summaryrefslogtreecommitdiffstats
path: root/package/network/services/ead/src/tinysrp/bn_lib.c
blob: cfa0d756651a9973f149e3875eac95665bb7b841 (plain)
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
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
/* crypto/bn/bn_lib.c */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young (eay@cryptsoft.com).
 * The implementation was written so as to conform with Netscapes SSL.
 *
 * This library is free for commercial and non-commercial use as long as
 * the following conditions are aheared to.  The following conditions
 * apply to all code found in this distribution, be it the RC4, RSA,
 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
 * included with this distribution is covered by the same copyright terms
 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
 *
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * If this package is used in a product, Eric Young should be given attribution
 * as the author of the parts of the library used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    "This product includes cryptographic software written by
 *     Eric Young (eay@cryptsoft.com)"
 *    The word 'cryptographic' can be left out if the rouines from the library
 *    being used are not cryptographic related :-).
 * 4. If you include any Windows specific code (or a derivative thereof) from
 *    the apps directory (application code) you must include an acknowledgement:
 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
 *
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.]
 */

#ifndef BN_DEBUG
# undef NDEBUG /* avoid conflicting definitions */
# define NDEBUG
#endif

#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "bn_lcl.h"

const char *BN_version="Big Number";

/* For a 32 bit machine
 * 2 -   4 ==  128
 * 3 -   8 ==  256
 * 4 -  16 ==  512
 * 5 -  32 == 1024
 * 6 -  64 == 2048
 * 7 - 128 == 4096
 * 8 - 256 == 8192
 */
static int bn_limit_bits=0;
static int bn_limit_num=8;        /* (1<<bn_limit_bits) */
static int bn_limit_bits_low=0;
static int bn_limit_num_low=8;    /* (1<<bn_limit_bits_low) */
static int bn_limit_bits_high=0;
static int bn_limit_num_high=8;   /* (1<<bn_limit_bits_high) */
static int bn_limit_bits_mont=0;
static int bn_limit_num_mont=8;   /* (1<<bn_limit_bits_mont) */

int BN_num_bits_word(BN_ULONG l)
	{
	static const char bits[256]={
		0,1,2,2,3,3,3,3,4,4,4,4,4,4,4,4,
		5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
		6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
		6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
		7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
		7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
		7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
		7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
		8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
		8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
		8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
		8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
		8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
		8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
		8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
		8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
		};

#if defined(SIXTY_FOUR_BIT_LONG)
	if (l & 0xffffffff00000000L)
		{
		if (l & 0xffff000000000000L)
			{
			if (l & 0xff00000000000000L)
				{
				return(bits[(int)(l>>56)]+56);
				}
			else    return(bits[(int)(l>>48)]+48);
			}
		else
			{
			if (l & 0x0000ff0000000000L)
				{
				return(bits[(int)(l>>40)]+40);
				}
			else    return(bits[(int)(l>>32)]+32);
			}
		}
	else
#else
#ifdef SIXTY_FOUR_BIT
	if (l & 0xffffffff00000000LL)
		{
		if (l & 0xffff000000000000LL)
			{
			if (l & 0xff00000000000000LL)
				{
				return(bits[(int)(l>>56)]+56);
				}
			else    return(bits[(int)(l>>48)]+48);
			}
		else
			{
			if (l & 0x0000ff0000000000LL)
				{
				return(bits[(int)(l>>40)]+40);
				}
			else    return(bits[(int)(l>>32)]+32);
			}
		}
	else
#endif
#endif
		{
#if defined(THIRTY_TWO_BIT) || defined(SIXTY_FOUR_BIT) || defined(SIXTY_FOUR_BIT_LONG)
		if (l & 0xffff0000L)
			{
			if (l & 0xff000000L)
				return(bits[(int)(l>>24L)]+24);
			else    return(bits[(int)(l>>16L)]+16);
			}
		else
#endif
			{
#if defined(SIXTEEN_BIT) || defined(THIRTY_TWO_BIT) || defined(SIXTY_FOUR_BIT) || defined(SIXTY_FOUR_BIT_LONG)
			if (l & 0xff00L)
				return(bits[(int)(l>>8)]+8);
			else
#endif
				return(bits[(int)(l   )]  );
			}
		}
	}

int BN_num_bits(const BIGNUM *a)
	{
	BN_ULONG l;
	int i;

	bn_check_top(a);

	if (a->top == 0) return(0);
	l=a->d[a->top-1];
	assert(l != 0);
	i=(a->top-1)*BN_BITS2;
	return(i+BN_num_bits_word(l));
	}

void BN_clear_free(BIGNUM *a)
	{
	int i;

	if (a == NULL) return;
	if (a->d != NULL)
		{
		memset(a->d,0,a->dmax*sizeof(a->d[0]));
		if (!(BN_get_flags(a,BN_FLG_STATIC_DATA)))
			free(a->d);
		}
	i=BN_get_flags(a,BN_FLG_MALLOCED);
	memset(a,0,sizeof(BIGNUM));
	if (i)
		free(a);
	}

void BN_free(BIGNUM *a)
	{
	if (a == NULL) return;
	if ((a->d != NULL) && !(BN_get_flags(a,BN_FLG_STATIC_DATA)))
		free(a->d);
	a->flags|=BN_FLG_FREE; /* REMOVE? */
	if (a->flags & BN_FLG_MALLOCED)
		free(a);
	}

void BN_init(BIGNUM *a)
	{
	memset(a,0,sizeof(BIGNUM));
	}

BIGNUM *BN_new(void)
	{
	BIGNUM *ret;

	if ((ret=(BIGNUM *)malloc(sizeof(BIGNUM))) == NULL)
		{
		return(NULL);
		}
	ret->flags=BN_FLG_MALLOCED;
	ret->top=0;
	ret->neg=0;
	ret->dmax=0;
	ret->d=NULL;
	return(ret);
	}

/* This is an internal function that should not be used in applications.
 * It ensures that 'b' has enough room for a 'words' word number number.
 * It is mostly used by the various BIGNUM routines. If there is an error,
 * NULL is returned. If not, 'b' is returned. */

BIGNUM *bn_expand2(BIGNUM *b, int words)
	{
	BN_ULONG *A,*a;
	const BN_ULONG *B;
	int i;

	bn_check_top(b);

	if (words > b->dmax)
		{
		bn_check_top(b);
		if (BN_get_flags(b,BN_FLG_STATIC_DATA))
			{
			return(NULL);
			}
		a=A=(BN_ULONG *)malloc(sizeof(BN_ULONG)*(words+1));
		if (A == NULL)
			{
			return(NULL);
			}
#if 1
		B=b->d;
		/* Check if the previous number needs to be copied */
		if (B != NULL)
			{
#if 0
			/* This lot is an unrolled loop to copy b->top
			 * BN_ULONGs from B to A
			 */
/*
 * I have nothing against unrolling but it's usually done for
 * several reasons, namely:
 * - minimize percentage of decision making code, i.e. branches;
 * - avoid cache trashing;
 * - make it possible to schedule loads earlier;
 * Now let's examine the code below. The cornerstone of C is
 * "programmer is always right" and that's what we love it for:-)
 * For this very reason C compilers have to be paranoid when it
 * comes to data aliasing and assume the worst. Yeah, but what
 * does it mean in real life? This means that loop body below will
 * be compiled to sequence of loads immediately followed by stores
 * as compiler assumes the worst, something in A==B+1 style. As a
 * result CPU pipeline is going to starve for incoming data. Secondly
 * if A and B happen to share same cache line such code is going to
 * cause severe cache trashing. Both factors have severe impact on
 * performance of modern CPUs and this is the reason why this
 * particular piece of code is #ifdefed away and replaced by more
 * "friendly" version found in #else section below. This comment
 * also applies to BN_copy function.
 *
 *                                      <appro@fy.chalmers.se>
 */
			for (i=b->top&(~7); i>0; i-=8)
				{
				A[0]=B[0]; A[1]=B[1]; A[2]=B[2]; A[3]=B[3];
				A[4]=B[4]; A[5]=B[5]; A[6]=B[6]; A[7]=B[7];
				A+=8;
				B+=8;
				}
			switch (b->top&7)
				{
			case 7:
				A[6]=B[6];
			case 6:
				A[5]=B[5];
			case 5:
				A[4]=B[4];
			case 4:
				A[3]=B[3];
			case 3:
				A[2]=B[2];
			case 2:
				A[1]=B[1];
			case 1:
				A[0]=B[0];
			case 0:
				/* I need the 'case 0' entry for utrix cc.
				 * If the optimizer is turned on, it does the
				 * switch table by doing
				 * a=top&7
				 * a--;
				 * goto jump_table[a];
				 * If top is 0, this makes us jump to 0xffffffc
				 * which is rather bad :-(.
				 * eric 23-Apr-1998
				 */
				;
				}
#else
			for (i=b->top>>2; i>0; i--,A+=4,B+=4)
				{
				/*
				 * The fact that the loop is unrolled
				 * 4-wise is a tribute to Intel. It's
				 * the one that doesn't have enough
				 * registers to accomodate more data.
				 * I'd unroll it 8-wise otherwise:-)
				 *
				 *              <appro@fy.chalmers.se>
				 */
				BN_ULONG a0,a1,a2,a3;
				a0=B[0]; a1=B[1]; a2=B[2]; a3=B[3];
				A[0]=a0; A[1]=a1; A[2]=a2; A[3]=a3;
				}
			switch (b->top&3)
				{
				case 3: A[2]=B[2];
				case 2: A[1]=B[1];
				case 1: A[0]=B[0];
				case 0: ; /* ultrix cc workaround, see above */
				}
#endif
			free(b->d);
			}

		b->d=a;
		b->dmax=words;

		/* Now need to zero any data between b->top and b->max */

		A= &(b->d[b->top]);
		for (i=(b->dmax - b->top)>>3; i>0; i--,A+=8)
			{
			A[0]=0; A[1]=0; A[2]=0; A[3]=0;
			A[4]=0; A[5]=0; A[6]=0; A[7]=0;
			}
		for (i=(b->dmax - b->top)&7; i>0; i--,A++)
			A[0]=0;
#else
			memset(A,0,sizeof(BN_ULONG)*(words+1));
			memcpy(A,b->d,sizeof(b->d[0])*b->top);
			b->d=a;
			b->max=words;
#endif

/*              memset(&(p[b->max]),0,((words+1)-b->max)*sizeof(BN_ULONG)); */
/*      { int i; for (i=b->max; i<words+1; i++) p[i]=i;} */

		}
	return(b);
	}

BIGNUM *BN_copy(BIGNUM *a, const BIGNUM *b)
	{
	int i;
	BN_ULONG *A;
	const BN_ULONG *B;

	bn_check_top(b);

	if (a == b) return(a);
	if (bn_wexpand(a,b->top) == NULL) return(NULL);

#if 1
	A=a->d;
	B=b->d;
	for (i=b->top>>2; i>0; i--,A+=4,B+=4)
		{
		BN_ULONG a0,a1,a2,a3;
		a0=B[0]; a1=B[1]; a2=B[2]; a3=B[3];
		A[0]=a0; A[1]=a1; A[2]=a2; A[3]=a3;
		}
	switch (b->top&3)
		{
		case 3: A[2]=B[2];
		case 2: A[1]=B[1];
		case 1: A[0]=B[0];
		case 0: ; /* ultrix cc workaround, see comments in bn_expand2 */
		}
#else
	memcpy(a->d,b->d,sizeof(b->d[0])*b->top);
#endif

/*      memset(&(a->d[b->top]),0,sizeof(a->d[0])*(a->max-b->top));*/
	a->top=b->top;
	if ((a->top == 0) && (a->d != NULL))
		a->d[0]=0;
	a->neg=b->neg;
	return(a);
	}

int BN_set_word(BIGNUM *a, BN_ULONG w)
	{
	int i,n;
	if (bn_expand(a,sizeof(BN_ULONG)*8) == NULL) return(0);

	n=sizeof(BN_ULONG)/BN_BYTES;
	a->neg=0;
	a->top=0;
	a->d[0]=(BN_ULONG)w&BN_MASK2;
	if (a->d[0] != 0) a->top=1;
	for (i=1; i<n; i++)
		{
		/* the following is done instead of
		 * w>>=BN_BITS2 so compilers don't complain
		 * on builds where sizeof(long) == BN_TYPES */
#ifndef SIXTY_FOUR_BIT /* the data item > unsigned long */
		w>>=BN_BITS4;
		w>>=BN_BITS4;
#else
		w=0;
#endif
		a->d[i]=(BN_ULONG)w&BN_MASK2;
		if (a->d[i] != 0) a->top=i+1;
		}
	return(1);
	}

/* ignore negative */
BIGNUM *BN_bin2bn(const unsigned char *s, int len, BIGNUM *ret)
	{
	unsigned int i,m;
	unsigned int n;
	BN_ULONG l;

	if (ret == NULL) ret=BN_new();
	if (ret == NULL) return(NULL);
	l=0;
	n=len;
	if (n == 0)
		{
		ret->top=0;
		return(ret);
		}
	if (bn_expand(ret,(int)(n+2)*8) == NULL)
		return(NULL);
	i=((n-1)/BN_BYTES)+1;
	m=((n-1)%(BN_BYTES));
	ret->top=i;
	while (n-- > 0)
		{
		l=(l<<8L)| *(s++);
		if (m-- == 0)
			{
			ret->d[--i]=l;
			l=0;
			m=BN_BYTES-1;
			}
		}
	/* need to call this due to clear byte at top if avoiding
	 * having the top bit set (-ve number) */
	bn_fix_top(ret);
	return(ret);
	}

/* ignore negative */
int BN_bn2bin(const BIGNUM *a, unsigned char *to)
	{
	int n,i;
	BN_ULONG l;

	n=i=BN_num_bytes(a);
	while (i-- > 0)
		{
		l=a->d[i/BN_BYTES];
		*(to++)=(unsigned char)(l>>(8*(i%BN_BYTES)))&0xff;
		}
	return(n);
	}

int BN_ucmp(const BIGNUM *a, const BIGNUM *b)
	{
	int i;
	BN_ULONG t1,t2,*ap,*bp;

	bn_check_top(a);
	bn_check_top(b);

	i=a->top-b->top;
	if (i != 0) return(i);
	ap=a->d;
	bp=b->d;
	for (i=a->top-1; i>=0; i--)
		{
		t1= ap[i];
		t2= bp[i];
		if (t1 != t2)
			return(t1 > t2?1:-1);
		}
	return(0);
	}

int BN_cmp(const BIGNUM *a, const BIGNUM *b)
	{
	int i;
	int gt,lt;
	BN_ULONG t1,t2;

	if ((a == NULL) || (b == NULL))
		{
		if (a != NULL)
			return(-1);
		else if (b != NULL)
			return(1);
		else
			return(0);
		}

	bn_check_top(a);
	bn_check_top(b);

	if (a->neg != b->neg)
		{
		if (a->neg)
			return(-1);
		else    return(1);
		}
	if (a->neg == 0)
		{ gt=1; lt= -1; }
	else    { gt= -1; lt=1; }

	if (a->top > b->top) return(gt);
	if (a->top < b->top) return(lt);
	for (i=a->top-1; i>=0; i--)
		{
		t1=a->d[i];
		t2=b->d[i];
		if (t1 > t2) return(gt);
		if (t1 < t2) return(lt);
		}
	return(0);
	}

int BN_is_bit_set(const BIGNUM *a, int n)
	{
	int i,j;

	if (n < 0) return(0);
	i=n/BN_BITS2;
	j=n%BN_BITS2;
	if (a->top <= i) return(0);
	return((a->d[i]&(((BN_ULONG)1)<<j))?1:0);
	}