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1
2 package ch.ethz.ssh2.crypto.digest;
3
4
10
11
35
36 public final class MD5 implements Digest
37 {
38 private int state0, state1, state2, state3;
39 private long count;
40 private final byte[] block = new byte[64];
41 private final int x[] = new int[16];
42
43 private static final byte[] padding = new byte[] { (byte) 128, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
44 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
45 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
46
47 public MD5()
48 {
49 reset();
50 }
51
52 private static final int FF(int a, int b, int c, int d, int x, int s, int ac)
53 {
54 a += ((b & c) | ((~b) & d)) + x + ac;
55 return ((a << s) | (a >>> (32 - s))) + b;
56 }
57
58 private static final int GG(int a, int b, int c, int d, int x, int s, int ac)
59 {
60 a += ((b & d) | (c & (~d))) + x + ac;
61 return ((a << s) | (a >>> (32 - s))) + b;
62 }
63
64 private static final int HH(int a, int b, int c, int d, int x, int s, int ac)
65 {
66 a += (b ^ c ^ d) + x + ac;
67 return ((a << s) | (a >>> (32 - s))) + b;
68 }
69
70 private static final int II(int a, int b, int c, int d, int x, int s, int ac)
71 {
72 a += (c ^ (b | (~d))) + x + ac;
73 return ((a << s) | (a >>> (32 - s))) + b;
74 }
75
76 private static final void encode(byte[] dst, int dstoff, int word)
77 {
78 dst[dstoff] = (byte) (word);
79 dst[dstoff + 1] = (byte) (word >> 8);
80 dst[dstoff + 2] = (byte) (word >> 16);
81 dst[dstoff + 3] = (byte) (word >> 24);
82 }
83
84 private final void transform(byte[] src, int pos)
85 {
86 int a = state0;
87 int b = state1;
88 int c = state2;
89 int d = state3;
90
91 for (int i = 0; i < 16; i++, pos += 4)
92 {
93 x[i] = (src[pos] & 0xff) | ((src[pos + 1] & 0xff) << 8) | ((src[pos + 2] & 0xff) << 16)
94 | ((src[pos + 3] & 0xff) << 24);
95 }
96
97
98
99 a = FF(a, b, c, d, x[0], 7, 0xd76aa478);
100 d = FF(d, a, b, c, x[1], 12, 0xe8c7b756);
101 c = FF(c, d, a, b, x[2], 17, 0x242070db);
102 b = FF(b, c, d, a, x[3], 22, 0xc1bdceee);
103 a = FF(a, b, c, d, x[4], 7, 0xf57c0faf);
104 d = FF(d, a, b, c, x[5], 12, 0x4787c62a);
105 c = FF(c, d, a, b, x[6], 17, 0xa8304613);
106 b = FF(b, c, d, a, x[7], 22, 0xfd469501);
107 a = FF(a, b, c, d, x[8], 7, 0x698098d8);
108 d = FF(d, a, b, c, x[9], 12, 0x8b44f7af);
109 c = FF(c, d, a, b, x[10], 17, 0xffff5bb1);
110 b = FF(b, c, d, a, x[11], 22, 0x895cd7be);
111 a = FF(a, b, c, d, x[12], 7, 0x6b901122);
112 d = FF(d, a, b, c, x[13], 12, 0xfd987193);
113 c = FF(c, d, a, b, x[14], 17, 0xa679438e);
114 b = FF(b, c, d, a, x[15], 22, 0x49b40821);
115
116
117 a = GG(a, b, c, d, x[1], 5, 0xf61e2562);
118 d = GG(d, a, b, c, x[6], 9, 0xc040b340);
119 c = GG(c, d, a, b, x[11], 14, 0x265e5a51);
120 b = GG(b, c, d, a, x[0], 20, 0xe9b6c7aa);
121 a = GG(a, b, c, d, x[5], 5, 0xd62f105d);
122 d = GG(d, a, b, c, x[10], 9, 0x2441453);
123 c = GG(c, d, a, b, x[15], 14, 0xd8a1e681);
124 b = GG(b, c, d, a, x[4], 20, 0xe7d3fbc8);
125 a = GG(a, b, c, d, x[9], 5, 0x21e1cde6);
126 d = GG(d, a, b, c, x[14], 9, 0xc33707d6);
127 c = GG(c, d, a, b, x[3], 14, 0xf4d50d87);
128 b = GG(b, c, d, a, x[8], 20, 0x455a14ed);
129 a = GG(a, b, c, d, x[13], 5, 0xa9e3e905);
130 d = GG(d, a, b, c, x[2], 9, 0xfcefa3f8);
131 c = GG(c, d, a, b, x[7], 14, 0x676f02d9);
132 b = GG(b, c, d, a, x[12], 20, 0x8d2a4c8a);
133
134
135 a = HH(a, b, c, d, x[5], 4, 0xfffa3942);
136 d = HH(d, a, b, c, x[8], 11, 0x8771f681);
137 c = HH(c, d, a, b, x[11], 16, 0x6d9d6122);
138 b = HH(b, c, d, a, x[14], 23, 0xfde5380c);
139 a = HH(a, b, c, d, x[1], 4, 0xa4beea44);
140 d = HH(d, a, b, c, x[4], 11, 0x4bdecfa9);
141 c = HH(c, d, a, b, x[7], 16, 0xf6bb4b60);
142 b = HH(b, c, d, a, x[10], 23, 0xbebfbc70);
143 a = HH(a, b, c, d, x[13], 4, 0x289b7ec6);
144 d = HH(d, a, b, c, x[0], 11, 0xeaa127fa);
145 c = HH(c, d, a, b, x[3], 16, 0xd4ef3085);
146 b = HH(b, c, d, a, x[6], 23, 0x4881d05);
147 a = HH(a, b, c, d, x[9], 4, 0xd9d4d039);
148 d = HH(d, a, b, c, x[12], 11, 0xe6db99e5);
149 c = HH(c, d, a, b, x[15], 16, 0x1fa27cf8);
150 b = HH(b, c, d, a, x[2], 23, 0xc4ac5665);
151
152
153 a = II(a, b, c, d, x[0], 6, 0xf4292244);
154 d = II(d, a, b, c, x[7], 10, 0x432aff97);
155 c = II(c, d, a, b, x[14], 15, 0xab9423a7);
156 b = II(b, c, d, a, x[5], 21, 0xfc93a039);
157 a = II(a, b, c, d, x[12], 6, 0x655b59c3);
158 d = II(d, a, b, c, x[3], 10, 0x8f0ccc92);
159 c = II(c, d, a, b, x[10], 15, 0xffeff47d);
160 b = II(b, c, d, a, x[1], 21, 0x85845dd1);
161 a = II(a, b, c, d, x[8], 6, 0x6fa87e4f);
162 d = II(d, a, b, c, x[15], 10, 0xfe2ce6e0);
163 c = II(c, d, a, b, x[6], 15, 0xa3014314);
164 b = II(b, c, d, a, x[13], 21, 0x4e0811a1);
165 a = II(a, b, c, d, x[4], 6, 0xf7537e82);
166 d = II(d, a, b, c, x[11], 10, 0xbd3af235);
167 c = II(c, d, a, b, x[2], 15, 0x2ad7d2bb);
168 b = II(b, c, d, a, x[9], 21, 0xeb86d391);
169
170 state0 += a;
171 state1 += b;
172 state2 += c;
173 state3 += d;
174 }
175
176 public final void reset()
177 {
178 count = 0;
179
180 state0 = 0x67452301;
181 state1 = 0xefcdab89;
182 state2 = 0x98badcfe;
183 state3 = 0x10325476;
184
185
186
187 for (int i = 0; i < 16; i++)
188 x[i] = 0;
189 }
190
191 public final void update(byte b)
192 {
193 final int space = 64 - ((int) (count & 0x3f));
194
195 count++;
196
197 block[64 - space] = b;
198
199 if (space == 1)
200 transform(block, 0);
201 }
202
203 public final void update(byte[] buff, int pos, int len)
204 {
205 int space = 64 - ((int) (count & 0x3f));
206
207 count += len;
208
209 while (len > 0)
210 {
211 if (len < space)
212 {
213 System.arraycopy(buff, pos, block, 64 - space, len);
214 break;
215 }
216
217 if (space == 64)
218 {
219 transform(buff, pos);
220 }
221 else
222 {
223 System.arraycopy(buff, pos, block, 64 - space, space);
224 transform(block, 0);
225 }
226
227 pos += space;
228 len -= space;
229 space = 64;
230 }
231 }
232
233 public final void update(byte[] b)
234 {
235 update(b, 0, b.length);
236 }
237
238 public final void digest(byte[] dst, int pos)
239 {
240 byte[] bits = new byte[8];
241
242 encode(bits, 0, (int) (count << 3));
243 encode(bits, 4, (int) (count >> 29));
244
245 int idx = (int) count & 0x3f;
246 int padLen = (idx < 56) ? (56 - idx) : (120 - idx);
247
248 update(padding, 0, padLen);
249 update(bits, 0, 8);
250
251 encode(dst, pos, state0);
252 encode(dst, pos + 4, state1);
253 encode(dst, pos + 8, state2);
254 encode(dst, pos + 12, state3);
255
256 reset();
257 }
258
259 public final void digest(byte[] dst)
260 {
261 digest(dst, 0);
262 }
263
264 public final int getDigestLength()
265 {
266 return 16;
267 }
268 }
269 |
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