A，B，C，D連續存放，共16個字節，128位。按十六進制依次輸出這個16個字節。
最後，用程序語言實現算法後，可以輸入以下幾個信息對程序作一個簡單的測試，看看程序有沒有錯誤。
MD5 ("") = d41d8cd98f00b204e9800998ecf8427e
MD5 ("a") = 0cc175b9c0f1b6a831c399e269772661
MD5 ("abc") = 900150983cd24fb0d6963f7d28e17f72
MD5 ("message digest") = f96b697d7cb7938d525a2f31aaf161d0
MD5 ("abcdefghijklmnopqrstuvwxyz") = c3fcd3d76192e4007dfb496cca67e13b
MD5 ("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789") =
d174ab98d277d9f5a5611c2c9f419d9f
MD5 ("123456789012345678901234567890123456789012345678901234567890123456789
01234567890") = 57edf4a22be3c955ac49da2e2107b67a
MD5算法之C#程序
MD5算法比較特別，最適合用匯編語言來寫，好多高級語言對之無能無力或效率極低。
比如我最開始嘗試用Python和Euphoria編寫，發現不太容易。相比而言，C#作為C家簇中新興的一門.Net語言，功能比較全面。花了一晚上的工夫終於用C#最先實現了MD5。
主要是由於對算法的一些細節不太注意，結果輸出總是不對，調試了好長時間。
//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.
* 四個非線性函數:
*
* 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))
*
* （&與，|或，~非，^異或）
*/
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 = $10000000
}
for(int i=0;ibs.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;ioutput[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;ka=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;ioutput[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;ib[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 "rnMD5 (""+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;
}
}
