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1 /*
2   Copyright (C) 1999, 2000, 2002 Aladdin Enterprises.  All rights reserved.
3 
4   This software is provided 'as-is', without any express or implied
5   warranty.  In no event will the authors be held liable for any damages
6   arising from the use of this software.
7 
8   Permission is granted to anyone to use this software for any purpose,
9   including commercial applications, and to alter it and redistribute it
10   freely, subject to the following restrictions:
11 
12   1. The origin of this software must not be misrepresented; you must not
13      claim that you wrote the original software. If you use this software
14      in a product, an acknowledgment in the product documentation would be
15      appreciated but is not required.
16   2. Altered source versions must be plainly marked as such, and must not be
17      misrepresented as being the original software.
18   3. This notice may not be removed or altered from any source distribution.
19 
20   L. Peter Deutsch
21   ghost@aladdin.com
22 
23  */
24 /* $Id: md5.c,v 1.6 2002/04/13 19:20:28 lpd Exp $ */
25 /*
26   Independent implementation of MD5 (RFC 1321).
27 
28   This code implements the MD5 Algorithm defined in RFC 1321, whose
29   text is available at
30         http://www.ietf.org/rfc/rfc1321.txt
31   The code is derived from the text of the RFC, including the test suite
32   (section A.5) but excluding the rest of Appendix A.  It does not include
33   any code or documentation that is identified in the RFC as being
34   copyrighted.
35 
36   The original and principal author of md5.c is L. Peter Deutsch
37   <ghost@aladdin.com>.  Other authors are noted in the change history
38   that follows (in reverse chronological order):
39 
40   2002-04-13 lpd Clarified derivation from RFC 1321; now handles byte order
41         either statically or dynamically; added missing #include <string.h>
42         in library.
43   2002-03-11 lpd Corrected argument list for main(), and added int return
44         type, in test program and T value program.
45   2002-02-21 lpd Added missing #include <stdio.h> in test program.
46   2000-07-03 lpd Patched to eliminate warnings about "constant is
47         unsigned in ANSI C, signed in traditional"; made test program
48         self-checking.
49   1999-11-04 lpd Edited comments slightly for automatic TOC extraction.
50   1999-10-18 lpd Fixed typo in header comment (ansi2knr rather than md5).
51   1999-05-03 lpd Original version.
52  */
53 
54 #include "md5.h"
55 #include <string.h>
56 #include <limits.h>
57 
58 #undef BYTE_ORDER       /* 1 = big-endian, -1 = little-endian, 0 = unknown */
59 #ifdef ARCH_IS_BIG_ENDIAN
60 #  define BYTE_ORDER (ARCH_IS_BIG_ENDIAN ? 1 : -1)
61 #else
62 #  define BYTE_ORDER 0
63 #endif
64 
65 #define T_MASK ((md5_word_t)~0)
66 #define T1 /* 0xd76aa478 */ (T_MASK ^ 0x28955b87)
67 #define T2 /* 0xe8c7b756 */ (T_MASK ^ 0x173848a9)
68 #define T3    0x242070db
69 #define T4 /* 0xc1bdceee */ (T_MASK ^ 0x3e423111)
70 #define T5 /* 0xf57c0faf */ (T_MASK ^ 0x0a83f050)
71 #define T6    0x4787c62a
72 #define T7 /* 0xa8304613 */ (T_MASK ^ 0x57cfb9ec)
73 #define T8 /* 0xfd469501 */ (T_MASK ^ 0x02b96afe)
74 #define T9    0x698098d8
75 #define T10 /* 0x8b44f7af */ (T_MASK ^ 0x74bb0850)
76 #define T11 /* 0xffff5bb1 */ (T_MASK ^ 0x0000a44e)
77 #define T12 /* 0x895cd7be */ (T_MASK ^ 0x76a32841)
78 #define T13    0x6b901122
79 #define T14 /* 0xfd987193 */ (T_MASK ^ 0x02678e6c)
80 #define T15 /* 0xa679438e */ (T_MASK ^ 0x5986bc71)
81 #define T16    0x49b40821
82 #define T17 /* 0xf61e2562 */ (T_MASK ^ 0x09e1da9d)
83 #define T18 /* 0xc040b340 */ (T_MASK ^ 0x3fbf4cbf)
84 #define T19    0x265e5a51
85 #define T20 /* 0xe9b6c7aa */ (T_MASK ^ 0x16493855)
86 #define T21 /* 0xd62f105d */ (T_MASK ^ 0x29d0efa2)
87 #define T22    0x02441453
88 #define T23 /* 0xd8a1e681 */ (T_MASK ^ 0x275e197e)
89 #define T24 /* 0xe7d3fbc8 */ (T_MASK ^ 0x182c0437)
90 #define T25    0x21e1cde6
91 #define T26 /* 0xc33707d6 */ (T_MASK ^ 0x3cc8f829)
92 #define T27 /* 0xf4d50d87 */ (T_MASK ^ 0x0b2af278)
93 #define T28    0x455a14ed
94 #define T29 /* 0xa9e3e905 */ (T_MASK ^ 0x561c16fa)
95 #define T30 /* 0xfcefa3f8 */ (T_MASK ^ 0x03105c07)
96 #define T31    0x676f02d9
97 #define T32 /* 0x8d2a4c8a */ (T_MASK ^ 0x72d5b375)
98 #define T33 /* 0xfffa3942 */ (T_MASK ^ 0x0005c6bd)
99 #define T34 /* 0x8771f681 */ (T_MASK ^ 0x788e097e)
100 #define T35    0x6d9d6122
101 #define T36 /* 0xfde5380c */ (T_MASK ^ 0x021ac7f3)
102 #define T37 /* 0xa4beea44 */ (T_MASK ^ 0x5b4115bb)
103 #define T38    0x4bdecfa9
104 #define T39 /* 0xf6bb4b60 */ (T_MASK ^ 0x0944b49f)
105 #define T40 /* 0xbebfbc70 */ (T_MASK ^ 0x4140438f)
106 #define T41    0x289b7ec6
107 #define T42 /* 0xeaa127fa */ (T_MASK ^ 0x155ed805)
108 #define T43 /* 0xd4ef3085 */ (T_MASK ^ 0x2b10cf7a)
109 #define T44    0x04881d05
110 #define T45 /* 0xd9d4d039 */ (T_MASK ^ 0x262b2fc6)
111 #define T46 /* 0xe6db99e5 */ (T_MASK ^ 0x1924661a)
112 #define T47    0x1fa27cf8
113 #define T48 /* 0xc4ac5665 */ (T_MASK ^ 0x3b53a99a)
114 #define T49 /* 0xf4292244 */ (T_MASK ^ 0x0bd6ddbb)
115 #define T50    0x432aff97
116 #define T51 /* 0xab9423a7 */ (T_MASK ^ 0x546bdc58)
117 #define T52 /* 0xfc93a039 */ (T_MASK ^ 0x036c5fc6)
118 #define T53    0x655b59c3
119 #define T54 /* 0x8f0ccc92 */ (T_MASK ^ 0x70f3336d)
120 #define T55 /* 0xffeff47d */ (T_MASK ^ 0x00100b82)
121 #define T56 /* 0x85845dd1 */ (T_MASK ^ 0x7a7ba22e)
122 #define T57    0x6fa87e4f
123 #define T58 /* 0xfe2ce6e0 */ (T_MASK ^ 0x01d3191f)
124 #define T59 /* 0xa3014314 */ (T_MASK ^ 0x5cfebceb)
125 #define T60    0x4e0811a1
126 #define T61 /* 0xf7537e82 */ (T_MASK ^ 0x08ac817d)
127 #define T62 /* 0xbd3af235 */ (T_MASK ^ 0x42c50dca)
128 #define T63    0x2ad7d2bb
129 #define T64 /* 0xeb86d391 */ (T_MASK ^ 0x14792c6e)
130 
131 
132 static void
md5_process(md5_state_t * pms,const md5_byte_t * data)133 md5_process(md5_state_t *pms, const md5_byte_t *data /*[64]*/)
134 {
135     md5_word_t
136         a = pms->abcd[0], b = pms->abcd[1],
137         c = pms->abcd[2], d = pms->abcd[3];
138     md5_word_t t;
139 #if BYTE_ORDER > 0
140     /* Define storage only for big-endian CPUs. */
141     md5_word_t X[16];
142 #else
143     /* Define storage for little-endian or both types of CPUs. */
144     md5_word_t xbuf[16];
145     const md5_word_t *X;
146 #endif
147 
148     {
149 #if BYTE_ORDER == 0
150         /*
151          * Determine dynamically whether this is a big-endian or
152          * little-endian machine, since we can use a more efficient
153          * algorithm on the latter.
154          */
155         static const int w = 1;
156 
157         if (*((const md5_byte_t *)&w)) /* dynamic little-endian */
158 #endif
159 #if BYTE_ORDER <= 0             /* little-endian */
160         {
161             /*
162              * On little-endian machines, we can process properly aligned
163              * data without copying it.
164              */
165             if (!((data - (const md5_byte_t *)0) & 3)) {
166                 /* data are properly aligned */
167                 X = (const md5_word_t *)data;
168             } else {
169                 /* not aligned */
170                 memcpy(xbuf, data, 64);
171                 X = xbuf;
172             }
173         }
174 #endif
175 #if BYTE_ORDER == 0
176         else                    /* dynamic big-endian */
177 #endif
178 #if BYTE_ORDER >= 0             /* big-endian */
179         {
180             /*
181              * On big-endian machines, we must arrange the bytes in the
182              * right order.
183              */
184             const md5_byte_t *xp = data;
185             int i;
186 
187 #  if BYTE_ORDER == 0
188             X = xbuf;           /* (dynamic only) */
189 #  else
190 #    define xbuf X              /* (static only) */
191 #  endif
192             for (i = 0; i < 16; ++i, xp += 4)
193                 xbuf[i] = xp[0] + (xp[1] << 8) + (xp[2] << 16) + (xp[3] << 24);
194         }
195 #endif
196     }
197 
198 #define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32 - (n))))
199 
200     /* Round 1. */
201     /* Let [abcd k s i] denote the operation
202        a = b + ((a + F(b,c,d) + X[k] + T[i]) <<< s). */
203 #define F(x, y, z) (((x) & (y)) | (~(x) & (z)))
204 #define SET(a, b, c, d, k, s, Ti)\
205   t = a + F(b,c,d) + X[k] + Ti;\
206   a = ROTATE_LEFT(t, s) + b
207     /* Do the following 16 operations. */
208     SET(a, b, c, d,  0,  7,  T1);
209     SET(d, a, b, c,  1, 12,  T2);
210     SET(c, d, a, b,  2, 17,  T3);
211     SET(b, c, d, a,  3, 22,  T4);
212     SET(a, b, c, d,  4,  7,  T5);
213     SET(d, a, b, c,  5, 12,  T6);
214     SET(c, d, a, b,  6, 17,  T7);
215     SET(b, c, d, a,  7, 22,  T8);
216     SET(a, b, c, d,  8,  7,  T9);
217     SET(d, a, b, c,  9, 12, T10);
218     SET(c, d, a, b, 10, 17, T11);
219     SET(b, c, d, a, 11, 22, T12);
220     SET(a, b, c, d, 12,  7, T13);
221     SET(d, a, b, c, 13, 12, T14);
222     SET(c, d, a, b, 14, 17, T15);
223     SET(b, c, d, a, 15, 22, T16);
224 #undef SET
225 
226      /* Round 2. */
227      /* Let [abcd k s i] denote the operation
228           a = b + ((a + G(b,c,d) + X[k] + T[i]) <<< s). */
229 #define G(x, y, z) (((x) & (z)) | ((y) & ~(z)))
230 #define SET(a, b, c, d, k, s, Ti)\
231   t = a + G(b,c,d) + X[k] + Ti;\
232   a = ROTATE_LEFT(t, s) + b
233      /* Do the following 16 operations. */
234     SET(a, b, c, d,  1,  5, T17);
235     SET(d, a, b, c,  6,  9, T18);
236     SET(c, d, a, b, 11, 14, T19);
237     SET(b, c, d, a,  0, 20, T20);
238     SET(a, b, c, d,  5,  5, T21);
239     SET(d, a, b, c, 10,  9, T22);
240     SET(c, d, a, b, 15, 14, T23);
241     SET(b, c, d, a,  4, 20, T24);
242     SET(a, b, c, d,  9,  5, T25);
243     SET(d, a, b, c, 14,  9, T26);
244     SET(c, d, a, b,  3, 14, T27);
245     SET(b, c, d, a,  8, 20, T28);
246     SET(a, b, c, d, 13,  5, T29);
247     SET(d, a, b, c,  2,  9, T30);
248     SET(c, d, a, b,  7, 14, T31);
249     SET(b, c, d, a, 12, 20, T32);
250 #undef SET
251 
252      /* Round 3. */
253      /* Let [abcd k s t] denote the operation
254           a = b + ((a + H(b,c,d) + X[k] + T[i]) <<< s). */
255 #define H(x, y, z) ((x) ^ (y) ^ (z))
256 #define SET(a, b, c, d, k, s, Ti)\
257   t = a + H(b,c,d) + X[k] + Ti;\
258   a = ROTATE_LEFT(t, s) + b
259      /* Do the following 16 operations. */
260     SET(a, b, c, d,  5,  4, T33);
261     SET(d, a, b, c,  8, 11, T34);
262     SET(c, d, a, b, 11, 16, T35);
263     SET(b, c, d, a, 14, 23, T36);
264     SET(a, b, c, d,  1,  4, T37);
265     SET(d, a, b, c,  4, 11, T38);
266     SET(c, d, a, b,  7, 16, T39);
267     SET(b, c, d, a, 10, 23, T40);
268     SET(a, b, c, d, 13,  4, T41);
269     SET(d, a, b, c,  0, 11, T42);
270     SET(c, d, a, b,  3, 16, T43);
271     SET(b, c, d, a,  6, 23, T44);
272     SET(a, b, c, d,  9,  4, T45);
273     SET(d, a, b, c, 12, 11, T46);
274     SET(c, d, a, b, 15, 16, T47);
275     SET(b, c, d, a,  2, 23, T48);
276 #undef SET
277 
278      /* Round 4. */
279      /* Let [abcd k s t] denote the operation
280           a = b + ((a + I(b,c,d) + X[k] + T[i]) <<< s). */
281 #define I(x, y, z) ((y) ^ ((x) | ~(z)))
282 #define SET(a, b, c, d, k, s, Ti)\
283   t = a + I(b,c,d) + X[k] + Ti;\
284   a = ROTATE_LEFT(t, s) + b
285      /* Do the following 16 operations. */
286     SET(a, b, c, d,  0,  6, T49);
287     SET(d, a, b, c,  7, 10, T50);
288     SET(c, d, a, b, 14, 15, T51);
289     SET(b, c, d, a,  5, 21, T52);
290     SET(a, b, c, d, 12,  6, T53);
291     SET(d, a, b, c,  3, 10, T54);
292     SET(c, d, a, b, 10, 15, T55);
293     SET(b, c, d, a,  1, 21, T56);
294     SET(a, b, c, d,  8,  6, T57);
295     SET(d, a, b, c, 15, 10, T58);
296     SET(c, d, a, b,  6, 15, T59);
297     SET(b, c, d, a, 13, 21, T60);
298     SET(a, b, c, d,  4,  6, T61);
299     SET(d, a, b, c, 11, 10, T62);
300     SET(c, d, a, b,  2, 15, T63);
301     SET(b, c, d, a,  9, 21, T64);
302 #undef SET
303 
304      /* Then perform the following additions. (That is increment each
305         of the four registers by the value it had before this block
306         was started.) */
307     pms->abcd[0] += a;
308     pms->abcd[1] += b;
309     pms->abcd[2] += c;
310     pms->abcd[3] += d;
311 }
312 
313 void
md5_init(md5_state_t * pms)314 md5_init(md5_state_t *pms)
315 {
316     pms->count[0] = pms->count[1] = 0;
317     pms->abcd[0] = 0x67452301;
318     pms->abcd[1] = /*0xefcdab89*/ T_MASK ^ 0x10325476;
319     pms->abcd[2] = /*0x98badcfe*/ T_MASK ^ 0x67452301;
320     pms->abcd[3] = 0x10325476;
321 }
322 
323 void
md5_append(md5_state_t * pms,const md5_byte_t * data,unsigned int nbytes)324 md5_append(md5_state_t *pms, const md5_byte_t *data, unsigned int nbytes)
325 {
326     const md5_byte_t *p = data;
327     unsigned int left = nbytes;
328     unsigned int offset = (pms->count[0] >> 3) & 63;
329     md5_word_t nbits = (md5_word_t)(nbytes << 3);
330 
331     if (nbytes <= 0)
332         return;
333 
334     /* this special case is handled recursively */
335     if (nbytes > INT_MAX - offset) {
336         unsigned int overlap;
337 
338         /* handle the append in two steps to prevent overflow */
339         overlap = 64 - offset;
340 
341         md5_append(pms, data, overlap);
342         md5_append(pms, data + overlap, nbytes - overlap);
343         return;
344     }
345 
346     /* Update the message length. */
347     pms->count[1] += nbytes >> 29;
348     pms->count[0] += nbits;
349     if (pms->count[0] < nbits)
350         pms->count[1]++;
351 
352     /* Process an initial partial block. */
353     if (offset) {
354         unsigned int copy = (offset + nbytes > 64 ? 64 - offset : nbytes);
355 
356         memcpy(pms->buf + offset, p, copy);
357         if (offset + copy < 64)
358             return;
359         p += copy;
360         left -= copy;
361         md5_process(pms, pms->buf);
362     }
363 
364     /* Process full blocks. */
365     for (; left >= 64; p += 64, left -= 64)
366         md5_process(pms, p);
367 
368     /* Process a final partial block. */
369     if (left)
370         memcpy(pms->buf, p, left);
371 }
372 
373 void
md5_finish(md5_state_t * pms,md5_byte_t digest[16])374 md5_finish(md5_state_t *pms, md5_byte_t digest[16])
375 {
376     static const md5_byte_t pad[64] = {
377         0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
378         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
379         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
380         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
381     };
382     md5_byte_t data[8];
383     int i;
384 
385     /* Save the length before padding. */
386     for (i = 0; i < 8; ++i)
387         data[i] = (md5_byte_t)(pms->count[i >> 2] >> ((i & 3) << 3));
388     /* Pad to 56 bytes mod 64. */
389     md5_append(pms, pad, ((55 - (pms->count[0] >> 3)) & 63) + 1);
390     /* Append the length. */
391     md5_append(pms, data, 8);
392     for (i = 0; i < 16; ++i)
393         digest[i] = (md5_byte_t)(pms->abcd[i >> 2] >> ((i & 3) << 3));
394 }
395