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
/* opqcp - Makes opaque copies of a group of sources to support a flavor
* of distribution with the security of an object-only version but the ability
* to recompile on a variety of machines like a source distribution.
*
* The idea is that there is a lot of information in good sources which is
* not needed by the compiler or linker, but which conveys the meaning of the
* program to a programmer. We try to write the most understandable programs
* possible, opqcp aspires to translate them into the least understandable.
*
* Comments, #includes, #define'ed constants and macros - stripped or
* expanded by pouring the source through the C preprocessor.
*
* Global symbols - translated into unreadable equivalents or preserved
* if needed to link to the program or function. A global dictionary
* must have previously been derived from the .o file symbol tables.
* (All C reserved keywords are preserved automatically.)
*
* Local identifiers - Translated into unreadable equivalents within
* a single source file. This applies to everything not in the global
* table (variables, typedefs, struct fields, etc.)
*
* Indentation/Whitespace - The tokens are packed on screen-width lines with
* all whitespace removed.
*
* Arguments (dash args precede file and destdir args.):
* -d dictfile - (Optional, may be repeated.) Contains a wordlist that is
* entered into a symbol table of global names. Lines with just a name
* mark that identifier as a clear global to preserve in the output.
* (All C reserved words are automatically preserved in this way.)
* Lines with a name and its translation separated by a blank character
* denote an opaque global which is translated the same everywhere.
* All other symbols will be locally translated and may be different in
* each source file.
*
* -Idir - (Optional, may be repeated.) Include directory arguments passed
* on to the C preprocessor.
*
* -f - Filter mode, just opacifies stdin to stdout. File and
* directory arguments are ignored and the input must already have
* been run through "cc -E" if preprocessing is desired.
*
* -t - Token trace (for testing). Forces filter mode, prints token
* types and values.
*
* filenames.c - (Required except in filter mode, may be repeated.)
* Source files to obfuscate.
*
* destdir - (One required as the last argument except in filter mode.)
* Where to put the opaque copies of the source files.
* The copies have the same names as the originals, but opqcp
* refuses to overwrite a file with itself.
*/
#include "misc.h"
#include "symtab.h"
#include "sys/types.h"
#include "sys/stat.h"
#include "ctype.h"
string c_keywords[] = /* From K&R, appendix A, section 2.3. */
{
"int", "char", "float", "double", "struct", "union", "enum", "long",
"short", "unsigned", "auto", "extern", "register", "typedef", "static",
"goto", "return", "sizeof", "break", "continue", "if", "else", "for",
"do", "while", "switch", "case", "default", "entry", "fortran", "asm",
"main", /* Reserved for main program functions. */
"void" /* Not in K&R, added since then. */
};
int n_keywords = sizeof c_keywords / sizeof( string );
main( argc, argv )
int argc;
string argv[];
{
boolean filter_mode = FALSE, token_trace = FALSE;
int i, j, k, l, arg_num;
hash_table * globals, * locals;
id * symbol;
string *name_ptr, *arg_ptr, arg;
static char I_args[BUFSIZ] = { '\0' };
char buffer[BUFSIZ], buffer2[BUFSIZ];
struct stat stat_buffer;
FILE * dict_in, * input, * output, * popen();
dev_t input_dev;
ino_t input_inode;
string directory, name, translation, index();
char chr, * chr_ptr , token[BUFSIZ], * token_end, string_type;
int token_length, line_length;
enum { NONE, SYMBOL, STRING, NUMBER, OTHER }
token_type, prev_token_type;
static string token_type_strings[] =
{ "none", "symbol", "string", "number", "other" };
boolean whitespace;
/* These characters will not be separated if they occur together. */
string op_diphthong_chars = "=!<>&|+-*/%&^";
/* Some simple macros to stream characters through the token recognizer. */
# define NEW_TOKEN ( token_end = token, *token_end = '\0' )
# define NEXT ( OUT, IN )
# define OUT ( *token_end++ = chr, *token_end = '\0' )
# define IN ( chr = getc( input ) )
# define NEW_LINE ( line_length = 0 )
int local_counter = 0;
# define NLOCALS 5000
static char local_names[NLOCALS][6];
/* Save a lot of hassle by putting the local name strings in a static
* array where they can be re-used. The var_value cells of the ids in
* a hashed symbol table are second class citizens in that they are not
* freed when the hash table is freed, although the var_name strings are.
*/
for ( i=0; i < NLOCALS/1000; i++ ) /* Initialize the local name strings. */
for ( j=0; j<=9; j++ )
for ( k=0; k<=9; k++ )
for ( l=0; l<=9; l++ )
{
chr_ptr = local_names[local_counter++];
*chr_ptr++ = 'l'; /* Leading letter. */
if ( i ) *chr_ptr++ = '0' + i; /* Thousands. */
if ( i || j ) *chr_ptr++ = '0' + j; /* Hundreds. */
if ( i || j || k ) *chr_ptr++ = '0' + k; /* Tens. */
*chr_ptr++ = '0' + l; /* Ones. */
*chr_ptr = '\0';
}
/* Start out the global dictionary with the C keywords. */
globals = new_hash_table( 1000 );
for ( i=0, name_ptr = c_keywords; i < n_keywords; i++, name_ptr++ )
new_symbol( *name_ptr, globals );
/* Process dash arguments. */
for ( arg_num=1, arg_ptr = &argv[1], arg = *arg_ptr;
arg_num < argc;
arg_num++, arg_ptr++, arg = *arg_ptr )
{
if ( arg[0] != '-' )
break; /* Only do dash args here. */
/* Process -d (global dictionary) args. */
if ( strcmp( arg, "-d" ) == 0 )
{
if ( ++arg_num >= argc-1 ) break; /* Ignore -d at the end. */
arg = *++arg_ptr;
if ( (dict_in = fopen( arg, "r" )) == NULL )
{
sprintf( buffer, "opqcp: Can't open dictionary %s\n", arg );
perror( buffer );
exit( 1 );
}
while( fgets( buffer, BUFSIZ, dict_in ) != NULL )
{
/* Trash the newline fgets puts in the buffer. */
buffer[ strlen(buffer)-1 ] = '\0';
/* Optional translation is separated from name by a blank. */
if ( (translation = index( buffer, ' ' )) != NULL )
*translation++ = '\0'; /* Terminate the name string. */
/* Link in a copy of the name string. */
name = NEW( char, strlen(buffer)+1 );
strcpy( name, buffer );
symbol = new_symbol( name, globals );
/* Translation will be NULL if symbol is to be left alone. */
if ( translation != NULL )
{
/* Link in a copy of the translation string. */
symbol->var_value = NEW( char, strlen(translation)+1 );
strcpy( symbol->var_value, translation );
}
}
fclose( dict_in );
}
/* Process -Idir (cpp include directory) argument(s). */
else if ( strncmp( arg, "-I", 2 ) == 0 )
{
strcat( I_args, " " );
strcat( I_args, arg );
}
/* Process a -t (token trace) argument. */
else if ( strcmp( arg, "-t" ) == 0 )
{
token_trace = TRUE; /* For testing. */
goto filter; /* Forces filter mode. */
}
/* Process a -f (filter mode) argument. */
else if ( strcmp( arg, "-f" ) == 0 )
{
filter:
filter_mode = TRUE; /* No-ops all of the file handling. */
input = stdin;
output = stdout;
}
else
break; /* Out if invalid dash arg. */
}
/* Usage message if bad dash flag or no file and dir args . */
if ( arg[0] == '-' || !filter_mode && argc-arg_num < 2 )
{
fprintf( stderr, "%s\n%s\n",
"usage: opqcp [-d dict]* [-Idir]* [srcfile]+ destdir",
" or opqcp [-d dict]* -f" );
exit( 2 );
}
/* Check that the last argument is a directory. */
if ( !filter_mode )
{
if ( stat( directory = argv[argc-1], &stat_buffer ) == -1 )
{
sprintf( buffer, "opqcp: Can't stat directory %s\n", directory );
perror( buffer );
exit( 1 );
}
if ( ! (stat_buffer.st_mode & S_IFDIR) )
{
fprintf( stderr, "opqcp: %s is not a directory.\n", directory );
exit( 1 );
}
}
/* Loop through the file arguments. */
for ( ; filter_mode || arg_num < argc-1; arg_num++, arg_ptr++ )
{
if ( filter_mode )
arg = "(stdin)";
else
{
arg = *arg_ptr;
/* Before opening the output file, check that it isn't the same
* as the input file. (This would result in clearing the file
* before it was read!)
*/
if ( stat( arg, &stat_buffer ) == -1 )
{
sprintf( buffer, "opqcp: Can't stat input file %s\n", arg );
perror( buffer );
continue; /* Go do next file arg. */
}
/* Might as well check that it's a plain file while we're here. */
if ( ! (stat_buffer.st_mode & S_IFREG) )
{
fprintf( stderr, "opqcp: %s is not a plain file.\n", arg );
continue; /* Go do next file arg. */
}
input_dev = stat_buffer.st_dev;
input_inode = stat_buffer.st_ino;
sprintf( buffer, "%s/%s", directory, arg ); /* Output file path. */
if ( stat( buffer, &stat_buffer ) == 0 )
{ /* We can only stat an already existing output file. */
/* Check for inode collision to guard against overwriting. */
if ( stat_buffer.st_dev == input_dev &&
stat_buffer.st_ino == input_inode )
{
fprintf( stderr, "opqcp: Can't copy file %s to itself.\n",
arg );
continue; /* Go on to next file arg. */
}
/* Check that it's a plain file while we're here. */
if ( ! (stat_buffer.st_mode & S_IFREG) )
{
fprintf( stderr, "opqcp: %s is not a plain file.\n",
buffer );
continue; /* Go on to next file arg. */
}
}
/* Open the opaque source file on the destination directory. */
if ( (output = fopen( buffer, "w" )) == NULL )
{
sprintf( buffer, "opqcp: Can't write file %s",arg );
perror( buffer );
continue; /* Go on to the next file. */
}
/* Copyright notice. */
fputs( "/* Licensed material, Copyright ", output );
fputs( "(c) 1985, University of Utah. */\n", output );
/* Read the source file through the C preprocessor. */
sprintf( buffer2, "cc -E %s %s", I_args, arg );
if ( (input = popen( buffer2, "r" )) == NULL )
{
sprintf( buffer2, "opqcp: Couldn't start cpp on %s.",arg );
perror( buffer2 );
fclose( output ); /* It was already opened. */
unlink( buffer ); /* Wipe out the empty output file. */
continue; /* Go on to the next file. */
}
}
/* Local dictionary lasts only through a single source file. */
locals = new_hash_table( 1000 );
local_counter = 0;
/* Transfer tokens from the cpp stream to a packed output file. */
chr = '\n'; /* In effect, the end of the line before the first line. */
NEW_LINE; /* Start first line of output. */
prev_token_type = NONE;
/* Back here at the beginning of each token. */
while( chr != EOF )
{
NEW_TOKEN; /* Set up to collect a token. */
token_type = NONE;
whitespace = FALSE;
/* Flush whitespace before a token. */
while( isspace( chr ) )
{
whitespace = TRUE;
if ( chr != '\n' )
IN; /* Character after blank or tab. */
else
{
IN; /* First character on a line. */
if ( chr == '#' )
{
/* Flush C preprocessor linenumber statements. */
while ( chr != '\n' && chr != EOF )
IN; /* Go until the newline is found. */
}
}
}
/* Identifiers, keywords, etc. Underscore is a letter. */
if ( isalpha( chr ) || chr == '_' )
{
token_type = SYMBOL;
/* Grab the alpha and then alphanumeric characters. */
NEXT;
while ( isalnum( chr ) || chr == '_' ) NEXT;
/* Look the symbol up in the global dictionary. */
if ( (symbol = find_symbol( token, globals )) != NULL )
{
/* Substitute a global translation if there is one. */
if ( symbol->var_value != NULL )
{
strcpy( token, symbol->var_value );
}
}
else
{
/* Look the symbol up in the local dictionary. */
if ( (symbol = find_symbol( token, locals )) == NULL )
{
/* New symbol, assign a local translation. */
name = NEW( char, strlen(token)+1 );
strcpy( name, token );
symbol = new_symbol( name, locals );
symbol->var_value = local_names[++local_counter];
}
/* Translate symbol to the local equivalent. */
strcpy( token, symbol->var_value );
}
}
/* Character constants and strings. */
else if ( chr == '"' || chr == '\'' )
{
token_type = STRING;
string_type = chr; /* Remember which kind of quote. */
NEXT; /* Stash quote, get first char of string. */
while ( chr != string_type )
{
if ( chr != '\\' )
NEXT; /* Stash non-backslash char, go ahead. */
else
/* Handle backslash escapes. */
{
NEXT; /* Stash backslash, go to escaped char. */
if ( string_type != '"' || chr != '\n' )
NEXT; /* Stash escaped char, go ahead. */
else
{
/* Weird special case. Strings can be
* continued onto the next line if they
* precede the newline with a backslash.
*/
NEXT; /* Stash escaped newline, go ahead. */
if ( strlen(token) + line_length > 77 )
fputs( "\n", output ); /* Break before. */
/* Put out the string with escaped newline. */
fputs( token, output );
/* Start a new line and a new token. */
NEW_LINE; NEW_TOKEN;
}
}
}
NEXT; /* Stash closing quote. */
}
/* Numbers. (This can be a bit simplified over a real
* lexical analyzer, since it only has to correctly
* recognize all valid number forms, not detect subtle
* syntax errors.)
*/
else if ( isdigit( chr ) )
{
number:
token_type = NUMBER;
/* Initial numeric part. */
if ( chr == '0' )
{ /* Could be an octal or hex constant, or just a "0". */
NEXT;
if ( chr == 'x' || chr == 'X' )
{
NEXT; /* Get first char of hex constant. */
while( isdigit( chr ) || chr >= 'a' && chr <= 'f'
|| chr >= 'A' && chr <= 'F' )
NEXT; /* Read through hex constant. */
}
else /* Octal integer constant. */
while ( isdigit( chr ) ) NEXT;
}
else
/* Decimal integer, or part of a floating pt number. */
while ( isdigit( chr ) ) NEXT;
/* Optional integer "l" suffix, fraction, or exponent. */
if ( chr == 'l' || chr == 'L' )
NEXT;
else
{
/* Optional fractional part on floats. */
if ( chr == '.' )
{
NEXT; /* Get first char of fraction. */
while ( isdigit( chr ) ) NEXT;
}
/* Optional exponent. */
if ( chr == 'e' || chr == 'E' )
{
NEXT; /* Get first char of exponent. */
/* Optional sign on exponent. */
if ( chr == '+' || chr == '-' ) NEXT;
while ( isdigit( chr ) ) NEXT; /* Exponent. */
}
}
}
/* Operators and single-character tokens for punctuation. */
else if( chr != EOF )
{
token_type = OTHER;
/* Dot may be either a leading decimal point on a number,
* or a structure access operator. We have a number if the
* following character is a digit.
*/
if ( chr == '.' )
{
NEXT;
if ( isdigit( chr ) )
goto number; /* Yep, leading decimal point. */
}
else /* Everything other than dots. */
{
/* Keep operator diphthongs contiguous. */
if ( index( op_diphthong_chars, chr ) != NULL )
while ( index( op_diphthong_chars, chr ) != NULL )
NEXT; /* Collect diphthong characters. */
else
NEXT; /* Single-character token. */
}
}
if ( token_trace )
fprintf( output, "type = %s, token = `",
token_type_strings[ (int)token_type ] );
/* Got a token in the buffer, pack it onto an output line. */
token_length = strlen( token );
if ( token_length + line_length > 77 ) /* Time for line break? */
{
fputs( "\n", output ); /* Line break. */
NEW_LINE; /* Start next line. */
}
/* Need to preserve blanks between symbols or numbers, and
* between operators next to = signs so they don't run together.
*/
else if ( (prev_token_type==SYMBOL || prev_token_type==NUMBER) &&
(token_type==SYMBOL || token_type==NUMBER) ||
token[0] == '=' && whitespace ) /* Space before =. */
{
fputs( " ", output );
line_length++;
}
/* Add token to the output stream. */
fputs( token, output );
line_length += token_length;
if ( token[token_length-1] == '=' && isspace( chr ) )
{
fputs( " ", output ); /* Space after = sign. */
line_length++;
}
if ( token_trace )
fprintf( output, "'\n" );
prev_token_type = token_type;
}
/* EOF. */
fputs( "\n", output ); /* End of line at end of file. */
if ( filter_mode )
exit( 0 ); /* Done. */
else
{
pclose( input );
fclose( output );
fr_hash_table( locals );
}
} /* Next file. */
}