 32 bits of the fractional part of the cube root of an integer n: // double x = Math.Pow(n, 1d / 3); // x = x - Math.Floor(x); // x = x * Math.Pow(2, 32); // return (uint)x; K256 = new Word32[] { 0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5, 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174, 0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da, 0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967, 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85, 0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070, 0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3, 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2 }; } static void DefineK512() { // The eighty 64-bit words in the array K512 are used in Sha-384, Sha-512, Sha-512/224, Sha-512/256. // They are obtained by taking the first 64 bits of the fractional // parts of the cube roots of the first eighty primes. K512 = new Word64[] { 0x428a2f98d728ae22, 0x7137449123ef65cd, 0xb5c0fbcfec4d3b2f, 0xe9b5dba58189dbbc, 0x3956c25bf348b538, 0x59f111f1b605d019, 0x923f82a4af194f9b, 0xab1c5ed5da6d8118, 0xd807aa98a3030242, 0x12835b0145706fbe, 0x243185be4ee4b28c, 0x550c7dc3d5ffb4e2, 0x72be5d74f27b896f, 0x80deb1fe3b1696b1, 0x9bdc06a725c71235, 0xc19bf174cf692694, 0xe49b69c19ef14ad2, 0xefbe4786384f25e3, 0x0fc19dc68b8cd5b5, 0x240ca1cc77ac9c65, 0x2de92c6f592b0275, 0x4a7484aa6ea6e483, 0x5cb0a9dcbd41fbd4, 0x76f988da831153b5, 0x983e5152ee66dfab, 0xa831c66d2db43210, 0xb00327c898fb213f, 0xbf597fc7beef0ee4, 0xc6e00bf33da88fc2, 0xd5a79147930aa725, 0x06ca6351e003826f, 0x142929670a0e6e70, 0x27b70a8546d22ffc, 0x2e1b21385c26c926, 0x4d2c6dfc5ac42aed, 0x53380d139d95b3df, 0x650a73548baf63de, 0x766a0abb3c77b2a8, 0x81c2c92e47edaee6, 0x92722c851482353b, 0xa2bfe8a14cf10364, 0xa81a664bbc423001, 0xc24b8b70d0f89791, 0xc76c51a30654be30, 0xd192e819d6ef5218, 0xd69906245565a910, 0xf40e35855771202a, 0x106aa07032bbd1b8, 0x19a4c116b8d2d0c8, 0x1e376c085141ab53, 0x2748774cdf8eeb99, 0x34b0bcb5e19b48a8, 0x391c0cb3c5c95a63, 0x4ed8aa4ae3418acb, 0x5b9cca4f7763e373, 0x682e6ff3d6b2b8a3, 0x748f82ee5defb2fc, 0x78a5636f43172f60, 0x84c87814a1f0ab72, 0x8cc702081a6439ec, 0x90befffa23631e28, 0xa4506cebde82bde9, 0xbef9a3f7b2c67915, 0xc67178f2e372532b, 0xca273eceea26619c, 0xd186b8c721c0c207, 0xeada7dd6cde0eb1e, 0xf57d4f7fee6ed178, 0x06f067aa72176fba, 0x0a637dc5a2c898a6, 0x113f9804bef90dae, 0x1b710b35131c471b, 0x28db77f523047d84, 0x32caab7b40c72493, 0x3c9ebe0a15c9bebc, 0x431d67c49c100d4c, 0x4cc5d4becb3e42b6, 0x597f299cfc657e2a, 0x5fcb6fab3ad6faec, 0x6c44198c4a475817 }; } static void DefineH0Sha1() { H0Sha1 = new Word32[] { 0x67452301, 0xefcdab89, 0x98badcfe, 0x10325476, 0xc3d2e1f0 }; } static void DefineH0Sha224() { H0Sha224 = new Word32[] { 0xc1059ed8, 0x367cd507, 0x3070dd17, 0xf70e5939, 0xffc00b31, 0x68581511, 0x64f98fa7, 0xbefa4fa4 }; } static void DefineH0Sha256() { // These eight 32-bit words are obtained by taking the first 32 bits of the // fractional parts of the square roots of the first 8 prime numbers. H0Sha256 = new Word32[] { 0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a, 0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19 }; } static void DefineH0Sha384() { // These eight 64-bit words are obtained by taking the first 64 bits of the // fractional parts of the square roots of the ninth through sixteenth prime numbers. H0Sha384 = new Word64[] { 0xcbbb9d5dc1059ed8, 0x629a292a367cd507, 0x9159015a3070dd17, 0x152fecd8f70e5939, 0x67332667ffc00b31, 0x8eb44a8768581511, 0xdb0c2e0d64f98fa7, 0x47b5481dbefa4fa4 }; } static void DefineH0Sha512() { // These eight 64-bit words are obtained by taking the first 64 bits of the // fractional parts of the square roots of the first eight prime numbers. H0Sha512 = new Word64[] { 0x6a09e667f3bcc908, 0xbb67ae8584caa73b, 0x3c6ef372fe94f82b, 0xa54ff53a5f1d36f1, 0x510e527fade682d1, 0x9b05688c2b3e6c1f, 0x1f83d9abfb41bd6b, 0x5be0cd19137e2179 }; } static void DefineH0Sha512_224() { // These eight 64-bit words are obtained from GenerateInitialHashSha512t(224) H0Sha512_224 = new Word64[] { 0x8c3d37c819544da2, 0x73e1996689dcd4d6, 0x1dfab7ae32ff9c82, 0x679dd514582f9fcf, 0x0f6d2b697bd44da8, 0x77e36f7304c48942, 0x3f9d85a86a1d36c8, 0x1112e6ad91d692a1 }; } static void DefineH0Sha512_256() { // These eight 64-bit words are obtained from GenerateInitialHashSha512t(256) H0Sha512_256 = new Word64[] { 0x22312194fc2bf72c, 0x9f555fa3c84c64c2, 0x2393b86b6f53b151, 0x963877195940eabd, 0x96283ee2a88effe3, 0xbe5e1e2553863992, 0x2b0199fc2c85b8aa, 0x0eb72ddc81c52ca2 }; } /* static Word64[] GenerateInitialHashSha512t(int t) { // t = number of bits. // We assume t is postive, divisible by 8 and is strictly less than 512. // Also assume numberBits != 384 (WHY does 384 get its own initial hash?) Word64[] H0 = new Word64[8]; for (int i = 0; i < 8; i++) { H0[i] = H0Sha512[i] ^ 0xa5a5a5a5a5a5a5a5; } byte[] B = ShaUtil.StringToByteArray("SHA-512/" + t.ToString()); // so arbitary! return ShaUtil.ByteArrayToWord64Array(Sha512(B)); ; } */ #endregion } // Helper Classes class Block512 { // A Block512 consists of an array of 16 elements of type Word32. public Word32[] words; public Block512(Word32[] words) { if (words.Length == 16) { this.words = words; } else { Console.WriteLine("ERROR: A block must be 16 words"); this.words = null; } } } class Block1024 { // A Block1024 consists of an array of 16 elements of type Word64. public Word64[] words; public Block1024(Word64[] words) { if (words.Length == 16) { this.words = words; } else { Console.WriteLine("ERROR: A block must be 16 words"); this.words = null; } } } static class ShaUtilities { #region Functions to convert between byte arrays and Word32 arrays, and Word64 arrays. public static bool ByteArraysEqual(byte[] B1, byte[] B2) { if ((B1 == null) && (B2 == null)) return true; if ((B1 == null) || (B2 == null)) return false; if (B1.Length != B2.Length) return false; for (int i = 0; i < B1.Length; i++) { if (B1[i] != B2[i]) return false; } return true; } public static byte[] StringToByteArray(string plaintext) { char[] c = plaintext.ToCharArray(); int numberBytes = plaintext.Length; byte[] b = new byte[numberBytes]; for (int i = 0; i < numberBytes; i++) { b[i] = Convert.ToByte(c[i]); } return b; } // Returns an array of 4 bytes. public static byte[] Word32ToByteArray(Word32 x) { byte[] b = BitConverter.GetBytes(x); Array.Reverse(b); return b; } // Returns an array of 8 bytes. public static byte[] Word64ToByteArray(Word64 x) { byte[] b = BitConverter.GetBytes(x); Array.Reverse(b); return b; } public static byte[] Word32ArrayToByteArray(Word32[] words) { List b = new List(); for (int i = 0; i < words.Length; i++) { b.AddRange(Word32ToByteArray(words[i])); } return b.ToArray(); } public static byte[] Word32ArrayToByteArray(Word32[] words, int startIndex, int numberWords) { // This overload is useful in Sha224 // assume 0 <= startIndex < words.Length and startIndex + numberWords <= words.Length List b = new List(); for (int i = startIndex; i < startIndex + numberWords; i++) { b.AddRange(Word32ToByteArray(words[i])); } return b.ToArray(); } public static byte[] Word64ArrayToByteArray(Word64[] words) { List b = new List(); for (int i = 0; i < words.Length; i++) { b.AddRange(Word64ToByteArray(words[i])); } return b.ToArray(); } public static Word32 ByteArrayToWord32(byte[] B, int startIndex) { // We assume: 0 <= startIndex < B. Length, and startIndex + 4 <= B.Length Word32 c = 256; Word32 output = 0; for (int i = startIndex; i < startIndex + 4; i++) { output = output * c + (Word32)B[i]; } return output; } public static Word64 ByteArrayToWord64(byte[] B, int startIndex) { // We assume: 0 <= startIndex < B. Length, and startIndex + 8 <= B.Length Word64 c = 256; Word64 output = 0; for (int i = startIndex; i < startIndex + 8; i++) { output = output * c + B[i]; } return output; } public static Word32[] ByteArrayToWord32Array(byte[] B) { // We assume B is not null, is not empty and number elements is divisible by 4 int numberBytes = B.Length; int n = numberBytes / 4; // 4 bytes for each Word32 Word32[] word32Array = new Word32[n]; for (int i = 0; i < n; i++) { word32Array[i] = ByteArrayToWord32(B, 4 * i); } return word32Array; } public static Word64[] ByteArrayToWord64Array(byte[] B) { // We assume B is not null, is not empty and number elements is divisible by 8 int numberWords = B.Length / 8; // 8 bytes for each Word32 Word64[] word64Array = new Word64[numberWords]; for (int i = 0; i < numberWords; i++) { word64Array[i] = ByteArrayToWord64(B, 8 * i); } return word64Array; } #endregion #region To string methods public static string ByteToBinaryString(byte b) { string binaryString = Convert.ToString(b, 2).PadLeft(8, '0'); return binaryString.Substring(0, 4) + "_" + binaryString.Substring(4, 4); } public static string ByteArrayToBinaryString(byte[] x) { string binaryString = ""; for (int i = 0; i < x.Length; i++) { binaryString += ByteToBinaryString(x[i]); if (i < x.Length - 1) { binaryString += " "; } } return binaryString; } public static string ByteToHexString(byte b) { return Convert.ToString(b, 16).PadLeft(2, '0'); } public static string ByteArrayToHexString(byte[] a) { string hexString = ""; for (int i = 0; i < a.Length; i++) { hexString += ByteToHexString(a[i]); } return hexString; } public static string Word32ToBinaryString(Word32 x) { return ByteArrayToBinaryString(Word32ToByteArray(x)); } public static string Word32ToHexString(Word32 x) { return ByteArrayToHexString(Word32ToByteArray(x)); } public static string Word64ToHexString(Word64 x) { return ByteArrayToHexString(Word64ToByteArray(x)); } public static string ByteArrayToString(byte[] X) { if (X == null) { Console.WriteLine("ERROR: The byte array is null"); return null; } string s = ""; for (int i = 0; i < X.Length; i++) { s += (char)X[i]; } return s; } #endregion } }