MD5算法之C#程序

using System;
using System.Collections.Generic;
using System.Text;
using System.Collections;    
using System.IO;    

namespace SocketHttpTest.BaseC.MD5
...{
        public class MD5
        ...{
                //static state variables    
                private static UInt32 A;
                private static UInt32 B;
                private static UInt32 C;
                private static UInt32 D;

                //number of bits to rotate in tranforming    
                private const int S11 = 7;
                private const int S12 = 12;
                private const int S13 = 17;
                private const int S14 = 22;
                private const int S21 = 5;
                private const int S22 = 9;
                private const int S23 = 14;
                private const int S24 = 20;
                private const int S31 = 4;
                private const int S32 = 11;
                private const int S33 = 16;
                private const int S34 = 23;
                private const int S41 = 6;
                private const int S42 = 10;
                private const int S43 = 15;
                private const int S44 = 21;


                /**//* F, G, H and I are basic MD5 functions.    
                 * 四个非线性函数:    
                 *    
                 * F(X,Y,Z) =(X&Y)|((~X)&Z)    
                 * G(X,Y,Z) =(X&Z)|(Y&(~Z))    
                 * H(X,Y,Z) =X^Y^Z    
                 * I(X,Y,Z)=Y^(X|(~Z))    
                 *    
                 * （&与，|或，~非，^异或）    
                 */
                private static UInt32 F(UInt32 x, UInt32 y, UInt32 z)
                ...{
                        return (x & y) | ((~x) & z);
                }
                private static UInt32 G(UInt32 x, UInt32 y, UInt32 z)
                ...{
                        return (x & z) | (y & (~z));
                }
                private static UInt32 H(UInt32 x, UInt32 y, UInt32 z)
                ...{
                        return x ^ y ^ z;
                }
                private static UInt32 I(UInt32 x, UInt32 y, UInt32 z)
                ...{
                        return y ^ (x | (~z));
                }

                /**//* FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.    
                 * Rotation is separate from addition to prevent recomputation.    
                 */
                private static void FF(ref UInt32 a, UInt32 b, UInt32 c, UInt32 d, UInt32 mj, int s, UInt32 ti)
                ...{
                        a = a + F(b, c, d) + mj + ti;
                        a = a << s | a >> (32 - s);
                        a += b;
                }
                private static void GG(ref UInt32 a, UInt32 b, UInt32 c, UInt32 d, UInt32 mj, int s, UInt32 ti)
                ...{
                        a = a + G(b, c, d) + mj + ti;
                        a = a << s | a >> (32 - s);
                        a += b;
                }
                private static void HH(ref UInt32 a, UInt32 b, UInt32 c, UInt32 d, UInt32 mj, int s, UInt32 ti)
                ...{
                        a = a + H(b, c, d) + mj + ti;
                        a = a << s | a >> (32 - s);
                        a += b;
                }
                private static void II(ref UInt32 a, UInt32 b, UInt32 c, UInt32 d, UInt32 mj, int s, UInt32 ti)
                ...{
                        a = a + I(b, c, d) + mj + ti;
                        a = a << s | a >> (32 - s);
                        a += b;
                }

                private static void MD5_Init()
                ...{
                        A = 0x67452301;    //in memory, this is 0x01234567    
                        B = 0xefcdab89;    //in memory, this is 0x89abcdef    
                        C = 0x98badcfe;    //in memory, this is 0xfedcba98    
                        D = 0x10325476;    //in memory, this is 0x76543210    
                }

                private static UInt32[] MD5_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 = 0;
                                ones = 0;
                                size = n + 8;
                        }
                        else
                        ...{
                                zeros = 63 - m + 56;
                                size = n + 64 - m + 64;
                        }

                        ArrayList bs = new ArrayList(input);
                        if (ones == 1)
                        ...{
                                bs.Add((byte)0x80); // 0x80 = 000000    
                        }
                        for (int i = 0; i < zeros; i++)
                        ...{
                                bs.Add((byte)0);
                        }

                        UInt64 N = (UInt64)n * 8;
                        byte h1 = (byte)(N & 0xFF);
                        byte h2 = (byte)((N >> 8) & 0xFF);
                        byte h3 = (byte)((N >> 16) & 0xFF);
                        byte h4 = (byte)((N >> 24) & 0xFF);
                        byte h5 = (byte)((N >> 32) & 0xFF);
                        byte h6 = (byte)((N >> 40) & 0xFF);
                        byte h7 = (byte)((N >> 48) & 0xFF);
                        byte h8 = (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)
                        ...{
                                
                                output[j] = (UInt32)(ts[i] | ts[i + 1] << 8 | ts[i + 2] << 16 | ts[i + 3] << 24);
                        }
                        return output;
                }
                private static UInt32[] MD5_Trasform(UInt32[] x)
                ...{

                        UInt32 a, b, c, d;

                        for (int k = 0; k < x.Length; k += 16)
                        ...{
                                a = A;
                                b = B;
                                c = C;
                                d = D;

                                /**//* Round 1 */
                                FF(ref a, b, c, d, x[k + 0], S11, 0xd76aa478); /**//* 1 */
                                FF(ref d, a, b, c, x[k + 1], S12, 0xe8c7b756); /**//* 2 */
                                FF(ref c, d, a, b, x[k + 2], S13, 0x242070db); /**//* 3 */
                                FF(ref b, c, d, a, x[k + 3], S14, 0xc1bdceee); /**//* 4 */
                                FF(ref a, b, c, d, x[k + 4], S11, 0xf57c0faf); /**//* 5 */
                                FF(ref d, a, b, c, x[k + 5], S12, 0x4787c62a); /**//* 6 */
                                FF(ref c, d, a, b, x[k + 6], S13, 0xa8304613); /**//* 7 */
                                FF(ref b, c, d, a, x[k + 7], S14, 0xfd469501); /**//* 8 */
                                FF(ref a, b, c, d, x[k + 8], S11, 0x698098d8); /**//* 9 */
                                FF(ref d, a, b, c, x[k + 9], S12, 0x8b44f7af); /**//* 10 */
                                FF(ref c, d, a, b, x[k + 10], S13, 0xffff5bb1); /**//* 11 */
                                FF(ref b, c, d, a, x[k + 11], S14, 0x895cd7be); /**//* 12 */
                                FF(ref a, b, c, d, x[k + 12], S11, 0x6b901122); /**//* 13 */
                                FF(ref d, a, b, c, x[k + 13], S12, 0xfd987193); /**//* 14 */
                                FF(ref c, d, a, b, x[k + 14], S13, 0xa679438e); /**//* 15 */
                                FF(ref b, c, d, a, x[k + 15], S14, 0x49b40821); /**//* 16 */

                                /**//* Round 2 */
                                GG(ref a, b, c, d, x[k + 1], S21, 0xf61e2562); /**//* 17 */
                                GG(ref d, a, b, c, x[k + 6], S22, 0xc040b340); /**//* 18 */
                                GG(ref c, d, a, b, x[k + 11], S23, 0x265e5a51); /**//* 19 */
                                GG(ref b, c, d, a, x[k + 0], S24, 0xe9b6c7aa); /**//* 20 */
                                GG(ref a, b, c, d, x[k + 5], S21, 0xd62f105d); /**//* 21 */
                                GG(ref d, a, b, c, x[k + 10], S22, 0x2441453); /**//* 22 */
                                GG(ref c, d, a, b, x[k + 15], S23, 0xd8a1e681); /**//* 23 */
                                GG(ref b, c, d, a, x[k + 4], S24, 0xe7d3fbc8); /**//* 24 */
                                GG(ref a, b, c, d, x[k + 9], S21, 0x21e1cde6); /**//* 25 */
                                GG(ref d, a, b, c, x[k + 14], S22, 0xc33707d6); /**//* 26 */
                                GG(ref c, d, a, b, x[k + 3], S23, 0xf4d50d87); /**//* 27 */
                                GG(ref b, c, d, a, x[k + 8], S24, 0x455a14ed); /**//* 28 */
                                GG(ref a, b, c, d, x[k + 13], S21, 0xa9e3e905); /**//* 29 */
                                GG(ref d, a, b, c, x[k + 2], S22, 0xfcefa3f8); /**//* 30 */
                                GG(ref c, d, a, b, x[k + 7], S23, 0x676f02d9); /**//* 31 */
                                GG(ref b, c, d, a, x[k + 12], S24, 0x8d2a4c8a); /**//* 32 */

                                /**//* Round 3 */
                                HH(ref a, b, c, d, x[k + 5], S31, 0xfffa3942); /**//* 33 */
                                HH(ref d, a, b, c, x[k + 8], S32, 0x8771f681); /**//* 34 */
                                HH(ref c, d, a, b, x[k + 11], S33, 0x6d9d6122); /**//* 35 */
                                HH(ref b, c, d, a, x[k + 14], S34, 0xfde5380c); /**//* 36 */
                                HH(ref a, b, c, d, x[k + 1], S31, 0xa4beea44); /**//* 37 */
                                HH(ref d, a, b, c, x[k + 4], S32, 0x4bdecfa9); /**//* 38 */
                                HH(ref c, d, a, b, x[k + 7], S33, 0xf6bb4b60); /**//* 39 */
                                HH(ref b, c, d, a, x[k + 10], S34, 0xbebfbc70); /**//* 40 */
                                HH(ref a, b, c, d, x[k + 13], S31, 0x289b7ec6); /**//* 41 */
                                HH(ref d, a, b, c, x[k + 0], S32, 0xeaa127fa); /**//* 42 */
                                HH(ref c, d, a, b, x[k + 3], S33, 0xd4ef3085); /**//* 43 */
                                HH(ref b, c, d, a, x[k + 6], S34, 0x4881d05); /**//* 44 */
                                HH(ref a, b, c, d, x[k + 9], S31, 0xd9d4d039); /**//* 45 */
                                HH(ref d, a, b, c, x[k + 12], S32, 0xe6db99e5); /**//* 46 */
                                HH(ref c, d, a, b, x[k + 15], S33, 0x1fa27cf8); /**//* 47 */
                                HH(ref b, c, d, a, x[k + 2], S34, 0xc4ac5665); /**//* 48 */

                                /**//* Round 4 */
                                II(ref a, b, c, d, x[k + 0], S41, 0xf4292244); /**//* 49 */
                                II(ref d, a, b, c, x[k + 7], S42, 0x432aff97); /**//* 50 */
                                II(ref c, d, a, b, x[k + 14], S43, 0xab9423a7); /**//* 51 */
                                II(ref b, c, d, a, x[k + 5], S44, 0xfc93a039); /**//* 52 */
                                II(ref a, b, c, d, x[k + 12], S41, 0x655b59c3); /**//* 53 */
                                II(ref d, a, b, c, x[k + 3], S42, 0x8f0ccc92); /**//* 54 */
                                II(ref c, d, a, b, x[k + 10], S43, 0xffeff47d); /**//* 55 */
                                II(ref b, c, d, a, x[k + 1], S44, 0x85845dd1); /**//* 56 */
                                II(ref a, b, c, d, x[k + 8], S41, 0x6fa87e4f); /**//* 57 */
                                II(ref d, a, b, c, x[k + 15], S42, 0xfe2ce6e0); /**//* 58 */
                                II(ref c, d, a, b, x[k + 6], S43, 0xa3014314); /**//* 59 */
                                II(ref b, c, d, a, x[k + 13], S44, 0x4e0811a1); /**//* 60 */
                                II(ref a, b, c, d, x[k + 4], S41, 0xf7537e82); /**//* 61 */
                                II(ref d, a, b, c, x[k + 11], S42, 0xbd3af235); /**//* 62 */
                                II(ref c, d, a, b, x[k + 2], S43, 0x2ad7d2bb); /**//* 63 */
                                II(ref b, c, d, a, x[k + 9], S44, 0xeb86d391); /**//* 64 */

                                A += a;
                                B += b;
                                C += c;
                                D += d;
                        }
                        return new UInt32[] ...{ A, B, C, D };
                }
                public static byte[] MD5Array(byte[] input)
                ...{
                        MD5_Init();
                        UInt32[] block = MD5_Append(input);
                        UInt32[] bits = MD5_Trasform(block);

                        /**//* Encodes bits (UInt32[]) into output (byte[]). Assumes len is    
                         * a multiple of 4.    
                                 */
                        byte[] output = new byte[bits.Length * 4];
                        for (int i = 0, j = 0; i < bits.Length; i++, j += 4)
                        ...{
                                
                                output[j] = (byte)(bits[i] & 0xff);
                                output[j + 1] = (byte)((bits[i] >> 8) & 0xff);
                                output[j + 2] = (byte)((bits[i] >> 16) & 0xff);
                                output[j + 3] = (byte)((bits[i] >> 24) & 0xff);
                        }
                        return output;
                }

                public static string ArrayToHexString(byte[] array, bool uppercase)
                ...{
                        string hexString = "";
                        string format = "x2";
                        if (uppercase)
                        ...{
                                format = "X2";
                        }
                        foreach (byte b in array)
                        ...{
                                hexString += b.ToString(format);
                        }
                        return hexString;
                }

                public static string MDString(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];
                        }
                        byte[] digest = MD5Array(b);
                        return ArrayToHexString(digest, false);
                }
                public static string MDFile(string fileName)
                ...{
                        FileStream fs = File.Open(fileName, FileMode.Open, FileAccess.Read);
                        byte[] array = new byte[fs.Length];
                        fs.Read(array, 0, (int)fs.Length);
                        byte[] digest = MD5Array(array);
                        fs.Close();
                        return ArrayToHexString(digest, false);
                }

                public static string Test(string message)
                ...{
                        return " MD5 ("" + message + "") = " + MD5.MDString(message);
                }
                public static string TestSuite()
                ...{
                        string s = "";
                        s += Test("");
                        s += Test("a");
                        s += Test("abc");
                        s += Test("message digest");
                        s += Test("abcdefghijklmnopqrstuvwxyz");
                        s += Test("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789");
                        s += Test("12345678901234567890123456789012345678901234567890123456789012345678901234567890");
                        return s;
                }
        }
}