File: bytestring.c

package info (click to toggle)
cardpeek 0.8.4-1.1
  • links: PTS
  • area: main
  • in suites: bookworm, bullseye
  • size: 3,496 kB
  • sloc: ansic: 11,114; sh: 4,266; makefile: 82; xml: 58; objc: 38
file content (837 lines) | stat: -rw-r--r-- 17,202 bytes parent folder | download | duplicates (4)
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
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
/********************************************************************** 
*
* This file is part of Cardpeek, the smart card reader utility.
*
* Copyright 2009-2013 by Alain Pannetrat <L1L1@gmx.com>
*
* Cardpeek is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Cardpeek is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Cardpeek.  If not, see <http://www.gnu.org/licenses/>.
*
*/

/* #include "misc.h" */
#include "bytestring.h"
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#ifndef _WIN32
#include <ctype.h>
#endif
#include "misc.h"
#include "a_string.h"

int bytestring_init(bytestring_t *bs, unsigned element_width)
{
  unsigned char mask;

  if (bs==NULL)
    return BYTESTRING_ERROR;

  switch (element_width) {
    case 1: mask=1; break;
    case 4: mask=0x0F; break;
    case 8: mask=0xFF; break;
    default: return BYTESTRING_ERROR;
  }

  bs->len=0;
  bs->alloc=0;
  bs->data=NULL;
  bs->width=element_width;
  bs->mask=mask;
  return BYTESTRING_OK;
}

bytestring_t* bytestring_new(unsigned element_width)
{
  bytestring_t *res=(bytestring_t*)malloc(sizeof(bytestring_t));

  if (bytestring_init(res,element_width)!=BYTESTRING_OK)
  {
    if (res) free(res);
    return NULL;
  }
  return res;
}

static unsigned hex_nibble(const char nibble)
{
  if (nibble<='9' && nibble>='0')
    return nibble-'0';
  if (nibble<='F' && nibble>='A')
    return nibble-'A'+10;
  if (nibble<='f' && nibble>='a')
    return nibble-'a'+10;
  return BYTESTRING_NPOS;
}

bytestring_t* bytestring_new_from_string(const char *str)
{
  unsigned width;
  bytestring_t *dat;
  
  if (str==NULL)
    return NULL;

  switch (*str) {
    case '8': width=8; break;
    case '4': width=4; break;
    case '1': width=1; break;
    default: return NULL;
  }
  str++;

  if (*str!=':')
    return NULL;
  
  dat=bytestring_new(width);
  bytestring_assign_digit_string(dat,++str);	  
  return dat;
}


bytestring_t* bytestring_duplicate(const bytestring_t *bs)
{
  bytestring_t* res=bytestring_new(bs->width);
  bytestring_assign_data(res,bs->len,bs->data);
  return res;
}

int bytestring_assign_data(bytestring_t* bs,
                        unsigned len, const unsigned char *data)
{
  unsigned i;
  bytestring_resize(bs,len);
  for (i=0;i<len;i++)
    bs->data[i]=data[i]&bs->mask;
  return BYTESTRING_OK;
}

int bytestring_assign_element(bytestring_t* bs,
			      unsigned len, unsigned char c)
{
  bytestring_resize(bs,len);
  memset(bs->data,c&bs->mask,len);
  return BYTESTRING_OK;
}

int bytestring_assign_digit_string(bytestring_t* bs,
				   const char *str)
{
  unsigned str_len;
  unsigned value;
  unsigned state;
  unsigned i;
  unsigned c;

  if (str==NULL)
    return BYTESTRING_ERROR;

  str_len = strlen(str);

  bytestring_clear(bs);
  if (bs->width==8)
  {
    state=0;
    value=0;
    for (i=0;i<str_len;i++)
    {
      c=hex_nibble(str[i]);
      if (c==BYTESTRING_NPOS)
	continue;
      value=(value<<4)|c;
      state++;
      if (state==2)
      {	
  	bytestring_pushback(bs,(unsigned char)value);
	state=0;
	value=0;
      }
    }
    if (state==1)
      bytestring_pushback(bs,(unsigned char)(value<<4));
  }
  else
  {
    for (i=0;i<str_len;i++)
    {
      value=hex_nibble(str[i]);
      if (value==BYTESTRING_NPOS)
	continue;
      bytestring_pushback(bs,(unsigned char)value);
    }
  }
  return BYTESTRING_OK;
}

int bytestring_copy(bytestring_t *bs,
                    const bytestring_t *src)
{
  if (bs!=src)
  {
    bs->width=src->width;
    bs->mask=src->mask;
    return bytestring_assign_data(bs,src->len,src->data);
  }
  return BYTESTRING_OK;
}

static int bs_convert_8_to_4(bytestring_t *bs,
		      const bytestring_t *src)
{
  unsigned u;
  bytestring_resize(bs,src->len*2);
  for (u=0;u<src->len;u++)
  {
    bs->data[u*2]=src->data[u]>>4;
    bs->data[u*2+1]=src->data[u]&0xF;
  }
  return BYTESTRING_OK;
}

static int bs_convert_8_to_1(bytestring_t *bs,
		      const bytestring_t *src)
{
  unsigned u;
  unsigned char c;

  bytestring_resize(bs,src->len*8);
  for (u=0;u<src->len;u++)
  {
    c=src->data[u];
    bs->data[u*8]=((c&128)>>7)&0x1;
    bs->data[u*8+1]=((c&64)>>6)&0x1;
    bs->data[u*8+2]=((c&32)>>5)&0x1;
    bs->data[u*8+3]=((c&16)>>4)&0x1;
    bs->data[u*8+4]=((c&8)>>3)&0x1;
    bs->data[u*8+5]=((c&4)>>2)&0x1;
    bs->data[u*8+6]=((c&2)>>1)&0x1;
    bs->data[u*8+7]=c&0x1;
  }
  return BYTESTRING_OK;
}

static int bs_convert_4_to_1(bytestring_t *bs,
		      const bytestring_t *src)
{
  unsigned u;
  unsigned char c;

  bytestring_resize(bs,src->len*4);
  for (u=0;u<src->len;u++)
  {
    c=src->data[u];
    bs->data[u*4]=((c&8)>>3)&0x1;
    bs->data[u*4+1]=((c&4)>>2)&0x1;
    bs->data[u*4+2]=((c&2)>>1)&0x1;
    bs->data[u*4+3]=c&0x1;
  }
  return BYTESTRING_OK;
}

static int bs_convert_4_to_8(bytestring_t *bs,
		      const bytestring_t *src)
{
  unsigned des_i;
  unsigned src_i;
  bytestring_resize(bs,(src->len+1)/2);

  if ((src->len&1)==1)
  {
    bs->data[0]=src->data[0];
    des_i=1;
    src_i=1;
  }
  else
  {
    des_i=0;
    src_i=0;
  }

  while (src_i<src->len)
  {
    bs->data[des_i]=src->data[src_i]<<4;
    bs->data[des_i]+=src->data[src_i+1];
    des_i+=1;
    src_i+=2;
  }
  return BYTESTRING_OK;
}

static int bs_convert_1_to_8(bytestring_t *bs,
		      const bytestring_t *src)
{
  unsigned src_i;
  unsigned dst_i;
  bytestring_resize(bs,(src->len+7)/8);

  if ((src->len&7)!=0)
  {
    bs->data[0]=0;
    for (src_i=0;src_i<(src->len&7);src_i++)
    {
      bs->data[0]<<=1;
      bs->data[0]|=src->data[src_i];
    }
    dst_i=1;
  }
  else
  {
    src_i=0;
    dst_i=0;
  }

  while (src_i<src->len)
  {
    bs->data[dst_i] =src->data[src_i++]<<7;
    bs->data[dst_i]|=src->data[src_i++]<<6;
    bs->data[dst_i]|=src->data[src_i++]<<5;
    bs->data[dst_i]|=src->data[src_i++]<<4;
    bs->data[dst_i]|=src->data[src_i++]<<3;
    bs->data[dst_i]|=src->data[src_i++]<<2;
    bs->data[dst_i]|=src->data[src_i++]<<1;
    bs->data[dst_i]|=src->data[src_i++];
    dst_i++;
  }
  return BYTESTRING_OK;
}

static int bs_convert_1_to_4(bytestring_t *bs,
		      const bytestring_t *src)
{
  unsigned src_i;
  unsigned dst_i;
  bytestring_resize(bs,(src->len+3)/4);

  if ((src->len&3)!=0)
  {
    bs->data[0]=0;
    for (src_i=0;src_i<(src->len&3);src_i++)
    {
      bs->data[0]<<=1;
      bs->data[0]|=src->data[src_i];
    }
    dst_i=1;
  }
  else
  {
    src_i=0;
    dst_i=0;
  }

  while (src_i<src->len)
  {
    bs->data[dst_i] =src->data[src_i++]<<3;
    bs->data[dst_i]|=src->data[src_i++]<<2;
    bs->data[dst_i]|=src->data[src_i++]<<1;
    bs->data[dst_i]|=src->data[src_i++];
    dst_i++;
  }
  return BYTESTRING_OK;
}

int bytestring_convert(bytestring_t *bs,
		       const bytestring_t *src)
{
  unsigned algo;
  bytestring_t* tmp;
  int retval;

  if (bs==src)
  {
    tmp=bytestring_duplicate(src);
    retval=bytestring_convert(bs,tmp);
    bytestring_free(tmp);
    return retval;
  }

  algo=src->width*10+bs->width;

  switch (algo) {
    case 11:
    case 44:
    case 88:
      return bytestring_copy(bs,src);
    case 14:
      return bs_convert_1_to_4(bs,src);
    case 18:
      return bs_convert_1_to_8(bs,src);
    case 41:
      return bs_convert_4_to_1(bs,src);
    case 48:
      return bs_convert_4_to_8(bs,src);
    case 81:
      return bs_convert_8_to_1(bs,src);
    case 84:
      return bs_convert_8_to_4(bs,src);
  }
  return BYTESTRING_ERROR;
}


int bytestring_append(bytestring_t *bs,
                      const bytestring_t *extra)
{
  bytestring_t* tmp;
  int retval;

  if (bs==extra)
  {
    tmp=bytestring_duplicate(extra);
    retval=bytestring_append(bs,tmp);
    bytestring_free(tmp);
    return retval;
  }
  return bytestring_append_data(bs,extra->len,extra->data);
}

int bytestring_append_data(bytestring_t *bs,
                           unsigned len, const unsigned char *data)
{
  unsigned i;
  unsigned old_len=bs->len;

  bytestring_resize(bs,bs->len+len);
  for (i=0;i<len;i++)
    bs->data[old_len+i]=data[i]&bs->mask;
  return BYTESTRING_OK;
}

int bytestring_append_element(bytestring_t* bs,
			      unsigned len, unsigned char c)
{
  unsigned i;
  unsigned old_len=bs->len;

  bytestring_resize(bs,bs->len+len);
  for (i=0;i<len;i++)
    bs->data[old_len+i]=c&bs->mask;
  return BYTESTRING_OK;
}

int bytestring_pushback(bytestring_t *bs,
                        unsigned char c)
{
  unsigned old_len=bs->len;

  bytestring_resize(bs,bs->len+1);
  bs->data[old_len]=c&bs->mask;
  return BYTESTRING_OK;
}

int bytestring_get_element(unsigned char* element,
			   const bytestring_t *bs,
			   int pos)
{
  if (pos<0)
    pos=(int)bs->len+pos;
  if (pos<(int)bs->len && pos>=0)
  {
    *element=bs->data[pos];
    return BYTESTRING_OK;
  }
  *element=0;
  return BYTESTRING_ERROR;
}

int bytestring_set_element(const bytestring_t *bs,
			   int pos, unsigned char element)
{
  if (pos<0)
    pos=(int)bs->len+pos;
  if (pos<(int)bs->len && pos>=0)
  {
    bs->data[pos]=element&bs->mask;
    return BYTESTRING_OK;
  }
  return BYTESTRING_ERROR;
}

int bytestring_invert(bytestring_t *bs)
{
  unsigned last=bs->len-1;
  unsigned c;
  unsigned char extra;

  for (c=0;c<bs->len/2;c++)
  {
    extra=bs->data[last-c];
    bs->data[last-c]=bs->data[c];
    bs->data[c]=extra;
  }
  return BYTESTRING_OK;
}

void bytestring_clear(bytestring_t *bs)
{
  bs->len=0;
}

const unsigned char *bytestring_get_data(const bytestring_t *bs)
{
  return bs->data;
}

int bytestring_erase(bytestring_t *bs,
                     unsigned pos,
                     unsigned len)
{
  if (pos>=bs->len)
    return BYTESTRING_OK;
  if (pos+len>=bs->len) 
    return bytestring_resize(bs,pos);
  memmove(bs->data+pos,bs->data+pos+len,bs->len-pos-len);
  bytestring_resize(bs,bs->len-len);
  return BYTESTRING_OK;
}

int bytestring_is_equal(const bytestring_t *a, const bytestring_t *b)
{
  unsigned u;
  if (a->width!=b->width)
    return 0;
  if (a->len!=b->len)
    return 0;
  for (u=0;u<a->len;u++)
    if (a->data[u]!=b->data[u]) return 0;
  return 1;
}

int bytestring_is_empty(const bytestring_t *bs)
{
  return bs->len==0;
}

int bytestring_is_printable(const bytestring_t *bs)
{
  unsigned u;

  if (bs->len==0)
    return 0;
  for (u=0;u<bs->len;u++)
  {
    if (bs->data[u]>127 || !isprint((char)(bs->data[u]))) return 0;
  }
  return 1;
}

int bytestring_insert_data(bytestring_t *bs,
                           unsigned pos,
                           unsigned len, const unsigned char* data)
{
  unsigned u;

  if (pos>=bs->len)
    return bytestring_append_data(bs,len,data);
  bytestring_resize(bs,bs->len+len);
  memmove(bs->data+pos+len,bs->data+pos,bs->len-pos);
  for (u=0;u<len;u++)
    bs->data[pos+u]=data[u]&bs->mask;
  return BYTESTRING_OK;
}

int bytestring_insert_element(bytestring_t *bs,
			      unsigned pos,
			      unsigned len, unsigned char c)
{
  unsigned u;

  if (pos>=bs->len)
    return bytestring_append_element(bs,len,c);
  bytestring_resize(bs,bs->len+len);
  memmove(bs->data+pos+len,bs->data+pos,bs->len-len-pos);
  for (u=0;u<len;u++)
    bs->data[pos+u]=c&bs->mask;
  return BYTESTRING_OK;
}

int bytestring_insert(bytestring_t *bs,
                      unsigned pos,
                      const bytestring_t *src)
{
  bytestring_t* tmp;
  int retval;

  if (bs==src)
  {
    tmp=bytestring_duplicate(src);
    retval=bytestring_insert(bs,pos,tmp);
    bytestring_free(tmp);
    return retval;
  }

  return bytestring_insert_data(bs,pos,src->len,src->data);
}

int bytestring_pad_left(bytestring_t *bs,
                        unsigned block_size, unsigned char c)
{
  unsigned pad = block_size-(bs->len%block_size);

  if (pad==block_size)
    return BYTESTRING_OK;
  return bytestring_insert_element(bs,0,pad,c);
}

int bytestring_pad_right(bytestring_t *bs,
                         unsigned block_size, unsigned char c)
{
  unsigned pad = block_size-(bs->len%block_size);

  if (pad==block_size)
    return BYTESTRING_OK;
  return bytestring_append_element(bs,pad,c);
}


int bytestring_resize(bytestring_t *bs, unsigned len)
{
  if (len>bs->len)
  {
    if (len>bs->alloc)
    {
      if (bs->alloc==0)
      {
	bs->alloc=(len<8?8:len);
	bs->data=(unsigned char *)malloc(bs->alloc);
      }
      else
      {
	while (bs->alloc<len) bs->alloc<<=1;
	bs->data=(unsigned char *)realloc(bs->data,bs->alloc);
	if (bs->data==NULL)
	{
	  bs->alloc=0;
	  return BYTESTRING_ERROR;
	}
      }
    }
  }
  bs->len=len;
  return BYTESTRING_OK;
}

unsigned bytestring_get_size(const bytestring_t *bs)
{
  return bs->len;
}

int bytestring_substr(bytestring_t* dst,
		      unsigned pos, unsigned len,
		      const bytestring_t *src)
{
  bytestring_t* tmp;
  int retval;

  if (dst==src)
  {
    tmp=bytestring_duplicate(src);
    retval=bytestring_substr(dst,pos,len,tmp);
    bytestring_free(tmp);
    return retval;
  }

  if (pos>src->len)
  {
    bytestring_clear(dst);
    return BYTESTRING_ERROR;
  }
  if (len==BYTESTRING_NPOS || len>src->len || pos+len>src->len)
    len = src->len-pos;
  return bytestring_assign_data(dst,len,src->data+pos);
}

static void x_bytestring_append_as_printable(a_string_t* dest, const bytestring_t *bs)
{
  unsigned u;
  char octal_form[5];

  for (u=0;u<bs->len;u++)
  {
    if (bs->data[u]>127 || !isprint((char)(bs->data[u])))
    {
      sprintf(octal_form,"\\%03o",bs->data[u]);
      a_strcat(dest,octal_form);
    }
    else
      a_strpushback(dest,(char)(bs->data[u]));
  }
}

const char HEXA[]="0123456789ABCDEF";

static void x_bytestring_append_as_digits(a_string_t* dest, const bytestring_t *bs)
{
  unsigned i;

  if (bs->width==8)
  {
    for (i=0;i<bs->len;i++)
    {
      a_strpushback(dest,HEXA[(bs->data[i]>>4)&0xF]);
      a_strpushback(dest,HEXA[bs->data[i]&0xF]);
    }
  }
  else
  {
    for (i=0;i<bs->len;i++)
      a_strpushback(dest,HEXA[bs->data[i]&0xF]);
  }
}

static int x_bytestring_set(bytestring_t *bs, unsigned bs_index, unsigned char v)
{
  if (bs_index>=bs->len) 
    bytestring_resize(bs,bs_index+1);
  bs->data[bs_index]=v;
  
  return BYTESTRING_OK;
}
static unsigned x_bytestring_get(bytestring_t *bs, unsigned bs_index)
{
  if (bs_index>=bs->len)
    return 0;
  return (unsigned)bs->data[bs_index];
}

static int x_bytestring_decimal_mul_add(bytestring_t *bs, unsigned mul_v, unsigned add_v)
{
  unsigned r;
  int bs_index;
  int i;

  for (bs_index=bs->len-1;bs_index>=0;bs_index--)
  {
    r=((unsigned)bs->data[bs_index])*mul_v;
    x_bytestring_set(bs,bs_index,r%10);
    r/=10;
    i=1;
    while (r)
    {
      r+=x_bytestring_get(bs,bs_index+i);
      if (x_bytestring_set(bs,bs_index+i,r%10)!=BYTESTRING_OK)
	return BYTESTRING_ERROR;
      r/=10;
      i++;
    }
  }
  r=x_bytestring_get(bs,0)+add_v;
  x_bytestring_set(bs,0,r%10);
  r/=10;
  i=1;
  while (r)
  {
    r+=x_bytestring_get(bs,i);
    if (x_bytestring_set(bs,i,r%10)!=BYTESTRING_OK)
      return BYTESTRING_ERROR;
    r/=10;
    i++;
  }
  return BYTESTRING_OK;
}

static void x_bytestring_append_as_integer(a_string_t *dest, const bytestring_t *bs)
{
  bytestring_t *b10;
  unsigned i;

  if (bs->len==0)
    return;
  
  b10 = bytestring_new(8);
  bytestring_pushback(b10,0);

  for (i=0;i<bs->len;i++)
    x_bytestring_decimal_mul_add(b10,1<<(bs->width),bs->data[i]);
  
  for (i=0;i<b10->len;i++)
    a_strpushback(dest,b10->data[b10->len-1-i]+'0');

  bytestring_free(b10);
}

char *bytestring_to_format(const char *format, const bytestring_t *bs)
{
  char tmp[10];
  a_string_t *s=a_strnew(NULL);

  while (*format)
  {
    if (*format!='%')
      a_strpushback(s,*format);
    else
    {
      format++;
      switch (*format) {
	case '%': a_strpushback(s,'%'); 
		  break;
	case 'I': x_bytestring_append_as_integer(s,bs);
		  break;
	case 'D': x_bytestring_append_as_digits(s,bs);
		  break;
	case 'S': a_strpushback(s,'0'+bs->width);
		  a_strpushback(s,':');
		  x_bytestring_append_as_digits(s,bs);
		  break;
	case 'w': a_strpushback(s,'0'+bs->width);
		  break;
	case 'P': x_bytestring_append_as_printable(s,bs);
		  break;
	case 'C': a_strncat(s,bs->len,(char *)bs->data);
		  break;
	case 'l': sprintf(tmp,"%i",bs->len);
		  a_strcat(s,tmp);
		  break;
	case 0:	  goto end_this_function;
	default:  log_printf(LOG_WARNING,"bytestring_to_format() does not recognize %%%c as a format identifier",*format);
      }
    }
    format++;
  } 

end_this_function:
  return a_strfinalize(s);
}


double bytestring_to_number(const bytestring_t *bs)
{
  unsigned i;
  unsigned coef = 0;
  double res = 0;

  if (bs->len==0)
    return 0;

  coef = 1<<(bs->width);

  for (i=0;i<bs->len;i++)
	res = (res*coef)+bs->data[i];

  return res;
}

void bytestring_release(bytestring_t *bs)
{
  if (bs->data)
    free(bs->data); 
  bs->data=NULL;
}

void bytestring_free(bytestring_t *bs)
{
  bytestring_release(bs);
  free(bs);
}