basex/basex.c

/*
 * version 1.5  2001-06-26
 *   slightly more robust
 *   "compression" levels
 *   '-I' for decode
 *   '-n' option
 *   ident strings can not contain whitespace
 * version 1.4  2001-06-24
 * version 1.3  1999-09-12
 * version 1.2  1995-03-01
 * version 1.1  1995-05-30
 * version 1.0  1994-12-13
 *
 * remember to transfer files with
 * Content-Encoding: 8bit
 * Content-Transfer-Encoding: 8bit
 *
 * this is written in ISO-C89
 * + getopt (e.g. -D_POSIX_C_SOURCE=2)
 *
 * basex -v -i "id" <input >output
 * basex -d -I -v <input >output
 *
 * -V           show version
 * -d           decode
 * -v           verbose
 * -i <id>      use identifier id
 * -I           print id to stderr on decryption
 * -n           do NOT create output
 * -1           VERY conservative
 * -5           rather conservative (almost rfc2822)
 * -7           non-rfc2822, but should work (default)
 * -9           maximum level (not that much better)
 *
 * ESCAPE -> ESCAPE 'A'
 * 0x00   -> ESCAPE 'B'
 * 0x0a   -> ESCAPE 'C'
 * 0x0d   -> ESCAPE 'D'
 * ESCAPE x, x != A-D unchanged
 *
 * uses adler32 checksum
 */

/* next include is for getopt only */
#include <unistd.h>

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define MAXLINE (60000+3)
#define ESCAPE  0xff
#define MAXBLK  5000000L                /* max. blksize on decode */
#define ID1     "BASEX ENCODED DATA"    /* file header */
#define ID2     "X"                     /* control header */
#define ID3     '|'                     /* data header */

char version[] = "basex version 1.5 - 2001-06-26";

typedef unsigned long u32;              /* 4 byte unsigned int */
typedef unsigned char u8;               /* 1 byte unsigned int */

int verbose   = 0;
int showident = 0;
int complevel = 7;
int nooutput  = 0;

int linelen;
int blklen;

extern char *optarg;
/*extern int optind, opterr, optopt; */

u32
adler32 (u8 * data, int len)
{
  u32 s1 = 1;
  u32 s2 = 0;
  u32 modulo = 65521;

  while (--len)
    {
      s1 += *data++;
      if (s1 >= modulo)
        s1 -= modulo;
        
      s2 += s1;
      if (s2 >= modulo)
        s2 -= modulo;
      
    };
  return (s2 << 16) + s1;
}

void
out_char (FILE * o, int code)
{
  static char line[MAXLINE + 1];
  static int llen = 0;

  if (code == -2)
    {
      if (llen)
        {
          line[llen] = 0;
          if (!nooutput)
            fprintf (o, "%c%s\n", ID3, line);
        }
    }
  else if (code == -1)
    {
      llen = 0;
    }
  else
    {
      line[llen++] = code;
      if (llen >= linelen)
        {
          llen = 0;
          line[linelen] = 0;
          if (!nooutput)
            fprintf (o, "%c%s\n", ID3, line);
        }
    }
}

int
encode (FILE * i, FILE * o, char *id)
{
  u8 *block;
  long blklen;
  int len;

  if (complevel <= 1)
    {
      linelen = 120;
      blklen  = 50000;
    }
  else if (complevel <= 5)
    {
      linelen = 996;
      blklen  = 50000;
    }
  else if (complevel <= 7)
    {
      linelen = 7996;
      blklen  = 50000;
    }
  else
    {
      linelen = 60000;
      blklen  = 5000000;
    }

  block = malloc (blklen);

  if (!block)
    {
      fprintf (stderr, "unable to allocate %ld bytes", blklen * 2);
      return 11;
    }

  if (!nooutput)
    {
      fprintf (o, "%s\n", ID1);
      fprintf (o, "%s VERSION 2\n", ID2);
      if (id)
        fprintf (o, "%s IDENT %s\n", ID2, id);
    }
  
  /*fprintf (o, "%s CODEC AFE0C0DE\n", ID2);*/ /* default */
  while ((len = fread (block, 1, blklen, i)) > 0)
    {
      u32 sum = adler32 (block, len);
      u8 *p = block;

      if (!nooutput)
        fprintf (o, "%s BLOCK %d %08lx\n", ID2, len, sum);

      out_char (o, -1);
      while (len--)
        {
          int c = *p++ ^ (u8) sum++;

          if (c == ESCAPE)
            {
              out_char (o, ESCAPE);
              if (len)
                {
                  switch (*p ^ (u8) sum)
                    {
                      case 'A':
                      case 'B':
                      case 'C':
                      case 'D':
                        out_char (o, 'A');
                        break;
                      default:
                        /* nothing */;
                    }
                }
              else
                out_char (o, 'A');
            }
          else if (c == 0x00)
            {
              out_char (o, ESCAPE);
              out_char (o, 'B');
            }
          else if (c == 0x0a)
            {
              out_char (o, ESCAPE);
              out_char (o, 'C');
            }
          else if (c == 0x0d)
            {
              out_char (o, ESCAPE);
              out_char (o, 'D');
            }
          else
            {
              out_char (o, c);
            }
        }
      
      out_char (o, -2);
    }
  
  if (!nooutput)
    fprintf (o, "%s END\n", ID2);

  free (block);

  return 0;
}

int
in_char (FILE * i, int code)
{
  static int llen;
  static char line[MAXLINE + 3];

  if (code == -1)
    {
      llen = MAXLINE + 1;
      return 0;
    }
  else
    {
      if (llen > MAXLINE
          || line[llen] == 0
          || line[llen] == '\r'
          || line[llen] == '\n')
        {
          do {
            if (!fgets (line, sizeof (line), i))
              {
                perror ("error on block read (file truncated?)");
                return -1;
              }
          } while (line[0] != ID3);

          llen = 1;
        }
      
      return (unsigned char) line[llen++];
    }
}

int
decodeblock (FILE * i, u8 * data, int len, int sum)
{
  int ch;

  (void) in_char (i, -1);

  while (len--)
    {
      ch = in_char (i, 0);
      if (ch < 0)
        return 8;
      
retry:
      if (ch == ESCAPE)
        {
          switch ((ch = in_char (i, 0)))
            {
              case 'A': ch = ESCAPE; break;
              case 'B': ch = 0x00;   break;
              case 'C': ch = 0x0a;   break;
              case 'D': ch = 0x0d;   break;
              
              default:
                *data++ = (u8) ESCAPE ^ (u8) sum++; len--;
                goto retry;
            }
        }
      
      *data++ = (u8) ch ^ (u8) sum++;
    }

  return 0;
}

int
decode (FILE * i, FILE * o)
{
  char input[255];
  char *opt = input + sizeof (ID2) - 1 + 1;
  long blklen;
  int err;
  u32 sum, sum2;

  u32 codec = 0xafe1c0de;
  int version = 0;
  char ident[255];

  ident[0] = 0;

  do
    {
      if (!fgets (input, sizeof (input), i))
        {
          perror ("unable to find start of encoded data");
          return 1;
        }
    }
  while (strncmp (input, ID1, sizeof (ID1) - 1));

  if (verbose)
    fprintf (stderr, "basex header found, processing options\n");

  for (;;)
    {
      if (!fgets (input, sizeof (input), i))
        {
          perror ("error while processing options");
          return 2;
        }
      
      if (strncmp (input, ID2, sizeof (ID2) - 1) || *(opt - 1) != ' ')
        {
          fprintf (stderr, "garbage instead of option, ignored\n");
        }
      else
        {
          if (sscanf (opt, "VERSION %d\n", &version) == 1)
            {
              if (verbose)
                fprintf (stderr, "option version %d\n", version);
              
              if (version != 2)
                {
                  fprintf (stderr, "unsupported version %d\n", version);
                  return 5;
                }
            }
          else if (sscanf (opt, "CODEC %8lx\n", &codec) == 1)
            {
              if (verbose)
                fprintf (stderr, "option codec %lx\n", codec);
            }
          else if (sscanf (opt, "IDENT %[^\n]\n", ident) == 1)
            {
              if (verbose || showident)
                fprintf (stderr, "option ident %s\n", ident);
            }
          else if (strcmp (opt, "END\n") == 0)
            {
              if (verbose)
                fprintf (stderr, "option end\n");
              
              return 0;
            }
          else if (sscanf (opt, "BLOCK %ld %08lx\n", &blklen, &sum) == 2)
            {
              u8 *block;

              if (verbose)
                fprintf (stderr, "option block len %ld, checksum %08lx\n", blklen, sum);
              
              if (blklen > MAXBLK)
                {
                  fprintf (stderr, "block length too large (%ld>%ld)\n", blklen, MAXBLK);
                  return 4;
                }

              switch (codec)
                {
                  case 0xafe1c0de:

                    block = malloc (blklen);

                    if (!block)
                      {
                        fprintf (stderr, "unable to allocate %ld bytes", blklen);
                        return 11;
                      }
                
                    err = decodeblock (i, block, blklen, sum);
                    if (err)
                      return err;
                    
                    sum2 = adler32 (block, blklen);
                    if (sum != sum2)
                      {
                        fprintf (stderr, "checksumming error %08lx != %08lx\n", sum, sum2);
                        return 9;
                      }
                    
                    if (!nooutput && fwrite (block, blklen, 1, o) <= 0)
                      {
                        perror ("write error");
                        return 10;
                      }

                    free (block);
                    break;
                  
                  default:
                    fprintf (stderr, "unknown codec %08lx\n", codec);
                    return 3;
                }
            }
          else
            {
              fprintf (stderr, "unknown or unrecognized option %s\n", opt);
              return 2;
            }
        }
    }
}

int
main (int argc, char *argv[])
{
  int dec = 0;
  char *id = 0;

  for (;;)
    {
      int c = getopt (argc, argv, "Vvdi:In123456789");

      if (c == EOF)
        break;

      switch (c)
        {
          case 'V':
            puts (version);
            exit (EXIT_SUCCESS);
            break;

          case 'v':
            verbose = 1;
            break;
          
          case 'd':
            dec = 1;
            break;
          
          case 'i':
            id = optarg;
            break;

          case 'I':
            showident = 1;
            break;

          case 'n':
            nooutput = 1;
            break;

          case '1':
          case '2':
          case '3':
          case '4':
            complevel = 1;
            break;
          case '5':
          case '6':
            complevel = 5;
            break;
          case '7':
          case '8':
            complevel = 7;
            break;
          case '9':
            complevel = 9;
            break;
          
          case '?':
            fprintf (stderr, "encode: basex [-v] [-n] [-i id] [-1 | -5 | -7 | -9]\n");
            fprintf (stderr, "decode: basex [-d] [-v] [-n] [-I]\n");
            break;
        }
    }

  if (verbose)
    fprintf (stderr, "mode %s\n", dec ? "decoding" : "encoding");

  if (dec)
    return decode (stdin, stdout);
  else
    return encode (stdin, stdout, id);
}

Revision:	1.2
Committed:	Sun Sep 23 21:18:52 2001 UTC (22 years, 7 months ago) by root
Content type:	text/plain
Branch:	MAIN
CVS Tags:	HEAD
Changes since 1.1:	+7 -6 lines
Log Message:	* empty log message *
#	Content
1	/*
2	* version 1.5 2001-06-26
3	* slightly more robust
4	* "compression" levels
5	* '-I' for decode
6	* '-n' option
7	* ident strings can not contain whitespace
8	* version 1.4 2001-06-24
9	* version 1.3 1999-09-12
10	* version 1.2 1995-03-01
11	* version 1.1 1995-05-30
12	* version 1.0 1994-12-13
13	*
14	* remember to transfer files with
15	* Content-Encoding: 8bit
16	* Content-Transfer-Encoding: 8bit
17	*
18	* this is written in ISO-C89
19	* + getopt (e.g. -D_POSIX_C_SOURCE=2)
20	*
21	* basex -v -i "id" <input >output
22	* basex -d -I -v <input >output
23	*
24	* -V show version
25	* -d decode
26	* -v verbose
27	* -i <id> use identifier id
28	* -I print id to stderr on decryption
29	* -n do NOT create output
30	* -1 VERY conservative
31	* -5 rather conservative (almost rfc2822)
32	* -7 non-rfc2822, but should work (default)
33	* -9 maximum level (not that much better)
34	*
35	* ESCAPE -> ESCAPE 'A'
36	* 0x00 -> ESCAPE 'B'
37	* 0x0a -> ESCAPE 'C'
38	* 0x0d -> ESCAPE 'D'
39	* ESCAPE x, x != A-D unchanged
40	*
41	* uses adler32 checksum
42	*/
43
44	/* next include is for getopt only */
45	#include <unistd.h>
46
47	#include <stdio.h>
48	#include <stdlib.h>
49	#include <string.h>
50
51	#define MAXLINE (60000+3)
52	#define ESCAPE 0xff
53	#define MAXBLK 5000000L /* max. blksize on decode */
54	#define ID1 "BASEX ENCODED DATA" /* file header */
55	#define ID2 "X" /* control header */
56	#define ID3 '\|' /* data header */
57
58	char version[] = "basex version 1.5 - 2001-06-26";
59
60	typedef unsigned long u32; /* 4 byte unsigned int */
61	typedef unsigned char u8; /* 1 byte unsigned int */
62
63	int verbose = 0;
64	int showident = 0;
65	int complevel = 7;
66	int nooutput = 0;
67
68	int linelen;
69	int blklen;
70
71	extern char *optarg;
72	/extern int optind, opterr, optopt; /
73
74	u32
75	adler32 (u8 * data, int len)
76	{
77	u32 s1 = 1;
78	u32 s2 = 0;
79	u32 modulo = 65521;
80
81	while (--len)
82	{
83	s1 += *data++;
84	if (s1 >= modulo)
85	s1 -= modulo;
86
87	s2 += s1;
88	if (s2 >= modulo)
89	s2 -= modulo;
90
91	};
92	return (s2 << 16) + s1;
93	}
94
95	void
96	out_char (FILE * o, int code)
97	{
98	static char line[MAXLINE + 1];
99	static int llen = 0;
100
101	if (code == -2)
102	{
103	if (llen)
104	{
105	line[llen] = 0;
106	if (!nooutput)
107	fprintf (o, "%c%s\n", ID3, line);
108	}
109	}
110	else if (code == -1)
111	{
112	llen = 0;
113	}
114	else
115	{
116	line[llen++] = code;
117	if (llen >= linelen)
118	{
119	llen = 0;
120	line[linelen] = 0;
121	if (!nooutput)
122	fprintf (o, "%c%s\n", ID3, line);
123	}
124	}
125	}
126
127	int
128	encode (FILE * i, FILE * o, char *id)
129	{
130	u8 *block;
131	long blklen;
132	int len;
133
134	if (complevel <= 1)
135	{
136	linelen = 120;
137	blklen = 50000;
138	}
139	else if (complevel <= 5)
140	{
141	linelen = 996;
142	blklen = 50000;
143	}
144	else if (complevel <= 7)
145	{
146	linelen = 7996;
147	blklen = 50000;
148	}
149	else
150	{
151	linelen = 60000;
152	blklen = 5000000;
153	}
154
155	block = malloc (blklen);
156
157	if (!block)
158	{
159	fprintf (stderr, "unable to allocate %ld bytes", blklen * 2);
160	return 11;
161	}
162
163	if (!nooutput)
164	{
165	fprintf (o, "%s\n", ID1);
166	fprintf (o, "%s VERSION 2\n", ID2);
167	if (id)
168	fprintf (o, "%s IDENT %s\n", ID2, id);
169	}
170
171	/fprintf (o, "%s CODEC AFE0C0DE\n", ID2);/ /* default */
172	while ((len = fread (block, 1, blklen, i)) > 0)
173	{
174	u32 sum = adler32 (block, len);
175	u8 *p = block;
176
177	if (!nooutput)
178	fprintf (o, "%s BLOCK %d %08lx\n", ID2, len, sum);
179
180	out_char (o, -1);
181	while (len--)
182	{
183	int c = *p++ ^ (u8) sum++;
184
185	if (c == ESCAPE)
186	{
187	out_char (o, ESCAPE);
188	if (len)
189	{
190	switch (*p ^ (u8) sum)
191	{
192	case 'A':
193	case 'B':
194	case 'C':
195	case 'D':
196	out_char (o, 'A');
197	break;
198	default:
199	/* nothing */;
200	}
201	}
202	else
203	out_char (o, 'A');
204	}
205	else if (c == 0x00)
206	{
207	out_char (o, ESCAPE);
208	out_char (o, 'B');
209	}
210	else if (c == 0x0a)
211	{
212	out_char (o, ESCAPE);
213	out_char (o, 'C');
214	}
215	else if (c == 0x0d)
216	{
217	out_char (o, ESCAPE);
218	out_char (o, 'D');
219	}
220	else
221	{
222	out_char (o, c);
223	}
224	}
225
226	out_char (o, -2);
227	}
228
229	if (!nooutput)
230	fprintf (o, "%s END\n", ID2);
231
232	free (block);
233
234	return 0;
235	}
236
237	int
238	in_char (FILE * i, int code)
239	{
240	static int llen;
241	static char line[MAXLINE + 3];
242
243	if (code == -1)
244	{
245	llen = MAXLINE + 1;
246	return 0;
247	}
248	else
249	{
250	if (llen > MAXLINE
251	\|\| line[llen] == 0
252	\|\| line[llen] == '\r'
253	\|\| line[llen] == '\n')
254	{
255	do {
256	if (!fgets (line, sizeof (line), i))
257	{
258	perror ("error on block read (file truncated?)");
259	return -1;
260	}
261	} while (line[0] != ID3);
262
263	llen = 1;
264	}
265
266	return (unsigned char) line[llen++];
267	}
268	}
269
270	int
271	decodeblock (FILE * i, u8 * data, int len, int sum)
272	{
273	int ch;
274
275	(void) in_char (i, -1);
276
277	while (len--)
278	{
279	ch = in_char (i, 0);
280	if (ch < 0)
281	return 8;
282
283	retry:
284	if (ch == ESCAPE)
285	{
286	switch ((ch = in_char (i, 0)))
287	{
288	case 'A': ch = ESCAPE; break;
289	case 'B': ch = 0x00; break;
290	case 'C': ch = 0x0a; break;
291	case 'D': ch = 0x0d; break;
292
293	default:
294	*data++ = (u8) ESCAPE ^ (u8) sum++; len--;
295	goto retry;
296	}
297	}
298
299	*data++ = (u8) ch ^ (u8) sum++;
300	}
301
302	return 0;
303	}
304
305	int
306	decode (FILE * i, FILE * o)
307	{
308	char input[255];
309	char *opt = input + sizeof (ID2) - 1 + 1;
310	long blklen;
311	int err;
312	u32 sum, sum2;
313
314	u32 codec = 0xafe1c0de;
315	int version = 0;
316	char ident[255];
317
318	ident[0] = 0;
319
320	do
321	{
322	if (!fgets (input, sizeof (input), i))
323	{
324	perror ("unable to find start of encoded data");
325	return 1;
326	}
327	}
328	while (strncmp (input, ID1, sizeof (ID1) - 1));
329
330	if (verbose)
331	fprintf (stderr, "basex header found, processing options\n");
332
333	for (;;)
334	{
335	if (!fgets (input, sizeof (input), i))
336	{
337	perror ("error while processing options");
338	return 2;
339	}
340
341	if (strncmp (input, ID2, sizeof (ID2) - 1) \|\| *(opt - 1) != ' ')
342	{
343	fprintf (stderr, "garbage instead of option, ignored\n");
344	}
345	else
346	{
347	if (sscanf (opt, "VERSION %d\n", &version) == 1)
348	{
349	if (verbose)
350	fprintf (stderr, "option version %d\n", version);
351
352	if (version != 2)
353	{
354	fprintf (stderr, "unsupported version %d\n", version);
355	return 5;
356	}
357	}
358	else if (sscanf (opt, "CODEC %8lx\n", &codec) == 1)
359	{
360	if (verbose)
361	fprintf (stderr, "option codec %lx\n", codec);
362	}
363	else if (sscanf (opt, "IDENT %[^\n]\n", ident) == 1)
364	{
365	if (verbose \|\| showident)
366	fprintf (stderr, "option ident %s\n", ident);
367	}
368	else if (strcmp (opt, "END\n") == 0)
369	{
370	if (verbose)
371	fprintf (stderr, "option end\n");
372
373	return 0;
374	}
375	else if (sscanf (opt, "BLOCK %ld %08lx\n", &blklen, &sum) == 2)
376	{
377	u8 *block;
378
379	if (verbose)
380	fprintf (stderr, "option block len %ld, checksum %08lx\n", blklen, sum);
381
382	if (blklen > MAXBLK)
383	{
384	fprintf (stderr, "block length too large (%ld>%ld)\n", blklen, MAXBLK);
385	return 4;
386	}
387
388	switch (codec)
389	{
390	case 0xafe1c0de:
391
392	block = malloc (blklen);
393
394	if (!block)
395	{
396	fprintf (stderr, "unable to allocate %ld bytes", blklen);
397	return 11;
398	}
399
400	err = decodeblock (i, block, blklen, sum);
401	if (err)
402	return err;
403
404	sum2 = adler32 (block, blklen);
405	if (sum != sum2)
406	{
407	fprintf (stderr, "checksumming error %08lx != %08lx\n", sum, sum2);
408	return 9;
409	}
410
411	if (!nooutput && fwrite (block, blklen, 1, o) <= 0)
412	{
413	perror ("write error");
414	return 10;
415	}
416
417	free (block);
418	break;
419
420	default:
421	fprintf (stderr, "unknown codec %08lx\n", codec);
422	return 3;
423	}
424	}
425	else
426	{
427	fprintf (stderr, "unknown or unrecognized option %s\n", opt);
428	return 2;
429	}
430	}
431	}
432	}
433
434	int
435	main (int argc, char *argv[])
436	{
437	int dec = 0;
438	char *id = 0;
439
440	for (;;)
441	{
442	int c = getopt (argc, argv, "Vvdi:In123456789");
443
444	if (c == EOF)
445	break;
446
447	switch (c)
448	{
449	case 'V':
450	puts (version);
451	exit (EXIT_SUCCESS);
452	break;
453
454	case 'v':
455	verbose = 1;
456	break;
457
458	case 'd':
459	dec = 1;
460	break;
461
462	case 'i':
463	id = optarg;
464	break;
465
466	case 'I':
467	showident = 1;
468	break;
469
470	case 'n':
471	nooutput = 1;
472	break;
473
474	case '1':
475	case '2':
476	case '3':
477	case '4':
478	complevel = 1;
479	break;
480	case '5':
481	case '6':
482	complevel = 5;
483	break;
484	case '7':
485	case '8':
486	complevel = 7;
487	break;
488	case '9':
489	complevel = 9;
490	break;
491
492	case '?':
493	fprintf (stderr, "encode: basex [-v] [-n] [-i id] [-1 \| -5 \| -7 \| -9]\n");
494	fprintf (stderr, "decode: basex [-d] [-v] [-n] [-I]\n");
495	break;
496	}
497	}
498
499	if (verbose)
500	fprintf (stderr, "mode %s\n", dec ? "decoding" : "encoding");
501
502	if (dec)
503	return decode (stdin, stdout);
504	else
505	return encode (stdin, stdout, id);
506	}
507