3 # Build log hardening check, checks build logs for missing hardening flags.
5 # Copyright (C) 2012 Simon Ruderich
7 # This program is free software: you can redistribute it and/or modify
8 # it under the terms of the GNU General Public License as published by
9 # the Free Software Foundation, either version 3 of the License, or
10 # (at your option) any later version.
12 # This program is distributed in the hope that it will be useful,
13 # but WITHOUT ANY WARRANTY; without even the implied warranty of
14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 # GNU General Public License for more details.
17 # You should have received a copy of the GNU General Public License
18 # along with this program. If not, see <http://www.gnu.org/licenses/>.
25 use Term::ANSIColor ();
26 use Text::ParseWords ();
28 our $VERSION = '0.01';
33 # Regex to catch compiler commands.
34 my $cc_regex = qr/(?:[a-z0-9_]+-(?:linux-|kfreebsd-)?gnu(?:eabi|eabihf)?-)?
35 (?<!\.)(?:cc|gcc|g\+\+|c\+\+)
37 # Regex to catch (GCC) compiler warnings.
38 my $warning_regex = qr/^(.+?):([0-9]+):[0-9]+: warning: (.+?) \[(.+?)\]$/;
40 # List of source file extensions which require preprocessing.
41 my @source_preprocess_compile_cpp = (
43 qw( cc cp cxx cpp CPP c++ C ),
47 my @source_preprocess_compile = (
53 @source_preprocess_compile_cpp,
55 qw( F FOR fpp FPP FTN F90 F95 F03 F08 ),
57 my @source_preprocess_no_compile = (
61 my @source_preprocess = (
62 @source_preprocess_compile,
63 @source_preprocess_no_compile,
65 # List of source file extensions which don't require preprocessing.
66 my @source_no_preprocess_compile_cpp = (
72 my @source_no_preprocess_compile = (
76 @source_no_preprocess_compile_cpp,
80 qw( f for ftn f90 f95 f03 f08 ),
82 my @source_no_preprocess_no_compile = (
86 my @source_no_preprocess = (
87 @source_no_preprocess_compile,
88 @source_no_preprocess_no_compile,
90 # List of header file extensions which require preprocessing.
91 my @header_preprocess = (
92 # C, C++, Objective-C, Objective-C++
95 qw( hh H hp hxx hpp HPP h++ tcc ),
98 # Hashes for fast extensions lookup to check if a file falls in one of these
100 my %extensions_no_preprocess = map { $_ => 1 } (
101 @source_no_preprocess,
103 my %extensions_preprocess = map { $_ => 1 } (
107 my %extensions_compile_link = map { $_ => 1 } (
109 @source_no_preprocess,
111 my %extensions_compile = map { $_ => 1 } (
112 @source_preprocess_compile,
113 @source_no_preprocess_compile,
115 my %extensions_no_compile = map { $_ => 1 } (
116 @source_preprocess_no_compile,
117 @source_no_preprocess_no_compile,
119 my %extensions_compile_cpp = map { $_ => 1 } (
120 @source_preprocess_compile_cpp,
121 @source_no_preprocess_compile_cpp,
123 my %extension = map { $_ => 1 } (
124 @source_no_preprocess,
125 @source_no_preprocess_compile,
126 @source_no_preprocess_compile_cpp,
127 @source_no_preprocess_no_compile,
130 @source_preprocess_compile,
131 @source_preprocess_compile_cpp,
132 @source_preprocess_no_compile,
135 # Regexp to match file extensions.
136 my $file_extension_regex = qr/
138 \S+ # Filename without extension.
140 ([^\\.\s]+) # File extension.
141 (?=\s|\\) # At end of word. Can't use \b because some files have non
142 # word characters at the end and because \b matches double
143 # extensions (like .cpp.o). Works always as all lines are
144 # terminated with "\n".
147 # Expected (hardening) flags. All flags are used as regexps.
152 my @def_cflags_format = (
155 '-Werror=format-security',
157 my @def_cflags_fortify = (
158 # fortify needs at least -O1, but -O2 is recommended anyway
160 my @def_cflags_stack = (
162 '--param=ssp-buffer-size=4',
164 my @def_cflags_pie = (
171 # @def_cxxflags_* is the same as @def_cflags_*.
172 my @def_cppflags = ();
173 my @def_cppflags_fortify = (
174 '-D_FORTIFY_SOURCE=2',
176 my @def_ldflags = ();
177 my @def_ldflags_relro = (
180 my @def_ldflags_bindnow = (
183 my @def_ldflags_pie = (
187 # Renaming rules for the output so the regex parts are not visible.
189 '-O(?:2|3)' => '-O2',
190 '-Wl,(-z,)?relro' => '-Wl,-z,relro',
191 '-Wl,(-z,)?now' => '-Wl,-z,now',
194 # Use colored (ANSI) output?
201 my ($message, $missing_flags_ref, $flag_renames_ref, $line) = @_;
203 # Rename flags if requested.
204 my @missing_flags = map {
205 (exists $flag_renames_ref->{$_})
206 ? $flag_renames_ref->{$_}
208 } @{$missing_flags_ref};
210 my $flags = join ' ', @missing_flags;
211 printf "%s (%s)%s %s",
212 error_color($message, 'red'), $flags, error_color(':', 'yellow'),
215 sub error_non_verbose_build {
219 error_color('NONVERBOSE BUILD', 'red'),
220 error_color(':', 'yellow'),
223 sub error_hardening_wrapper {
225 error_color('HARDENING WRAPPER', 'red'),
226 error_color(':', 'yellow'),
227 'no checks possible, aborting';
230 my ($message, $color) = @_;
233 return Term::ANSIColor::colored($message, $color);
240 my ($line, @flags) = @_;
242 foreach my $flag (@flags) {
243 return 1 if $line =~ /\s$flag(?:\s|\\)/;
249 my ($line, $missing_flags_ref, @flags) = @_;
251 my @missing_flags = ();
252 foreach my $flag (@flags) {
253 if ($line !~ /\s$flag(?:\s|\\)/) {
254 push @missing_flags, $flag;
258 return 1 if scalar @missing_flags == 0;
260 @{$missing_flags_ref} = @missing_flags;
264 # Modifies $missing_flags_ref array.
265 sub pic_pie_conflict {
266 my ($line, $pie, $missing_flags_ref, @flags_pie) = @_;
268 return 0 if not $pie;
269 return 0 if not any_flags_used($line, ('-fPIC', '-fpic'));
271 my %flags = map { $_ => 1 } @flags_pie;
273 # Remove all PIE flags from @missing_flags as they are not required with
276 not exists $flags{$_}
277 } @{$missing_flags_ref};
278 @{$missing_flags_ref} = @result;
280 # We got a conflict when no flags are left, thus only PIE flags were
281 # missing. If other flags were missing abort because the conflict is not
283 return scalar @result == 0;
286 sub is_non_verbose_build {
287 my ($line, $next_line, $skip_ref) = @_;
289 if (not ($line =~ /^checking if you want to see long compiling messages\.\.\. no/
290 or $line =~ /^\s*\[?(?:CC|CCLD|CXX|CXXLD|LD|LINK)\]?\s+(.+?)$/
291 or $line =~ /^\s*(?:C|c)ompiling\s+(.+?)(?:\.\.\.)?$/
292 or $line =~ /^\s*(?:B|b)uilding (?:program|shared library)\s+(.+?)$/
293 or $line =~ /^\s*\[[\d ]+%\] Building (?:C|CXX) object (.+?)$/)) {
299 # On the first pass we only check if this line is verbose or not.
300 return 1 if not defined $next_line;
302 # Second pass, we have access to the next line.
305 # CMake and other build systems print the non-verbose messages also when
306 # building verbose. If a compiler and the file name occurs in the next
307 # line, treat it as verbose build.
309 # Get filename, we can't use the complete path as only parts of it are
310 # used in the real compiler command.
311 $file =~ m{/([a-zA-Z0-9._-]+)$};
314 if ($next_line =~ /\Q$file\E/ and $next_line =~ /$cc_regex/o) {
315 # We still have to skip the current line as it doesn't contain any
325 sub extension_found {
326 my ($extensions_ref, @extensions) = @_;
329 foreach my $extension (@extensions) {
330 if (exists $extensions_ref->{$extension}) {
341 # Parse command line arguments.
343 my $option_version = 0;
345 my $option_bindnow = 0;
347 my $option_arch = undef;
348 my $option_buildd = 0;
350 if (not Getopt::Long::GetOptions(
351 'help|h|?' => \$option_help,
352 'version' => \$option_version,
354 'pie' => \$option_pie,
355 'bindnow' => \$option_bindnow,
356 'all' => \$option_all,
358 'color' => \$option_color,
359 'arch=s' => \$option_arch,
360 'buildd' => \$option_buildd,
363 Pod::Usage::pod2usage(2);
367 Pod::Usage::pod2usage(1);
369 if ($option_version) {
370 print "blhc $VERSION Copyright (C) 2012 Simon Ruderich
372 This program is free software: you can redistribute it and/or modify
373 it under the terms of the GNU General Public License as published by
374 the Free Software Foundation, either version 3 of the License, or
375 (at your option) any later version.
377 This program is distributed in the hope that it will be useful,
378 but WITHOUT ANY WARRANTY; without even the implied warranty of
379 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
380 GNU General Public License for more details.
382 You should have received a copy of the GNU General Public License
383 along with this program. If not, see <http://www.gnu.org/licenses/>.
396 FILE: foreach my $file (@ARGV) {
397 open my $fh, '<', $file or die "$!: $file";
399 # Hardening options. Not all architectures support all hardening options.
400 my $harden_format = 1;
401 my $harden_fortify = 1;
402 my $harden_stack = 1;
403 my $harden_relro = 1;
404 my $harden_bindnow = $option_bindnow; # defaults to 0
405 my $harden_pie = $option_pie; # defaults to 0
407 while (my $line = <$fh>) {
408 # dpkg-buildflags only provides hardening flags since 1.16.1, don't
409 # check for hardening flags in buildd mode if an older dpkg-dev is
410 # used. Default flags (-g -O2) are still checked.
412 # Packages which were built before 1.16.1 but used their own hardening
413 # flags are not checked.
414 if ($option_buildd and $line =~ /^Toolchain package versions: /) {
415 require Dpkg::Version;
416 if ($line !~ /dpkg-dev_(\S+)/
417 or Dpkg::Version::version_compare($1, '1.16.1') < 0) {
427 # If hardening wrapper is used (wraps calls to gcc and adds hardening
428 # flags automatically) we can't perform any checks, abort.
429 if ($line =~ /^Build-Depends: .*\bhardening-wrapper\b/) {
430 error_hardening_wrapper();
435 # We skip over unimportant lines at the beginning of the log to
436 # prevent false positives.
437 last if $line =~ /^dpkg-buildpackage:/;
440 # Input lines, contain only the lines with compiler commands.
443 my $continuation = 0;
444 my $complete_line = undef;
445 while (my $line = <$fh>) {
446 # And stop at the end of the build log. Package details (reported by
447 # the buildd logs) are not important for us. This also prevents false
449 last if $line =~ /^Build finished at \d{8}-\d{4}$/;
451 # Detect architecture automatically unless overridden.
453 and $line =~ /^dpkg-buildpackage: host architecture (.+)$/) {
457 # Ignore compiler warnings for now.
458 next if $line =~ /$warning_regex/o;
460 if ($line =~ /\033/) { # esc
461 # Remove all ANSI color sequences which are sometimes used in
462 # non-verbose builds.
463 $line = Term::ANSIColor::colorstrip($line);
464 # Also strip '\0xf' (delete previous character), used by Elinks'
467 # And "ESC(B" which seems to be used on armhf and hurd (not sure
469 $line =~ s/\033\(B//g;
472 # Check if this line indicates a non verbose build.
473 my $non_verbose = is_non_verbose_build($line);
475 # One line may contain multiple commands (";"). Treat each one as
476 # single line. parse_line() is slow, only use it when necessary.
477 my @line = (not $line =~ /;/)
480 # Ensure newline at the line end - necessary for
481 # correct parsing later.
484 } Text::ParseWords::parse_line(';', 1, $line);
485 foreach $line (@line) {
489 # Join lines, but leave the "\" in place so it's clear where
490 # the original line break was.
491 chomp $complete_line;
492 $complete_line .= ' ' . $line;
494 # Line continuation, line ends with "\".
495 if ($line =~ /\\\s*$/) {
497 # Start line continuation.
498 if (not defined $complete_line) {
499 $complete_line = $line;
504 if (not $continuation) {
505 # Use the complete line if a line continuation occurred.
506 if (defined $complete_line) {
507 $line = $complete_line;
508 $complete_line = undef;
511 # Ignore lines with no compiler commands.
512 next if $line !~ /\b$cc_regex(?:\s|\\)/o and not $non_verbose;
514 # Ignore false positives.
516 # `./configure` output.
517 next if not $non_verbose
518 and $line =~ /^(?:checking|(?:C|c)onfigure:) /;
519 next if $line =~ /^\s*(?:Host\s+)?(?:C\s+)?
520 (?:C|c)ompiler[\s.]*:?\s+
522 (?:\s-std=[a-z0-9:+]+)?\s*$
524 or $line =~ /^\s*(?:- )?(?:HOST_)?(?:CC|CXX)\s*=\s*$cc_regex\s*$/o
525 or $line =~ /^\s*-- Check for working (?:C|CXX) compiler: /
526 or $line =~ /^\s*(?:echo )?Using [A-Z_]+\s*=\s*/;
528 next if $line =~ /^Making [a-z]+ in \S+/; # e.g. "[...] in c++"
530 # Check if additional hardening options were used. Used to
531 # ensure they are used for the complete build.
532 $harden_pie = 1 if any_flags_used($line, @def_cflags_pie, @def_ldflags_pie);
533 $harden_bindnow = 1 if any_flags_used($line, @def_ldflags_bindnow);
542 if (scalar @input == 0) {
543 print "No compiler commands!\n";
548 # Option or auto detected.
550 # The following was partially copied from dpkg-dev 1.16.1.2
551 # (/usr/share/perl5/Dpkg/Vendor/Debian.pm, add_hardening_flags()),
552 # copyright Raphaël Hertzog <hertzog@debian.org>, Kees Cook
553 # <kees@debian.org>, Canonical, Ltd. licensed under GPL version 2 or
554 # later. Keep it in sync.
557 my ($abi, $os, $cpu) = Dpkg::Arch::debarch_to_debtriplet($option_arch);
559 # Disable unsupported hardening options.
560 if ($cpu =~ /^(ia64|alpha|mips|mipsel|hppa)$/ or $option_arch eq 'arm') {
563 if ($cpu =~ /^(ia64|hppa|avr32)$/) {
570 my @cflags = @def_cflags;
571 my @cxxflags = @def_cxxflags;
572 my @cppflags = @def_cppflags;
573 my @ldflags = @def_ldflags;
574 # Check the specified hardening options, same order as dpkg-buildflags.
576 @cflags = (@cflags, @def_cflags_pie);
577 @cxxflags = (@cxxflags, @def_cflags_pie);
578 @ldflags = (@ldflags, @def_ldflags_pie);
581 @cflags = (@cflags, @def_cflags_stack);
582 @cxxflags = (@cxxflags, @def_cflags_stack);
584 if ($harden_fortify) {
585 @cflags = (@cflags, @def_cflags_fortify);
586 @cxxflags = (@cxxflags, @def_cflags_fortify);
587 @cppflags = (@cppflags, @def_cppflags_fortify);
589 if ($harden_format) {
590 @cflags = (@cflags, @def_cflags_format);
591 @cxxflags = (@cxxflags, @def_cflags_format);
594 @ldflags = (@ldflags, @def_ldflags_relro);
596 if ($harden_bindnow) {
597 @ldflags = (@ldflags, @def_ldflags_bindnow);
600 for (my $i = 0; $i < scalar @input; $i++) {
601 my $line = $input[$i];
604 if (is_non_verbose_build($line, $input[$i + 1], \$skip)) {
605 error_non_verbose_build($line);
609 # Even if it's a verbose build, we might have to skip this line.
612 # Remove everything until and including the compiler command. Makes
613 # checks easier and faster.
614 $line =~ s/^.*?$cc_regex//o;
616 # Skip unnecessary tests when only preprocessing.
617 my $flag_preprocess = 0;
623 # Preprocess, compile, assemble.
624 if ($line =~ /\s(-E|-S|-c)\b/) {
626 $flag_preprocess = 1 if $1 eq '-E';
627 $compile = 1 if $1 eq '-S' or $1 eq '-c';
628 # Otherwise assume we are linking.
633 # Get all file extensions on this line.
634 my @extensions = $line =~ /$file_extension_regex/go;
635 # Ignore all unknown extensions to speedup the search below.
636 @extensions = grep { exists $extension{$_} } @extensions;
638 # These file types don't require preprocessing.
639 if (extension_found(\%extensions_no_preprocess, @extensions)) {
642 # These file types require preprocessing.
643 if (extension_found(\%extensions_preprocess, @extensions)) {
647 # If there are source files then it's compiling/linking in one step
648 # and we must check both. We only check for source files here, because
649 # header files cause too many false positives.
650 if (not $flag_preprocess
651 and extension_found(\%extensions_compile_link, @extensions)) {
652 # Assembly files don't need CFLAGS.
653 if (not extension_found(\%extensions_compile, @extensions)
654 and extension_found(\%extensions_no_compile, @extensions)) {
662 # Assume CXXFLAGS are required when a C++ file is specified in the
666 and extension_found(\%extensions_compile_cpp, @extensions)) {
671 # Check hardening flags.
673 if ($compile and not all_flags_used($line, \@missing, @cflags)
674 # Libraries linked with -fPIC don't have to (and can't) be
675 # linked with -fPIE as well. It's no error if only PIE flags
677 and not pic_pie_conflict($line, $harden_pie, \@missing, @def_cflags_pie)
678 # Assume dpkg-buildflags returns the correct flags.
679 and not $line =~ /`dpkg-buildflags --get CFLAGS`/) {
680 error_flags('CFLAGS missing', \@missing, \%flag_renames, $input[$i]);
682 } elsif ($compile_cpp and not all_flags_used($line, \@missing, @cflags)
683 # Libraries linked with -fPIC don't have to (and can't) be
684 # linked with -fPIE as well. It's no error if only PIE flags
686 and not pic_pie_conflict($line, $harden_pie, \@missing, @def_cflags_pie)
687 # Assume dpkg-buildflags returns the correct flags.
688 and not $line =~ /`dpkg-buildflags --get CXXFLAGS`/) {
689 error_flags('CXXFLAGS missing', \@missing, \%flag_renames, $input[$i]);
692 if ($preprocess and not all_flags_used($line, \@missing, @cppflags)
693 # Assume dpkg-buildflags returns the correct flags.
694 and not $line =~ /`dpkg-buildflags --get CPPFLAGS`/) {
695 error_flags('CPPFLAGS missing', \@missing, \%flag_renames, $input[$i]);
698 if ($link and not all_flags_used($line, \@missing, @ldflags)
699 # Same here, -fPIC conflicts with -fPIE.
700 and not pic_pie_conflict($line, $harden_pie, \@missing, @def_ldflags_pie)
701 # Assume dpkg-buildflags returns the correct flags.
702 and not $line =~ /`dpkg-buildflags --get LDFLAGS`/) {
703 error_flags('LDFLAGS missing', \@missing, \%flag_renames, $input[$i]);
716 blhc - build log hardening check, checks build logs for missing hardening flags
720 B<blhc> [options] <dpkg-buildpackage build log file>..
722 --all force +all (+pie, +bindnow) check
723 --arch set architecture (autodetected)
724 --bindnow force +bindbow check
725 --buildd parser mode for buildds
726 --color use colored output
727 --pie force +pie check
728 --help available options
729 --version version number and license
733 blhc is a small tool which checks build logs for missing hardening flags and
734 other important warnings. It's licensed under the GPL 3 or later.
742 Force check for all +all (+pie, +bindnow) hardening flags. By default it's
747 Set the specific architecture (e.g. amd64, armel, etc.), automatically
748 disables hardening flags not available on this architecture. Is detected
749 automatically if dpkg-buildpackage is used.
753 Force check for all +bindnow hardening flags. By default it's auto detected.
757 Special mode for buildds when automatically parsing log files. The following
758 changes are in effect:
764 Don't check hardening flags in old log files (if dpkg-dev << 1.16.1 is
771 Use colored (ANSI) output for warning messages.
775 Force check for all +pie hardening flags. By default it's auto detected.
777 =item B<-h -? --help>
779 Print available options.
783 Print version number and license.
787 Auto detection for B<--pie> and B<--bindnow> only works if at least one
788 command uses the required hardening flag (e.g. -fPIE). Then it's required for
789 all other commands as well.
793 The exit status is a "bit mask", each listed status is ORed when the error
794 condition occurs to get the result.
804 No compiler commands were found.
808 Invalid arguments/options given to blhc.
816 Missing hardening flags.
820 Hardening wrapper detected, no tests performed.
826 Simon Ruderich, E<lt>simon@ruderich.orgE<gt>
828 =head1 COPYRIGHT AND LICENSE
830 Copyright (C) 2012 by Simon Ruderich
832 This program is free software: you can redistribute it and/or modify
833 it under the terms of the GNU General Public License as published by
834 the Free Software Foundation, either version 3 of the License, or
835 (at your option) any later version.
837 This program is distributed in the hope that it will be useful,
838 but WITHOUT ANY WARRANTY; without even the implied warranty of
839 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
840 GNU General Public License for more details.
842 You should have received a copy of the GNU General Public License
843 along with this program. If not, see <http://www.gnu.org/licenses/>.