md5算法之c#程序.txt

MD5算法之C#程序

MD5算法之C#程序

MD5算法比较特别，最适合用汇编语言来写，好多高级语言对之无能无力或效率极低。 
比如我最开始尝试用Python和Euphoria编写，发现不太容易。相比而言，C#作为C家簇 
中新兴的一门.net语言，功能比较全面。花了一晚上的工夫终于用C#最先实现了MD5。 
主要是由于对算法的一些细节不太注意，结果输出总是不对，调试了好长时间。 

[code] 
//源文件：md5.cs 
// MD5 Alogrithm 
// by rufi 2004.6.20 http://rufi.yculblog.com/ 
using System; 
using System.Collections; 
using System.IO; 

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 "\r\nMD5 (\""+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;     
 } 
} 
[/code]