summaryrefslogtreecommitdiffstats
path: root/dbus/dbus-sha.c
blob: 04e353a06d1aa6827c5e160bf043702625710dee (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
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
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
/* dbus-sha.c SHA-1 implementation
 *
 * Copyright (C) 2003 Red Hat Inc.
 * Copyright (C) 1995 A. M. Kuchling
 *
 * Licensed under the Academic Free License version 2.1
 *
 * This program 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 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

#include "dbus-internals.h"
#include "dbus-sha.h"
#include "dbus-marshal-basic.h" /* for byteswap routines */
#include <string.h>

/* The following comments have the history of where this code
 * comes from. I actually copied it from GNet in GNOME CVS.
 * - hp@redhat.com
 */

/*
 *  sha.h : Implementation of the Secure Hash Algorithm
 *
 * Part of the Python Cryptography Toolkit, version 1.0.0
 *
 * Copyright (C) 1995, A.M. Kuchling
 *
 * Distribute and use freely; there are no restrictions on further
 * dissemination and usage except those imposed by the laws of your
 * country of residence.
 *
 */

/* SHA: NIST's Secure Hash Algorithm */

/* Based on SHA code originally posted to sci.crypt by Peter Gutmann
   in message <30ajo5$oe8@ccu2.auckland.ac.nz>.
   Modified to test for endianness on creation of SHA objects by AMK.
   Also, the original specification of SHA was found to have a weakness
   by NSA/NIST.  This code implements the fixed version of SHA.
*/

/* Here's the first paragraph of Peter Gutmann's posting:

The following is my SHA (FIPS 180) code updated to allow use of the "fixed"
SHA, thanks to Jim Gillogly and an anonymous contributor for the information on
what's changed in the new version.  The fix is a simple change which involves
adding a single rotate in the initial expansion function.  It is unknown
whether this is an optimal solution to the problem which was discovered in the
SHA or whether it's simply a bandaid which fixes the problem with a minimum of
effort (for example the reengineering of a great many Capstone chips).
*/

/**
 * @defgroup DBusSHA SHA implementation
 * @ingroup  DBusInternals
 * @brief SHA-1 hash
 *
 * Types and functions related to computing SHA-1 hash.
 */

/**
 * @defgroup DBusSHAInternals SHA implementation details
 * @ingroup  DBusInternals
 * @brief Internals of SHA implementation.
 *
 * The implementation of SHA-1 (see http://www.itl.nist.gov/fipspubs/fip180-1.htm).
 * This SHA implementation was written by A.M. Kuchling
 *
 * @{
 */

#ifndef DOXYGEN_SHOULD_SKIP_THIS

/* The SHA block size and message digest sizes, in bytes */

#define SHA_DATASIZE    64
#define SHA_DIGESTSIZE  20

/* The SHA f()-functions.  The f1 and f3 functions can be optimized to
   save one boolean operation each - thanks to Rich Schroeppel,
   rcs@cs.arizona.edu for discovering this */

/*#define f1(x,y,z) ( ( x & y ) | ( ~x & z ) )          // Rounds  0-19 */
#define f1(x,y,z)  ( z ^ ( x & ( y ^ z ) ) )           /* Rounds  0-19 */
#define f2(x,y,z)  ( x ^ y ^ z )                       /* Rounds 20-39 */
/*#define f3(x,y,z) ( ( x & y ) | ( x & z ) | ( y & z ) )   // Rounds 40-59 */
#define f3(x,y,z)  ( ( x & y ) | ( z & ( x | y ) ) )   /* Rounds 40-59 */
#define f4(x,y,z)  ( x ^ y ^ z )                       /* Rounds 60-79 */

/* The SHA Mysterious Constants */

#define K1  0x5A827999L                                 /* Rounds  0-19 */
#define K2  0x6ED9EBA1L                                 /* Rounds 20-39 */
#define K3  0x8F1BBCDCL                                 /* Rounds 40-59 */
#define K4  0xCA62C1D6L                                 /* Rounds 60-79 */

/* SHA initial values */

#define h0init  0x67452301L
#define h1init  0xEFCDAB89L
#define h2init  0x98BADCFEL
#define h3init  0x10325476L
#define h4init  0xC3D2E1F0L

/* Note that it may be necessary to add parentheses to these macros if they
   are to be called with expressions as arguments */
/* 32-bit rotate left - kludged with shifts */

#define ROTL(n,X) ( ( ( X ) << n ) | ( ( X ) >> ( 32 - n ) ) )

/* The initial expanding function.  The hash function is defined over an
   80-word expanded input array W, where the first 16 are copies of the input
   data, and the remaining 64 are defined by

        W[ i ] = W[ i - 16 ] ^ W[ i - 14 ] ^ W[ i - 8 ] ^ W[ i - 3 ]

   This implementation generates these values on the fly in a circular
   buffer - thanks to Colin Plumb, colin@nyx10.cs.du.edu for this
   optimization.

   The updated SHA changes the expanding function by adding a rotate of 1
   bit.  Thanks to Jim Gillogly, jim@rand.org, and an anonymous contributor
   for this information */

#define expand(W,i) ( W[ i & 15 ] = ROTL( 1, ( W[ i & 15 ] ^ W[ (i - 14) & 15 ] ^ \
                                                 W[ (i - 8) & 15 ] ^ W[ (i - 3) & 15 ] ) ) )


/* The prototype SHA sub-round.  The fundamental sub-round is:

        a' = e + ROTL( 5, a ) + f( b, c, d ) + k + data;
        b' = a;
        c' = ROTL( 30, b );
        d' = c;
        e' = d;

   but this is implemented by unrolling the loop 5 times and renaming the
   variables ( e, a, b, c, d ) = ( a', b', c', d', e' ) each iteration.
   This code is then replicated 20 times for each of the 4 functions, using
   the next 20 values from the W[] array each time */

#define subRound(a, b, c, d, e, f, k, data) \
   ( e += ROTL( 5, a ) + f( b, c, d ) + k + data, b = ROTL( 30, b ) )

#endif /* !DOXYGEN_SHOULD_SKIP_THIS */

/* Perform the SHA transformation.  Note that this code, like MD5, seems to
   break some optimizing compilers due to the complexity of the expressions
   and the size of the basic block.  It may be necessary to split it into
   sections, e.g. based on the four subrounds

   Note that this corrupts the context->data area */

static void
SHATransform(dbus_uint32_t *digest, dbus_uint32_t *data)
{
  dbus_uint32_t A, B, C, D, E;     /* Local vars */
  dbus_uint32_t eData[16];       /* Expanded data */

  /* Set up first buffer and local data buffer */
  A = digest[0];
  B = digest[1];
  C = digest[2];
  D = digest[3];
  E = digest[4];
  memmove (eData, data, SHA_DATASIZE);

  /* Heavy mangling, in 4 sub-rounds of 20 interations each. */
  subRound (A, B, C, D, E, f1, K1, eData[0]);
  subRound (E, A, B, C, D, f1, K1, eData[1]);
  subRound (D, E, A, B, C, f1, K1, eData[2]);
  subRound (C, D, E, A, B, f1, K1, eData[3]);
  subRound (B, C, D, E, A, f1, K1, eData[4]);
  subRound (A, B, C, D, E, f1, K1, eData[5]);
  subRound (E, A, B, C, D, f1, K1, eData[6]);
  subRound (D, E, A, B, C, f1, K1, eData[7]);
  subRound (C, D, E, A, B, f1, K1, eData[8]);
  subRound (B, C, D, E, A, f1, K1, eData[9]);
  subRound (A, B, C, D, E, f1, K1, eData[10]);
  subRound (E, A, B, C, D, f1, K1, eData[11]);
  subRound (D, E, A, B, C, f1, K1, eData[12]);
  subRound (C, D, E, A, B, f1, K1, eData[13]);
  subRound (B, C, D, E, A, f1, K1, eData[14]);
  subRound (A, B, C, D, E, f1, K1, eData[15]);
  subRound (E, A, B, C, D, f1, K1, expand ( eData, 16) );
  subRound (D, E, A, B, C, f1, K1, expand ( eData, 17) );
  subRound (C, D, E, A, B, f1, K1, expand ( eData, 18) );
  subRound (B, C, D, E, A, f1, K1, expand ( eData, 19) );

  subRound (A, B, C, D, E, f2, K2, expand ( eData, 20) );
  subRound (E, A, B, C, D, f2, K2, expand ( eData, 21) );
  subRound (D, E, A, B, C, f2, K2, expand ( eData, 22) );
  subRound (C, D, E, A, B, f2, K2, expand ( eData, 23) );
  subRound (B, C, D, E, A, f2, K2, expand ( eData, 24) );
  subRound (A, B, C, D, E, f2, K2, expand ( eData, 25) );
  subRound (E, A, B, C, D, f2, K2, expand ( eData, 26) );
  subRound (D, E, A, B, C, f2, K2, expand ( eData, 27) );
  subRound (C, D, E, A, B, f2, K2, expand ( eData, 28) );
  subRound (B, C, D, E, A, f2, K2, expand ( eData, 29) );
  subRound (A, B, C, D, E, f2, K2, expand ( eData, 30) );
  subRound (E, A, B, C, D, f2, K2, expand ( eData, 31) );
  subRound (D, E, A, B, C, f2, K2, expand ( eData, 32) );
  subRound (C, D, E, A, B, f2, K2, expand ( eData, 33) );
  subRound (B, C, D, E, A, f2, K2, expand ( eData, 34) );
  subRound (A, B, C, D, E, f2, K2, expand ( eData, 35) );
  subRound (E, A, B, C, D, f2, K2, expand ( eData, 36) );
  subRound (D, E, A, B, C, f2, K2, expand ( eData, 37) );
  subRound (C, D, E, A, B, f2, K2, expand ( eData, 38) );
  subRound (B, C, D, E, A, f2, K2, expand ( eData, 39) );

  subRound (A, B, C, D, E, f3, K3, expand ( eData, 40) );
  subRound (E, A, B, C, D, f3, K3, expand ( eData, 41) );
  subRound (D, E, A, B, C, f3, K3, expand ( eData, 42) );
  subRound (C, D, E, A, B, f3, K3, expand ( eData, 43) );
  subRound (B, C, D, E, A, f3, K3, expand ( eData, 44) );
  subRound (A, B, C, D, E, f3, K3, expand ( eData, 45) );
  subRound (E, A, B, C, D, f3, K3, expand ( eData, 46) );
  subRound (D, E, A, B, C, f3, K3, expand ( eData, 47) );
  subRound (C, D, E, A, B, f3, K3, expand ( eData, 48) );
  subRound (B, C, D, E, A, f3, K3, expand ( eData, 49) );
  subRound (A, B, C, D, E, f3, K3, expand ( eData, 50) );
  subRound (E, A, B, C, D, f3, K3, expand ( eData, 51) );
  subRound (D, E, A, B, C, f3, K3, expand ( eData, 52) );
  subRound (C, D, E, A, B, f3, K3, expand ( eData, 53) );
  subRound (B, C, D, E, A, f3, K3, expand ( eData, 54) );
  subRound (A, B, C, D, E, f3, K3, expand ( eData, 55) );
  subRound (E, A, B, C, D, f3, K3, expand ( eData, 56) );
  subRound (D, E, A, B, C, f3, K3, expand ( eData, 57) );
  subRound (C, D, E, A, B, f3, K3, expand ( eData, 58) );
  subRound (B, C, D, E, A, f3, K3, expand ( eData, 59) );

  subRound (A, B, C, D, E, f4, K4, expand ( eData, 60) );
  subRound (E, A, B, C, D, f4, K4, expand ( eData, 61) );
  subRound (D, E, A, B, C, f4, K4, expand ( eData, 62) );
  subRound (C, D, E, A, B, f4, K4, expand ( eData, 63) );
  subRound (B, C, D, E, A, f4, K4, expand ( eData, 64) );
  subRound (A, B, C, D, E, f4, K4, expand ( eData, 65) );
  subRound (E, A, B, C, D, f4, K4, expand ( eData, 66) );
  subRound (D, E, A, B, C, f4, K4, expand ( eData, 67) );
  subRound (C, D, E, A, B, f4, K4, expand ( eData, 68) );
  subRound (B, C, D, E, A, f4, K4, expand ( eData, 69) );
  subRound (A, B, C, D, E, f4, K4, expand ( eData, 70) );
  subRound (E, A, B, C, D, f4, K4, expand ( eData, 71) );
  subRound (D, E, A, B, C, f4, K4, expand ( eData, 72) );
  subRound (C, D, E, A, B, f4, K4, expand ( eData, 73) );
  subRound (B, C, D, E, A, f4, K4, expand ( eData, 74) );
  subRound (A, B, C, D, E, f4, K4, expand ( eData, 75) );
  subRound (E, A, B, C, D, f4, K4, expand ( eData, 76) );
  subRound (D, E, A, B, C, f4, K4, expand ( eData, 77) );
  subRound (C, D, E, A, B, f4, K4, expand ( eData, 78) );
  subRound (B, C, D, E, A, f4, K4, expand ( eData, 79) );

  /* Build message digest */
  digest[0] += A;
  digest[1] += B;
  digest[2] += C;
  digest[3] += D;
  digest[4] += E;
}

/* When run on a little-endian CPU we need to perform byte reversal on an
   array of longwords. */

#ifdef WORDS_BIGENDIAN
#define swap_words(buffer, byte_count)
#else
static void
swap_words (dbus_uint32_t *buffer,
            int            byte_count)
{
  byte_count /= sizeof (dbus_uint32_t);
  while (byte_count--)
    {
      *buffer = DBUS_UINT32_SWAP_LE_BE (*buffer);
      ++buffer;
    }
}
#endif

static void
sha_init (DBusSHAContext *context)
{
  /* Set the h-vars to their initial values */
  context->digest[0] = h0init;
  context->digest[1] = h1init;
  context->digest[2] = h2init;
  context->digest[3] = h3init;
  context->digest[4] = h4init;

  /* Initialise bit count */
  context->count_lo = context->count_hi = 0;
}

static void
sha_append (DBusSHAContext      *context,
            const unsigned char *buffer,
            unsigned int         count)
{
  dbus_uint32_t tmp;
  unsigned int dataCount;

  /* Update bitcount */
  tmp = context->count_lo;
  if (( context->count_lo = tmp + ( ( dbus_uint32_t) count << 3) ) < tmp)
    context->count_hi++;             /* Carry from low to high */
  context->count_hi += count >> 29;

  /* Get count of bytes already in data */
  dataCount = (int) (tmp >> 3) & 0x3F;

  /* Handle any leading odd-sized chunks */
  if (dataCount)
    {
      unsigned char *p = (unsigned char *) context->data + dataCount;

      dataCount = SHA_DATASIZE - dataCount;
      if (count < dataCount)
        {
          memmove (p, buffer, count);
          return;
        }
      memmove (p, buffer, dataCount);
      swap_words (context->data, SHA_DATASIZE);
      SHATransform (context->digest, context->data);
      buffer += dataCount;
      count -= dataCount;
    }

  /* Process data in SHA_DATASIZE chunks */
  while (count >= SHA_DATASIZE)
    {
      memmove (context->data, buffer, SHA_DATASIZE);
      swap_words (context->data, SHA_DATASIZE);
      SHATransform (context->digest, context->data);
      buffer += SHA_DATASIZE;
      count -= SHA_DATASIZE;
    }

  /* Handle any remaining bytes of data. */
  memmove (context->data, buffer, count);
}


/* Final wrapup - pad to SHA_DATASIZE-byte boundary with the bit pattern
   1 0* (64-bit count of bits processed, MSB-first) */

static void
sha_finish (DBusSHAContext *context, unsigned char digest[20])
{
  int count;
  unsigned char *data_p;

  /* Compute number of bytes mod 64 */
  count = (int) context->count_lo;
  count = (count >> 3) & 0x3F;

  /* Set the first char of padding to 0x80.  This is safe since there is
     always at least one byte free */
  data_p = (unsigned char *) context->data + count;
  *data_p++ = 0x80;

  /* Bytes of padding needed to make 64 bytes */
  count = SHA_DATASIZE - 1 - count;

  /* Pad out to 56 mod 64 */
  if (count < 8)
    {
      /* Two lots of padding:  Pad the first block to 64 bytes */
      memset (data_p, 0, count);
      swap_words (context->data, SHA_DATASIZE);
      SHATransform (context->digest, context->data);

      /* Now fill the next block with 56 bytes */
      memset (context->data, 0, SHA_DATASIZE - 8);
    }
  else
    /* Pad block to 56 bytes */
    memset (data_p, 0, count - 8);

  /* Append length in bits and transform */
  context->data[14] = context->count_hi;
  context->data[15] = context->count_lo;

  swap_words (context->data, SHA_DATASIZE - 8);
  SHATransform (context->digest, context->data);
  swap_words (context->digest, SHA_DIGESTSIZE);
  memmove (digest, context->digest, SHA_DIGESTSIZE);
}

/** @} */ /* End of internals */

/**
 * @addtogroup DBusSHA
 *
 * @{
 */

/**
 * Initializes the SHA context.
 *
 * @param context an uninitialized context, typically on the stack.
 */
void
_dbus_sha_init (DBusSHAContext *context)
{
  sha_init (context);
}

/**
 * Feeds more data into an existing shasum computation.
 *
 * @param context the SHA context
 * @param data the additional data to hash
 */
void
_dbus_sha_update (DBusSHAContext   *context,
                  const DBusString *data)
{
  unsigned int inputLen;
  const unsigned char *input;

  input = (const unsigned char*) _dbus_string_get_const_data (data);
  inputLen = _dbus_string_get_length (data);

  sha_append (context, input, inputLen);
}

/**
 * SHA finalization. Ends an SHA message-digest operation, writing the
 * the message digest and zeroing the context.  The results are
 * returned as a raw 20-byte digest, not as the ascii-hex-digits
 * string form of the digest.
 *
 * @param context the SHA context
 * @param results string to append the 20-byte SHA digest to
 * @returns #FALSE if not enough memory to append the digest
 *
 */
dbus_bool_t
_dbus_sha_final (DBusSHAContext   *context,
                 DBusString       *results)
{
  unsigned char digest[20];

  sha_finish (context, digest);

  if (!_dbus_string_append_len (results, digest, 20))
    return FALSE;

  /* some kind of security paranoia, though it seems pointless
   * to me given the nonzeroed stuff flying around
   */
  _DBUS_ZERO(*context);

  return TRUE;
}

/**
 * Computes the ASCII hex-encoded shasum of the given data and
 * appends it to the output string.
 *
 * @param data input data to be hashed
 * @param ascii_output string to append ASCII shasum to
 * @returns #FALSE if not enough memory
 */
dbus_bool_t
_dbus_sha_compute (const DBusString *data,
                   DBusString       *ascii_output)
{
  DBusSHAContext context;
  DBusString digest;

  _dbus_sha_init (&context);

  _dbus_sha_update (&context, data);

  if (!_dbus_string_init (&digest))
    return FALSE;

  if (!_dbus_sha_final (&context, &digest))
    goto error;

  if (!_dbus_string_hex_encode (&digest, 0, ascii_output,
                                _dbus_string_get_length (ascii_output)))
    goto error;

  _dbus_string_free (&digest);
  
  return TRUE;

 error:
  _dbus_string_free (&digest);
  return FALSE;
}

/** @} */ /* end of exported functions */

#ifdef DBUS_BUILD_TESTS
#include "dbus-test.h"
#include <stdio.h>

static dbus_bool_t
check_sha_binary (const unsigned char *input,
                  int                  input_len,
                  const char          *expected)
{
  DBusString input_str;
  DBusString expected_str;
  DBusString results;

  _dbus_string_init_const_len (&input_str, input, input_len);
  _dbus_string_init_const (&expected_str, expected);

  if (!_dbus_string_init (&results))
    _dbus_assert_not_reached ("no memory for SHA-1 results");

  if (!_dbus_sha_compute (&input_str, &results))
    _dbus_assert_not_reached ("no memory for SHA-1 results");

  if (!_dbus_string_equal (&expected_str, &results))
    {
      _dbus_warn ("Expected hash %s got %s for SHA-1 sum\n",
                  expected,
                  _dbus_string_get_const_data (&results));
      _dbus_string_free (&results);
      return FALSE;
    }

  _dbus_string_free (&results);
  return TRUE;
}

static dbus_bool_t
check_sha_str (const char *input,
               const char *expected)
{
  return check_sha_binary (input, strlen (input), expected);
}

static dbus_bool_t
decode_compact_string (const DBusString *line,
                       DBusString       *decoded)
{
  int n_bits;
  dbus_bool_t current_b;
  int offset;
  int next;
  long val;
  int length_bytes;
  
  offset = 0;
  next = 0;

  if (!_dbus_string_parse_int (line, offset, &val, &next))
    {
      fprintf (stderr, "could not parse length at start of compact string: %s\n",
               _dbus_string_get_const_data (line));
      return FALSE;
    }

  _dbus_string_skip_blank (line, next, &next);
  
  offset = next;
  if (!_dbus_string_parse_int (line, offset, &val, &next))
    {
      fprintf (stderr, "could not parse start bit 'b' in compact string: %s\n",
               _dbus_string_get_const_data (line));
      return FALSE;
    }
  
  if (!(val == 0 || val == 1))
    {
      fprintf (stderr, "the value 'b' must be 0 or 1, see sha-1/Readme.txt\n");
      return FALSE;
    }

  _dbus_string_skip_blank (line, next, &next);
  
  current_b = val;
  n_bits = 0;
  
  while (next < _dbus_string_get_length (line))
    {
      int total_bits;
      
      offset = next;

      if (_dbus_string_get_byte (line, offset) == '^')
        break;
      
      if (!_dbus_string_parse_int (line, offset, &val, &next))
        {
          fprintf (stderr, "could not parse bit count in compact string\n");
          return FALSE;
        }

      /* We now append "val" copies of "current_b" bits to the string */
      total_bits = n_bits + val;
      while (n_bits < total_bits)
        {
          int byte_containing_next_bit = n_bits / 8;
          int bit_containing_next_bit = 7 - (n_bits % 8);
          unsigned char old_byte;
          
          if (byte_containing_next_bit >= _dbus_string_get_length (decoded))
            {
              if (!_dbus_string_set_length (decoded, byte_containing_next_bit + 1))
                _dbus_assert_not_reached ("no memory to extend to next byte");
            }

          old_byte = _dbus_string_get_byte (decoded, byte_containing_next_bit);
          old_byte |= current_b << bit_containing_next_bit;

#if 0
          printf ("Appending bit %d to byte %d at bit %d resulting in byte 0x%x\n",
                  current_b, byte_containing_next_bit,
                  bit_containing_next_bit, old_byte);
#endif
          
          _dbus_string_set_byte (decoded, byte_containing_next_bit, old_byte);
          
          ++n_bits;
        }

      _dbus_string_skip_blank (line, next, &next);
          
      current_b = !current_b;
    }

  length_bytes = (n_bits / 8 + ((n_bits % 8) ? 1 : 0));
  
  if (_dbus_string_get_length (decoded) != length_bytes)
    {
      fprintf (stderr, "Expected length %d bytes %d bits for compact string, got %d bytes\n",
               length_bytes, n_bits, _dbus_string_get_length (decoded));
      return FALSE;
    }
  else
    return TRUE;
}

static dbus_bool_t
get_next_expected_result (DBusString *results,
                          DBusString *result)
{
  DBusString line;
  dbus_bool_t retval;

  retval = FALSE;
  
  if (!_dbus_string_init (&line))
    _dbus_assert_not_reached ("no memory");
  
 next_iteration:
  while (_dbus_string_pop_line (results, &line))
    {
      _dbus_string_delete_leading_blanks (&line);

      if (_dbus_string_get_length (&line) == 0)
        goto next_iteration;
      else if (_dbus_string_starts_with_c_str (&line, "#"))
        goto next_iteration;
      else if (_dbus_string_starts_with_c_str (&line, "H>"))
        {
          /* don't print */
        }
      else if (_dbus_string_starts_with_c_str (&line, "D>") ||
               _dbus_string_starts_with_c_str (&line, "<D"))
        goto next_iteration;
      else
        {
          int i;
          
          if (!_dbus_string_move (&line, 0, result, 0))
            _dbus_assert_not_reached ("no memory");

          i = 0;
          while (i < _dbus_string_get_length (result))
            {
              switch (_dbus_string_get_byte (result, i))
                {
                case 'A':
                  _dbus_string_set_byte (result, i, 'a');
                  break;
                case 'B':
                  _dbus_string_set_byte (result, i, 'b');
                  break;
                case 'C':
                  _dbus_string_set_byte (result, i, 'c');
                  break;
                case 'D':
                  _dbus_string_set_byte (result, i, 'd');
                  break;
                case 'E':
                  _dbus_string_set_byte (result, i, 'e');
                  break;
                case 'F':
                  _dbus_string_set_byte (result, i, 'f');
                  break;
                case '^':
                case ' ':
                  _dbus_string_delete (result, i, 1);
                  --i; /* to offset ++i below */
                  break;
                }

              ++i;
            }
          
          break;
        }
    }
  
  retval = TRUE;
  
  /* out: */
  _dbus_string_free (&line);
  return retval;
}

static dbus_bool_t
process_test_data (const char *test_data_dir)
{
  DBusString tests_file;
  DBusString results_file;
  DBusString tests;
  DBusString results;
  DBusString line;
  DBusString tmp;
  int line_no;
  dbus_bool_t retval;
  int success_count;
  DBusError error = DBUS_ERROR_INIT;

  retval = FALSE;
  
  if (!_dbus_string_init (&tests_file))
    _dbus_assert_not_reached ("no memory");

  if (!_dbus_string_init (&results_file))
    _dbus_assert_not_reached ("no memory");

  if (!_dbus_string_init (&tests))
    _dbus_assert_not_reached ("no memory");

  if (!_dbus_string_init (&results))
    _dbus_assert_not_reached ("no memory");

  if (!_dbus_string_init (&line))
    _dbus_assert_not_reached ("no memory");
  
  if (!_dbus_string_append (&tests_file, test_data_dir))
    _dbus_assert_not_reached ("no memory");

  if (!_dbus_string_append (&results_file, test_data_dir))
    _dbus_assert_not_reached ("no memory");

  _dbus_string_init_const (&tmp, "sha-1/byte-messages.sha1");
  if (!_dbus_concat_dir_and_file (&tests_file, &tmp))
    _dbus_assert_not_reached ("no memory");

  _dbus_string_init_const (&tmp, "sha-1/byte-hashes.sha1");
  if (!_dbus_concat_dir_and_file (&results_file, &tmp))
    _dbus_assert_not_reached ("no memory");

  if (!_dbus_file_get_contents (&tests, &tests_file, &error))
    {
      fprintf (stderr, "could not load test data file %s: %s\n",
               _dbus_string_get_const_data (&tests_file),
               error.message);
      dbus_error_free (&error);
      goto out;
    }

  if (!_dbus_file_get_contents (&results, &results_file, &error))
    {
      fprintf (stderr, "could not load results data file %s: %s\n",
               _dbus_string_get_const_data (&results_file), error.message);
      dbus_error_free (&error);
      goto out;
    }

  success_count = 0;
  line_no = 0;
 next_iteration:
  while (_dbus_string_pop_line (&tests, &line))
    {
      line_no += 1;

      _dbus_string_delete_leading_blanks (&line);

      if (_dbus_string_get_length (&line) == 0)
        goto next_iteration;
      else if (_dbus_string_starts_with_c_str (&line, "#"))
        goto next_iteration;
      else if (_dbus_string_starts_with_c_str (&line, "H>"))
        {
          printf ("SHA-1: %s\n", _dbus_string_get_const_data (&line));

          if (_dbus_string_find (&line, 0, "Type 3", NULL))
            {
              /* See sha-1/Readme.txt - the "Type 3" tests are
               * random seeds, rather than data to be hashed.
               * we'd have to do a little bit more implementation
               * to use those tests.
               */
              
              printf (" (ending tests due to Type 3 tests seen - this is normal)\n");
              break;
            }
        }
      else if (_dbus_string_starts_with_c_str (&line, "D>") ||
               _dbus_string_starts_with_c_str (&line, "<D"))
        goto next_iteration;
      else
        {
          DBusString test;
          DBusString result;
          DBusString next_line;
          DBusString expected;
          dbus_bool_t success;

          success = FALSE;
          
          if (!_dbus_string_init (&next_line))
            _dbus_assert_not_reached ("no memory");

          if (!_dbus_string_init (&expected))
            _dbus_assert_not_reached ("no memory");
          
          if (!_dbus_string_init (&test))
            _dbus_assert_not_reached ("no memory");

          if (!_dbus_string_init (&result))
            _dbus_assert_not_reached ("no memory");

          /* the "compact strings" are "^"-terminated not
           * newline-terminated so readahead to find the
           * "^"
           */
          while (!_dbus_string_find (&line, 0, "^", NULL) &&
                 _dbus_string_pop_line (&tests, &next_line))
            {
              if (!_dbus_string_append_byte (&line, ' ') ||
                  !_dbus_string_move (&next_line, 0, &line,
                                      _dbus_string_get_length (&line)))
                _dbus_assert_not_reached ("no memory");
            }
          
          if (!decode_compact_string (&line, &test))
            {
              fprintf (stderr, "Failed to decode line %d as a compact string\n",
                       line_no);
              goto failure;
            }
          
          if (!_dbus_sha_compute (&test, &result))
            _dbus_assert_not_reached ("no memory for SHA-1 result");

          if (!get_next_expected_result (&results, &expected))
            {
              fprintf (stderr, "Failed to read an expected result\n");
              goto failure;
            }
          
          if (!_dbus_string_equal (&result, &expected))
            {              
              fprintf (stderr, " for line %d got hash %s expected %s\n",
                       line_no,
                       _dbus_string_get_const_data (&result),
                       _dbus_string_get_const_data (&expected));
              goto failure;
            }
          else
            {
              success_count += 1;
            }

          success = TRUE;

        failure:
          _dbus_string_free (&test);
          _dbus_string_free (&result);
          _dbus_string_free (&next_line);
          _dbus_string_free (&expected);

          if (!success)
            goto out;
        }
    }

  retval = TRUE;

  printf ("Passed the %d SHA-1 tests in the test file\n",
          success_count);
  
 out:
  _dbus_string_free (&tests_file);
  _dbus_string_free (&results_file);
  _dbus_string_free (&tests);
  _dbus_string_free (&results);
  _dbus_string_free (&line);

  return retval;
}

/**
 * @ingroup DBusSHAInternals
 * Unit test for SHA computation.
 *
 * @returns #TRUE on success.
 */
dbus_bool_t
_dbus_sha_test (const char *test_data_dir)
{
  unsigned char all_bytes[256];
  int i;

  if (test_data_dir != NULL)
    {
      if (!process_test_data (test_data_dir))
        return FALSE;
    }
  else
    printf ("No test data dir\n");
  
  i = 0;
  while (i < 256)
    {
      all_bytes[i] = i;
      ++i;
    }

  if (!check_sha_binary (all_bytes, 256,
                         "4916d6bdb7f78e6803698cab32d1586ea457dfc8"))
    return FALSE;

#define CHECK(input,expected) if (!check_sha_str (input, expected)) return FALSE

  CHECK ("", "da39a3ee5e6b4b0d3255bfef95601890afd80709");
  CHECK ("a", "86f7e437faa5a7fce15d1ddcb9eaeaea377667b8");
  CHECK ("abc", "a9993e364706816aba3e25717850c26c9cd0d89d");
  CHECK ("message digest", "c12252ceda8be8994d5fa0290a47231c1d16aae3");
  CHECK ("abcdefghijklmnopqrstuvwxyz", "32d10c7b8cf96570ca04ce37f2a19d84240d3a89");
  CHECK ("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789",
         "761c457bf73b14d27e9e9265c46f4b4dda11f940");
  CHECK ("12345678901234567890123456789012345678901234567890123456789012345678901234567890",
         "50abf5706a150990a08b2c5ea40fa0e585554732");

  return TRUE;
}

#endif /* DBUS_BUILD_TESTS */