1 /*************************************************
2 md5 类实现了RSA Data Security, Inc.在提交给IETF
3 的RFC1321中的MD5 message-digest 算法。
4 *************************************************/
5 public class MD5 {
6 /* 下面这些S11-S44实际上是一个4*4的矩阵，在原始的C实现中是用#define 实现的，
7 这里把它们实现成为static final是表示了只读，切能在同一个进程空间内的多个
8 Instance间共享*/
9 static final int S11 = 7;
10 static final int S12 = 12;
11 static final int S13 = 17;
12 static final int S14 = 22;
13
14 static final int S21 = 5;
15 static final int S22 = 9;
16 static final int S23 = 14;
17 static final int S24 = 20;
18
19 static final int S31 = 4;
20 static final int S32 = 11;
21 static final int S33 = 16;
22 static final int S34 = 23;
23
24 static final int S41 = 6;
25 static final int S42 = 10;
26 static final int S43 = 15;
27 static final int S44 = 21;
28
29 static final byte[] PADDING = { -128, 0, 0, 0, 0, 0, 0, 0, 0,
30 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
31 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
32 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
33 /* 下面的三个成员是MD5计算过程中用到的3个核心数据，在原始的C实现中
34 被定义到MD5_CTX结构中
35
36 */
37 private long[] state = new long[4]; // state (ABCD)
38 private long[] count = new long[2]; // number of bits, modulo 2^64 (lsb first)
39 private byte[] buffer = new byte[64]; // input buffer
40
41 /* digestHexStr是MD5的唯一一个公共成员，是最新一次计算结果的
42 16进制ASCII表示.
43 */
44 public String digestHexStr;
45
46 /* digest,是最新一次计算结果的2进制内部表示，表示128bit的MD5值.
47 */
48 private byte[] digest = new byte[16];
49
50 /*
51 getMD5ofStr是类MD5最主要的公共方法，入口参数是你想要进行MD5变换的字符串
52 返回的是变换完的结果，这个结果是从公共成员digestHexStr取得的．
53 */
54 public String getMD5ofStr(String inbuf) {
55 md5Init();
56 md5Update(inbuf.getBytes(), inbuf.length());
57 md5Final();
58 digestHexStr = "";
59 for (int i = 0; i < 16; i++) {
60 digestHexStr += byteHEX(digest[i]);
61 }
62 return digestHexStr;
63
64 }
65 // 这是MD5这个类的标准构造函数，JavaBean要求有一个public的并且没有参数的构造函数
66 public MD5() {
67 md5Init();
68
69 return;
70 }
71 /* md5Init是一个初始化函数，初始化核心变量，装入标准的幻数 */
72 private void md5Init() {
73 count[0] = 0L;
74 count[1] = 0L;
75 ///* Load magic initialization constants.
76
77 state[0] = 0x67452301L;
78 state[1] = 0xefcdab89L;
79 state[2] = 0x98badcfeL;
80 state[3] = 0x10325476L;
81
82 return;
83 }
84 /* F, G, H ,I 是4个基本的MD5函数，在原始的MD5的C实现中，由于它们是
85 简单的位运算，可能出于效率的考虑把它们实现成了宏，在java中，我们把它们
86 实现成了private方法，名字保持了原来C中的。 */
87
88 private long F(long x, long y, long z) {
89 return (x & y) | ((~x) & z);
90
91 }
92 private long G(long x, long y, long z) {
93 return (x & z) | (y & (~z));
94
95 }
96 private long H(long x, long y, long z) {
97 return x ^ y ^ z;
98 }
99
100 private long I(long x, long y, long z) {
101 return y ^ (x | (~z));
102 }
103
104 /*
105 FF,GG,HH和II将调用F,G,H,I进行近一步变换
106 FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
107 Rotation is separate from addition to prevent recomputation.
108 */
109
110 private long FF(long a, long b, long c, long d, long x, long s,
111 long ac) {
112 a += F (b, c, d) + x + ac;
113 a = ((int) a << s) | ((int) a >>> (32 - s));
114 a += b;
115 return a;
116 }
117
118 private long GG(long a, long b, long c, long d, long x, long s,
119 long ac) {
120 a += G (b, c, d) + x + ac;
121 a = ((int) a << s) | ((int) a >>> (32 - s));
122 a += b;
123 return a;
124 }
125 private long HH(long a, long b, long c, long d, long x, long s,
126 long ac) {
127 a += H (b, c, d) + x + ac;
128 a = ((int) a << s) | ((int) a >>> (32 - s));
129 a += b;
130 return a;
131 }
132 private long II(long a, long b, long c, long d, long x, long s,
133 long ac) {
134 a += I (b, c, d) + x + ac;
135 a = ((int) a << s) | ((int) a >>> (32 - s));
136 a += b;
137 return a;
138 }
139 /*
140 md5Update是MD5的主计算过程，inbuf是要变换的字节串，inputlen是长度，这个
141 函数由getMD5ofStr调用，调用之前需要调用md5init，因此把它设计成private的
142 */
143 private void md5Update(byte[] inbuf, int inputLen) {
144
145 int i, index, partLen;
146 byte[] block = new byte[64];
147 index = (int)(count[0] >>> 3) & 0x3F;
148 // /* Update number of bits */
149 if ((count[0] += (inputLen << 3)) < (inputLen << 3))
150 count[1]++;
151 count[1] += (inputLen >>> 29);
152
153 partLen = 64 - index;
154
155 // Transform as many times as possible.
156 if (inputLen >= partLen) {
157 md5Memcpy(buffer, inbuf, index, 0, partLen);
158 md5Transform(buffer);
159
160 for (i = partLen; i + 63 < inputLen; i += 64) {
161
162 md5Memcpy(block, inbuf, 0, i, 64);
163 md5Transform (block);
164 }
165 index = 0;
166
167 } else
168
169 i = 0;
170
171 ///* Buffer remaining input */
172 md5Memcpy(buffer, inbuf, index, i, inputLen - i);
173
174 }
175
176 /*
177 md5Final整理和填写输出结果
178 */
179 private void md5Final () {
180 byte[] bits = new byte[8];
181 int index, padLen;
182
183 ///* Save number of bits */
184 Encode (bits, count, 8);
185
186 ///* Pad out to 56 mod 64.
187 index = (int)(count[0] >>> 3) & 0x3f;
188 padLen = (index < 56) ? (56 - index) : (120 - index);
189 md5Update (PADDING, padLen);
190
191 ///* Append length (before padding) */
192 md5Update(bits, 8);
193
194 ///* Store state in digest */
195 Encode (digest, state, 16);
196
197 }
198
199 /* md5Memcpy是一个内部使用的byte数组的块拷贝函数，从input的inpos开始把len长度的
200 字节拷贝到output的outpos位置开始
201 */
202
203 private void md5Memcpy (byte[] output, byte[] input,
204 int outpos, int inpos, int len)
205 {
206 int i;
207
208 for (i = 0; i < len; i++)
209 output[outpos + i] = input[inpos + i];
210 }
211
212 /*
213 md5Transform是MD5核心变换程序，有md5Update调用，block是分块的原始字节
214 */
215 private void md5Transform (byte block[]) {
216 long a = state[0], b = state[1], c = state[2], d = state[3];
217 long[] x = new long[16];
218
219 Decode (x, block, 64);
220
221 /* Round 1 */
222 a = FF (a, b, c, d, x[0], S11, 0xd76aa478L); /* 1 */
223 d = FF (d, a, b, c, x[1], S12, 0xe8c7b756L); /* 2 */
224 c = FF (c, d, a, b, x[2], S13, 0x242070dbL); /* 3 */
225 b = FF (b, c, d, a, x[3], S14, 0xc1bdceeeL); /* 4 */
226 a = FF (a, b, c, d, x[4], S11, 0xf57c0fafL); /* 5 */
227 d = FF (d, a, b, c, x[5], S12, 0x4787c62aL); /* 6 */
228 c = FF (c, d, a, b, x[6], S13, 0xa8304613L); /* 7 */
229 b = FF (b, c, d, a, x[7], S14, 0xfd469501L); /* 8 */
230 a = FF (a, b, c, d, x[8], S11, 0x698098d8L); /* 9 */
231 d = FF (d, a, b, c, x[9], S12, 0x8b44f7afL); /* 10 */
232 c = FF (c, d, a, b, x[10], S13, 0xffff5bb1L); /* 11 */
233 b = FF (b, c, d, a, x[11], S14, 0x895cd7beL); /* 12 */
234 a = FF (a, b, c, d, x[12], S11, 0x6b901122L); /* 13 */
235 d = FF (d, a, b, c, x[13], S12, 0xfd987193L); /* 14 */
236 c = FF (c, d, a, b, x[14], S13, 0xa679438eL); /* 15 */
237 b = FF (b, c, d, a, x[15], S14, 0x49b40821L); /* 16 */
238
239 /* Round 2 */
240 a = GG (a, b, c, d, x[1], S21, 0xf61e2562L); /* 17 */
241 d = GG (d, a, b, c, x[6], S22, 0xc040b340L); /* 18 */
242 c = GG (c, d, a, b, x[11], S23, 0x265e5a51L); /* 19 */
243 b = GG (b, c, d, a, x[0], S24, 0xe9b6c7aaL); /* 20 */
244 a = GG (a, b, c, d, x[5], S21, 0xd62f105dL); /* 21 */
245 d = GG (d, a, b, c, x[10], S22, 0x2441453L); /* 22 */
246 c = GG (c, d, a, b, x[15], S23, 0xd8a1e681L); /* 23 */
247 b = GG (b, c, d, a, x[4], S24, 0xe7d3fbc8L); /* 24 */
248 a = GG (a, b, c, d, x[9], S21, 0x21e1cde6L); /* 25 */
249 d = GG (d, a, b, c, x[14], S22, 0xc33707d6L); /* 26 */
250 c = GG (c, d, a, b, x[3], S23, 0xf4d50d87L); /* 27 */
251 b = GG (b, c, d, a, x[8], S24, 0x455a14edL); /* 28 */
252 a = GG (a, b, c, d, x[13], S21, 0xa9e3e905L); /* 29 */
253 d = GG (d, a, b, c, x[2], S22, 0xfcefa3f8L); /* 30 */
254 c = GG (c, d, a, b, x[7], S23, 0x676f02d9L); /* 31 */
255 b = GG (b, c, d, a, x[12], S24, 0x8d2a4c8aL); /* 32 */
256
257 /* Round 3 */
258 a = HH (a, b, c, d, x[5], S31, 0xfffa3942L); /* 33 */
259 d = HH (d, a, b, c, x[8], S32, 0x8771f681L); /* 34 */
260 c = HH (c, d, a, b, x[11], S33, 0x6d9d6122L); /* 35 */
261 b = HH (b, c, d, a, x[14], S34, 0xfde5380cL); /* 36 */
262 a = HH (a, b, c, d, x[1], S31, 0xa4beea44L); /* 37 */
263 d = HH (d, a, b, c, x[4], S32, 0x4bdecfa9L); /* 38 */
264 c = HH (c, d, a, b, x[7], S33, 0xf6bb4b60L); /* 39 */
265 b = HH (b, c, d, a, x[10], S34, 0xbebfbc70L); /* 40 */
266 a = HH (a, b, c, d, x[13], S31, 0x289b7ec6L); /* 41 */
267 d = HH (d, a, b, c, x[0], S32, 0xeaa127faL); /* 42 */
268 c = HH (c, d, a, b, x[3], S33, 0xd4ef3085L); /* 43 */
269 b = HH (b, c, d, a, x[6], S34, 0x4881d05L); /* 44 */
270 a = HH (a, b, c, d, x[9], S31, 0xd9d4d039L); /* 45 */
271 d = HH (d, a, b, c, x[12], S32, 0xe6db99e5L); /* 46 */
272 c = HH (c, d, a, b, x[15], S33, 0x1fa27cf8L); /* 47 */
273 b = HH (b, c, d, a, x[2], S34, 0xc4ac5665L); /* 48 */
274
275 /* Round 4 */
276 a = II (a, b, c, d, x[0], S41, 0xf4292244L); /* 49 */
277 d = II (d, a, b, c, x[7], S42, 0x432aff97L); /* 50 */
278 c = II (c, d, a, b, x[14], S43, 0xab9423a7L); /* 51 */
279 b = II (b, c, d, a, x[5], S44, 0xfc93a039L); /* 52 */
280 a = II (a, b, c, d, x[12], S41, 0x655b59c3L); /* 53 */
281 d = II (d, a, b, c, x[3], S42, 0x8f0ccc92L); /* 54 */
282 c = II (c, d, a, b, x[10], S43, 0xffeff47dL); /* 55 */
283 b = II (b, c, d, a, x[1], S44, 0x85845dd1L); /* 56 */
284 a = II (a, b, c, d, x[8], S41, 0x6fa87e4fL); /* 57 */
285 d = II (d, a, b, c, x[15], S42, 0xfe2ce6e0L); /* 58 */
286 c = II (c, d, a, b, x[6], S43, 0xa3014314L); /* 59 */
287 b = II (b, c, d, a, x[13], S44, 0x4e0811a1L); /* 60 */
288 a = II (a, b, c, d, x[4], S41, 0xf7537e82L); /* 61 */
289 d = II (d, a, b, c, x[11], S42, 0xbd3af235L); /* 62 */
290 c = II (c, d, a, b, x[2], S43, 0x2ad7d2bbL); /* 63 */
291 b = II (b, c, d, a, x[9], S44, 0xeb86d391L); /* 64 */
292
293 state[0] += a;
294 state[1] += b;
295 state[2] += c;
296 state[3] += d;
297
298 }
299
300 /*Encode把long数组按顺序拆成byte数组，因为java的long类型是64bit的，
301 只拆低32bit，以适应原始C实现的用途
302 */
303 private void Encode (byte[] output, long[] input, int len) {
304 int i, j;
305
306 for (i = 0, j = 0; j < len; i++, j += 4) {
307 output[j] = (byte)(input[i] & 0xffL);
308 output[j + 1] = (byte)((input[i] >>> 8) & 0xffL);
309 output[j + 2] = (byte)((input[i] >>> 16) & 0xffL);
310 output[j + 3] = (byte)((input[i] >>> 24) & 0xffL);
311 }
312 }
313
314 /*Decode把byte数组按顺序合成成long数组，因为java的long类型是64bit的，
315 只合成低32bit，高32bit清零，以适应原始C实现的用途
316 */
317 private void Decode (long[] output, byte[] input, int len) {
318 int i, j;
319
320
321 for (i = 0, j = 0; j < len; i++, j += 4)
322 output[i] = b2iu(input[j]) |
323 (b2iu(input[j + 1]) << 8) |
324 (b2iu(input[j + 2]) << 16) |
325 (b2iu(input[j + 3]) << 24);
326
327 return;
328 }
329
330 /*
331 b2iu是我写的一个把byte按照不考虑正负号的原则的＂升位＂程序，因为java没有unsigned运算
332 */
333 public static long b2iu(byte b) {
334 return b < 0 ? b & 0x7F + 128 : b;
335 }
336
337 /*byteHEX()，用来把一个byte类型的数转换成十六进制的ASCII表示，
338 因为java中的byte的toString无法实现这一点，我们又没有C语言中的
339 sprintf(outbuf,"%02X",ib)
340 */
341 public static String byteHEX(byte ib) {
342 char[] Digit = { ‘0‘,‘1‘,‘2‘,‘3‘,‘4‘,‘5‘,‘6‘,‘7‘,‘8‘,‘9‘,
343 ‘A‘,‘B‘,‘C‘,‘D‘,‘E‘,‘F‘ };
344 char [] ob = new char[2];
345 ob[0] = Digit[(ib >>> 4) & 0X0F];
346 ob[1] = Digit[ib & 0X0F];
347 String s = new String(ob);
348 return s;
349 }
350 public static void main(String args[]){
351 MD5 md5 = new MD5();
352 System.out.println(md5.getMD5ofStr("admin"));
353 }
354 }
转载自：http://www.iteye.com/topic/746281
时间： 2024-10-10 15:04:14