{

// 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<byte> 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<byte> 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

};

}

/*

#endregion

{

// 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;

}

}

{

// 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;

}

}

{

#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++)