数字签名标准（Digital Signature Standard DSS）里面定义的数字签名算法（Digital Signature Algorithm DSA）
参考：
http://www.cnblogs.com/FlyingBread/archive/2007/01/02/610206.html
http://www.cnblogs.com/FlyingBread/archive/2007/01/02/610206.html#commentform
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Collections;
namespace SHA_1_HashAlgorithm
{
public class SHA1Core
{
// state variables
private static UInt32 Message_Digest1 = 0x67452301;
private static UInt32 Message_Digest2 = 0xEFCDAB89;
private static UInt32 Message_Digest3 = 0x98BADCFE;
private static UInt32 Message_Digest4 = 0x10325476;
private static UInt32 Message_Digest5 = 0xC3D2E1F0;
private static UInt32 SHA1CircularShift(int bits, UInt32 word)
{
return ((word << bits) & 0xFFFFFFFF) | (word) >> (32 - (bits));
}
private static void SHA1_Init()
{
Message_Digest1 = 0x67452301;
Message_Digest2 = 0xEFCDAB89;
Message_Digest3 = 0x98BADCFE;
Message_Digest4 = 0x10325476;
Message_Digest5 = 0xC3D2E1F0;
}
private static UInt32[] SHA1_Append(byte[] input)
{
int zeros = 0;
int ones = 1;
int size = 0;
int n = input.Length;
int m = n % 64;
if (m < 56)
{
zeros = 55 - m;
size = n - m + 64;
}
else if (m == 56)
{
zeros = 63;
ones = 1;
size = n + 8 + 64;
}
else
{
zeros = 63 - m + 56;
size = n + 64 - m + 64;
}
ArrayList bs = new ArrayList(input);
if (ones == 1)
{
bs.Add((byte)0x80); // 0x80 = 10000000
}
for (int i = 0; i < zeros; i++)
{
bs.Add((byte)0);
}
UInt64 N = (UInt64)n * 8;
byte h8 = (byte)(N & 0xFF);
byte h7 = (byte)((N >> 8) & 0xFF);
byte h6 = (byte)((N >> 16) & 0xFF);
byte h5 = (byte)((N >> 24) & 0xFF);
byte h4 = (byte)((N >> 32) & 0xFF);
byte h3 = (byte)((N >> 40) & 0xFF);
byte h2 = (byte)((N >> 48) & 0xFF);
byte h1 = (byte)(N >> 56);
bs.Add(h1);
bs.Add(h2);
bs.Add(h3);
bs.Add(h4);
bs.Add(h5);
bs.Add(h6);
bs.Add(h7);
bs.Add(h8);
byte[] ts = (byte[])bs.ToArray(typeof(byte));
/* Decodes input (byte[]) into output (UInt32[]). Assumes len is
* a multiple of 4.
*/
UInt32[] output = new UInt32[size / 4];
for (Int64 i = 0, j = 0; i < size; j++, i += 4)
{
UInt32 temp = 0;
temp = temp | (((UInt32)ts[i]) << 24);
temp = temp | (((UInt32)ts[i + 1]) << 16);
temp = temp | (((UInt32)ts[i + 2]) << 8);
temp = temp | (((UInt32)ts[i + 3]));
output[j] = temp;
}
return output;
}
private static UInt32[] SHA1_Transform(UInt32[] x)
{
SHA1_Init();
UInt32[] K = {
0x5A827999,
0x6ED9EBA1,
0x8F1BBCDC,
0xCA62C1D6
};
int t;
UInt32 temp;
UInt32[] W = new UInt32[80];
UInt32 A, B, C, D, E;
for (int k = 0; k < x.Length; k += 16)
{
for (t = 0; t < 16; t++)
{
W[t] = x[t + k];
}
for (t = 16; t < 80; t++)
{
W[t] = SHA1CircularShift(1, W[t - 3] ^ W[t - 8] ^ W[t - 14] ^ W[t - 16]);
}
A = Message_Digest1;
B = Message_Digest2;
C = Message_Digest3;
D = Message_Digest4;
E = Message_Digest5;
for (t = 0; t < 20; t++)
{
temp = SHA1CircularShift(5, A) +
((B & C) | ((~B) & D)) + E + W[t] + K[0];
temp &= 0xFFFFFFFF;
E = D;
D = C;
C = SHA1CircularShift(30, B);
B = A;
A = temp;
}
for (t = 20; t < 40; t++)
{
temp = SHA1CircularShift(5, A) + (B ^ C ^ D) + E + W[t] + K[1];
temp &= 0xFFFFFFFF;
E = D;
D = C;
C = SHA1CircularShift(30, B);
B = A;
A = temp;
}
for (t = 40; t < 60; t++)
{
temp = SHA1CircularShift(5, A) +
((B & C) | (B & D) | (C & D)) + E + W[t] + K[2];
temp &= 0xFFFFFFFF;
E = D;
D = C;
C = SHA1CircularShift(30, B);
B = A;
A = temp;
}
for (t = 60; t < 80; t++)
{
temp = SHA1CircularShift(5, A) + (B ^ C ^ D) + E + W[t] + K[3];
temp &= 0xFFFFFFFF;
E = D;
D = C;
C = SHA1CircularShift(30, B);
B = A;
A = temp;
}
Message_Digest1 = (Message_Digest1 + A) & 0xFFFFFFFF;
Message_Digest2 = (Message_Digest2 + B) & 0xFFFFFFFF;
Message_Digest3 = (Message_Digest3 + C) & 0xFFFFFFFF;
Message_Digest4 = (Message_Digest4 + D) & 0xFFFFFFFF;
Message_Digest5 = (Message_Digest5 + E) & 0xFFFFFFFF;
}
return new UInt32[] { Message_Digest1, Message_Digest2, Message_Digest3, Message_Digest4, Message_Digest5 };
}
public static string SHA1Array(UInt32[] input)
{
StringBuilder sb = new StringBuilder();
for (int i = 0; i < input.Length; i++)
{
sb.Append(String.Format("{0:X8}", input[i]).ToUpper());
}
return sb.ToString();
}
private static UInt32[] ComputeHash(string message)
{
char[] c = message.ToCharArray();
byte[] b = new byte[c.Length];
for (int i = 0; i < c.Length; i++)
{
b[i] = (byte)c[i];
}
UInt32[] output = SHA1_Append(b);
UInt32[] str = SHA1_Transform(output);
return str;
}
public static byte[] ComputeHashBytes(byte[] src)
{
UInt32[] output = SHA1_Append(src);
UInt32[] str = SHA1_Transform(output);
byte[] buff = new byte[str.Length * 4];
for (int i = 0; i < str.Length; i++)
{
buff[i*4] = Convert.ToByte((str[i] >> 24) & 0xff);
buff[i*4+1] = Convert.ToByte((str[i] >> 16) & 0xff);
buff[i*4+2] = Convert.ToByte((str[i] >> 8) & 0xff);
buff[i*4+3] = Convert.ToByte((str[i] ) & 0xff);
}
return buff;
}
}
}
Unit Test ：
/// <summary>
///A test for ComputeHashBytes
///</summary>
[TestMethod()]
public void ComputeHashBytes_Strong_Test()
{
Encoding encoding = Encoding.Default;
Random rand1=new Random();
for (int i = 0; i < 100; i++)
{
if (i % 2 == 0)
{
encoding = Encoding.Default;
}
else if (i % 3 == 0)
{
encoding = Encoding.ASCII;
}
else if (i % 5 == 0)
{
encoding = Encoding.UTF8;
}
else if (i % 7 == 0)
{
encoding = Encoding.Unicode;
}
RNGCryptoServiceProvider rand = new RNGCryptoServiceProvider();
byte[] src = new byte[rand1.Next(1, 40000)];
rand.GetBytes(src);
SHA1CryptoServiceProvider cryp = new SHA1CryptoServiceProvider();
byte[] expected = cryp.ComputeHash(src);
byte[] actual;
actual = SHA1Core.ComputeHashBytes(src);
string exStr = encoding.GetString(expected);
string acStr = encoding.GetString(actual);
Assert.AreEqual(exStr, acStr);
}
}
