w32tex
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unzcrash.c
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1 
2 /* A test program written to test robustness to decompression of
3  corrupted data. Usage is
4  unzcrash filename
5  and the program will read the specified file, compress it (in memory),
6  and then repeatedly decompress it, each time with a different bit of
7  the compressed data inverted, so as to test all possible one-bit errors.
8  This should not cause any invalid memory accesses. If it does,
9  I want to know about it!
10 
11  PS. As you can see from the above description, the process is
12  incredibly slow. A file of size eg 5KB will cause it to run for
13  many hours.
14 */
15 
16 /* ------------------------------------------------------------------
17  This file is part of bzip2/libbzip2, a program and library for
18  lossless, block-sorting data compression.
19 
20  bzip2/libbzip2 version 1.0.6 of 6 September 2010
21  Copyright (C) 1996-2010 Julian Seward <jseward@bzip.org>
22 
23  Please read the WARNING, DISCLAIMER and PATENTS sections in the
24  README file.
25 
26  This program is released under the terms of the license contained
27  in the file LICENSE.
28  ------------------------------------------------------------------ */
29 
30 
31 #include <stdio.h>
32 #include <assert.h>
33 #include "bzlib.h"
34 
35 #define M_BLOCK 1000000
36 
37 typedef unsigned char uchar;
38 
39 #define M_BLOCK_OUT (M_BLOCK + 1000000)
42 uchar zbuf[M_BLOCK + 600 + (M_BLOCK / 100)];
43 
44 int nIn, nOut, nZ;
45 
46 static char *bzerrorstrings[] = {
47  "OK"
48  ,"SEQUENCE_ERROR"
49  ,"PARAM_ERROR"
50  ,"MEM_ERROR"
51  ,"DATA_ERROR"
52  ,"DATA_ERROR_MAGIC"
53  ,"IO_ERROR"
54  ,"UNEXPECTED_EOF"
55  ,"OUTBUFF_FULL"
56  ,"???" /* for future */
57  ,"???" /* for future */
58  ,"???" /* for future */
59  ,"???" /* for future */
60  ,"???" /* for future */
61  ,"???" /* for future */
62 };
63 
64 void flip_bit ( int bit )
65 {
66  int byteno = bit / 8;
67  int bitno = bit % 8;
68  uchar mask = 1 << bitno;
69  //fprintf ( stderr, "(byte %d bit %d mask %d)",
70  // byteno, bitno, (int)mask );
71  zbuf[byteno] ^= mask;
72 }
73 
74 int main ( int argc, char** argv )
75 {
76  FILE* f;
77  int r;
78  int bit;
79  int i;
80 
81  if (argc != 2) {
82  fprintf ( stderr, "usage: unzcrash filename\n" );
83  return 1;
84  }
85 
86  f = fopen ( argv[1], "r" );
87  if (!f) {
88  fprintf ( stderr, "unzcrash: can't open %s\n", argv[1] );
89  return 1;
90  }
91 
92  nIn = fread ( inbuf, 1, M_BLOCK, f );
93  fprintf ( stderr, "%d bytes read\n", nIn );
94 
95  nZ = M_BLOCK;
97  zbuf, &nZ, inbuf, nIn, 9, 0, 30 );
98 
99  assert (r == BZ_OK);
100  fprintf ( stderr, "%d after compression\n", nZ );
101 
102  for (bit = 0; bit < nZ*8; bit++) {
103  fprintf ( stderr, "bit %d ", bit );
104  flip_bit ( bit );
105  nOut = M_BLOCK_OUT;
107  outbuf, &nOut, zbuf, nZ, 0, 0 );
108  fprintf ( stderr, " %d %s ", r, bzerrorstrings[-r] );
109 
110  if (r != BZ_OK) {
111  fprintf ( stderr, "\n" );
112  } else {
113  if (nOut != nIn) {
114  fprintf(stderr, "nIn/nOut mismatch %d %d\n", nIn, nOut );
115  return 1;
116  } else {
117  for (i = 0; i < nOut; i++)
118  if (inbuf[i] != outbuf[i]) {
119  fprintf(stderr, "mismatch at %d\n", i );
120  return 1;
121  }
122  if (i == nOut) fprintf(stderr, "really ok!\n" );
123  }
124  }
125 
126  flip_bit ( bit );
127  }
128 
129 #if 0
130  assert (nOut == nIn);
131  for (i = 0; i < nOut; i++) {
132  if (inbuf[i] != outbuf[i]) {
133  fprintf ( stderr, "difference at %d !\n", i );
134  return 1;
135  }
136  }
137 #endif
138 
139  fprintf ( stderr, "all ok\n" );
140  return 0;
141 }
#define fopen
Definition: xxstdio.h:21
#define fread
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int BZ2_bzBuffToBuffDecompress(char *dest, unsigned int *destLen, char *source, unsigned int sourceLen, int small, int verbosity)
Definition: bzlib.c:1300
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Definition: bzlib.c:1248
#define BZ_OK
Definition: bzlib.h:33
int nOut
Definition: unzcrash.c:44
int nIn
Definition: unzcrash.c:44
int main(int argc, char **argv)
Definition: unzcrash.c:74
static char * bzerrorstrings[]
Definition: unzcrash.c:46
#define M_BLOCK
Definition: unzcrash.c:35
uchar inbuf[1000000]
Definition: unzcrash.c:40
unsigned char uchar
Definition: unzcrash.c:37
void flip_bit(int bit)
Definition: unzcrash.c:64
uchar zbuf[1000000+600+(1000000/100)]
Definition: unzcrash.c:42
uchar outbuf[(1000000+1000000)]
Definition: unzcrash.c:41
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Definition: unzcrash.c:44
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Definition: unzcrash.c:39
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