source: trunk/src/3rdparty/des/des.cpp

Last change on this file was 2, checked in by Dmitry A. Kuminov, 16 years ago

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1/*
2 * Implementation of DES encryption for NTLM
3 *
4 * Copyright 1997-2005 Simon Tatham.
5 *
6 * This software is released under the MIT license.
7 */
8
9/*
10 * Description of DES
11 * ------------------
12 *
13 * Unlike the description in FIPS 46, I'm going to use _sensible_ indices:
14 * bits in an n-bit word are numbered from 0 at the LSB to n-1 at the MSB.
15 * And S-boxes are indexed by six consecutive bits, not by the outer two
16 * followed by the middle four.
17 *
18 * The DES encryption routine requires a 64-bit input, and a key schedule K
19 * containing 16 48-bit elements.
20 *
21 * First the input is permuted by the initial permutation IP.
22 * Then the input is split into 32-bit words L and R. (L is the MSW.)
23 * Next, 16 rounds. In each round:
24 * (L, R) <- (R, L xor f(R, K[i]))
25 * Then the pre-output words L and R are swapped.
26 * Then L and R are glued back together into a 64-bit word. (L is the MSW,
27 * again, but since we just swapped them, the MSW is the R that came out
28 * of the last round.)
29 * The 64-bit output block is permuted by the inverse of IP and returned.
30 *
31 * Decryption is identical except that the elements of K are used in the
32 * opposite order. (This wouldn't work if that word swap didn't happen.)
33 *
34 * The function f, used in each round, accepts a 32-bit word R and a
35 * 48-bit key block K. It produces a 32-bit output.
36 *
37 * First R is expanded to 48 bits using the bit-selection function E.
38 * The resulting 48-bit block is XORed with the key block K to produce
39 * a 48-bit block X.
40 * This block X is split into eight groups of 6 bits. Each group of 6
41 * bits is then looked up in one of the eight S-boxes to convert
42 * it to 4 bits. These eight groups of 4 bits are glued back
43 * together to produce a 32-bit preoutput block.
44 * The preoutput block is permuted using the permutation P and returned.
45 *
46 * Key setup maps a 64-bit key word into a 16x48-bit key schedule. Although
47 * the approved input format for the key is a 64-bit word, eight of the
48 * bits are discarded, so the actual quantity of key used is 56 bits.
49 *
50 * First the input key is converted to two 28-bit words C and D using
51 * the bit-selection function PC1.
52 * Then 16 rounds of key setup occur. In each round, C and D are each
53 * rotated left by either 1 or 2 bits (depending on which round), and
54 * then converted into a key schedule element using the bit-selection
55 * function PC2.
56 *
57 * That's the actual algorithm. Now for the tedious details: all those
58 * painful permutations and lookup tables.
59 *
60 * IP is a 64-to-64 bit permutation. Its output contains the following
61 * bits of its input (listed in order MSB to LSB of output).
62 *
63 * 6 14 22 30 38 46 54 62 4 12 20 28 36 44 52 60
64 * 2 10 18 26 34 42 50 58 0 8 16 24 32 40 48 56
65 * 7 15 23 31 39 47 55 63 5 13 21 29 37 45 53 61
66 * 3 11 19 27 35 43 51 59 1 9 17 25 33 41 49 57
67 *
68 * E is a 32-to-48 bit selection function. Its output contains the following
69 * bits of its input (listed in order MSB to LSB of output).
70 *
71 * 0 31 30 29 28 27 28 27 26 25 24 23 24 23 22 21 20 19 20 19 18 17 16 15
72 * 16 15 14 13 12 11 12 11 10 9 8 7 8 7 6 5 4 3 4 3 2 1 0 31
73 *
74 * The S-boxes are arbitrary table-lookups each mapping a 6-bit input to a
75 * 4-bit output. In other words, each S-box is an array[64] of 4-bit numbers.
76 * The S-boxes are listed below. The first S-box listed is applied to the
77 * most significant six bits of the block X; the last one is applied to the
78 * least significant.
79 *
80 * 14 0 4 15 13 7 1 4 2 14 15 2 11 13 8 1
81 * 3 10 10 6 6 12 12 11 5 9 9 5 0 3 7 8
82 * 4 15 1 12 14 8 8 2 13 4 6 9 2 1 11 7
83 * 15 5 12 11 9 3 7 14 3 10 10 0 5 6 0 13
84 *
85 * 15 3 1 13 8 4 14 7 6 15 11 2 3 8 4 14
86 * 9 12 7 0 2 1 13 10 12 6 0 9 5 11 10 5
87 * 0 13 14 8 7 10 11 1 10 3 4 15 13 4 1 2
88 * 5 11 8 6 12 7 6 12 9 0 3 5 2 14 15 9
89 *
90 * 10 13 0 7 9 0 14 9 6 3 3 4 15 6 5 10
91 * 1 2 13 8 12 5 7 14 11 12 4 11 2 15 8 1
92 * 13 1 6 10 4 13 9 0 8 6 15 9 3 8 0 7
93 * 11 4 1 15 2 14 12 3 5 11 10 5 14 2 7 12
94 *
95 * 7 13 13 8 14 11 3 5 0 6 6 15 9 0 10 3
96 * 1 4 2 7 8 2 5 12 11 1 12 10 4 14 15 9
97 * 10 3 6 15 9 0 0 6 12 10 11 1 7 13 13 8
98 * 15 9 1 4 3 5 14 11 5 12 2 7 8 2 4 14
99 *
100 * 2 14 12 11 4 2 1 12 7 4 10 7 11 13 6 1
101 * 8 5 5 0 3 15 15 10 13 3 0 9 14 8 9 6
102 * 4 11 2 8 1 12 11 7 10 1 13 14 7 2 8 13
103 * 15 6 9 15 12 0 5 9 6 10 3 4 0 5 14 3
104 *
105 * 12 10 1 15 10 4 15 2 9 7 2 12 6 9 8 5
106 * 0 6 13 1 3 13 4 14 14 0 7 11 5 3 11 8
107 * 9 4 14 3 15 2 5 12 2 9 8 5 12 15 3 10
108 * 7 11 0 14 4 1 10 7 1 6 13 0 11 8 6 13
109 *
110 * 4 13 11 0 2 11 14 7 15 4 0 9 8 1 13 10
111 * 3 14 12 3 9 5 7 12 5 2 10 15 6 8 1 6
112 * 1 6 4 11 11 13 13 8 12 1 3 4 7 10 14 7
113 * 10 9 15 5 6 0 8 15 0 14 5 2 9 3 2 12
114 *
115 * 13 1 2 15 8 13 4 8 6 10 15 3 11 7 1 4
116 * 10 12 9 5 3 6 14 11 5 0 0 14 12 9 7 2
117 * 7 2 11 1 4 14 1 7 9 4 12 10 14 8 2 13
118 * 0 15 6 12 10 9 13 0 15 3 3 5 5 6 8 11
119 *
120 * P is a 32-to-32 bit permutation. Its output contains the following
121 * bits of its input (listed in order MSB to LSB of output).
122 *
123 * 16 25 12 11 3 20 4 15 31 17 9 6 27 14 1 22
124 * 30 24 8 18 0 5 29 23 13 19 2 26 10 21 28 7
125 *
126 * PC1 is a 64-to-56 bit selection function. Its output is in two words,
127 * C and D. The word C contains the following bits of its input (listed
128 * in order MSB to LSB of output).
129 *
130 * 7 15 23 31 39 47 55 63 6 14 22 30 38 46
131 * 54 62 5 13 21 29 37 45 53 61 4 12 20 28
132 *
133 * And the word D contains these bits.
134 *
135 * 1 9 17 25 33 41 49 57 2 10 18 26 34 42
136 * 50 58 3 11 19 27 35 43 51 59 36 44 52 60
137 *
138 * PC2 is a 56-to-48 bit selection function. Its input is in two words,
139 * C and D. These are treated as one 56-bit word (with C more significant,
140 * so that bits 55 to 28 of the word are bits 27 to 0 of C, and bits 27 to
141 * 0 of the word are bits 27 to 0 of D). The output contains the following
142 * bits of this 56-bit input word (listed in order MSB to LSB of output).
143 *
144 * 42 39 45 32 55 51 53 28 41 50 35 46 33 37 44 52 30 48 40 49 29 36 43 54
145 * 15 4 25 19 9 1 26 16 5 11 23 8 12 7 17 0 22 3 10 14 6 20 27 24
146 */
147
148/*
149 * Implementation details
150 * ----------------------
151 *
152 * If you look at the code in this module, you'll find it looks
153 * nothing _like_ the above algorithm. Here I explain the
154 * differences...
155 *
156 * Key setup has not been heavily optimised here. We are not
157 * concerned with key agility: we aren't codebreakers. We don't
158 * mind a little delay (and it really is a little one; it may be a
159 * factor of five or so slower than it could be but it's still not
160 * an appreciable length of time) while setting up. The only tweaks
161 * in the key setup are ones which change the format of the key
162 * schedule to speed up the actual encryption. I'll describe those
163 * below.
164 *
165 * The first and most obvious optimisation is the S-boxes. Since
166 * each S-box always targets the same four bits in the final 32-bit
167 * word, so the output from (for example) S-box 0 must always be
168 * shifted left 28 bits, we can store the already-shifted outputs
169 * in the lookup tables. This reduces lookup-and-shift to lookup,
170 * so the S-box step is now just a question of ORing together eight
171 * table lookups.
172 *
173 * The permutation P is just a bit order change; it's invariant
174 * with respect to OR, in that P(x)|P(y) = P(x|y). Therefore, we
175 * can apply P to every entry of the S-box tables and then we don't
176 * have to do it in the code of f(). This yields a set of tables
177 * which might be called SP-boxes.
178 *
179 * The bit-selection function E is our next target. Note that E is
180 * immediately followed by the operation of splitting into 6-bit
181 * chunks. Examining the 6-bit chunks coming out of E we notice
182 * they're all contiguous within the word (speaking cyclically -
183 * the end two wrap round); so we can extract those bit strings
184 * individually rather than explicitly running E. This would yield
185 * code such as
186 *
187 * y |= SPboxes[0][ (rotl(R, 5) ^ top6bitsofK) & 0x3F ];
188 * t |= SPboxes[1][ (rotl(R,11) ^ next6bitsofK) & 0x3F ];
189 *
190 * and so on; and the key schedule preparation would have to
191 * provide each 6-bit chunk separately.
192 *
193 * Really we'd like to XOR in the key schedule element before
194 * looking up bit strings in R. This we can't do, naively, because
195 * the 6-bit strings we want overlap. But look at the strings:
196 *
197 * 3322222222221111111111
198 * bit 10987654321098765432109876543210
199 *
200 * box0 XXXXX X
201 * box1 XXXXXX
202 * box2 XXXXXX
203 * box3 XXXXXX
204 * box4 XXXXXX
205 * box5 XXXXXX
206 * box6 XXXXXX
207 * box7 X XXXXX
208 *
209 * The bit strings we need to XOR in for boxes 0, 2, 4 and 6 don't
210 * overlap with each other. Neither do the ones for boxes 1, 3, 5
211 * and 7. So we could provide the key schedule in the form of two
212 * words that we can separately XOR into R, and then every S-box
213 * index is available as a (cyclically) contiguous 6-bit substring
214 * of one or the other of the results.
215 *
216 * The comments in Eric Young's libdes implementation point out
217 * that two of these bit strings require a rotation (rather than a
218 * simple shift) to extract. It's unavoidable that at least _one_
219 * must do; but we can actually run the whole inner algorithm (all
220 * 16 rounds) rotated one bit to the left, so that what the `real'
221 * DES description sees as L=0x80000001 we see as L=0x00000003.
222 * This requires rotating all our SP-box entries one bit to the
223 * left, and rotating each word of the key schedule elements one to
224 * the left, and rotating L and R one bit left just after IP and
225 * one bit right again just before FP. And in each round we convert
226 * a rotate into a shift, so we've saved a few per cent.
227 *
228 * That's about it for the inner loop; the SP-box tables as listed
229 * below are what I've described here (the original S value,
230 * shifted to its final place in the input to P, run through P, and
231 * then rotated one bit left). All that remains is to optimise the
232 * initial permutation IP.
233 *
234 * IP is not an arbitrary permutation. It has the nice property
235 * that if you take any bit number, write it in binary (6 bits),
236 * permute those 6 bits and invert some of them, you get the final
237 * position of that bit. Specifically, the bit whose initial
238 * position is given (in binary) as fedcba ends up in position
239 * AcbFED (where a capital letter denotes the inverse of a bit).
240 *
241 * We have the 64-bit data in two 32-bit words L and R, where bits
242 * in L are those with f=1 and bits in R are those with f=0. We
243 * note that we can do a simple transformation: suppose we exchange
244 * the bits with f=1,c=0 and the bits with f=0,c=1. This will cause
245 * the bit fedcba to be in position cedfba - we've `swapped' bits c
246 * and f in the position of each bit!
247 *
248 * Better still, this transformation is easy. In the example above,
249 * bits in L with c=0 are bits 0x0F0F0F0F, and those in R with c=1
250 * are 0xF0F0F0F0. So we can do
251 *
252 * difference = ((R >> 4) ^ L) & 0x0F0F0F0F
253 * R ^= (difference << 4)
254 * L ^= difference
255 *
256 * to perform the swap. Let's denote this by bitswap(4,0x0F0F0F0F).
257 * Also, we can invert the bit at the top just by exchanging L and
258 * R. So in a few swaps and a few of these bit operations we can
259 * do:
260 *
261 * Initially the position of bit fedcba is fedcba
262 * Swap L with R to make it Fedcba
263 * Perform bitswap( 4,0x0F0F0F0F) to make it cedFba
264 * Perform bitswap(16,0x0000FFFF) to make it ecdFba
265 * Swap L with R to make it EcdFba
266 * Perform bitswap( 2,0x33333333) to make it bcdFEa
267 * Perform bitswap( 8,0x00FF00FF) to make it dcbFEa
268 * Swap L with R to make it DcbFEa
269 * Perform bitswap( 1,0x55555555) to make it acbFED
270 * Swap L with R to make it AcbFED
271 *
272 * (In the actual code the four swaps are implicit: R and L are
273 * simply used the other way round in the first, second and last
274 * bitswap operations.)
275 *
276 * The final permutation is just the inverse of IP, so it can be
277 * performed by a similar set of operations.
278 */
279
280struct des_context {
281 quint32 k0246[16], k1357[16];
282};
283
284#define rotl(x, c) ( (x << c) | (x >> (32-c)) )
285#define rotl28(x, c) ( ( (x << c) | (x >> (28-c)) ) & 0x0FFFFFFF)
286
287static quint32 bitsel(quint32 * input, const int *bitnums, int size)
288{
289 quint32 ret = 0;
290 while (size--) {
291 int bitpos = *bitnums++;
292 ret <<= 1;
293 if (bitpos >= 0)
294 ret |= 1 & (input[bitpos / 32] >> (bitpos % 32));
295 }
296 return ret;
297}
298
299static inline void des_key_setup(quint32 key_msw, quint32 key_lsw,
300 struct des_context *sched)
301{
302 /* Tables are modified to work with 56-bit key */
303 static const int PC1_Cbits[] = {
304 6, 13, 20, 27, 34, 41, 48, 55, 5, 12, 19, 26, 33, 40,
305 47, 54, 4, 11, 18, 25, 32, 39, 46, 53, 3, 10, 17, 24
306 };
307 static const int PC1_Dbits[] = {
308 0, 7, 14, 21, 28, 35, 42, 49, 1, 8, 15, 22, 29, 36,
309 43, 50, 2, 9, 16, 23, 30, 37, 44, 51, 31, 38, 45, 52
310 };
311 /*
312 * The bit numbers in the two lists below don't correspond to
313 * the ones in the above description of PC2, because in the
314 * above description C and D are concatenated so `bit 28' means
315 * bit 0 of C. In this implementation we're using the standard
316 * `bitsel' function above and C is in the second word, so bit
317 * 0 of C is addressed by writing `32' here.
318 */
319 static const int PC2_0246[] = {
320 49, 36, 59, 55, -1, -1, 37, 41, 48, 56, 34, 52, -1, -1, 15, 4,
321 25, 19, 9, 1, -1, -1, 12, 7, 17, 0, 22, 3, -1, -1, 46, 43
322 };
323 static const int PC2_1357[] = {
324 -1, -1, 57, 32, 45, 54, 39, 50, -1, -1, 44, 53, 33, 40, 47, 58,
325 -1, -1, 26, 16, 5, 11, 23, 8, -1, -1, 10, 14, 6, 20, 27, 24
326 };
327 static const int leftshifts[] = {
328 1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1
329 };
330
331 quint32 C, D;
332 quint32 buf[2];
333 int i;
334
335 buf[0] = key_lsw;
336 buf[1] = key_msw;
337
338 C = bitsel(buf, PC1_Cbits, 28);
339 D = bitsel(buf, PC1_Dbits, 28);
340
341 for (i = 0; i < 16; i++) {
342 C = rotl28(C, leftshifts[i]);
343 D = rotl28(D, leftshifts[i]);
344 buf[0] = D;
345 buf[1] = C;
346 sched->k0246[i] = bitsel(buf, PC2_0246, 32);
347 sched->k1357[i] = bitsel(buf, PC2_1357, 32);
348 }
349}
350
351static const quint32 SPboxes[8][64] = {
352 {0x01010400, 0x00000000, 0x00010000, 0x01010404,
353 0x01010004, 0x00010404, 0x00000004, 0x00010000,
354 0x00000400, 0x01010400, 0x01010404, 0x00000400,
355 0x01000404, 0x01010004, 0x01000000, 0x00000004,
356 0x00000404, 0x01000400, 0x01000400, 0x00010400,
357 0x00010400, 0x01010000, 0x01010000, 0x01000404,
358 0x00010004, 0x01000004, 0x01000004, 0x00010004,
359 0x00000000, 0x00000404, 0x00010404, 0x01000000,
360 0x00010000, 0x01010404, 0x00000004, 0x01010000,
361 0x01010400, 0x01000000, 0x01000000, 0x00000400,
362 0x01010004, 0x00010000, 0x00010400, 0x01000004,
363 0x00000400, 0x00000004, 0x01000404, 0x00010404,
364 0x01010404, 0x00010004, 0x01010000, 0x01000404,
365 0x01000004, 0x00000404, 0x00010404, 0x01010400,
366 0x00000404, 0x01000400, 0x01000400, 0x00000000,
367 0x00010004, 0x00010400, 0x00000000, 0x01010004},
368
369 {0x80108020, 0x80008000, 0x00008000, 0x00108020,
370 0x00100000, 0x00000020, 0x80100020, 0x80008020,
371 0x80000020, 0x80108020, 0x80108000, 0x80000000,
372 0x80008000, 0x00100000, 0x00000020, 0x80100020,
373 0x00108000, 0x00100020, 0x80008020, 0x00000000,
374 0x80000000, 0x00008000, 0x00108020, 0x80100000,
375 0x00100020, 0x80000020, 0x00000000, 0x00108000,
376 0x00008020, 0x80108000, 0x80100000, 0x00008020,
377 0x00000000, 0x00108020, 0x80100020, 0x00100000,
378 0x80008020, 0x80100000, 0x80108000, 0x00008000,
379 0x80100000, 0x80008000, 0x00000020, 0x80108020,
380 0x00108020, 0x00000020, 0x00008000, 0x80000000,
381 0x00008020, 0x80108000, 0x00100000, 0x80000020,
382 0x00100020, 0x80008020, 0x80000020, 0x00100020,
383 0x00108000, 0x00000000, 0x80008000, 0x00008020,
384 0x80000000, 0x80100020, 0x80108020, 0x00108000},
385
386 {0x00000208, 0x08020200, 0x00000000, 0x08020008,
387 0x08000200, 0x00000000, 0x00020208, 0x08000200,
388 0x00020008, 0x08000008, 0x08000008, 0x00020000,
389 0x08020208, 0x00020008, 0x08020000, 0x00000208,
390 0x08000000, 0x00000008, 0x08020200, 0x00000200,
391 0x00020200, 0x08020000, 0x08020008, 0x00020208,
392 0x08000208, 0x00020200, 0x00020000, 0x08000208,
393 0x00000008, 0x08020208, 0x00000200, 0x08000000,
394 0x08020200, 0x08000000, 0x00020008, 0x00000208,
395 0x00020000, 0x08020200, 0x08000200, 0x00000000,
396 0x00000200, 0x00020008, 0x08020208, 0x08000200,
397 0x08000008, 0x00000200, 0x00000000, 0x08020008,
398 0x08000208, 0x00020000, 0x08000000, 0x08020208,
399 0x00000008, 0x00020208, 0x00020200, 0x08000008,
400 0x08020000, 0x08000208, 0x00000208, 0x08020000,
401 0x00020208, 0x00000008, 0x08020008, 0x00020200},
402
403 {0x00802001, 0x00002081, 0x00002081, 0x00000080,
404 0x00802080, 0x00800081, 0x00800001, 0x00002001,
405 0x00000000, 0x00802000, 0x00802000, 0x00802081,
406 0x00000081, 0x00000000, 0x00800080, 0x00800001,
407 0x00000001, 0x00002000, 0x00800000, 0x00802001,
408 0x00000080, 0x00800000, 0x00002001, 0x00002080,
409 0x00800081, 0x00000001, 0x00002080, 0x00800080,
410 0x00002000, 0x00802080, 0x00802081, 0x00000081,
411 0x00800080, 0x00800001, 0x00802000, 0x00802081,
412 0x00000081, 0x00000000, 0x00000000, 0x00802000,
413 0x00002080, 0x00800080, 0x00800081, 0x00000001,
414 0x00802001, 0x00002081, 0x00002081, 0x00000080,
415 0x00802081, 0x00000081, 0x00000001, 0x00002000,
416 0x00800001, 0x00002001, 0x00802080, 0x00800081,
417 0x00002001, 0x00002080, 0x00800000, 0x00802001,
418 0x00000080, 0x00800000, 0x00002000, 0x00802080},
419
420 {0x00000100, 0x02080100, 0x02080000, 0x42000100,
421 0x00080000, 0x00000100, 0x40000000, 0x02080000,
422 0x40080100, 0x00080000, 0x02000100, 0x40080100,
423 0x42000100, 0x42080000, 0x00080100, 0x40000000,
424 0x02000000, 0x40080000, 0x40080000, 0x00000000,
425 0x40000100, 0x42080100, 0x42080100, 0x02000100,
426 0x42080000, 0x40000100, 0x00000000, 0x42000000,
427 0x02080100, 0x02000000, 0x42000000, 0x00080100,
428 0x00080000, 0x42000100, 0x00000100, 0x02000000,
429 0x40000000, 0x02080000, 0x42000100, 0x40080100,
430 0x02000100, 0x40000000, 0x42080000, 0x02080100,
431 0x40080100, 0x00000100, 0x02000000, 0x42080000,
432 0x42080100, 0x00080100, 0x42000000, 0x42080100,
433 0x02080000, 0x00000000, 0x40080000, 0x42000000,
434 0x00080100, 0x02000100, 0x40000100, 0x00080000,
435 0x00000000, 0x40080000, 0x02080100, 0x40000100},
436
437 {0x20000010, 0x20400000, 0x00004000, 0x20404010,
438 0x20400000, 0x00000010, 0x20404010, 0x00400000,
439 0x20004000, 0x00404010, 0x00400000, 0x20000010,
440 0x00400010, 0x20004000, 0x20000000, 0x00004010,
441 0x00000000, 0x00400010, 0x20004010, 0x00004000,
442 0x00404000, 0x20004010, 0x00000010, 0x20400010,
443 0x20400010, 0x00000000, 0x00404010, 0x20404000,
444 0x00004010, 0x00404000, 0x20404000, 0x20000000,
445 0x20004000, 0x00000010, 0x20400010, 0x00404000,
446 0x20404010, 0x00400000, 0x00004010, 0x20000010,
447 0x00400000, 0x20004000, 0x20000000, 0x00004010,
448 0x20000010, 0x20404010, 0x00404000, 0x20400000,
449 0x00404010, 0x20404000, 0x00000000, 0x20400010,
450 0x00000010, 0x00004000, 0x20400000, 0x00404010,
451 0x00004000, 0x00400010, 0x20004010, 0x00000000,
452 0x20404000, 0x20000000, 0x00400010, 0x20004010},
453
454 {0x00200000, 0x04200002, 0x04000802, 0x00000000,
455 0x00000800, 0x04000802, 0x00200802, 0x04200800,
456 0x04200802, 0x00200000, 0x00000000, 0x04000002,
457 0x00000002, 0x04000000, 0x04200002, 0x00000802,
458 0x04000800, 0x00200802, 0x00200002, 0x04000800,
459 0x04000002, 0x04200000, 0x04200800, 0x00200002,
460 0x04200000, 0x00000800, 0x00000802, 0x04200802,
461 0x00200800, 0x00000002, 0x04000000, 0x00200800,
462 0x04000000, 0x00200800, 0x00200000, 0x04000802,
463 0x04000802, 0x04200002, 0x04200002, 0x00000002,
464 0x00200002, 0x04000000, 0x04000800, 0x00200000,
465 0x04200800, 0x00000802, 0x00200802, 0x04200800,
466 0x00000802, 0x04000002, 0x04200802, 0x04200000,
467 0x00200800, 0x00000000, 0x00000002, 0x04200802,
468 0x00000000, 0x00200802, 0x04200000, 0x00000800,
469 0x04000002, 0x04000800, 0x00000800, 0x00200002},
470
471 {0x10001040, 0x00001000, 0x00040000, 0x10041040,
472 0x10000000, 0x10001040, 0x00000040, 0x10000000,
473 0x00040040, 0x10040000, 0x10041040, 0x00041000,
474 0x10041000, 0x00041040, 0x00001000, 0x00000040,
475 0x10040000, 0x10000040, 0x10001000, 0x00001040,
476 0x00041000, 0x00040040, 0x10040040, 0x10041000,
477 0x00001040, 0x00000000, 0x00000000, 0x10040040,
478 0x10000040, 0x10001000, 0x00041040, 0x00040000,
479 0x00041040, 0x00040000, 0x10041000, 0x00001000,
480 0x00000040, 0x10040040, 0x00001000, 0x00041040,
481 0x10001000, 0x00000040, 0x10000040, 0x10040000,
482 0x10040040, 0x10000000, 0x00040000, 0x10001040,
483 0x00000000, 0x10041040, 0x00040040, 0x10000040,
484 0x10040000, 0x10001000, 0x10001040, 0x00000000,
485 0x10041040, 0x00041000, 0x00041000, 0x00001040,
486 0x00001040, 0x00040040, 0x10000000, 0x10041000}
487};
488
489#define f(R, K0246, K1357) (\
490 s0246 = R ^ K0246, \
491 s1357 = R ^ K1357, \
492 s0246 = rotl(s0246, 28), \
493 SPboxes[0] [(s0246 >> 24) & 0x3F] | \
494 SPboxes[1] [(s1357 >> 24) & 0x3F] | \
495 SPboxes[2] [(s0246 >> 16) & 0x3F] | \
496 SPboxes[3] [(s1357 >> 16) & 0x3F] | \
497 SPboxes[4] [(s0246 >> 8) & 0x3F] | \
498 SPboxes[5] [(s1357 >> 8) & 0x3F] | \
499 SPboxes[6] [(s0246 ) & 0x3F] | \
500 SPboxes[7] [(s1357 ) & 0x3F])
501
502#define bitswap(L, R, n, mask) (\
503 swap = mask & ( (R >> n) ^ L ), \
504 R ^= swap << n, \
505 L ^= swap)
506
507/* Initial permutation */
508#define IP(L, R) (\
509 bitswap(R, L, 4, 0x0F0F0F0F), \
510 bitswap(R, L, 16, 0x0000FFFF), \
511 bitswap(L, R, 2, 0x33333333), \
512 bitswap(L, R, 8, 0x00FF00FF), \
513 bitswap(R, L, 1, 0x55555555))
514
515/* Final permutation */
516#define FP(L, R) (\
517 bitswap(R, L, 1, 0x55555555), \
518 bitswap(L, R, 8, 0x00FF00FF), \
519 bitswap(L, R, 2, 0x33333333), \
520 bitswap(R, L, 16, 0x0000FFFF), \
521 bitswap(R, L, 4, 0x0F0F0F0F))
522
523static void
524des_encipher(quint32 *output, quint32 L, quint32 R,
525 struct des_context *sched)
526{
527 quint32 swap, s0246, s1357;
528
529 IP(L, R);
530
531 L = rotl(L, 1);
532 R = rotl(R, 1);
533
534 L ^= f(R, sched->k0246[0], sched->k1357[0]);
535 R ^= f(L, sched->k0246[1], sched->k1357[1]);
536 L ^= f(R, sched->k0246[2], sched->k1357[2]);
537 R ^= f(L, sched->k0246[3], sched->k1357[3]);
538 L ^= f(R, sched->k0246[4], sched->k1357[4]);
539 R ^= f(L, sched->k0246[5], sched->k1357[5]);
540 L ^= f(R, sched->k0246[6], sched->k1357[6]);
541 R ^= f(L, sched->k0246[7], sched->k1357[7]);
542 L ^= f(R, sched->k0246[8], sched->k1357[8]);
543 R ^= f(L, sched->k0246[9], sched->k1357[9]);
544 L ^= f(R, sched->k0246[10], sched->k1357[10]);
545 R ^= f(L, sched->k0246[11], sched->k1357[11]);
546 L ^= f(R, sched->k0246[12], sched->k1357[12]);
547 R ^= f(L, sched->k0246[13], sched->k1357[13]);
548 L ^= f(R, sched->k0246[14], sched->k1357[14]);
549 R ^= f(L, sched->k0246[15], sched->k1357[15]);
550
551 L = rotl(L, 31);
552 R = rotl(R, 31);
553
554 swap = L;
555 L = R;
556 R = swap;
557
558 FP(L, R);
559
560 output[0] = L;
561 output[1] = R;
562}
563
564#define GET_32BIT_MSB_FIRST(cp) \
565 (((unsigned long)(unsigned char)(cp)[3]) | \
566 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
567 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
568 ((unsigned long)(unsigned char)(cp)[0] << 24))
569
570#define PUT_32BIT_MSB_FIRST(cp, value) do { \
571 (cp)[3] = (value); \
572 (cp)[2] = (value) >> 8; \
573 (cp)[1] = (value) >> 16; \
574 (cp)[0] = (value) >> 24; } while (0)
575
576static inline void
577des_cbc_encrypt(unsigned char *dest, const unsigned char *src,
578 struct des_context *sched)
579{
580 quint32 out[2], L, R;
581
582 L = GET_32BIT_MSB_FIRST(src);
583 R = GET_32BIT_MSB_FIRST(src + 4);
584 des_encipher(out, L, R, sched);
585 PUT_32BIT_MSB_FIRST(dest, out[0]);
586 PUT_32BIT_MSB_FIRST(dest + 4, out[1]);
587}
588
589
590static unsigned char *
591deshash(unsigned char *dst, const unsigned char *key,
592 const unsigned char *src)
593{
594 struct des_context ctx;
595
596 des_key_setup(GET_32BIT_MSB_FIRST(key) >> 8,
597 GET_32BIT_MSB_FIRST(key + 3), &ctx);
598
599 des_cbc_encrypt(dst, src, &ctx);
600
601 return dst;
602}
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