This file is indexed.

/usr/bin/hardening-check is in hardening-includes 2.7ubuntu2.

This file is owned by root:root, with mode 0o755.

The actual contents of the file can be viewed below.

  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
#!/usr/bin/perl
# Report the hardening characterists of a set of binaries.
# Copyright (C) 2009-2013 Kees Cook <kees@debian.org>
# License: GPLv2 or newer
use strict;
use warnings;
use Getopt::Long qw(:config no_ignore_case bundling);
use Pod::Usage;
use IPC::Open3;
use Symbol qw(gensym);
use Term::ANSIColor;

my $skip_pie = 0;
my $skip_stackprotector = 0;
my $skip_fortify = 0;
my $skip_relro = 0;
my $skip_bindnow = 0;
my $report_functions = 0;
my $find_libc_functions = 0;
my $color = 0;
my $lintian = 0;
my $verbose = 0;
my $debug = 0;
my $quiet = 0;
my $help = 0;
my $man = 0;

GetOptions(
        "nopie|p+" => \$skip_pie,
        "nostackprotector|s+" => \$skip_stackprotector,
        "nofortify|f+" => \$skip_fortify,
        "norelro|r+" => \$skip_relro,
        "nobindnow|b+" => \$skip_bindnow,
        "report-functions|R!" => \$report_functions,
        "find-libc-functions|F!" => \$find_libc_functions,
        "color|c!" => \$color,
        "lintian|l!" => \$lintian,
        "verbose|v!" => \$verbose,
        "debug!" => \$debug,
        "quiet|q!" => \$quiet,
        "help|h|?" => \$help,
        "man|H" => \$man,
    ) or pod2usage(2);
pod2usage(1) if $help;
pod2usage(-exitstatus => 0, -verbose => 2, -noperldoc => 1) if $man;

my $overall = 0;
my $rc = 0;
my $report = "";
my @tags;
my %libc = (
    'asprintf' => 1,
    'confstr' => 1,
    'dprintf' => 1,
    'fdelt' => 1,
    'fgets' => 1,
    'fgets_unlocked' => 1,
    'fgetws' => 1,
    'fgetws_unlocked' => 1,
    'fprintf' => 1,
    'fread' => 1,
    'fread_unlocked' => 1,
    'fwprintf' => 1,
    'getcwd' => 1,
    'getdomainname' => 1,
    'getgroups' => 1,
    'gethostname' => 1,
    'getlogin_r' => 1,
    'gets' => 1,
    'getwd' => 1,
    'longjmp' => 1,
    'mbsnrtowcs' => 1,
    'mbsrtowcs' => 1,
    'mbstowcs' => 1,
    'memcpy' => 1,
    'memmove' => 1,
    'mempcpy' => 1,
    'memset' => 1,
    'obstack_printf' => 1,
    'obstack_vprintf' => 1,
    'poll' => 1,
    'ppoll' => 1,
    'pread64' => 1,
    'pread' => 1,
    'printf' => 1,
    'ptsname_r' => 1,
    'read' => 1,
    'readlink' => 1,
    'readlinkat' => 1,
    'realpath' => 1,
    'recv' => 1,
    'recvfrom' => 1,
    'snprintf' => 1,
    'sprintf' => 1,
    'stpcpy' => 1,
    'stpncpy' => 1,
    'strcat' => 1,
    'strcpy' => 1,
    'strncat' => 1,
    'strncpy' => 1,
    'swprintf' => 1,
    'syslog' => 1,
    'ttyname_r' => 1,
    'vasprintf' => 1,
    'vdprintf' => 1,
    'vfprintf' => 1,
    'vfwprintf' => 1,
    'vprintf' => 1,
    'vsnprintf' => 1,
    'vsprintf' => 1,
    'vswprintf' => 1,
    'vsyslog' => 1,
    'vwprintf' => 1,
    'wcpcpy' => 1,
    'wcpncpy' => 1,
    'wcrtomb' => 1,
    'wcscat' => 1,
    'wcscpy' => 1,
    'wcsncat' => 1,
    'wcsncpy' => 1,
    'wcsnrtombs' => 1,
    'wcsrtombs' => 1,
    'wcstombs' => 1,
    'wctomb' => 1,
    'wmemcpy' => 1,
    'wmemmove' => 1,
    'wmempcpy' => 1,
    'wmemset' => 1,
    'wprintf' => 1,
);

# Report a good test.
sub good {
    my ($name, $msg_color, $msg) = @_;
    $msg_color = colored($msg_color, 'green') if $color;
    if (defined $msg) {
        $msg_color .= $msg;
    }
    good_msg("$name: $msg_color");
}
sub good_msg($) {
    my ($msg) = @_;
    if ($quiet == 0) {
        $report .= "\n$msg";
    }
}

sub unknown {
    my ($name, $msg) = @_;
    $msg = colored($msg, 'yellow') if $color;
    good_msg("$name: $msg");
}

# Report a failed test, possibly ignoring it.
sub bad($$$$$) {
    my ($name, $file, $long_name, $msg, $ignore) = @_;

    $msg = colored($msg, 'red') if $color;

    $msg = "$long_name: " . $msg;
    if ($ignore) {
        $msg .= " (ignored)";
    }
    else {
        $rc = 1;
        if ($lintian) {
            push(@tags, "$name:$file");
        }
    }
    $report .= "\n$msg";
}

# Safely run list-based command line and return stdout.
sub output(@) {
    my (@cmd) = @_;
    my ($pid, $stdout, $stderr);
    if ($debug) {
        print join(" ", @cmd),"\n";
    }
    $stdout = gensym;
    $stderr = gensym;
    $pid = open3(gensym, $stdout, $stderr, @cmd);
    my $collect = "";
    while ( <$stdout> ) {
        $collect .= $_;
    }
    waitpid($pid, 0);
    my $rc = $?;
    if ($rc != 0) {
        while ( <$stderr> ) {
            print STDERR;
        }
        return "";
    }
    return $collect;
}

# Find the libc used in this executable, if any.
sub find_libc($) {
    my ($file) = @_;
    my $ldd = output("ldd", $file);
    $ldd =~ /^\s*libc\.so\.\S+\s+\S+\s+(\S+)/m;
    return $1 || "";
}

sub find_functions($$) {
    my ($file, $undefined) = @_;
    my (%funcs);

    # Catch "NOTYPE" for object archives.
    my $func_regex = " (I?FUNC|NOTYPE) ";

    my $relocs = output("readelf", "-sW", $file);
    for my $line (split("\n", $relocs)) {
        next if ($line !~ /$func_regex/);
        next if ($undefined && $line !~ /$func_regex.* UND /);

        $line =~ s/ \([0-9]+\)$//;
        $line =~ s/.* //;
        $line =~ s/@.*//;
        $funcs{$line} = 1;
    }

    return \%funcs;
}


$ENV{'LANG'} = "C";

if ($find_libc_functions) {
    pod2usage(1) if (!defined($ARGV[0]));
    my $libc_path = find_libc($ARGV[0]);

    my $funcs = find_functions($libc_path, 0);
    for my $func (sort(keys(%{$funcs}))) {
        if ($func =~ /^__(\S+)_chk$/) {
            print "    '$1' => 1,\n";
        }
    }
    exit(0);
}
die "List of libc functions not defined!" if (scalar(keys %libc) < 1);

my $name;
foreach my $file (@ARGV) {
    $rc = 0;
    my $elf = 1;

    $report = "$file:";
    @tags = ();

    # Get program headers.
    my $PROG_REPORT=output("readelf", "-lW", $file);
    if (length($PROG_REPORT) == 0) {
        $overall = 1;
        next;
    }

    # Get ELF headers.
    my $DYN_REPORT=output("readelf", "-dW", $file);

    # Get list of all symbols needing external resolution.
    my $functions = find_functions($file, 1);

    # PIE
    # First, verify this is an executable, not a library. This seems to be
    # best seen by checking for the PHDR program header.
    $name = " Position Independent Executable";
    $PROG_REPORT =~ /^Elf file type is (\S+)/m;
    my $elftype = $1 || "";
    if ($elftype eq "DYN") {
        if ($PROG_REPORT =~ /^ *\bPHDR\b/m) {
            # Executable, DYN ELF type.
            good($name, "yes");
        }
        else {
            # Shared library, DYN ELF type.
            good($name, "no, regular shared library (ignored)");
        }
    }
    elsif ($elftype eq "EXEC") {
        # Executable, EXEC ELF type.
        bad("no-pie", $file, $name,
            "no, normal executable!", $skip_pie);
    }
    else {
        $elf = 0;
        # Is this an ar file with objects?
        open(AR, "<$file");
        my $header = <AR>;
        close(AR);
        if ($header eq "!<arch>\n") {
            good($name, "no, object archive (ignored)");
        }
        else {
            # ELF type is neither DYN nor EXEC.
            bad("unknown-elf", $file, $name,
                "not a known ELF type!? ($elftype)", 0);
        }
    }

    # Stack-protected
    $name = " Stack protected";
    if (defined($functions->{'__stack_chk_fail'}) ||
        (!$elf && defined($functions->{'__stack_chk_fail_local'}))) {
        good($name, "yes")
    }
    else {
        bad("no-stackprotector", $file, $name,
            "no, not found!", $skip_stackprotector);
    }

    # Fortified Source
    $name = " Fortify Source functions";
    my @unprotected;
    my @protected;
    for my $name (keys(%libc)) {
        if (defined($functions->{$name})) {
            push(@unprotected, $name);
        }
        if (defined($functions->{"__${name}_chk"})) {
            push(@protected, $name);
        }
    }
    if ($#protected > -1) {
        if ($#unprotected == -1) {
            # Certain.
            good($name, "yes");
        }
        else {
            # Vague, due to possible compile-time optimization,
            # multiple linkages, etc. Assume "yes" for now.
            good($name, "yes", " (some protected functions found)");
        }
    }
    else {
        if ($#unprotected == -1) {
            unknown($name, "unknown, no protectable libc functions used");
        }
        else {
            # Vague, since it's possible to have the compile-time
            # optimizations do away with them, or be unverifiable
            # at runtime. Assume "no" for now.
            bad("no-fortify-functions", $file, $name,
                "no, only unprotected functions found!", $skip_fortify);
        }
    }
    if ($verbose) {
        for my $name (@unprotected) {
            good_msg("\tunprotected: $name");
        }
        for my $name (@protected) {
            good_msg("\tprotected: $name");
        }
    }

    # Format
    # Unfortunately, I haven't thought of a way to test for this after
    # compilation. What it really needs is a lintian-like check that
    # reviews the build logs and looks for the warnings, or that the
    # argument is changed to use -Werror=format-security to stop the build.

    # RELRO
    $name = " Read-only relocations";
    if ($PROG_REPORT =~ /^ *\bGNU_RELRO\b/m) {
        good($name, "yes");
    } else {
        if ($elf) {
            bad("no-relro", $file, $name, "no, not found!", $skip_relro);
        } else {
            good($name, "no", ", non-ELF (ignored)");
        }
    }

    # BIND_NOW
    # This marking keeps changing:
    # 0x0000000000000018 (BIND_NOW)           
    # 0x000000006ffffffb (FLAGS)              Flags: BIND_NOW
    # 0x000000006ffffffb (FLAGS_1)            Flags: NOW

    $name = " Immediate binding";
    if ($DYN_REPORT =~ /^\s*\S+\s+\(BIND_NOW\)/m ||
        $DYN_REPORT =~ /^\s*\S+\s+\(FLAGS\).*\bBIND_NOW\b/m ||
        $DYN_REPORT =~ /^\s*\S+\s+\(FLAGS_1\).*\bNOW\b/m) {
        good($name, "yes");
    } else {
        if ($elf) {
            bad("no-bindnow", $file, $name, "no, not found!", $skip_bindnow);
        } else {
            good($name, "no", ", non-ELF (ignored)");
        }
    }

    if (!$lintian && (!$quiet || $rc != 0)) {
        print $report,"\n";
    }

    if ($report_functions) {
        for my $name (keys(%{$functions})) {
            print $name,"\n";
        }
    }

    if (!$lintian && $rc) {
        $overall = $rc;
    }

    if ($lintian) {
        for my $tag (@tags) {
            print $tag, "\n";
        }
    }
}

exit($overall);

__END__

=pod

=head1 NAME

hardening-check - check binaries for security hardening features

=head1 SYNOPSIS

hardening-check [options] [ELF ...]

Examine a given set of ELF binaries and check for several security hardening
features, failing if they are not all found.

=head1 DESCRIPTION

This utility checks a given list of ELF binaries for several security
hardening features that can be compiled into an executable. These
features are:

=over 8

=item B<Position Independent Executable>

This indicates that the executable was built in such a way (PIE) that
the "text" section of the program can be relocated in memory. To take
full advantage of this feature, the executing kernel must support text
Address Space Layout Randomization (ASLR).

=item B<Stack Protected>

This indicates that there is evidence that the ELF was compiled with the
L<gcc(1)> option B<-fstack-protector> (e.g. uses B<__stack_chk_fail>). The
program will be resistant to having its stack overflowed.

When an executable was built without any character arrays being allocated
on the stack, this check will lead to false alarms (since there is no
use of B<__stack_chk_fail>), even though it was compiled with the correct
options.

=item B<Fortify Source functions>

This indicates that the executable was compiled with
B<-D_FORTIFY_SOURCE=2> and B<-O1> or higher. This causes certain unsafe
glibc functions with their safer counterparts (e.g. B<strncpy> instead
of B<strcpy>), or replaces calls that are verifiable at runtime with the
runtime-check version (e.g. B<__memcpy_chk> insteade of B<memcpy>).

When an executable was built such that the fortified versions of the glibc
functions are not useful (e.g. use is verified as safe at compile time, or
use cannot be verified at runtime), this check will lead to false alarms.
In an effort to mitigate this, the check will pass if any fortified function
is found, and will fail if only unfortified functions are found. Uncheckable
conditions also pass (e.g. no functions that could be fortified are found, or
not linked against glibc).

=item B<Read-only relocations>

This indicates that the executable was build with B<-Wl,-z,relro> to
have ELF markings (RELRO) that ask the runtime linker to mark any
regions of the relocation table as "read-only" if they were resolved
before execution begins. This reduces the possible areas of memory in
a program that can be used by an attacker that performs a successful
memory corruption exploit.

=item B<Immediate binding>

This indicates that the executable was built with B<-Wl,-z,now> to have
ELF markings (BIND_NOW) that ask the runtime linker to resolve all
relocations before starting program execution. When combined with RELRO
above, this further reduces the regions of memory available to memory
corruption attacks.

=back

=head1 OPTIONS

=over 8

=item B<--nopie>, B<-p>

No not require that the checked binaries be built as PIE.

=item B<--nostackprotector>, B<-s>

No not require that the checked binaries be built with the stack protector.

=item B<--nofortify>, B<-f>

No not require that the checked binaries be built with Fority Source.

=item B<--norelro>, B<-r>

No not require that the checked binaries be built with RELRO.

=item B<--nobindnow>, B<-b>

No not require that the checked binaries be built with BIND_NOW.

=item B<--quiet>, B<-q>

Only report failures.

=item B<--verbose>, B<-v>

Report verbosely on failures.

=item B<--report-functions>, B<-R>

After the report, display all external functions needed by the ELF.

=item B<--find-libc-functions>, B<-F>

Instead of the regular report, locate the libc for the first ELF on the
command line and report all the known "fortified" functions exported by
libc.

=item B<--color>, B<-c>

Enable colorized status output.

=item B<--lintian>, B<-l>

Switch reporting to lintian-check-parsable output.

=item B<--debug>

Report some debugging during processing.

=item B<--help>, B<-h>, B<-?>

Print a brief help message and exit.

=item B<--man>, B<-H>

Print the manual page and exit.

=back

=head1 RETURN VALUE

When all checked binaries have all checkable hardening features detected,
this program will finish with an exit code of 0. If any check fails, the
exit code with be 1. Individual checks can be disabled via command line
options.

=head1 AUTHOR

Kees Cook <kees@debian.org>

=head1 COPYRIGHT AND LICENSE

Copyright 2009-2013 Kees Cook <kees@debian.org>.

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; version 2 or later.

=head1 SEE ALSO

L<gcc(1)>, L<hardening-wrapper(1)>

=cut