File: des.cpp

package info (click to toggle)
libcrypto++ 5.6.4-8
  • links: PTS
  • area: main
  • in suites: buster
  • size: 11,896 kB
  • ctags: 13,256
  • sloc: cpp: 69,231; sh: 4,117; asm: 4,090; makefile: 373
file content (453 lines) | stat: -rw-r--r-- 13,759 bytes parent folder | download | duplicates (3)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
// des.cpp - modified by Wei Dai from Phil Karn's des.c
// The original code and all modifications are in the public domain.

/*
 * This is a major rewrite of my old public domain DES code written
 * circa 1987, which in turn borrowed heavily from Jim Gillogly's 1977
 * public domain code. I pretty much kept my key scheduling code, but
 * the actual encrypt/decrypt routines are taken from from Richard
 * Outerbridge's DES code as printed in Schneier's "Applied Cryptography."
 *
 * This code is in the public domain. I would appreciate bug reports and
 * enhancements.
 *
 * Phil Karn KA9Q, karn@unix.ka9q.ampr.org, August 1994.
 */

#include "pch.h"
#include "misc.h"
#include "des.h"

NAMESPACE_BEGIN(CryptoPP)

typedef BlockGetAndPut<word32, BigEndian> Block;

// Richard Outerbridge's initial permutation algorithm
/*
inline void IPERM(word32 &left, word32 &right)
{
	word32 work;

	work = ((left >> 4) ^ right) & 0x0f0f0f0f;
	right ^= work;
	left ^= work << 4;
	work = ((left >> 16) ^ right) & 0xffff;
	right ^= work;
	left ^= work << 16;
	work = ((right >> 2) ^ left) & 0x33333333;
	left ^= work;
	right ^= (work << 2);
	work = ((right >> 8) ^ left) & 0xff00ff;
	left ^= work;
	right ^= (work << 8);
	right = rotl(right, 1);
	work = (left ^ right) & 0xaaaaaaaa;
	left ^= work;
	right ^= work;
	left = rotl(left, 1);
}
inline void FPERM(word32 &left, word32 &right)
{
	word32 work;

	right = rotr(right, 1);
	work = (left ^ right) & 0xaaaaaaaa;
	left ^= work;
	right ^= work;
	left = rotr(left, 1);
	work = ((left >> 8) ^ right) & 0xff00ff;
	right ^= work;
	left ^= work << 8;
	work = ((left >> 2) ^ right) & 0x33333333;
	right ^= work;
	left ^= work << 2;
	work = ((right >> 16) ^ left) & 0xffff;
	left ^= work;
	right ^= work << 16;
	work = ((right >> 4) ^ left) & 0x0f0f0f0f;
	left ^= work;
	right ^= work << 4;
}
*/

// Wei Dai's modification to Richard Outerbridge's initial permutation
// algorithm, this one is faster if you have access to rotate instructions
// (like in MSVC)
static inline void IPERM(word32 &left, word32 &right)
{
	word32 work;

	right = rotlFixed(right, 4U);
	work = (left ^ right) & 0xf0f0f0f0;
	left ^= work;
	right = rotrFixed(right^work, 20U);
	work = (left ^ right) & 0xffff0000;
	left ^= work;
	right = rotrFixed(right^work, 18U);
	work = (left ^ right) & 0x33333333;
	left ^= work;
	right = rotrFixed(right^work, 6U);
	work = (left ^ right) & 0x00ff00ff;
	left ^= work;
	right = rotlFixed(right^work, 9U);
	work = (left ^ right) & 0xaaaaaaaa;
	left = rotlFixed(left^work, 1U);
	right ^= work;
}

static inline void FPERM(word32 &left, word32 &right)
{
	word32 work;

	right = rotrFixed(right, 1U);
	work = (left ^ right) & 0xaaaaaaaa;
	right ^= work;
	left = rotrFixed(left^work, 9U);
	work = (left ^ right) & 0x00ff00ff;
	right ^= work;
	left = rotlFixed(left^work, 6U);
	work = (left ^ right) & 0x33333333;
	right ^= work;
	left = rotlFixed(left^work, 18U);
	work = (left ^ right) & 0xffff0000;
	right ^= work;
	left = rotlFixed(left^work, 20U);
	work = (left ^ right) & 0xf0f0f0f0;
	right ^= work;
	left = rotrFixed(left^work, 4U);
}

void DES::Base::UncheckedSetKey(const byte *userKey, unsigned int length, const NameValuePairs &)
{
	AssertValidKeyLength(length);

	RawSetKey(GetCipherDirection(), userKey);
}

#ifndef CRYPTOPP_IMPORTS

/* Tables defined in the Data Encryption Standard documents
 * Three of these tables, the initial permutation, the final
 * permutation and the expansion operator, are regular enough that
 * for speed, we hard-code them. They're here for reference only.
 * Also, the S and P boxes are used by a separate program, gensp.c,
 * to build the combined SP box, Spbox[]. They're also here just
 * for reference.
 */
#ifdef notdef
/* initial permutation IP */
static byte ip[] = {
	   58, 50, 42, 34, 26, 18, 10,  2,
	   60, 52, 44, 36, 28, 20, 12,  4,
	   62, 54, 46, 38, 30, 22, 14,  6,
	   64, 56, 48, 40, 32, 24, 16,  8,
	   57, 49, 41, 33, 25, 17,  9,  1,
	   59, 51, 43, 35, 27, 19, 11,  3,
	   61, 53, 45, 37, 29, 21, 13,  5,
	   63, 55, 47, 39, 31, 23, 15,  7
};

/* final permutation IP^-1 */
static byte fp[] = {
	   40,  8, 48, 16, 56, 24, 64, 32,
	   39,  7, 47, 15, 55, 23, 63, 31,
	   38,  6, 46, 14, 54, 22, 62, 30,
	   37,  5, 45, 13, 53, 21, 61, 29,
	   36,  4, 44, 12, 52, 20, 60, 28,
	   35,  3, 43, 11, 51, 19, 59, 27,
	   34,  2, 42, 10, 50, 18, 58, 26,
	   33,  1, 41,  9, 49, 17, 57, 25
};
/* expansion operation matrix */
static byte ei[] = {
	   32,  1,  2,  3,  4,  5,
		4,  5,  6,  7,  8,  9,
		8,  9, 10, 11, 12, 13,
	   12, 13, 14, 15, 16, 17,
	   16, 17, 18, 19, 20, 21,
	   20, 21, 22, 23, 24, 25,
	   24, 25, 26, 27, 28, 29,
	   28, 29, 30, 31, 32,  1
};
/* The (in)famous S-boxes */
static byte sbox[8][64] = {
	   /* S1 */
	   14,  4, 13,  1,  2, 15, 11,  8,  3, 10,  6, 12,  5,  9,  0,  7,
		0, 15,  7,  4, 14,  2, 13,  1, 10,  6, 12, 11,  9,  5,  3,  8,
		4,  1, 14,  8, 13,  6,  2, 11, 15, 12,  9,  7,  3, 10,  5,  0,
	   15, 12,  8,  2,  4,  9,  1,  7,  5, 11,  3, 14, 10,  0,  6, 13,

	   /* S2 */
	   15,  1,  8, 14,  6, 11,  3,  4,  9,  7,  2, 13, 12,  0,  5, 10,
		3, 13,  4,  7, 15,  2,  8, 14, 12,  0,  1, 10,  6,  9, 11,  5,
		0, 14,  7, 11, 10,  4, 13,  1,  5,  8, 12,  6,  9,  3,  2, 15,
	   13,  8, 10,  1,  3, 15,  4,  2, 11,  6,  7, 12,  0,  5, 14,  9,

	   /* S3 */
	   10,  0,  9, 14,  6,  3, 15,  5,  1, 13, 12,  7, 11,  4,  2,  8,
	   13,  7,  0,  9,  3,  4,  6, 10,  2,  8,  5, 14, 12, 11, 15,  1,
	   13,  6,  4,  9,  8, 15,  3,  0, 11,  1,  2, 12,  5, 10, 14,  7,
		1, 10, 13,  0,  6,  9,  8,  7,  4, 15, 14,  3, 11,  5,  2, 12,

	   /* S4 */
		7, 13, 14,  3,  0,  6,  9, 10,  1,  2,  8,  5, 11, 12,  4, 15,
	   13,  8, 11,  5,  6, 15,  0,  3,  4,  7,  2, 12,  1, 10, 14,  9,
	   10,  6,  9,  0, 12, 11,  7, 13, 15,  1,  3, 14,  5,  2,  8,  4,
		3, 15,  0,  6, 10,  1, 13,  8,  9,  4,  5, 11, 12,  7,  2, 14,

	   /* S5 */
		2, 12,  4,  1,  7, 10, 11,  6,  8,  5,  3, 15, 13,  0, 14,  9,
	   14, 11,  2, 12,  4,  7, 13,  1,  5,  0, 15, 10,  3,  9,  8,  6,
		4,  2,  1, 11, 10, 13,  7,  8, 15,  9, 12,  5,  6,  3,  0, 14,
	   11,  8, 12,  7,  1, 14,  2, 13,  6, 15,  0,  9, 10,  4,  5,  3,

	   /* S6 */
	   12,  1, 10, 15,  9,  2,  6,  8,  0, 13,  3,  4, 14,  7,  5, 11,
	   10, 15,  4,  2,  7, 12,  9,  5,  6,  1, 13, 14,  0, 11,  3,  8,
		9, 14, 15,  5,  2,  8, 12,  3,  7,  0,  4, 10,  1, 13, 11,  6,
		4,  3,  2, 12,  9,  5, 15, 10, 11, 14,  1,  7,  6,  0,  8, 13,

	   /* S7 */
		4, 11,  2, 14, 15,  0,  8, 13,  3, 12,  9,  7,  5, 10,  6,  1,
	   13,  0, 11,  7,  4,  9,  1, 10, 14,  3,  5, 12,  2, 15,  8,  6,
		1,  4, 11, 13, 12,  3,  7, 14, 10, 15,  6,  8,  0,  5,  9,  2,
		6, 11, 13,  8,  1,  4, 10,  7,  9,  5,  0, 15, 14,  2,  3, 12,

	   /* S8 */
	   13,  2,  8,  4,  6, 15, 11,  1, 10,  9,  3, 14,  5,  0, 12,  7,
		1, 15, 13,  8, 10,  3,  7,  4, 12,  5,  6, 11,  0, 14,  9,  2,
		7, 11,  4,  1,  9, 12, 14,  2,  0,  6, 10, 13, 15,  3,  5,  8,
		2,  1, 14,  7,  4, 10,  8, 13, 15, 12,  9,  0,  3,  5,  6, 11
};

/* 32-bit permutation function P used on the output of the S-boxes */
static byte p32i[] = {
	   16,  7, 20, 21,
	   29, 12, 28, 17,
		1, 15, 23, 26,
		5, 18, 31, 10,
		2,  8, 24, 14,
	   32, 27,  3,  9,
	   19, 13, 30,  6,
	   22, 11,  4, 25
};
#endif

/* permuted choice table (key) */
static const byte pc1[] = {
	   57, 49, 41, 33, 25, 17,  9,
		1, 58, 50, 42, 34, 26, 18,
	   10,  2, 59, 51, 43, 35, 27,
	   19, 11,  3, 60, 52, 44, 36,

	   63, 55, 47, 39, 31, 23, 15,
		7, 62, 54, 46, 38, 30, 22,
	   14,  6, 61, 53, 45, 37, 29,
	   21, 13,  5, 28, 20, 12,  4
};

/* number left rotations of pc1 */
static const byte totrot[] = {
	   1,2,4,6,8,10,12,14,15,17,19,21,23,25,27,28
};

/* permuted choice key (table) */
static const byte pc2[] = {
	   14, 17, 11, 24,  1,  5,
		3, 28, 15,  6, 21, 10,
	   23, 19, 12,  4, 26,  8,
	   16,  7, 27, 20, 13,  2,
	   41, 52, 31, 37, 47, 55,
	   30, 40, 51, 45, 33, 48,
	   44, 49, 39, 56, 34, 53,
	   46, 42, 50, 36, 29, 32
};

/* End of DES-defined tables */

/* bit 0 is left-most in byte */
static const int bytebit[] = {
	   0200,0100,040,020,010,04,02,01
};

/* Set key (initialize key schedule array) */
void RawDES::RawSetKey(CipherDir dir, const byte *key)
{
#if (_MSC_VER >= 1600) || (__cplusplus >= 201103L)
# define register /* Define to nothing for C++11 and above */
#endif

	SecByteBlock buffer(56+56+8);
	byte *const pc1m=buffer;                 /* place to modify pc1 into */
	byte *const pcr=pc1m+56;                 /* place to rotate pc1 into */
	byte *const ks=pcr+56;
	register int i,j,l;
	int m;

	for (j=0; j<56; j++) {          /* convert pc1 to bits of key */
		l=pc1[j]-1;             /* integer bit location  */
		m = l & 07;             /* find bit              */
		pc1m[j]=(key[l>>3] &    /* find which key byte l is in */
			bytebit[m])     /* and which bit of that byte */
			? 1 : 0;        /* and store 1-bit result */
	}
	for (i=0; i<16; i++) {          /* key chunk for each iteration */
		memset(ks,0,8);         /* Clear key schedule */
		for (j=0; j<56; j++)    /* rotate pc1 the right amount */
			pcr[j] = pc1m[(l=j+totrot[i])<(j<28? 28 : 56) ? l: l-28];
		/* rotate left and right halves independently */
		for (j=0; j<48; j++){   /* select bits individually */
			/* check bit that goes to ks[j] */
			if (pcr[pc2[j]-1]){
				/* mask it in if it's there */
				l= j % 6;
				ks[j/6] |= bytebit[l] >> 2;
			}
		}
		/* Now convert to odd/even interleaved form for use in F */
		k[2*i] = ((word32)ks[0] << 24)
			| ((word32)ks[2] << 16)
			| ((word32)ks[4] << 8)
			| ((word32)ks[6]);
		k[2*i+1] = ((word32)ks[1] << 24)
			| ((word32)ks[3] << 16)
			| ((word32)ks[5] << 8)
			| ((word32)ks[7]);
	}

	if (dir==DECRYPTION)     // reverse key schedule order
		for (i=0; i<16; i+=2)
		{
			std::swap(k[i], k[32-2-i]);
			std::swap(k[i+1], k[32-1-i]);
		}
}

void RawDES::RawProcessBlock(word32 &l_, word32 &r_) const
{
	word32 l = l_, r = r_;
	const word32 *kptr=k;

	for (unsigned i=0; i<8; i++)
	{
		word32 work = rotrFixed(r, 4U) ^ kptr[4*i+0];
		l ^= Spbox[6][(work) & 0x3f]
		  ^  Spbox[4][(work >> 8) & 0x3f]
		  ^  Spbox[2][(work >> 16) & 0x3f]
		  ^  Spbox[0][(work >> 24) & 0x3f];
		work = r ^ kptr[4*i+1];
		l ^= Spbox[7][(work) & 0x3f]
		  ^  Spbox[5][(work >> 8) & 0x3f]
		  ^  Spbox[3][(work >> 16) & 0x3f]
		  ^  Spbox[1][(work >> 24) & 0x3f];

		work = rotrFixed(l, 4U) ^ kptr[4*i+2];
		r ^= Spbox[6][(work) & 0x3f]
		  ^  Spbox[4][(work >> 8) & 0x3f]
		  ^  Spbox[2][(work >> 16) & 0x3f]
		  ^  Spbox[0][(work >> 24) & 0x3f];
		work = l ^ kptr[4*i+3];
		r ^= Spbox[7][(work) & 0x3f]
		  ^  Spbox[5][(work >> 8) & 0x3f]
		  ^  Spbox[3][(work >> 16) & 0x3f]
		  ^  Spbox[1][(work >> 24) & 0x3f];
	}

	l_ = l; r_ = r;
}

void DES_EDE2::Base::UncheckedSetKey(const byte *userKey, unsigned int length, const NameValuePairs &)
{
	AssertValidKeyLength(length);

	m_des1.RawSetKey(GetCipherDirection(), userKey);
	m_des2.RawSetKey(ReverseCipherDir(GetCipherDirection()), userKey+8);
}

void DES_EDE2::Base::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
{
	word32 l,r;
	Block::Get(inBlock)(l)(r);
	IPERM(l,r);
	m_des1.RawProcessBlock(l, r);
	m_des2.RawProcessBlock(r, l);
	m_des1.RawProcessBlock(l, r);
	FPERM(l,r);
	Block::Put(xorBlock, outBlock)(r)(l);
}

void DES_EDE3::Base::UncheckedSetKey(const byte *userKey, unsigned int length, const NameValuePairs &)
{
	AssertValidKeyLength(length);

	m_des1.RawSetKey(GetCipherDirection(), userKey + (IsForwardTransformation() ? 0 : 16));
	m_des2.RawSetKey(ReverseCipherDir(GetCipherDirection()), userKey + 8);
	m_des3.RawSetKey(GetCipherDirection(), userKey + (IsForwardTransformation() ? 16 : 0));
}

void DES_EDE3::Base::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
{
	word32 l,r;
	Block::Get(inBlock)(l)(r);
	IPERM(l,r);
	m_des1.RawProcessBlock(l, r);
	m_des2.RawProcessBlock(r, l);
	m_des3.RawProcessBlock(l, r);
	FPERM(l,r);
	Block::Put(xorBlock, outBlock)(r)(l);
}

#endif	// #ifndef CRYPTOPP_IMPORTS

static inline bool CheckParity(byte b)
{
	unsigned int a = b ^ (b >> 4);
	return ((a ^ (a>>1) ^ (a>>2) ^ (a>>3)) & 1) == 1;
}

bool DES::CheckKeyParityBits(const byte *key)
{
	for (unsigned int i=0; i<8; i++)
		if (!CheckParity(key[i]))
			return false;
	return true;
}

void DES::CorrectKeyParityBits(byte *key)
{
	for (unsigned int i=0; i<8; i++)
		if (!CheckParity(key[i]))
			key[i] ^= 1;
}

// Encrypt or decrypt a block of data in ECB mode
void DES::Base::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
{
	word32 l,r;
	Block::Get(inBlock)(l)(r);
	IPERM(l,r);
	RawProcessBlock(l, r);
	FPERM(l,r);
	Block::Put(xorBlock, outBlock)(r)(l);
}

void DES_XEX3::Base::UncheckedSetKey(const byte *key, unsigned int length, const NameValuePairs &)
{
	AssertValidKeyLength(length);

	if (!m_des.get())
		m_des.reset(new DES::Encryption);

	memcpy(m_x1, key + (IsForwardTransformation() ? 0 : 16), BLOCKSIZE);
	m_des->RawSetKey(GetCipherDirection(), key + 8);
	memcpy(m_x3, key + (IsForwardTransformation() ? 16 : 0), BLOCKSIZE);
}

void DES_XEX3::Base::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
{
	xorbuf(outBlock, inBlock, m_x1, BLOCKSIZE);
	m_des->ProcessAndXorBlock(outBlock, xorBlock, outBlock);
	xorbuf(outBlock, m_x3, BLOCKSIZE);
}

NAMESPACE_END