summaryrefslogtreecommitdiffstats
path: root/src/file_jpg.c
blob: 40e98ce1384c53b58777be2568cb53c514a7cd9d (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
/*

    File: file_jpg.c

    Copyright (C) 1998-2007 Christophe GRENIER <grenier@cgsecurity.org>
  
    This software 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 the Free Software Foundation, Inc., 51
    Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#include <stdio.h>
#include "types.h"
#ifdef HAVE_SETJMP_H
#include <setjmp.h>
#endif
#ifdef HAVE_JPEGLIB_H
#include <jpeglib.h>
#endif
#include "filegen.h"
#include "common.h"
#include "log.h"

extern const file_hint_t file_hint_indd;

static void register_header_check_jpg(file_stat_t *file_stat);
static int header_check_jpg(const unsigned char *buffer, const unsigned int buffer_size, const unsigned int safe_header_only, const file_recovery_t *file_recovery, file_recovery_t *file_recovery_new);
static void file_check_jpg(file_recovery_t *file_recovery);

const file_hint_t file_hint_jpg= {
  .extension="jpg",
  .description="JPG picture",
  .min_header_distance=0,
  .max_filesize=50*1024*1024,
  .recover=1,
  .register_header_check=&register_header_check_jpg
};

static const unsigned char jpg_header_app0[4]= { 0xff,0xd8,0xff,0xe0};
static const unsigned char jpg_header_app1[4]= { 0xff,0xd8,0xff,0xe1};
static const unsigned char jpg_footer[2]= { 0xff,0xd9};

static void register_header_check_jpg(file_stat_t *file_stat)
{
  register_header_check(0, jpg_header_app0,sizeof(jpg_header_app0), &header_check_jpg, file_stat);
  register_header_check(0, jpg_header_app1,sizeof(jpg_header_app1), &header_check_jpg, file_stat);
}

static int header_check_jpg(const unsigned char *buffer, const unsigned int buffer_size, const unsigned int safe_header_only, const file_recovery_t *file_recovery, file_recovery_t *file_recovery_new)
{
  if(file_recovery!=NULL && file_recovery->file_stat!=NULL &&
      file_recovery->file_stat->file_hint==&file_hint_indd)
    return 0;
  if(memcmp(buffer,jpg_header_app0,sizeof(jpg_header_app0))==0 ||
      memcmp(buffer,jpg_header_app1,sizeof(jpg_header_app1))==0)
  {
    unsigned int i=2;
    reset_file_recovery(file_recovery_new);
    file_recovery_new->extension=file_hint_jpg.extension;
    file_recovery_new->data_check=NULL;
    file_recovery_new->file_check=&file_check_jpg;
    do
    {
      if(buffer[i]==0xff && buffer[i+1]==0xe0)
      { /* APP0 */
	i+=2+(buffer[i+2]<<8)+buffer[i+3];
      }
      else if(buffer[i]==0xff && buffer[i+1]==0xe1)
      { /* APP1 Exif information */
	i+=2+(buffer[i+2]<<8)+buffer[i+3];
      }
      else
      {
	file_recovery_new->min_filesize=288;
	return 1;
      }
    } while(i<6*512 && i<buffer_size);
    file_recovery_new->min_filesize=i;
    return 1;
  }
  return 0;
}

#if defined(HAVE_LIBJPEG) && defined(HAVE_JPEGLIB_H)
struct my_error_mgr {
  struct jpeg_error_mgr pub;	/* "public" fields, must be the first field */

  jmp_buf setjmp_buffer;	/* for return to caller */
};

static void my_output_message (j_common_ptr cinfo);
static void my_error_exit (j_common_ptr cinfo);
static void my_emit_message (j_common_ptr cinfo, int msg_level);

static void my_output_message (j_common_ptr cinfo)
{
  struct my_error_mgr *myerr = (struct my_error_mgr *) cinfo->err;
#ifdef DEBUG
  {
    char buffermsg[JMSG_LENGTH_MAX];
    /* Create the message */
    (*cinfo->err->format_message) (cinfo, buffermsg);
    log_error("test_jpeg error %s\n",buffermsg);
  }
#endif
  longjmp(myerr->setjmp_buffer, 1);
}

static void my_error_exit (j_common_ptr cinfo)
{
  struct my_error_mgr *myerr = (struct my_error_mgr *) cinfo->err;
  (*cinfo->err->output_message) (cinfo);
  /* Return control to the setjmp point */
  longjmp(myerr->setjmp_buffer, 1);
}

static void my_emit_message (j_common_ptr cinfo, int msg_level)
{
  struct my_error_mgr *myerr = (struct my_error_mgr *) cinfo->err;
  struct jpeg_error_mgr *err = &myerr->pub;

  if (msg_level < 0) {
    /* It's a warning message.  Since corrupt files may generate many warnings,
     * the policy implemented here is to show only the first warning,
     * unless trace_level >= 3.
     */
    if (err->num_warnings == 0 || err->trace_level >= 3)
      (*err->output_message) (cinfo);
    /* Always count warnings in num_warnings. */
    err->num_warnings++;
    /* Return control to the setjmp point */
    longjmp(myerr->setjmp_buffer, 1);
  } else {
    /* It's a trace message.  Show it if trace_level >= msg_level. */
    if (err->trace_level >= msg_level)
      (*err->output_message) (cinfo);
  }
}

typedef struct {
  struct jpeg_source_mgr pub;	/* public fields */

  FILE * infile;		/* source stream */
  JOCTET * buffer;		/* start of buffer */
  boolean start_of_file;	/* have we gotten any data yet? */
  unsigned long int file_size;
} my_source_mgr;

#define JPG_INPUT_BUF_SIZE  4096	/* choose an efficiently fread'able size */

/*
 * Initialize source --- called by jpeg_read_header
 * before any data is actually read.
 */

static void jpg_init_source (j_decompress_ptr cinfo)
{
  my_source_mgr * src = (my_source_mgr *) cinfo->src;

  /* We reset the empty-input-file flag for each image,
   * but we don't clear the input buffer.
   * This is correct behavior for reading a series of images from one source.
   */
  src->start_of_file = TRUE;
  src->file_size = 0;
}


/*
 * Fill the input buffer --- called whenever buffer is emptied.
 *
 * In typical applications, this should read fresh data into the buffer
 * (ignoring the current state of next_input_byte & bytes_in_buffer),
 * reset the pointer & count to the start of the buffer, and return TRUE
 * indicating that the buffer has been reloaded.  It is not necessary to
 * fill the buffer entirely, only to obtain at least one more byte.
 *
 * There is no such thing as an EOF return.  If the end of the file has been
 * reached, the routine has a choice of ERREXIT() or inserting fake data into
 * the buffer.  In most cases, generating a warning message and inserting a
 * fake EOI marker is the best course of action --- this will allow the
 * decompressor to output however much of the image is there.  However,
 * the resulting error message is misleading if the real problem is an empty
 * input file, so we handle that case specially.
 *
 * In applications that need to be able to suspend compression due to input
 * not being available yet, a FALSE return indicates that no more data can be
 * obtained right now, but more may be forthcoming later.  In this situation,
 * the decompressor will return to its caller (with an indication of the
 * number of scanlines it has read, if any).  The application should resume
 * decompression after it has loaded more data into the input buffer.  Note
 * that there are substantial restrictions on the use of suspension --- see
 * the documentation.
 *
 * When suspending, the decompressor will back up to a convenient restart point
 * (typically the start of the current MCU). next_input_byte & bytes_in_buffer
 * indicate where the restart point will be if the current call returns FALSE.
 * Data beyond this point must be rescanned after resumption, so move it to
 * the front of the buffer rather than discarding it.
 */

static boolean jpg_fill_input_buffer (j_decompress_ptr cinfo)
{
  my_source_mgr * src = (my_source_mgr *) cinfo->src;
  size_t nbytes;
  nbytes = fread(src->buffer, 1, JPG_INPUT_BUF_SIZE, src->infile);
  if (nbytes <= 0) {
    if (src->start_of_file)	/* Treat empty input file as fatal error */
    {
      // (cinfo)->err->msg_code = JERR_INPUT_EMPTY;
      (*(cinfo)->err->error_exit) ((j_common_ptr)cinfo);;
    }
    // cinfo->err->msg_code = JWRN_JPEG_EOF;
    (*(cinfo)->err->emit_message) ((j_common_ptr)cinfo, -1);
    /* Insert a fake EOI marker */
    src->buffer[0] = (JOCTET) 0xFF;
    src->buffer[1] = (JOCTET) JPEG_EOI;
    nbytes = 2;
  }
  src->pub.next_input_byte = src->buffer;
  src->pub.bytes_in_buffer = nbytes;
  src->start_of_file = FALSE;
  src->file_size += nbytes;
  return TRUE;
}


/*
 * Skip data --- used to skip over a potentially large amount of
 * uninteresting data (such as an APPn marker).
 *
 * Writers of suspendable-input applications must note that skip_input_data
 * is not granted the right to give a suspension return.  If the skip extends
 * beyond the data currently in the buffer, the buffer can be marked empty so
 * that the next read will cause a fill_input_buffer call that can suspend.
 * Arranging for additional bytes to be discarded before reloading the input
 * buffer is the application writer's problem.
 */

static void jpg_skip_input_data (j_decompress_ptr cinfo, long num_bytes)
{
  my_source_mgr * src = (my_source_mgr *) cinfo->src;

  /* Just a dumb implementation for now.  Could use fseek() except
   * it doesn't work on pipes.  Not clear that being smart is worth
   * any trouble anyway --- large skips are infrequent.
   */
  if (num_bytes > 0) {
    while (num_bytes > (long) src->pub.bytes_in_buffer) {
      num_bytes -= (long) src->pub.bytes_in_buffer;
      (void) jpg_fill_input_buffer(cinfo);
      /* note we assume that fill_input_buffer will never return FALSE,
       * so suspension need not be handled.
       */
    }
    src->pub.next_input_byte += (size_t) num_bytes;
    src->pub.bytes_in_buffer -= (size_t) num_bytes;
  }
}

/*
 * An additional method that can be provided by data source modules is the
 * resync_to_restart method for error recovery in the presence of RST markers.
 * For the moment, this source module just uses the default resync method
 * provided by the JPEG library.  That method assumes that no backtracking
 * is possible.
 */


/*
 * Terminate source --- called by jpeg_finish_decompress
 * after all data has been read.  Often a no-op.
 *
 * NB: *not* called by jpeg_abort or jpeg_destroy; surrounding
 * application must deal with any cleanup that should happen even
 * for error exit.
 */

static void jpg_term_source (j_decompress_ptr cinfo)
{
  /* no work necessary here */
}


/*
 * Prepare for input from a stdio stream.
 * The caller must have already opened the stream, and is responsible
 * for closing it after finishing decompression.
 */

static void jpeg_testdisk_src (j_decompress_ptr cinfo, FILE * infile)
{
  my_source_mgr * src;

  /* The source object and input buffer are made permanent so that a series
   * of JPEG images can be read from the same file by calling jpeg_testdisk_src
   * only before the first one.  (If we discarded the buffer at the end of
   * one image, we'd likely lose the start of the next one.)
   * This makes it unsafe to use this manager and a different source
   * manager serially with the same JPEG object.  Caveat programmer.
   */
  if (cinfo->src == NULL) {	/* first time for this JPEG object? */
    cinfo->src = (struct jpeg_source_mgr *)
      (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
				  sizeof(my_source_mgr));
    src = (my_source_mgr *) cinfo->src;
    src->buffer = (JOCTET *)
      (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
				  JPG_INPUT_BUF_SIZE * sizeof(JOCTET));
  }

  src = (my_source_mgr *) cinfo->src;
  src->pub.init_source = jpg_init_source;
  src->pub.fill_input_buffer = jpg_fill_input_buffer;
  src->pub.skip_input_data = jpg_skip_input_data;
  src->pub.resync_to_restart = jpeg_resync_to_restart; /* use default method */
  src->pub.term_source = jpg_term_source;
  src->infile = infile;
  src->pub.bytes_in_buffer = 0; /* forces fill_input_buffer on first read */
  src->pub.next_input_byte = NULL; /* until buffer loaded */
}
#endif

static void file_check_jpg(file_recovery_t *file_recovery)
{
  FILE* infile=file_recovery->handle;
  uint64_t jpeg_size;
#if defined(HAVE_LIBJPEG) && defined(HAVE_JPEGLIB_H)
  static struct my_error_mgr jerr;
  static struct jpeg_decompress_struct cinfo;
#endif
  file_recovery->file_size=0;
  file_recovery->offset_error=0;
#if defined(HAVE_LIBJPEG) && defined(HAVE_JPEGLIB_H)
  {
    JSAMPARRAY buffer;		/* Output row buffer */
    int row_stride;		/* physical row width in output buffer */
    fseek(infile,0,SEEK_SET);
    cinfo.err = jpeg_std_error(&jerr.pub);
    jerr.pub.output_message = my_output_message;
    jerr.pub.error_exit = my_error_exit;
    jerr.pub.emit_message= my_emit_message;
    // jerr.pub.emit_message = my_emit_message;
    /* Establish the setjmp return context for my_error_exit to use. */
    if (setjmp(jerr.setjmp_buffer)) 
    {
      /* If we get here, the JPEG code has signaled an error.
       * We need to clean up the JPEG object and return.
       */
      /* Not accurate */
      // jpeg_size=ftell(infile);
      my_source_mgr * src;
      src = (my_source_mgr *) cinfo.src;
      jpeg_size=src->file_size - src->pub.bytes_in_buffer;
      // log_error("JPG error at offset %llu\n", (long long unsigned)jpeg_size);
      jpeg_destroy_decompress(&cinfo);
      if(jpeg_size>0)
	file_recovery->offset_error=jpeg_size;
      return;
    }
    jpeg_create_decompress(&cinfo);
    cinfo.two_pass_quantize = FALSE;
    cinfo.dither_mode = JDITHER_NONE;
    cinfo.desired_number_of_colors = 0;
    cinfo.dct_method = JDCT_FASTEST;
    cinfo.do_fancy_upsampling = FALSE;
    cinfo.raw_data_out = TRUE;

    jpeg_testdisk_src(&cinfo, infile);
    (void) jpeg_read_header(&cinfo, TRUE);
    (void) jpeg_start_decompress(&cinfo);
    row_stride = cinfo.output_width * cinfo.output_components;
    buffer = (*cinfo.mem->alloc_sarray)
      ((j_common_ptr) &cinfo, JPOOL_IMAGE, row_stride, 1);
    while (cinfo.output_scanline < cinfo.output_height) {
      (void) jpeg_read_scanlines(&cinfo, buffer, 1);
    }
    (void) jpeg_finish_decompress(&cinfo);
    {
      my_source_mgr * src;
      src = (my_source_mgr *) cinfo.src;
      jpeg_size=src->file_size - src->pub.bytes_in_buffer;
    }
    jpeg_destroy_decompress(&cinfo);
  }
#else
  /* Not accurate */
  jpeg_size=ftell(infile);
#endif
//    log_error("JPG size: %llu\n", (long long unsigned)jpeg_size);
  if(jpeg_size<=0)
    return;
#if defined(HAVE_LIBJPEG) && defined(HAVE_JPEGLIB_H)
  if(jerr.pub.num_warnings>0)
  {
    file_recovery->offset_error=jpeg_size;
    return;
  }
#endif
  file_recovery->file_size=jpeg_size;
  file_search_footer(file_recovery, jpg_footer,sizeof(jpg_footer));
}