讲得不清楚，或者说很费解。最后不得不拿出C语言的源程序来调试，这对于理解算法是很不
利的。于是就总结了一下我摸索到的一些要点。
1.来历
MD5的全称是message-digest algorithm 5(信息-摘要算法，在90年代初由mit laboratory
for computer science和rsa data security inc的ronald l. rivest开发出来，
经md2、md3和md4发展而来。http://www.ietf.org/rfc/rfc1321.txt，是一份最权威的文档，
由ronald l. rivest在1992年8月向ieft提交。
2.用途
MD5的作用是对一段信息(message)生成信息摘要(message-digest)，该摘要对该信息具有
唯一性,可以作为数字签名。用于验证文件的有效性(是否有丢失或损坏的数据),对用户
密码的加密，在哈希函数中计算散列值。
3.特点
输入一个任意长度的字节串，生成一个128位的整数。由于算法的某些不可逆特征，在加密应用
上有较好的安全性。并且，MD5算法的使用不需要支付任何版权费用。
4.说明
唯一性和不可逆性都不是绝对的，从理论上分析是一种多对一的关系，但两个不同的信息产生
相同摘要的概率很小。不可逆是指从输出反推输入所需的运算量和计算时间太大，使用穷搜字
典的方法又需要太多的存储空间。
5.算法描述
算法输入是一个字节串，每个字节是8个bit.
算法的执行分为以下几个步骤：
第一步，补位：
MD5算法先对输入的数据进行补位，使得数据的长度(以byte为单位)对64求余的结果是56。
即数据扩展至LEN=K*64+56个字节，K为整数。
补位方法：补一个1，然后补0至满足上述要求。相当于补一个0x80的字节，再补值
为0的字节。这一步里总共补充的字节数为0～63个。
第二步，附加数据长度：
用一个64位的整数表示数据的原始长度(以bit为单位)，将这个数字的8个字节按低位的在前，
高位在后的顺序附加在补位后的数据后面。这时，数据被填补后的总长度为：
LEN = K*64+56+8=(K+1)*64 Bytes。
※注意那个64位整数是输入数据的原始长度而不是填充字节后的长度,我就在这里栽了跟头.
第三步，初始化MD5参数：
有四个32位整数变量 (A,B,C,D) 用来计算信息摘要，每一个变量被初始化成以下
以十六进制数表示的数值，低位的字节在前面。
word A: 01 23 45 67
word B: 89 ab cd ef
word C: fe dc ba 98
word D: 76 54 32 10
※注意低位的字节在前面指的是Little Endian平台上内存中字节的排列方式，
而在程序中书写时，要写成：
A=0x67452301
B=0xefcdab89
C=0x98badcfe
D=0x10325476
第四步，定义四个MD5基本的按位操作函数：
X，Y，Z为32位整数。
F(X,Y,Z) = (X and Y) or (not(X) and Z)
G(X,Y,Z) = (X and Z) or (Y and not(Z))
H(X,Y,Z) = X xor Y xor Z
I(X,Y,Z) = Y xor (X or not(Z))
再定义四个分别用于四轮变换的函数。
设Mj表示消息的第j个子分组（从0到15），<<<s表示循环左移s位，则四种操作为：
FF(a,b,c,d,Mj,s,ti)表示a=b+((a+(F(b,c,d)+Mj+ti)<<<s)
GG(a,b,c,d,Mj,s,ti)表示a=b+((a+(G(b,c,d)+Mj+ti)<<<s)
HH(a,b,c,d,Mj,s,ti)表示a=b+((a+(H(b,c,d)+Mj+ti)<<<s)
II(a,b,c,d,Mj,s,ti)表示a=b+((a+(I(b,c,d)+Mj+ti)<<<s)
第五步，对输入数据作变换。
处理数据，N是总的字节数，以64个字节为一组，每组作一次循环，每次循环进行四轮操作。
要变换的64个字节用16个32位的整数数组M[0 ...15]表示。而数组T[1 ... 64]表示一组常数，
T[i]为4294967296*abs(sin(i))的32位整数部分，i的单位是弧度,i的取值从1到64。
具体过程如下：
/* 设置主循环变量 */
For i = 0 to N/16-1 do
/*每循环一次，把数据原文存放在16个元素的数组X中. */
For j = 0 to 15 do
Set X[j] to M[i*16+j].
end /结束对J的循环
/* Save A as AA, B as BB, C as CC, and D as DD.
*/
AA = A
BB = B
CC = C
DD = D
/* 第1轮*/
/* 以 [abcd k s i]表示如下操作
a = b + ((a + F(b,c,d) + X[k] + T[i]) <<< s). */
/* Do the following 16 operations. */
[ABCD 0 7 1] [DABC 1 12 2] [CDAB 2 17 3] [BCDA 3 22 4]
[ABCD 4 7 5] [DABC 5 12 6] [CDAB 6 17 7] [BCDA 7 22 8]
[ABCD 8 7 9] [DABC 9 12 10] [CDAB 10 17 11] [BCDA 11 22 12]
[ABCD 12 7 13] [DABC 13 12 14] [CDAB 14 17 15] [BCDA 15 22 16]
/* 第2轮* */
/* 以 [abcd k s i]表示如下操作
a = b + ((a + G(b,c,d) + X[k] + T[i]) <<< s). */
/* Do the following 16 operations. */
[ABCD 1 5 17] [DABC 6 9 18] [CDAB 11 14 19] [BCDA 0 20 20]
[ABCD 5 5 21] [DABC 10 9 22] [CDAB 15 14 23] [BCDA 4 20 24]
[ABCD 9 5 25] [DABC 14 9 26] [CDAB 3 14 27] [BCDA 8 20 28]
[ABCD 13 5 29] [DABC 2 9 30] [CDAB 7 14 31] [BCDA 12 20 32]
/* 第3轮*/
/* 以 [abcd k s i]表示如下操作
a = b + ((a + H(b,c,d) + X[k] + T[i]) <<< s). */
/* Do the following 16 operations. */
[ABCD 5 4 33] [DABC 8 11 34] [CDAB 11 16 35] [BCDA 14 23 36]
[ABCD 1 4 37] [DABC 4 11 38] [CDAB 7 16 39] [BCDA 10 23 40]
[ABCD 13 4 41] [DABC 0 11 42] [CDAB 3 16 43] [BCDA 6 23 44]
[ABCD 9 4 45] [DABC 12 11 46] [CDAB 15 16 47] [BCDA 2 23 48]
/* 第4轮*/
/* 以 [abcd k s i]表示如下操作
a = b + ((a + I(b,c,d) + X[k] + T[i]) <<< s). */
/* Do the following 16 operations. */
[ABCD 0 6 49] [DABC 7 10 50] [CDAB 14 15 51] [BCDA 5 21 52]
[ABCD 12 6 53] [DABC 3 10 54] [CDAB 10 15 55] [BCDA 1 21 56]
[ABCD 8 6 57] [DABC 15 10 58] [CDAB 6 15 59] [BCDA 13 21 60]
[ABCD 4 6 61] [DABC 11 10 62] [CDAB 2 15 63] [BCDA 9 21 64]
/* 然后进行如下操作 */
A = A + AA
B = B + BB
C = C + CC
D = D + DD
Next i /* 结束对I的循环*/
第六步，输出结果。
A，B，C，D连续存放，共16个字节，128位。按十六进制依次输出这个16个字节。
最后，用程序语言实现算法后，可以输入以下几个信息对程序作一个简单的测试，
看看程序有没有错误。
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]
1
//源文件：md5.cs
2// MD5 Alogrithm
3// by rufi 2004.6.20 http://rufi.yculblog.com/
4using System;
5using System.Collections;
6using System.IO;
7
8
public class MD5 {
9
//static state variables
10private static UInt32 A;
11private static UInt32 B;
12private static UInt32 C;
13private static UInt32 D;
14
15//number of bits to rotate in tranforming
16private const int S11 = 7;
17private const int S12 = 12;
18private const int S13 = 17;
19private const int S14 = 22;
20private const int S21 = 5;
21private const int S22 = 9;
22private const int S23 = 14;
23private const int S24 = 20;
24private const int S31 = 4;
25private const int S32 = 11;
26private const int S33 = 16;
27private const int S34 = 23;
28private const int S41 = 6;
29private const int S42 = 10;
30private const int S43 = 15;
31private const int S44 = 21;
32
33
34
/* F, G, H and I are basic MD5 functions.
35* 四个非线性函数:
36*
37* F(X,Y,Z) =(X&Y)|((~X)&Z)
38* G(X,Y,Z) =(X&Z)|(Y&(~Z))
39* H(X,Y,Z) =X^Y^Z
40* I(X,Y,Z)=Y^(X|(~Z))
41*
42* （&与，|或，~非，^异或）
43
*/
44private static UInt32 F(UInt32 x,UInt32 y,UInt32 z){
45return (x&y)|((~x)&z);
46}
47private static UInt32 G(UInt32 x,UInt32 y,UInt32 z){
48return (x&z)|(y&(~z));
49}
50private static UInt32 H(UInt32 x,UInt32 y,UInt32 z){
51return x^y^z;
52}
53private static UInt32 I(UInt32 x,UInt32 y,UInt32 z){
54return y^(x|(~z));
55}
56
57/* FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
58* Rotation is separate from addition to prevent recomputation.
59*/
60private static void FF(ref UInt32 a,UInt32 b,UInt32 c,UInt32 d,UInt32 mj,int s,UInt32 ti){
61a = a + F(b,c,d) + mj + ti;
62a = a << s | a >> (32-s);
63a += b;
64}
65private static void GG(ref UInt32 a,UInt32 b,UInt32 c,UInt32 d,UInt32 mj,int s,UInt32 ti){
66a = a + G(b,c,d) + mj + ti;
67a = a << s | a >> (32-s);
68a += b;
69}
70private static void HH(ref UInt32 a,UInt32 b,UInt32 c,UInt32 d,UInt32 mj,int s,UInt32 ti){
71a = a + H(b,c,d) + mj + ti;
72a = a << s | a >> (32-s);
73a += b;
74}
75private static void II(ref UInt32 a,UInt32 b,UInt32 c,UInt32 d,UInt32 mj,int s,UInt32 ti){
76a = a + I(b,c,d) + mj + ti;
77a = a << s | a >> (32-s);
78a += b;
79}
80
81private static void MD5_Init(){
82A=0x67452301; //in memory, this is 0x01234567
83B=0xefcdab89; //in memory, this is 0x89abcdef
84C=0x98badcfe; //in memory, this is 0xfedcba98
85D=0x10325476; //in memory, this is 0x76543210
86}
87
88private static UInt32[] MD5_Append(byte[] input){
89int zeros=0;
90int ones =1;
91int size=0;
92int n = input.Length;
93int m = n%64;
94if( m < 56 ){
95zeros = 55-m;
96size=n-m+64;
97}
98else if (m==56){
99zeros = 0;
100ones = 0;
101size=n+8;
102}
103else{
104zeros = 63-m+56;
105size=n+64-m+64;
106}
107
108ArrayList bs = new ArrayList(input);
109if(ones==1){
110bs.Add( (byte)0x80 ); // 0x80 = $10000000
111}
112for(int i=0;i<zeros;i++){
113bs.Add( (byte)0 );
114}
115
116UInt64 N = (UInt64) n * 8;
117byte h1=(byte)(N&0xFF);
118byte h2=(byte)((N>>8)&0xFF);
119byte h3=(byte)((N>>16)&0xFF);
120byte h4=(byte)((N>>24)&0xFF);
121byte h5=(byte)((N>>32)&0xFF);
122byte h6=(byte)((N>>40)&0xFF);
123byte h7=(byte)((N>>48)&0xFF);
124byte h8=(byte)(N>>56);
125bs.Add(h1);
126bs.Add(h2);
127bs.Add(h3);
128bs.Add(h4);
129bs.Add(h5);
130bs.Add(h6);
131bs.Add(h7);
132bs.Add(h8);
133byte[] ts=(byte[])bs.ToArray(typeof(byte));
134
135/* Decodes input (byte[]) into output (UInt32[]). Assumes len is
136* a multiple of 4.
137*/
138UInt32[] output = new UInt32[size/4];
139for(Int64 i=0,j=0;i<size;j++,i+=4){
140output[j]=(UInt32)(ts[i] | ts[i+1]<<8 | ts[i+2]<<16 | ts[i+3]<<24);
141}
142return output;
143}
144private static UInt32[] MD5_Trasform(UInt32[] x){
145
146UInt32 a,b,c,d;
147
148for(int k=0;k<x.Length;k+=16){
149a=A;
150b=B;
151c=C;
152d=D;
153
154/* Round 1 */
155FF (ref a, b, c, d, x[k+ 0], S11, 0xd76aa478); /* 1 */
156FF (ref d, a, b, c, x[k+ 1], S12, 0xe8c7b756); /* 2 */
157FF (ref c, d, a, b, x[k+ 2], S13, 0x242070db); /* 3 */
158FF (ref b, c, d, a, x[k+ 3], S14, 0xc1bdceee); /* 4 */
159FF (ref a, b, c, d, x[k+ 4], S11, 0xf57c0faf); /* 5 */
160FF (ref d, a, b, c, x[k+ 5], S12, 0x4787c62a); /* 6 */
161FF (ref c, d, a, b, x[k+ 6], S13, 0xa8304613); /* 7 */
162FF (ref b, c, d, a, x[k+ 7], S14, 0xfd469501); /* 8 */
163FF (ref a, b, c, d, x[k+ 8], S11, 0x698098d8); /* 9 */
164FF (ref d, a, b, c, x[k+ 9], S12, 0x8b44f7af); /* 10 */
165FF (ref c, d, a, b, x[k+10], S13, 0xffff5bb1); /* 11 */
166FF (ref b, c, d, a, x[k+11], S14, 0x895cd7be); /* 12 */
167FF (ref a, b, c, d, x[k+12], S11, 0x6b901122); /* 13 */
168FF (ref d, a, b, c, x[k+13], S12, 0xfd987193); /* 14 */
169FF (ref c, d, a, b, x[k+14], S13, 0xa679438e); /* 15 */
170FF (ref b, c, d, a, x[k+15], S14, 0x49b40821); /* 16 */
171
172/* Round 2 */
173GG (ref a, b, c, d, x[k+ 1], S21, 0xf61e2562); /* 17 */
174GG (ref d, a, b, c, x[k+ 6], S22, 0xc040b340); /* 18 */
175GG (ref c, d, a, b, x[k+11], S23, 0x265e5a51); /* 19 */
176GG (ref b, c, d, a, x[k+ 0], S24, 0xe9b6c7aa); /* 20 */
177GG (ref a, b, c, d, x[k+ 5], S21, 0xd62f105d); /* 21 */
178GG (ref d, a, b, c, x[k+10], S22, 0x2441453); /* 22 */
179GG (ref c, d, a, b, x[k+15], S23, 0xd8a1e681); /* 23 */
180GG (ref b, c, d, a, x[k+ 4], S24, 0xe7d3fbc8); /* 24 */
181GG (ref a, b, c, d, x[k+ 9], S21, 0x21e1cde6); /* 25 */
182GG (ref d, a, b, c, x[k+14], S22, 0xc33707d6); /* 26 */
183GG (ref c, d, a, b, x[k+ 3], S23, 0xf4d50d87); /* 27 */
184GG (ref b, c, d, a, x[k+ 8], S24, 0x455a14ed); /* 28 */
185GG (ref a, b, c, d, x[k+13], S21, 0xa9e3e905); /* 29 */
186GG (ref d, a, b, c, x[k+ 2], S22, 0xfcefa3f8); /* 30 */
187GG (ref c, d, a, b, x[k+ 7], S23, 0x676f02d9); /* 31 */
188GG (ref b, c, d, a, x[k+12], S24, 0x8d2a4c8a); /* 32 */
189
190/* Round 3 */
191HH (ref a, b, c, d, x[k+ 5], S31, 0xfffa3942); /* 33 */
192HH (ref d, a, b, c, x[k+ 8], S32, 0x8771f681); /* 34 */
193HH (ref c, d, a, b, x[k+11], S33, 0x6d9d6122); /* 35 */
194HH (ref b, c, d, a, x[k+14], S34, 0xfde5380c); /* 36 */
195HH (ref a, b, c, d, x[k+ 1], S31, 0xa4beea44); /* 37 */
196HH (ref d, a, b, c, x[k+ 4], S32, 0x4bdecfa9); /* 38 */
197HH (ref c, d, a, b, x[k+ 7], S33, 0xf6bb4b60); /* 39 */
198HH (ref b, c, d, a, x[k+10], S34, 0xbebfbc70); /* 40 */
199HH (ref a, b, c, d, x[k+13], S31, 0x289b7ec6); /* 41 */
200HH (ref d, a, b, c, x[k+ 0], S32, 0xeaa127fa); /* 42 */
201HH (ref c, d, a, b, x[k+ 3], S33, 0xd4ef3085); /* 43 */
202HH (ref b, c, d, a, x[k+ 6], S34, 0x4881d05); /* 44 */
203HH (ref a, b, c, d, x[k+ 9], S31, 0xd9d4d039); /* 45 */
204HH (ref d, a, b, c, x[k+12], S32, 0xe6db99e5); /* 46 */
205HH (ref c, d, a, b, x[k+15], S33, 0x1fa27cf8); /* 47 */
206HH (ref b, c, d, a, x[k+ 2], S34, 0xc4ac5665); /* 48 */
207
208/* Round 4 */
209II (ref a, b, c, d, x[k+ 0], S41, 0xf4292244); /* 49 */
210II (ref d, a, b, c, x[k+ 7], S42, 0x432aff97); /* 50 */
211II (ref c, d, a, b, x[k+14], S43, 0xab9423a7); /* 51 */
212II (ref b, c, d, a, x[k+ 5], S44, 0xfc93a039); /* 52 */
213II (ref a, b, c, d, x[k+12], S41, 0x655b59c3); /* 53 */
214II (ref d, a, b, c, x[k+ 3], S42, 0x8f0ccc92); /* 54 */
215II (ref c, d, a, b, x[k+10], S43, 0xffeff47d); /* 55 */
216II (ref b, c, d, a, x[k+ 1], S44, 0x85845dd1); /* 56 */
217II (ref a, b, c, d, x[k+ 8], S41, 0x6fa87e4f); /* 57 */
218II (ref d, a, b, c, x[k+15], S42, 0xfe2ce6e0); /* 58 */
219II (ref c, d, a, b, x[k+ 6], S43, 0xa3014314); /* 59 */
220II (ref b, c, d, a, x[k+13], S44, 0x4e0811a1); /* 60 */
221II (ref a, b, c, d, x[k+ 4], S41, 0xf7537e82); /* 61 */
222II (ref d, a, b, c, x[k+11], S42, 0xbd3af235); /* 62 */
223II (ref c, d, a, b, x[k+ 2], S43, 0x2ad7d2bb); /* 63 */
224II (ref b, c, d, a, x[k+ 9], S44, 0xeb86d391); /* 64 */
225
226A+=a;
227B+=b;
228C+=c;
229D+=d;
230}
231return new UInt32[]{A,B,C,D};
232}
233public static byte[] MD5Array(byte[] input){
234MD5_Init();
235UInt32[] block = MD5_Append(input);
236UInt32[] bits = MD5_Trasform(block);
237
238/* Encodes bits (UInt32[]) into output (byte[]). Assumes len is
239* a multiple of 4.
240*/
241byte[] output=new byte[bits.Length*4];
242for(int i=0,j=0;i<bits.Length;i++,j+=4){
243output[j] = (byte)(bits[i] & 0xff);
244output[j+1] = (byte)((bits[i] >> 8) & 0xff);
245output[j+2] = (byte)((bits[i] >> 16) & 0xff);
246output[j+3] = (byte)((bits[i] >> 24) & 0xff);
247}
248return output;
249}
250
251public static string ArrayToHexString(byte[] array,bool uppercase){
252string hexString="";
253string format="x2";
254if(uppercase){
255format="X2";
256}
257foreach(byte b in array){
258hexString += b.ToString(format);
259}
260return hexString;
261}
262
263public static string MDString(string message){
264char[] c = message.ToCharArray();
265byte[] b = new byte[c.Length];
266for(int i=0;i<c.Length;i++){
267b[i]=(byte)c[i];
268}
269byte[] digest = MD5Array(b);
270return ArrayToHexString(digest,false);
271}
272public static string MDFile(string fileName){
273FileStream fs=File.Open(fileName,FileMode.Open,FileAccess.Read);
274byte[] array=new byte[fs.Length];
275fs.Read(array,0,(int)fs.Length);
276byte[] digest = MD5Array(array);
277fs.Close();
278return ArrayToHexString(digest,false);
279}
280
281public static string Test(string message){
282return "rnMD5 (""+message+"") = " + MD5.MDString(message);
283}
284public static string TestSuite(){
285string s = "";
286s+=Test("");
287s+=Test("a");
288s+=Test("abc");
289s+=Test("message digest");
290s+=Test("abcdefghijklmnopqrstuvwxyz");
291s+=Test("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789");
292s+=Test("12345678901234567890123456789012345678901234567890123456789012345678901234567890");
293return s;
294}
295
}
296
[/code] //源文件：md5.cs 2
// MD5 Alogrithm 3
// by rufi 2004.6.20 http://rufi.yculblog.com/ 4
using System; 5
using System.Collections; 6
using System.IO; 7
8
public class MD5 { 
9
//static state variables 10
private static UInt32 A; 11
private static UInt32 B; 12
private static UInt32 C; 13
private static UInt32 D; 14
15
//number of bits to rotate in tranforming 16
private const int S11 = 7; 17
private const int S12 = 12; 18
private const int S13 = 17; 19
private const int S14 = 22; 20
private const int S21 = 5; 21
private const int S22 = 9; 22
private const int S23 = 14; 23
private const int S24 = 20; 24
private const int S31 = 4; 25
private const int S32 = 11; 26
private const int S33 = 16; 27
private const int S34 = 23; 28
private const int S41 = 6; 29
private const int S42 = 10; 30
private const int S43 = 15; 31
private const int S44 = 21; 32
33
34
/* F, G, H and I are basic MD5 functions. 
35
* 四个非线性函数: 36
* 37
* F(X,Y,Z) =(X&Y)|((~X)&Z) 38
* G(X,Y,Z) =(X&Z)|(Y&(~Z)) 39
* H(X,Y,Z) =X^Y^Z 40
* I(X,Y,Z)=Y^(X|(~Z)) 41
* 42
* （&与，|或，~非，^异或） 43
*/ 44
private static UInt32 F(UInt32 x,UInt32 y,UInt32 z){ 45
return (x&y)|((~x)&z); 46
} 47
private static UInt32 G(UInt32 x,UInt32 y,UInt32 z){ 48
return (x&z)|(y&(~z)); 49
} 50
private static UInt32 H(UInt32 x,UInt32 y,UInt32 z){ 51
return x^y^z; 52
} 53
private static UInt32 I(UInt32 x,UInt32 y,UInt32 z){ 54
return y^(x|(~z)); 55
} 56
57
/* FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4. 58
* Rotation is separate from addition to prevent recomputation. 59
*/ 60
private static void FF(ref UInt32 a,UInt32 b,UInt32 c,UInt32 d,UInt32 mj,int s,UInt32 ti){ 61
a = a + F(b,c,d) + mj + ti; 62
a = a << s | a >> (32-s); 63
a += b; 64
} 65
private static void GG(ref UInt32 a,UInt32 b,UInt32 c,UInt32 d,UInt32 mj,int s,UInt32 ti){ 66
a = a + G(b,c,d) + mj + ti; 67
a = a << s | a >> (32-s); 68
a += b; 69
} 70
private static void HH(ref UInt32 a,UInt32 b,UInt32 c,UInt32 d,UInt32 mj,int s,UInt32 ti){ 71
a = a + H(b,c,d) + mj + ti; 72
a = a << s | a >> (32-s); 73
a += b; 74
} 75
private static void II(ref UInt32 a,UInt32 b,UInt32 c,UInt32 d,UInt32 mj,int s,UInt32 ti){ 76
a = a + I(b,c,d) + mj + ti; 77
a = a << s | a >> (32-s); 78
a += b; 79
} 80
81
private static void MD5_Init(){ 82
A=0x67452301; //in memory, this is 0x01234567 83
B=0xefcdab89; //in memory, this is 0x89abcdef 84
C=0x98badcfe; //in memory, this is 0xfedcba98 85
D=0x10325476; //in memory, this is 0x76543210 86
} 87
88
private static UInt32[] MD5_Append(byte[] input){ 89
int zeros=0; 90
int ones =1; 91
int size=0; 92
int n = input.Length; 93
int m = n%64; 94
if( m < 56 ){ 95
zeros = 55-m; 96
size=n-m+64; 97
} 98
else if (m==56){ 99
zeros = 0; 100
ones = 0; 101
size=n+8; 102
} 103
else{ 104
zeros = 63-m+56; 105
size=n+64-m+64; 106
} 107
108
ArrayList bs = new ArrayList(input); 109
if(ones==1){ 110
bs.Add( (byte)0x80 ); // 0x80 = $10000000 111
} 112
for(int i=0;i<zeros;i++){ 113
bs.Add( (byte)0 ); 114
} 115
116
UInt64 N = (UInt64) n * 8; 117
byte h1=(byte)(N&0xFF); 118
byte h2=(byte)((N>>8)&0xFF); 119
byte h3=(byte)((N>>16)&0xFF); 120
byte h4=(byte)((N>>24)&0xFF); 121
byte h5=(byte)((N>>32)&0xFF); 122
byte h6=(byte)((N>>40)&0xFF); 123
byte h7=(byte)((N>>48)&0xFF); 124
byte h8=(byte)(N>>56); 125
bs.Add(h1); 126
bs.Add(h2); 127
bs.Add(h3); 128
bs.Add(h4); 129
bs.Add(h5); 130
bs.Add(h6); 131
bs.Add(h7); 132
bs.Add(h8); 133
byte[] ts=(byte[])bs.ToArray(typeof(byte)); 134
135
/* Decodes input (byte[]) into output (UInt32[]). Assumes len is 136
* a multiple of 4. 137
*/ 138
UInt32[] output = new UInt32[size/4]; 139
for(Int64 i=0,j=0;i<size;j++,i+=4){ 140
output[j]=(UInt32)(ts[i] | ts[i+1]<<8 | ts[i+2]<<16 | ts[i+3]<<24); 141
} 142
return output; 143
} 144
private static UInt32[] MD5_Trasform(UInt32[] x){ 145
146
UInt32 a,b,c,d; 147
148
for(int k=0;k<x.Length;k+=16){ 149
a=A; 150
b=B; 151
c=C; 152
d=D; 153
154
/* Round 1 */ 155
FF (ref a, b, c, d, x[k+ 0], S11, 0xd76aa478); /* 1 */ 156
FF (ref d, a, b, c, x[k+ 1], S12, 0xe8c7b756); /* 2 */ 157
FF (ref c, d, a, b, x[k+ 2], S13, 0x242070db); /* 3 */ 158
FF (ref b, c, d, a, x[k+ 3], S14, 0xc1bdceee); /* 4 */ 159
FF (ref a, b, c, d, x[k+ 4], S11, 0xf57c0faf); /* 5 */ 160
FF (ref d, a, b, c, x[k+ 5], S12, 0x4787c62a); /* 6 */ 161
FF (ref c, d, a, b, x[k+ 6], S13, 0xa8304613); /* 7 */ 162
FF (ref b, c, d, a, x[k+ 7], S14, 0xfd469501); /* 8 */ 163
FF (ref a, b, c, d, x[k+ 8], S11, 0x698098d8); /* 9 */ 164
FF (ref d, a, b, c, x[k+ 9], S12, 0x8b44f7af); /* 10 */ 165
FF (ref c, d, a, b, x[k+10], S13, 0xffff5bb1); /* 11 */ 166
FF (ref b, c, d, a, x[k+11], S14, 0x895cd7be); /* 12 */ 167
FF (ref a, b, c, d, x[k+12], S11, 0x6b901122); /* 13 */ 168
FF (ref d, a, b, c, x[k+13], S12, 0xfd987193); /* 14 */ 169
FF (ref c, d, a, b, x[k+14], S13, 0xa679438e); /* 15 */ 170
FF (ref b, c, d, a, x[k+15], S14, 0x49b40821); /* 16 */ 171
172
/* Round 2 */ 173
GG (ref a, b, c, d, x[k+ 1], S21, 0xf61e2562); /* 17 */ 174
GG (ref d, a, b, c, x[k+ 6], S22, 0xc040b340); /* 18 */ 175
GG (ref c, d, a, b, x[k+11], S23, 0x265e5a51); /* 19 */ 176
GG (ref b, c, d, a, x[k+ 0], S24, 0xe9b6c7aa); /* 20 */ 177
GG (ref a, b, c, d, x[k+ 5], S21, 0xd62f105d); /* 21 */ 178
GG (ref d, a, b, c, x[k+10], S22, 0x2441453); /* 22 */ 179
GG (ref c, d, a, b, x[k+15], S23, 0xd8a1e681); /* 23 */ 180
GG (ref b, c, d, a, x[k+ 4], S24, 0xe7d3fbc8); /* 24 */ 181
GG (ref a, b, c, d, x[k+ 9], S21, 0x21e1cde6); /* 25 */ 182
GG (ref d, a, b, c, x[k+14], S22, 0xc33707d6); /* 26 */ 183
GG (ref c, d, a, b, x[k+ 3], S23, 0xf4d50d87); /* 27 */ 184
GG (ref b, c, d, a, x[k+ 8], S24, 0x455a14ed); /* 28 */ 185
GG (ref a, b, c, d, x[k+13], S21, 0xa9e3e905); /* 29 */ 186
GG (ref d, a, b, c, x[k+ 2], S22, 0xfcefa3f8); /* 30 */ 187
GG (ref c, d, a, b, x[k+ 7], S23, 0x676f02d9); /* 31 */ 188
GG (ref b, c, d, a, x[k+12], S24, 0x8d2a4c8a); /* 32 */ 189
190
/* Round 3 */ 191
HH (ref a, b, c, d, x[k+ 5], S31, 0xfffa3942); /* 33 */ 192
HH (ref d, a, b, c, x[k+ 8], S32, 0x8771f681); /* 34 */ 193
HH (ref c, d, a, b, x[k+11], S33, 0x6d9d6122); /* 35 */ 194
HH (ref b, c, d, a, x[k+14], S34, 0xfde5380c); /* 36 */ 195
HH (ref a, b, c, d, x[k+ 1], S31, 0xa4beea44); /* 37 */ 196
HH (ref d, a, b, c, x[k+ 4], S32, 0x4bdecfa9); /* 38 */ 197
HH (ref c, d, a, b, x[k+ 7], S33, 0xf6bb4b60); /* 39 */ 198
HH (ref b, c, d, a, x[k+10], S34, 0xbebfbc70); /* 40 */ 199
HH (ref a, b, c, d, x[k+13], S31, 0x289b7ec6); /* 41 */ 200
HH (ref d, a, b, c, x[k+ 0], S32, 0xeaa127fa); /* 42 */ 201
HH (ref c, d, a, b, x[k+ 3], S33, 0xd4ef3085); /* 43 */ 202
HH (ref b, c, d, a, x[k+ 6], S34, 0x4881d05); /* 44 */ 203
HH (ref a, b, c, d, x[k+ 9], S31, 0xd9d4d039); /* 45 */ 204
HH (ref d, a, b, c, x[k+12], S32, 0xe6db99e5); /* 46 */ 205
HH (ref c, d, a, b, x[k+15], S33, 0x1fa27cf8); /* 47 */ 206
HH (ref b, c, d, a, x[k+ 2], S34, 0xc4ac5665); /* 48 */ 207
208
/* Round 4 */ 209
II (ref a, b, c, d, x[k+ 0], S41, 0xf4292244); /* 49 */ 210
II (ref d, a, b, c, x[k+ 7], S42, 0x432aff97); /* 50 */ 211
II (ref c, d, a, b, x[k+14], S43, 0xab9423a7); /* 51 */ 212
II (ref b, c, d, a, x[k+ 5], S44, 0xfc93a039); /* 52 */ 213
II (ref a, b, c, d, x[k+12], S41, 0x655b59c3); /* 53 */ 214
II (ref d, a, b, c, x[k+ 3], S42, 0x8f0ccc92); /* 54 */ 215
II (ref c, d, a, b, x[k+10], S43, 0xffeff47d); /* 55 */ 216
II (ref b, c, d, a, x[k+ 1], S44, 0x85845dd1); /* 56 */ 217
II (ref a, b, c, d, x[k+ 8], S41, 0x6fa87e4f); /* 57 */ 218
II (ref d, a, b, c, x[k+15], S42, 0xfe2ce6e0); /* 58 */ 219
II (ref c, d, a, b, x[k+ 6], S43, 0xa3014314); /* 59 */ 220
II (ref b, c, d, a, x[k+13], S44, 0x4e0811a1); /* 60 */ 221
II (ref a, b, c, d, x[k+ 4], S41, 0xf7537e82); /* 61 */ 222
II (ref d, a, b, c, x[k+11], S42, 0xbd3af235); /* 62 */ 223
II (ref c, d, a, b, x[k+ 2], S43, 0x2ad7d2bb); /* 63 */ 224
II (ref b, c, d, a, x[k+ 9], S44, 0xeb86d391); /* 64 */ 225
226
A+=a; 227
B+=b; 228
C+=c; 229
D+=d; 230
} 231
return new UInt32[]{A,B,C,D}; 232
} 233
public static byte[] MD5Array(byte[] input){ 234
MD5_Init(); 235
UInt32[] block = MD5_Append(input); 236
UInt32[] bits = MD5_Trasform(block); 237
238
/* Encodes bits (UInt32[]) into output (byte[]). Assumes len is 239
* a multiple of 4. 240
*/ 241
byte[] output=new byte[bits.Length*4]; 242
for(int i=0,j=0;i<bits.Length;i++,j+=4){ 243
output[j] = (byte)(bits[i] & 0xff); 244
output[j+1] = (byte)((bits[i] >> 8) & 0xff); 245
output[j+2] = (byte)((bits[i] >> 16) & 0xff); 246
output[j+3] = (byte)((bits[i] >> 24) & 0xff); 247
} 248
return output; 249
} 250
251
public static string ArrayToHexString(byte[] array,bool uppercase){ 252
string hexString=""; 253
string format="x2"; 254
if(uppercase){ 255
format="X2"; 256
} 257
foreach(byte b in array){ 258
hexString += b.ToString(format); 259
} 260
return hexString; 261
} 262
263
public static string MDString(string message){ 264
char[] c = message.ToCharArray(); 265
byte[] b = new byte[c.Length]; 266
for(int i=0;i<c.Length;i++){ 267
b[i]=(byte)c[i]; 268
} 269
byte[] digest = MD5Array(b); 270
return ArrayToHexString(digest,false); 271
} 272
public static string MDFile(string fileName){ 273
FileStream fs=File.Open(fileName,FileMode.Open,FileAccess.Read); 274
byte[] array=new byte[fs.Length]; 275
fs.Read(array,0,(int)fs.Length); 276
byte[] digest = MD5Array(array); 277
fs.Close(); 278
return ArrayToHexString(digest,false); 279
} 280
281
public static string Test(string message){ 282
return "rnMD5 (""+message+"") = " + MD5.MDString(message); 283
} 284
public static string TestSuite(){ 285
string s = ""; 286
s+=Test(""); 287
s+=Test("a"); 288
s+=Test("abc"); 289
s+=Test("message digest"); 290
s+=Test("abcdefghijklmnopqrstuvwxyz"); 291
s+=Test("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"); 292
s+=Test("12345678901234567890123456789012345678901234567890123456789012345678901234567890"); 293
return s; 294
} 295
} 296
Hello! I Am David.DU.