3 # Build log hardening check, checks build logs for missing hardening flags.
5 # Copyright (C) 2012-2013 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 Text::ParseWords ();
27 our $VERSION = '0.04';
32 # Regex to catch compiler commands.
34 (?<!\s-) # ignore options, e.g. "-c++" [sic!] (used by swig)
35 (?<!\.) # ignore file names, e.g. "test.gcc"
36 (?:cc|gcc|g\+\+|c\+\+)
37 (?:-[\d.]+)? # version suffix, e.g. "gcc-4.6"
39 # Full regex which matches the complete compiler name. Used in a few places to
40 # prevent false negatives.
41 my $cc_regex_full = qr/
42 (?:[a-z0-9_]+-(?:linux-|kfreebsd-)?gnu(?:eabi|eabihf)?-)?
45 # Regex to check if a line contains a compiler command.
46 my $cc_regex_normal = qr/
49 # Regex to catch (GCC) compiler warnings.
50 my $warning_regex = qr/^(.+?):(\d+):\d+: warning: (.+?) \[(.+?)\]$/;
51 # Regex to catch libtool commands and not lines which show commands executed
52 # by libtool (e.g. libtool: link: ...).
53 my $libtool_regex = qr/\blibtool\s.*--mode=/;
55 # List of source file extensions which require preprocessing.
56 my @source_preprocess_compile_cpp = (
58 qw( cc cp cxx cpp CPP c++ C ),
62 my @source_preprocess_compile = (
68 @source_preprocess_compile_cpp,
70 qw( F FOR fpp FPP FTN F90 F95 F03 F08 ),
72 my @source_preprocess_no_compile = (
76 my @source_preprocess = (
77 @source_preprocess_compile,
78 @source_preprocess_no_compile,
80 # List of source file extensions which don't require preprocessing.
81 my @source_no_preprocess_compile_cpp = (
87 my @source_no_preprocess_compile_ada = (
90 # If you add another file, fix use of @source_no_preprocess_compile_ada
91 # below (search for $compile_ada).
93 my @source_no_preprocess_compile = (
97 @source_no_preprocess_compile_cpp,
101 qw( f for ftn f90 f95 f03 f08 ),
103 @source_no_preprocess_compile_ada,
105 my @source_no_preprocess_no_compile = (
111 my @source_no_preprocess = (
112 @source_no_preprocess_compile,
113 @source_no_preprocess_no_compile,
115 # List of header file extensions which require preprocessing.
116 my @header_preprocess = (
117 # C, C++, Objective-C, Objective-C++
120 qw( hh H hp hxx hpp HPP h++ tcc ),
124 # Normal object files.
126 # Libtool object files.
128 # Dynamic libraries. bzip2 uses .sho.
134 # Hashes for fast extensions lookup to check if a file falls in one of these
136 my %extensions_no_preprocess = map { $_ => 1 } (
137 # There's no @header_no_preprocess.
138 @source_no_preprocess,
140 my %extensions_preprocess = map { $_ => 1 } (
144 my %extensions_compile_link = map { $_ => 1 } (
146 @source_no_preprocess,
148 my %extensions_compile = map { $_ => 1 } (
149 @source_preprocess_compile,
150 @source_no_preprocess_compile,
152 my %extensions_no_compile = map { $_ => 1 } (
153 @source_preprocess_no_compile,
154 @source_no_preprocess_no_compile,
156 my %extensions_compile_cpp = map { $_ => 1 } (
157 @source_preprocess_compile_cpp,
158 @source_no_preprocess_compile_cpp,
160 my %extensions_object = map { $_ => 1 } (
163 my %extension = map { $_ => 1 } (
164 @source_no_preprocess,
170 # Regexp to match file extensions.
171 my $file_extension_regex = qr/
173 \S+ # Filename without extension.
175 ([^\/\\.,;:\s]+)# File extension.
176 (?=\s|\\) # At end of word. Can't use \b because some files have non
177 # word characters at the end and because \b matches double
178 # extensions (like .cpp.o). Works always as all lines are
179 # terminated with "\n".
182 # Expected (hardening) flags. All flags are used as regexps (and compiled to
183 # real regexps below for better execution speed).
186 '-O(?:2|3)', # keep at index 1, search for @def_cflags_debug to change it
188 my @def_cflags_debug = (
189 # These flags indicate a debug build which disables checks for -O2.
193 my @def_cflags_format = (
194 '-Wformat(?:=2)?', # -Wformat=2 implies -Wformat, accept it too
195 '-Werror=format-security', # implies -Wformat-security
197 my @def_cflags_fortify = (
198 # fortify needs at least -O1, but -O2 is recommended anyway
200 my @def_cflags_stack = (
202 '--param[= ]ssp-buffer-size=4',
204 my @def_cflags_pie = (
210 # @def_cxxflags_* is the same as @def_cflags_*.
211 my @def_cppflags = ();
212 my @def_cppflags_fortify = (
213 '-D_FORTIFY_SOURCE=2', # must be first, see cppflags_fortify_broken()
214 # If you add another flag fix hack below (search for "Hack to fix").
216 my @def_cppflags_fortify_bad = (
217 # These flags may overwrite -D_FORTIFY_SOURCE=2.
219 '-D_FORTIFY_SOURCE=0',
220 '-D_FORTIFY_SOURCE=1',
222 my @def_ldflags = ();
223 my @def_ldflags_relro = (
226 my @def_ldflags_bindnow = (
229 my @def_ldflags_pie = (
233 my @def_ldflags_pic = (
238 # References to all flags checked by the flag checker.
242 \@def_cflags_fortify,
247 \@def_cppflags_fortify,
250 \@def_ldflags_bindnow,
253 # References to all used flags.
254 my @flag_refs_all = (
257 \@def_cppflags_fortify_bad,
260 # Renaming rules for the output so the regex parts are not visible. Also
261 # stores string values of flag regexps above, see compile_flag_regexp().
263 '-O(?:2|3)' => '-O2',
264 '-Wformat(?:=2)?' => '-Wformat',
265 '--param[= ]ssp-buffer-size=4' => '--param=ssp-buffer-size=4',
266 '-Wl,(?:-z,)?relro' => '-Wl,-z,relro',
267 '-Wl,(?:-z,)?now' => '-Wl,-z,now',
271 no_compiler_commands => 1 << 0,
272 # used by POD::Usage => 1 << 1,
273 non_verbose_build => 1 << 2,
274 flags_missing => 1 << 3,
275 hardening_wrapper => 1 << 4,
276 invalid_cmake => 1 << 5,
280 no_compiler_commands => 'I-no-compiler-commands',
281 non_verbose_build => 'W-compiler-flags-hidden',
282 flags_missing => 'W-dpkg-buildflags-missing',
283 hardening_wrapper => 'I-hardening-wrapper-used',
284 invalid_cmake => 'I-invalid-cmake-used',
287 # Statistics of missing flags and non-verbose build commands. Used for
291 preprocess_missing => 0,
293 compile_missing => 0,
295 compile_cpp_missing => 0,
299 commands_nonverbose => 0,
302 # Use colored (ANSI) output?
308 # Only works for single-level arrays with no undef values. Thanks to perlfaq4.
310 my ($first_ref, $second_ref) = @_;
312 return 0 if scalar @{$first_ref} != scalar @{$second_ref};
314 my $length = scalar @{$first_ref};
315 for (my $i = 0; $i < $length; $i++) {
316 return 0 if $first_ref->[$i] ne $second_ref->[$i];
323 my ($message, $missing_flags_ref, $flag_renames_ref, $line) = @_;
325 # Get string value of qr//-escaped regexps and if requested rename them.
326 my @missing_flags = map {
327 $flag_renames_ref->{$_}
328 } @{$missing_flags_ref};
330 my $flags = join ' ', @missing_flags;
331 printf '%s (%s)%s %s',
332 error_color($message, 'red'), $flags, error_color(':', 'yellow'),
337 sub error_non_verbose_build {
341 error_color('NONVERBOSE BUILD', 'red'),
342 error_color(':', 'yellow'),
347 sub error_invalid_cmake {
351 error_color('INVALID CMAKE', 'red'),
352 error_color(':', 'yellow'),
357 sub error_hardening_wrapper {
359 error_color('HARDENING WRAPPER', 'red'),
360 error_color(':', 'yellow'),
361 'no checks possible, aborting';
366 my ($message, $color) = @_;
369 return Term::ANSIColor::colored($message, $color);
376 my ($line, @flags) = @_;
378 foreach my $flag (@flags) {
379 return 1 if $line =~ /$flag/;
385 my ($line, $missing_flags_ref, @flags) = @_;
387 my @missing_flags = ();
388 foreach my $flag (@flags) {
389 if (not $line =~ /$flag/) {
390 push @missing_flags, $flag;
394 return 1 if scalar @missing_flags == 0;
396 @{$missing_flags_ref} = @missing_flags;
400 sub cppflags_fortify_broken {
401 my ($line, $missing_flags) = @_;
403 # This doesn't take the position into account, but is a simple solution.
404 # And if the build system tries to force -D_FORTIFY_SOURCE=0/1, something
407 if (any_flags_used($line, @def_cppflags_fortify_bad)) {
408 # $def_cppflags_fortify[0] must be -D_FORTIFY_SOURCE=2!
409 push @{$missing_flags}, $def_cppflags_fortify[0];
416 # Modifies $missing_flags_ref array.
417 sub pic_pie_conflict {
418 my ($line, $pie, $missing_flags_ref, @flags_pie) = @_;
420 return 0 if not $pie;
421 return 0 if not any_flags_used($line, @def_ldflags_pic);
423 my %flags = map { $_ => 1 } @flags_pie;
425 # Remove all PIE flags from @missing_flags as they are not required with
428 not exists $flags{$_}
429 } @{$missing_flags_ref};
430 @{$missing_flags_ref} = @result;
432 # We got a conflict when no flags are left, thus only PIE flags were
433 # missing. If other flags were missing abort because the conflict is not
435 return scalar @result == 0;
438 sub is_non_verbose_build {
439 my ($line, $next_line, $skip_ref) = @_;
441 if ($line =~ /$libtool_regex/o) {
442 # libtool's --silent hides the real compiler flags.
443 if ($line =~ /\s--silent/) {
445 # If --silent is not present, skip this line as some compiler flags
446 # might be missing (e.g. -fPIE) which are handled correctly by libtool
447 # internally. libtool displays the real compiler command on the next
448 # line, so the flags are checked as usual.
455 if (not (index($line, 'checking if you want to see long compiling messages... no') == 0
456 or $line =~ /^\s*\[?(?:CC|CCLD|C\+\+|CXX|CXXLD|LD|LINK)\]?\s+(.+?)$/
457 or $line =~ /^\s*[Cc]ompiling\s+(.+?)(?:\.\.\.)?$/
458 or $line =~ /^\s*[Bb]uilding (?:program|shared library)\s+(.+?)$/
459 or $line =~ /^\s*\[[\d ]+%\] Building (?:C|CXX) object (.+?)$/)) {
465 # C++ compiler setting.
466 return 0 if $line =~ /^\s*C\+\+.+?:\s+(?:yes|no)\s*$/;
467 return 0 if $line =~ /^\s*C\+\+ Library: stdc\+\+$/;
468 # "Compiling" non binary files.
469 return 0 if $line =~ /^\s*Compiling \S+\.(?:py|el)['"]?\s*(?:\.\.\.)?$/;
470 # "Compiling" with no file name.
471 if ($line =~ /^\s*[Cc]ompiling\s+(.+?)(?:\.\.\.)?$/) {
472 # $file_extension_regex may need spaces around the filename.
473 return 0 if not " $1 " =~ /$file_extension_regex/o;
478 # On the first pass we only check if this line is verbose or not.
479 return 1 if not defined $next_line;
481 # Second pass, we have access to the next line.
484 # CMake and other build systems print the non-verbose messages also when
485 # building verbose. If a compiler and the file name occurs in the next
486 # line, treat it as verbose build.
488 # Get filename, we can't use the complete path as only parts of it are
489 # used in the real compiler command.
490 $file =~ m{/([^/\s]+)$};
493 if (index($next_line, $file) != -1 and $next_line =~ /$cc_regex/o) {
494 # Not a non-verbose line, but we still have to skip the current line
495 # as it doesn't contain any compiler commands.
504 # Remove @flags from $flag_refs_ref, uses $flag_renames_ref as reference.
506 my ($flag_refs_ref, $flag_renames_ref, @flags) = @_;
508 my %removes = map { $_ => 1 } @flags;
509 foreach my $flags (@{$flag_refs_ref}) {
511 # Flag found as string.
512 not exists $removes{$_}
513 # Flag found as string representation of regexp.
514 and (not defined $flag_renames_ref->{$_}
515 or not exists $removes{$flag_renames_ref->{$_}})
522 # Modifies $flag_renames_ref hash.
523 sub compile_flag_regexp {
524 my ($flag_renames_ref, @flags) = @_;
527 foreach my $flag (@flags) {
528 # Compile flag regexp for faster execution.
529 my $regex = qr/\s$flag(?:\s|\\)/;
531 # Store flag name in replacement string for correct flags in messages
532 # with qr//ed flag regexps.
533 $flag_renames_ref->{$regex}
534 = (exists $flag_renames_ref->{$flag})
535 ? $flag_renames_ref->{$flag}
538 push @result, $regex;
543 # Does any extension in @extensions exist in %{$extensions_ref}?
544 sub extension_found {
545 my ($extensions_ref, @extensions) = @_;
547 foreach my $extension (@extensions) {
548 if (exists $extensions_ref->{$extension}) {
558 # Parse command line arguments.
560 my $option_version = 0;
562 my $option_bindnow = 0;
563 my @option_ignore_arch = ();
564 my @option_ignore_flag = ();
565 my @option_ignore_arch_flag = ();
566 my @option_ignore_line = ();
567 my @option_ignore_arch_line = ();
569 my $option_arch = undef;
570 my $option_buildd = 0;
572 if (not Getopt::Long::GetOptions(
573 'help|h|?' => \$option_help,
574 'version' => \$option_version,
576 'pie' => \$option_pie,
577 'bindnow' => \$option_bindnow,
578 'all' => \$option_all,
580 'ignore-arch=s' => \@option_ignore_arch,
581 'ignore-flag=s' => \@option_ignore_flag,
582 'ignore-arch-flag=s' => \@option_ignore_arch_flag,
583 'ignore-line=s' => \@option_ignore_line,
584 'ignore-arch-line=s' => \@option_ignore_arch_line,
586 'color' => \$option_color,
587 'arch=s' => \$option_arch,
588 'buildd' => \$option_buildd,
591 Pod::Usage::pod2usage(2);
595 Pod::Usage::pod2usage(1);
597 if ($option_version) {
599 blhc $VERSION Copyright (C) 2012-2013 Simon Ruderich
601 This program is free software: you can redistribute it and/or modify
602 it under the terms of the GNU General Public License as published by
603 the Free Software Foundation, either version 3 of the License, or
604 (at your option) any later version.
606 This program is distributed in the hope that it will be useful,
607 but WITHOUT ANY WARRANTY; without even the implied warranty of
608 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
609 GNU General Public License for more details.
611 You should have received a copy of the GNU General Public License
612 along with this program. If not, see <http://www.gnu.org/licenses/>.
618 if (scalar @ARGV == 0) {
620 Pod::Usage::pod2usage(2);
623 # Don't load Term::ANSIColor in buildd mode because Term::ANSIColor is not
624 # installed on Debian's buildds.
625 if (not $option_buildd) {
626 require Term::ANSIColor;
634 # Precompiled ignores for faster lookup.
635 my %option_ignore_arch_flag = ();
636 my %option_ignore_arch_line = ();
638 # Strip flags which should be ignored.
639 if (scalar @option_ignore_flag > 0) {
640 remove_flags(\@flag_refs, \%flag_renames, @option_ignore_flag);
642 # Same for arch specific ignore flags, but only prepare here.
643 if (scalar @option_ignore_arch_flag > 0) {
644 foreach my $ignore (@option_ignore_arch_flag) {
645 my ($ignore_arch, $ignore_flag) = split /:/, $ignore, 2;
647 if (not $ignore_arch or not $ignore_flag) {
648 printf STDERR 'Value "%s" invalid for option ignore-arch-flag '
649 . '("arch:flag" expected)' . "\n", $ignore;
651 Pod::Usage::pod2usage(2);
654 push @{$option_ignore_arch_flag{$ignore_arch}}, $ignore_flag;
658 # Precompile all flag regexps. any_flags_used(), all_flags_used() get a lot
660 foreach my $flags (@flag_refs_all) {
661 @{$flags} = compile_flag_regexp(\%flag_renames, @{$flags});
664 # Precompile ignore line regexps, also anchor at beginning and end of line.
665 foreach my $ignore (@option_ignore_line) {
666 $ignore = qr/^$ignore$/;
668 # Same for arch specific ignore lines.
669 if (scalar @option_ignore_arch_line > 0) {
670 foreach my $ignore (@option_ignore_arch_line) {
671 my ($ignore_arch, $ignore_line) = split /:/, $ignore, 2;
673 if (not $ignore_arch or not $ignore_line) {
674 printf STDERR 'Value "%s" invalid for option ignore-arch-line '
675 . '("arch:line" expected)' . "\n", $ignore;
677 Pod::Usage::pod2usage(2);
680 push @{$option_ignore_arch_line{$ignore_arch}}, qr/^$ignore_line$/;
688 foreach my $file (@ARGV) {
689 print "checking '$file'...\n" if scalar @ARGV > 1;
691 -f $file or die "No such file: $file";
693 open my $fh, '<', $file or die $!;
695 # Architecture of this file.
696 my $arch = $option_arch;
698 # Hardening options. Not all architectures support all hardening options.
699 my $harden_format = 1;
700 my $harden_fortify = 1;
701 my $harden_stack = 1;
702 my $harden_relro = 1;
703 my $harden_bindnow = $option_bindnow; # defaults to 0
704 my $harden_pie = $option_pie; # defaults to 0
706 # Does this build log use ada? Ada also uses gcc as compiler but uses
707 # different CFLAGS. But only perform ada checks if an ada compiler used
708 # for performance reasons.
711 while (my $line = <$fh>) {
712 # Detect architecture automatically unless overridden. For buildd logs
713 # only, doesn't use the dpkg-buildpackage header. Necessary to ignore
714 # build logs which aren't built (wrong architecture, build error,
717 if (index($line, 'Build Architecture: ') == 0) {
718 $arch = substr $line, 20, -1; # -1 to ignore '\n' at the end
719 # For old logs (sbuild << 0.63.0-1).
720 } elsif (index($line, 'Architecture: ') == 0) {
721 $arch = substr $line, 14, -1; # -1 to ignore '\n' at the end
725 # dpkg-buildflags only provides hardening flags since 1.16.1, don't
726 # check for hardening flags in buildd mode if an older dpkg-dev is
727 # used. Default flags (-g -O2) are still checked.
729 # Packages which were built before 1.16.1 but used their own hardening
730 # flags are not checked.
732 and index($line, 'Toolchain package versions: ') == 0) {
733 require Dpkg::Version;
734 if (not $line =~ /\bdpkg-dev_(\S+)/
735 or Dpkg::Version::version_compare($1, '1.16.1') < 0) {
745 # The following two versions of CMake in Debian obeyed CPPFLAGS, but
746 # this was later dropped because upstream rejected the patch. Thus
747 # build logs with these versions will have fortify hardening flags
748 # enabled, even though they may be not correctly set and are missing
749 # when build with later CMake versions. Thanks to Aron Xu for letting
751 if (index($line, 'Package versions: ') == 0
752 and $line =~ /\bcmake_(\S+)/
753 and ($1 eq '2.8.7-1' or $1 eq '2.8.7-2')) {
754 if (not $option_buildd) {
755 error_invalid_cmake($1);
756 $exit |= $exit_code{invalid_cmake};
758 print "$buildd_tag{invalid_cmake}|$1|\n";
762 # Debian's build daemons use "Filtered Build-Depends:" (or just
763 # "Build-Depends:" in older versions) for the build dependencies, but
764 # pbuilder uses "Depends:"; support both.
765 if (index($line, 'Filtered Build-Depends: ') == 0
766 or index($line, 'Build-Depends: ') == 0
767 or index($line, 'Depends: ') == 0) {
768 # If hardening wrapper is used (wraps calls to gcc and adds
769 # hardening flags automatically) we can't perform any checks,
771 if ($line =~ /\bhardening-wrapper\b/) {
772 if (not $option_buildd) {
773 error_hardening_wrapper();
774 $exit |= $exit_code{hardening_wrapper};
776 print "$buildd_tag{hardening_wrapper}||\n";
782 if ($line =~ /\bgnat\b/) {
787 # We skip over unimportant lines at the beginning of the log to
788 # prevent false positives.
789 last if index($line, 'dpkg-buildpackage: ') == 0;
792 # Input lines, contain only the lines with compiler commands.
794 # Non-verbose lines in the input. Used to reduce calls to
795 # is_non_verbose_build() (which is quite slow) in the second loop when
796 # it's already clear if a line is non-verbose or not.
797 my @input_nonverbose = ();
799 my $continuation = 0;
800 my $complete_line = undef;
802 while (my $line = <$fh>) {
803 # And stop at the end of the build log. Package details (reported by
804 # the buildd logs) are not important for us. This also prevents false
806 last if index($line, 'Build finished at ') == 0
807 and $line =~ /^Build finished at \d{8}-\d{4}$/;
809 if (not $continuation) {
813 # Detect architecture automatically unless overridden.
815 and index($line, 'dpkg-buildpackage: host architecture ') == 0) {
816 $arch = substr $line, 37, -1; # -1 to ignore '\n' at the end
818 # Old buildd logs use e.g. "host architecture is alpha", remove
819 # the "is", otherwise debarch_to_debtriplet() will not detect the
821 if (index($arch, 'is ') == 0) {
822 $arch = substr $arch, 3;
826 # Ignore compiler warnings for now.
827 next if $line =~ /$warning_regex/o;
829 if (not $option_buildd and index($line, "\033") != -1) { # \033 = esc
830 # Remove all ANSI color sequences which are sometimes used in
831 # non-verbose builds.
832 $line = Term::ANSIColor::colorstrip($line);
833 # Also strip '\0xf' (delete previous character), used by Elinks'
836 # And "ESC(B" which seems to be used on armhf and hurd (not sure
838 $line =~ s/\033\(B//g;
841 # Check if this line indicates a non verbose build.
843 $non_verbose |= is_non_verbose_build($line, undef, \$skip);
846 # One line may contain multiple commands (";"). Treat each one as
847 # single line. parse_line() is slow, only use it when necessary.
848 my @line = (index($line, ';') == -1)
851 # Ensure newline at the line end - necessary for
852 # correct parsing later.
855 } Text::ParseWords::parse_line(';', 1, $line);
856 foreach my $line (@line) {
860 # Join lines, but leave the "\" in place so it's clear where
861 # the original line break was.
862 chomp $complete_line;
863 $complete_line .= ' ' . $line;
865 # Line continuation, line ends with "\".
866 if ($line =~ /\\$/) {
868 # Start line continuation.
869 if (not defined $complete_line) {
870 $complete_line = $line;
875 # Use the complete line if a line continuation occurred.
876 if (defined $complete_line) {
877 $line = $complete_line;
878 $complete_line = undef;
881 # Ignore lines with no compiler commands.
882 next if not $non_verbose
883 and not $line =~ /$cc_regex_normal/o;
884 # Ignore lines with no filenames with extensions. May miss some
885 # non-verbose builds (e.g. "gcc -o test" [sic!]), but shouldn't be
886 # a problem as the log will most likely contain other non-verbose
887 # commands which are detected.
888 next if not $non_verbose
889 and not $line =~ /$file_extension_regex/o;
891 # Ignore false positives.
893 # `./configure` output.
894 next if not $non_verbose
895 and $line =~ /^(?:checking|[Cc]onfigure:) /;
896 next if $line =~ /^\s*(?:Host\s+)?(?:C(?:\+\+)?\s+)?
897 [Cc]ompiler[\s.]*:?\s+
899 next if $line =~ m{^\s*(?:-\s)?(?:HOST_)?(?:CC|CXX)
900 \s*=\s*$cc_regex_full
901 # optional compiler options, don't allow
902 # "everything" here to prevent false negatives
903 \s*(?:\s-\S+)*\s*$}xo;
904 # `moc-qt4`/`moc-qt5` contain '-I.../linux-g++' in their command
905 # line (or similar for other architectures) which gets recognized
906 # as a compiler line, but `moc-qt*` is only a preprocessor for Qt
907 # C++ files. No hardening flags are relevant during this step,
908 # thus ignore `moc-qt*` lines. The resulting files will be
909 # compiled in a separate step (and therefore checked).
910 next if $line =~ m{^\S+/bin/moc(?:-qt[45])?
912 -I\S+/mkspecs/[a-z]+-g\++(?:-64)?
914 # Ignore false positives when the line contains only CC=gcc but no
916 if ($line =~ /(.*)CC=$cc_regex_full(.*)/o) {
919 next if not $before =~ /$cc_regex_normal/o
920 and not $after =~ /$cc_regex_normal/o;
923 # Check if additional hardening options were used. Used to ensure
924 # they are used for the complete build.
925 $harden_pie = 1 if any_flags_used($line, @def_cflags_pie,
927 $harden_bindnow = 1 if any_flags_used($line, @def_ldflags_bindnow);
930 push @input_nonverbose, $non_verbose;
936 # Ignore arch if requested.
937 if (scalar @option_ignore_arch > 0 and $arch) {
938 foreach my $ignore (@option_ignore_arch) {
939 if ($arch eq $ignore) {
940 print "ignoring architecture '$arch'\n";
946 if (scalar @input == 0) {
947 if (not $option_buildd) {
948 print "No compiler commands!\n";
949 $exit |= $exit_code{no_compiler_commands};
951 print "$buildd_tag{no_compiler_commands}||\n";
956 if ($option_buildd) {
957 $statistics{commands} += scalar @input;
960 # Option or auto detected.
962 # The following was partially copied from dpkg-dev 1.17.11
963 # (/usr/share/perl5/Dpkg/Vendor/Debian.pm, add_hardening_flags()),
964 # copyright Raphaël Hertzog <hertzog@debian.org>, Kees Cook
965 # <kees@debian.org>, Canonical, Ltd. licensed under GPL version 2 or
966 # later. Keep it in sync.
969 my ($abi, $os, $cpu) = Dpkg::Arch::debarch_to_debtriplet($arch);
971 # Disable unsupported hardening options.
972 if ($os !~ /^(?:linux|knetbsd|hurd)$/ or
973 $cpu =~ /^(?:hppa|mips|mipsel|avr32)$/) {
976 if ($cpu =~ /^(?:ia64|alpha|mips|mipsel|hppa)$/ or $arch eq 'arm') {
979 if ($cpu =~ /^(?:ia64|hppa|avr32)$/) {
986 my @cflags = @def_cflags;
987 my @cxxflags = @def_cxxflags;
988 my @cppflags = @def_cppflags;
989 my @ldflags = @def_ldflags;
990 # Check the specified hardening options, same order as dpkg-buildflags.
992 @cflags = (@cflags, @def_cflags_pie);
993 @cxxflags = (@cxxflags, @def_cflags_pie);
994 @ldflags = (@ldflags, @def_ldflags_pie);
997 @cflags = (@cflags, @def_cflags_stack);
998 @cxxflags = (@cxxflags, @def_cflags_stack);
1000 if ($harden_fortify) {
1001 @cflags = (@cflags, @def_cflags_fortify);
1002 @cxxflags = (@cxxflags, @def_cflags_fortify);
1003 @cppflags = (@cppflags, @def_cppflags_fortify);
1005 if ($harden_format) {
1006 @cflags = (@cflags, @def_cflags_format);
1007 @cxxflags = (@cxxflags, @def_cflags_format);
1009 if ($harden_relro) {
1010 @ldflags = (@ldflags, @def_ldflags_relro);
1012 if ($harden_bindnow) {
1013 @ldflags = (@ldflags, @def_ldflags_bindnow);
1016 # Stores normal CFLAGS when @cflags_ada are temporarily used.
1018 # Ada CFLAGS, only set if ada is used.
1020 # Ada doesn't support format hardening flags, see #680117 for more
1021 # information. Filter them out if ada is used.
1022 if ($ada and $harden_format) {
1023 @cflags_ada = grep {
1025 foreach my $flag (@def_cflags_format) {
1026 $ok = 0 if $_ eq $flag;
1032 # Hack to fix cppflags_fortify_broken() if --ignore-flag
1033 # -D_FORTIFY_SOURCE=2 is used to ignore missing fortification. Only works
1034 # as long as @def_cppflags_fortify contains only one variable.
1035 if (scalar @def_cppflags_fortify == 0) {
1036 $harden_fortify = 0;
1039 # Ignore flags for this arch if requested.
1040 if ($arch and exists $option_ignore_arch_flag{$arch}) {
1041 my @local_flag_refs = (\@cflags, \@cxxflags, \@cppflags, \@ldflags);
1043 remove_flags(\@local_flag_refs,
1045 @{$option_ignore_arch_flag{$arch}});
1048 my @ignore_line = @option_ignore_line;
1049 # Ignore lines for this arch if requested.
1050 if ($arch and exists $option_ignore_arch_line{$arch}) {
1051 @ignore_line = (@ignore_line, @{$option_ignore_arch_line{$arch}});
1055 for (my $i = 0; $i < scalar @input; $i++) {
1056 my $line = $input[$i];
1058 # Ignore line if requested.
1059 foreach my $ignore (@ignore_line) {
1060 next LINE if $line =~ /$ignore/;
1064 if ($input_nonverbose[$i]
1065 and is_non_verbose_build($line, $input[$i + 1], \$skip)) {
1066 if (not $option_buildd) {
1067 error_non_verbose_build($line);
1068 $exit |= $exit_code{non_verbose_build};
1070 $statistics{commands_nonverbose}++;
1074 # Even if it's a verbose build, we might have to skip this line (see
1075 # is_non_verbose_build()).
1078 # Remove everything until and including the compiler command. Makes
1079 # checks easier and faster.
1080 $line =~ s/^.*?$cc_regex//o;
1081 # "([...] test.c)" is not detected as 'test.c' - fix this by removing
1082 # the brace and similar characters at the line end.
1083 $line =~ s/['")]+$//;
1085 # Skip unnecessary tests when only preprocessing.
1086 my $flag_preprocess = 0;
1093 # Preprocess, compile, assemble.
1094 if ($line =~ /\s(-E|-S|-c)\b/) {
1096 $flag_preprocess = 1 if $1 eq '-E';
1097 $compile = 1 if $1 eq '-S' or $1 eq '-c';
1098 # Dependency generation for Makefiles. The other flags (-MF -MG -MP
1099 # -MT -MQ) are always used with -M/-MM.
1100 } elsif ($line =~ /\s(?:-M|-MM)\b/) {
1102 # Otherwise assume we are linking.
1107 # -MD/-MMD also cause dependency generation, but they don't imply -E!
1108 if ($line =~ /\s(?:-MD|-MMD)\b/) {
1110 $flag_preprocess = 0;
1113 # Dependency generation for Makefiles, no preprocessing or other flags
1115 next if $dependency;
1117 # Get all file extensions on this line.
1118 my @extensions = $line =~ /$file_extension_regex/go;
1119 # Ignore all unknown extensions to speedup the search below.
1120 @extensions = grep { exists $extension{$_} } @extensions;
1122 # These file types don't require preprocessing.
1123 if (extension_found(\%extensions_no_preprocess, @extensions)) {
1126 # These file types require preprocessing.
1127 if (extension_found(\%extensions_preprocess, @extensions)) {
1131 if (not $flag_preprocess) {
1132 # If there are source files then it's compiling/linking in one
1133 # step and we must check both. We only check for source files
1134 # here, because header files cause too many false positives.
1135 if (extension_found(\%extensions_compile_link, @extensions)) {
1136 # Assembly files don't need CFLAGS.
1137 if (not extension_found(\%extensions_compile, @extensions)
1138 and extension_found(\%extensions_no_compile, @extensions)) {
1140 # But the rest does.
1144 # No compilable extensions found, either linking or compiling
1147 # If there are also no object files we are just compiling headers
1148 # (.h -> .h.gch). Don't check for linker flags in this case. Due
1149 # to our liberal checks for compiler lines, this also reduces the
1150 # number of false positives considerably.
1152 and not extension_found(\%extensions_object, @extensions)) {
1157 my $compile_cpp = 0;
1158 my $compile_ada = 0;
1159 # Assume CXXFLAGS are required when a C++ file is specified in the
1162 and extension_found(\%extensions_compile_cpp, @extensions)) {
1165 # Ada needs special CFLAGS, use them if only ada files are compiled.
1168 and array_equal(\@extensions,
1169 \@source_no_preprocess_compile_ada)) {
1171 @cflags_backup = @cflags;
1172 @cflags = @cflags_ada;
1175 if ($option_buildd) {
1176 $statistics{preprocess}++ if $preprocess;
1177 $statistics{compile}++ if $compile;
1178 $statistics{compile_cpp}++ if $compile_cpp;
1179 $statistics{link}++ if $link;
1182 # Check if there are flags indicating a debug build. If that's true,
1183 # skip the check for -O2. This prevents fortification, but that's fine
1184 # for a debug build.
1185 if (any_flags_used($line, @def_cflags_debug)) {
1186 remove_flags([\@cflags], \%flag_renames, $def_cflags[1]);
1189 # Check hardening flags.
1191 if ($compile and not all_flags_used($line, \@missing, @cflags)
1192 # Libraries linked with -fPIC don't have to (and can't) be
1193 # linked with -fPIE as well. It's no error if only PIE flags
1195 and not pic_pie_conflict($line, $harden_pie, \@missing, @def_cflags_pie)
1196 # Assume dpkg-buildflags returns the correct flags.
1197 and index($line, '`dpkg-buildflags --get CFLAGS`') == -1) {
1198 if (not $option_buildd) {
1199 error_flags('CFLAGS missing', \@missing, \%flag_renames, $input[$i]);
1200 $exit |= $exit_code{flags_missing};
1202 $statistics{compile_missing}++;
1204 } elsif ($compile_cpp and not all_flags_used($line, \@missing, @cflags)
1205 # Libraries linked with -fPIC don't have to (and can't) be
1206 # linked with -fPIE as well. It's no error if only PIE flags
1208 and not pic_pie_conflict($line, $harden_pie, \@missing, @def_cflags_pie)
1209 # Assume dpkg-buildflags returns the correct flags.
1210 and index($line, '`dpkg-buildflags --get CXXFLAGS`') == -1) {
1211 if (not $option_buildd) {
1212 error_flags('CXXFLAGS missing', \@missing, \%flag_renames, $input[$i]);
1213 $exit |= $exit_code{flags_missing};
1215 $statistics{compile_cpp_missing}++;
1219 and (not all_flags_used($line, \@missing, @cppflags)
1220 # The fortify flag might be overwritten, detect that.
1222 and cppflags_fortify_broken($line, \@missing)))
1223 # Assume dpkg-buildflags returns the correct flags.
1224 and index($line, '`dpkg-buildflags --get CPPFLAGS`') == -1) {
1225 if (not $option_buildd) {
1226 error_flags('CPPFLAGS missing', \@missing, \%flag_renames, $input[$i]);
1227 $exit |= $exit_code{flags_missing};
1229 $statistics{preprocess_missing}++;
1232 if ($link and not all_flags_used($line, \@missing, @ldflags)
1233 # Same here, -fPIC conflicts with -fPIE.
1234 and not pic_pie_conflict($line, $harden_pie, \@missing, @def_ldflags_pie)
1235 # Assume dpkg-buildflags returns the correct flags.
1236 and index($line, '`dpkg-buildflags --get LDFLAGS`') == -1) {
1237 if (not $option_buildd) {
1238 error_flags('LDFLAGS missing', \@missing, \%flag_renames, $input[$i]);
1239 $exit |= $exit_code{flags_missing};
1241 $statistics{link_missing}++;
1245 # Restore normal CFLAGS.
1247 @cflags = @cflags_backup;
1252 # Print statistics for buildd mode, only output in this mode.
1253 if ($option_buildd) {
1256 if ($statistics{preprocess_missing}) {
1257 push @warning, sprintf 'CPPFLAGS %d (of %d)',
1258 $statistics{preprocess_missing},
1259 $statistics{preprocess};
1261 if ($statistics{compile_missing}) {
1262 push @warning, sprintf 'CFLAGS %d (of %d)',
1263 $statistics{compile_missing},
1264 $statistics{compile};
1266 if ($statistics{compile_cpp_missing}) {
1267 push @warning, sprintf 'CXXFLAGS %d (of %d)',
1268 $statistics{compile_cpp_missing},
1269 $statistics{compile_cpp};
1271 if ($statistics{link_missing}) {
1272 push @warning, sprintf 'LDFLAGS %d (of %d)',
1273 $statistics{link_missing},
1276 if (scalar @warning) {
1277 local $" = ', '; # array join string
1278 print "$buildd_tag{flags_missing}|@warning missing|\n";
1281 if ($statistics{commands_nonverbose}) {
1282 printf "$buildd_tag{non_verbose_build}|%d (of %d) hidden|\n",
1283 $statistics{commands_nonverbose},
1284 $statistics{commands},
1296 blhc - build log hardening check, checks build logs for missing hardening flags
1300 B<blhc> [I<options>] I<< <dpkg-buildpackage build log file>.. >>
1304 blhc is a small tool which checks build logs for missing hardening flags. It's
1305 licensed under the GPL 3 or later.
1307 It's designed to check build logs generated by Debian's dpkg-buildpackage (or
1308 tools using dpkg-buildpackage like pbuilder or sbuild (which is used for the
1309 official buildd build logs)) to help maintainers detect missing hardening
1310 flags in their packages.
1312 Only gcc is detected as compiler at the moment. If other compilers support
1313 hardening flags as well, please report them.
1315 If there's no output, no flags are missing and the build log is fine.
1317 See F<README> for details about performed checks, auto-detection and
1326 Force check for all +all (+pie, +bindnow) hardening flags. By default it's
1329 =item B<--arch> I<architecture>
1331 Set the specific architecture (e.g. amd64, armel, etc.), automatically
1332 disables hardening flags not available on this architecture. Is detected
1333 automatically if dpkg-buildpackage is used.
1337 Force check for all +bindnow hardening flags. By default it's auto detected.
1341 Special mode for buildds when automatically parsing log files. The following
1342 changes are in effect:
1348 Print tags instead of normal warnings, see L</"BUILDD TAGS"> for a list of
1353 Don't check hardening flags in old log files (if dpkg-dev << 1.16.1 is
1358 Don't require Term::ANSIColor.
1362 Return exit code 0, unless there was a error (-I, -W messages don't count as
1369 Use colored (ANSI) output for warning messages.
1371 =item B<--ignore-arch> I<arch>
1373 Ignore build logs from architectures matching I<arch>. I<arch> is a string.
1375 Used to prevent false positives. This option can be specified multiple times.
1377 =item B<--ignore-arch-flag> I<arch>:I<flag>
1379 Like B<--ignore-flag>, but only ignore flag on I<arch>.
1381 =item B<--ignore-arch-line> I<arch>:I<line>
1383 Like B<--ignore-line>, but only ignore line on I<arch>.
1385 =item B<--ignore-flag> I<flag>
1387 Don't print an error when the specific flag is missing in a compiler line.
1388 I<flag> is a string.
1390 Used to prevent false positives. This option can be specified multiple times.
1392 =item B<--ignore-line> I<regex>
1394 Ignore lines matching the given Perl regex. I<regex> is automatically anchored
1395 at the beginning and end of the line to prevent false negatives.
1397 B<NOTE>: Not the input lines are checked, but the lines which are displayed in
1398 warnings (which have line continuation resolved).
1400 Used to prevent false positives. This option can be specified multiple times.
1404 Force check for all +pie hardening flags. By default it's auto detected.
1406 =item B<-h -? --help>
1408 Print available options.
1412 Print version number and license.
1416 Auto detection for B<--pie> and B<--bindnow> only works if at least one
1417 command uses the required hardening flag (e.g. -fPIE). Then it's required for
1418 all other commands as well.
1422 Normal usage, parse a single log file.
1424 blhc path/to/log/file
1426 If there's no output, no flags are missing and the build log is fine.
1428 Parse multiple log files. The exit code is ORed over all files.
1430 blhc path/to/directory/with/log/files/*
1432 Don't treat missing C<-g> as error:
1434 blhc --ignore-flag -g path/to/log/file
1436 Don't treat missing C<-pie> on kfreebsd-amd64 as error:
1438 blhc --ignore-arch-flag kfreebsd-amd64:-pie path/to/log/file
1440 Ignore lines consisting exactly of C<./script gcc file> which would cause a
1443 blhc --ignore-line '\./script gcc file' path/to/log/file
1445 Ignore lines matching C<./script gcc file> somewhere in the line.
1447 blhc --ignore-line '.*\./script gcc file.*' path/to/log/file
1449 Use blhc with pbuilder.
1451 pbuilder path/to/package.dsc | tee path/log/file
1452 blhc path/to/file || echo flags missing
1456 The following tags are used in I<--buildd> mode. In braces the additional data
1461 =item B<I-hardening-wrapper-used>
1463 The package uses hardening-wrapper which intercepts calls to gcc and adds
1464 hardening flags. The build log doesn't contain any hardening flags and thus
1465 can't be checked by blhc.
1467 =item B<W-compiler-flags-hidden> (summary of hidden lines)
1469 Build log contains lines which hide the real compiler flags. For example:
1476 Most of the time either C<export V=1> or C<export verbose=1> in
1477 F<debian/rules> fixes builds with hidden compiler flags. Sometimes C<.SILENT>
1478 in a F<Makefile> must be removed. And as last resort the F<Makefile> must be
1479 patched to remove the C<@>s hiding the real compiler commands.
1481 =item B<W-dpkg-buildflags-missing> (summary of missing flags)
1483 CPPFLAGS, CFLAGS, CXXFLAGS, LDFLAGS missing.
1485 =item B<I-invalid-cmake-used> (version)
1487 By default CMake ignores CPPFLAGS thus missing those hardening flags. Debian
1488 patched CMake in versions 2.8.7-1 and 2.8.7-2 to respect CPPFLAGS, but this
1489 patch was rejected by upstream and later reverted in Debian. Thus those two
1490 versions show correct usage of CPPFLAGS even if the package doesn't correctly
1491 handle them (for example by passing them to CFLAGS). To prevent false
1492 negatives just blacklist those two versions.
1494 =item B<I-no-compiler-commands>
1496 No compiler commands were detected. Either the log contains none or they were
1497 not correctly detected by blhc (please report the bug in this case).
1503 The exit status is a "bit mask", each listed status is ORed when the error
1504 condition occurs to get the result.
1514 No compiler commands were found.
1518 Invalid arguments/options given to blhc.
1526 Missing hardening flags.
1530 Hardening wrapper detected, no tests performed.
1534 Invalid CMake version used. See B<I-invalid-cmake-used> under L</"BUILDD
1535 TAGS"> for a detailed explanation.
1541 Simon Ruderich, E<lt>simon@ruderich.orgE<gt>
1543 Thanks to to Bernhard R. Link E<lt>brlink@debian.orgE<gt> and Jaria Alto
1544 E<lt>jari.aalto@cante.netE<gt> for their valuable input and suggestions.
1546 =head1 LICENSE AND COPYRIGHT
1548 Copyright (C) 2012-2013 by Simon Ruderich
1550 This program is free software: you can redistribute it and/or modify
1551 it under the terms of the GNU General Public License as published by
1552 the Free Software Foundation, either version 3 of the License, or
1553 (at your option) any later version.
1555 This program is distributed in the hope that it will be useful,
1556 but WITHOUT ANY WARRANTY; without even the implied warranty of
1557 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
1558 GNU General Public License for more details.
1560 You should have received a copy of the GNU General Public License
1561 along with this program. If not, see <http://www.gnu.org/licenses/>.
1565 L<hardening-check(1)>, L<dpkg-buildflags(1)>