public static byte[] SHA1(byte[] message)
{
// Initialize buffers
uint h0 = 0x67452301;
uint h1 = 0xEFCDAB89;
uint h2 = 0x98BADCFE;
uint h3 = 0x10325476;
uint h4 = 0xC3D2E1F0;
// Pad message
int ml = message.Length + 1;
byte[] msg = new byte[ml + ((960 - (ml * 8 % 512)) % 512) / 8 + 8];
Array.Copy(message, msg, message.Length);
msg[message.Length] = 0x80;
long len = message.Length * 8;
for (int i = 0; i < 8; ++i)
{
msg[msg.Length - 1 - i] = (byte)((len >> (i * 8)) & 255);
}
//Support.WriteToArray(msg, message.Length * 8, msg.Length - 8);
//for (int i = 0; i <4; ++i) msg[msg.Length - 5 - i] = (byte)(((message.Length*8) >> (i * 8)) & 255);
int chunks = msg.Length / 64;
// Perform hashing for each 512-bit block
for (int i = 0; i < chunks; ++i)
{
// Split block into words (allocated out here to prevent massive garbage buildup)
uint[] w = new uint[80];
// Compute initial source data from padded message
for (int j = 0; j < 16; ++j)
{
w[j] |= (uint)((msg[i * 64 + j * 4] << 24) | (msg[i * 64 + j * 4 + 1] << 16) | (msg[i * 64 + j * 4 + 2] << 8) | (msg[i * 64 + j * 4 + 3] << 0));
}
// Expand words
for (int j = 16; j < 80; ++j)
{
w[j] = Rot(w[j - 3] ^ w[j - 8] ^ w[j - 14] ^ w[j - 16], 1);
}
// Initialize chunk-hash
uint
a = h0,
b = h1,
c = h2,
d = h3,
e = h4;
// Do hash rounds
for (int t = 0; t < 80; ++t)
{
uint tmp = Rot(a, 5) + func(t, b, c, d) + e + K(t) + w[t];
e = d;
d = c;
c = Rot(b, 30);
b = a;
a = tmp;
}
// Add to result
h0 += a;
h1 += b;
h2 += c;
h3 += d;
h4 += e;
}
return(Support.WriteContiguous(new byte[20], 0, Support.SwapEndian(h0), Support.SwapEndian(h1), Support.SwapEndian(h2), Support.SwapEndian(h3), Support.SwapEndian(h4)));
}
