# Build log hardening check, checks build logs for missing hardening flags.
-# Copyright (C) 2012-2017 Simon Ruderich
+# Copyright (C) 2012-2019 Simon Ruderich
#
# 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
use Getopt::Long ();
use Text::ParseWords ();
-our $VERSION = '0.07';
+our $VERSION = '0.09';
# CONSTANTS/VARIABLES
# fortify needs at least -O1, but -O2 is recommended anyway
);
my @def_cflags_stack = (
- '-fstack-protector',
+ '-fstack-protector', # keep first, used by cflags_stack_broken()
'--param[= ]ssp-buffer-size=4',
);
my @def_cflags_stack_strong = (
- '-fstack-protector-strong',
+ '-fstack-protector-strong', # keep first, used by cflags_stack_broken()
+);
+my @def_cflags_stack_bad = (
+ # Blacklist all stack protector options for simplicity.
+ '-fno-stack-protector',
+ '-fno-stack-protector-all',
+ '-fno-stack-protector-strong',
);
my @def_cflags_pie = (
'-fPIE',
\@def_cflags_fortify,
\@def_cflags_stack,
\@def_cflags_stack_strong,
+ \@def_cflags_stack_bad,
\@def_cflags_pie,
\@def_cxxflags,
\@def_cppflags,
}
sub error_flags {
- my ($message, $missing_flags_ref, $flag_renames_ref, $line) = @_;
+ my ($message, $missing_flags_ref, $flag_renames_ref, $line, $number) = @_;
# Get string value of qr//-escaped regexps and if requested rename them.
my @missing_flags = map {
} @{$missing_flags_ref};
my $flags = join ' ', @missing_flags;
+ printf '%d:', $number if defined $number;
printf '%s (%s)%s %s',
error_color($message, 'red'), $flags, error_color(':', 'yellow'),
$line;
return;
}
sub error_non_verbose_build {
- my ($line) = @_;
+ my ($line, $number) = @_;
+ printf '%d:', $number if defined $number;
printf '%s%s %s',
error_color('NONVERBOSE BUILD', 'red'),
error_color(':', 'yellow'),
@{$missing_flags_ref} = @missing_flags;
return 0;
}
+# Check if any of \@bad_flags occurs after $good_flag. Doesn't check if
+# $good_flag is present.
+sub flag_overwritten {
+ my ($line, $good_flag, $bad_flags) = @_;
+
+ if (not any_flags_used($line, @{$bad_flags})) {
+ return 0;
+ }
+
+ my $bad_pos = 0;
+ foreach my $flag (@{$bad_flags}) {
+ while ($line =~ /$flag/g) {
+ if ($bad_pos < $+[0]) {
+ $bad_pos = $+[0];
+ }
+ }
+ }
+ my $good_pos = 0;
+ while ($line =~ /$good_flag/g) {
+ $good_pos = $+[0];
+ }
+ if ($good_pos > $bad_pos) {
+ return 0;
+ }
+ return 1;
+}
sub cppflags_fortify_broken {
my ($line, $missing_flags) = @_;
- # This doesn't take the position into account, but is a simple solution.
- # And if the build system tries to force -D_FORTIFY_SOURCE=0/1, something
- # is wrong anyway.
+ # $def_cppflags_fortify[0] must be -D_FORTIFY_SOURCE=2!
+ my $fortify_source = $def_cppflags_fortify[0];
- if (any_flags_used($line, @def_cppflags_fortify_bad)) {
- # $def_cppflags_fortify[0] must be -D_FORTIFY_SOURCE=2!
- push @{$missing_flags}, $def_cppflags_fortify[0];
- return 1;
+ # Some build systems enable/disable fortify source multiple times, check
+ # the final result.
+ if (not flag_overwritten($line,
+ $fortify_source,
+ \@def_cppflags_fortify_bad)) {
+ return 0;
}
+ push @{$missing_flags}, $fortify_source;
+ return 1;
+}
- return 0;
+sub cflags_stack_broken {
+ my ($line, $missing_flags, $strong) = @_;
+
+ my $flag = $strong ? $def_cflags_stack_strong[0]
+ : $def_cflags_stack[0];
+
+ if (not flag_overwritten($line, $flag, \@def_cflags_stack_bad)) {
+ return 0;
+ }
+ push @{$missing_flags}, $flag;
+ return 1;
}
# Modifies $missing_flags_ref array.
my $option_all = 0;
my $option_arch = undef;
my $option_buildd = 0;
+my $option_debian = 0;
$option_color = 0;
+my $option_line_numbers = 0;
if (not Getopt::Long::GetOptions(
'help|h|?' => \$option_help,
'version' => \$option_version,
'color' => \$option_color,
'arch=s' => \$option_arch,
'buildd' => \$option_buildd,
+ 'debian' => \$option_debian,
+ 'line-numbers' => \$option_line_numbers,
)) {
require Pod::Usage;
Pod::Usage::pod2usage(2);
}
if ($option_version) {
print <<"EOF";
-blhc $VERSION Copyright (C) 2012-2017 Simon Ruderich
+blhc $VERSION Copyright (C) 2012-2019 Simon Ruderich
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
my $parallel = 10;
# Don't check for PIE flags if automatically applied by the compiler. Only
- # used in buildd mode.
+ # used in buildd and Debian mode.
my $disable_harden_pie = 0;
+ if ($option_debian) {
+ $disable_harden_pie = 1;
+ }
+ my $number = 0;
while (my $line = <$fh>) {
+ $number++;
+
# Detect architecture automatically unless overridden. For buildd logs
# only, doesn't use the dpkg-buildpackage header. Necessary to ignore
# build logs which aren't built (wrong architecture, build error,
# This flags is not always available, but if it is use it.
if ($line =~ /^DEB_BUILD_OPTIONS=.*\bparallel=(\d+)/) {
- $parallel = $1;
+ $parallel = $1 * 2;
}
# We skip over unimportant lines at the beginning of the log to
# is_non_verbose_build() (which is quite slow) in the second loop when
# it's already clear if a line is non-verbose or not.
my @input_nonverbose = ();
+ # Input line number.
+ my @input_number = ();
my $continuation = 0;
my $complete_line = undef;
my $non_verbose;
while (my $line = <$fh>) {
+ $number++;
+
# And stop at the end of the build log. Package details (reported by
# the buildd logs) are not important for us. This also prevents false
# positives.
# treated as a normal compiler line.
next if $line =~ m{^\s*rm\s+};
# Some build systems emit "gcc > file".
- next if $line =~ m{$cc_regex_normal\s*>\s*\S+};
+ next if $line =~ m{$cc_regex_normal\s*>\s*\S+}o;
+ # Hex output may contain "cc".
+ next if $line =~ m#(?:\b[0-9a-fA-F]{2,}\b\s*){5}#;
# Check if additional hardening options were used. Used to ensure
# they are used for the complete build.
push @input, $line;
push @input_nonverbose, $non_verbose;
+ push @input_number, $number if $option_line_numbers;
}
}
# Option or auto detected.
if ($arch) {
- # The following was partially copied from dpkg-dev 1.18.24
- # (/usr/share/perl5/Dpkg/Vendor/Debian.pm, _add_hardening_flags()),
- # copyright Raphaël Hertzog <hertzog@debian.org>, Kees Cook
- # <kees@debian.org>, Canonical, Ltd. licensed under GPL version 2 or
- # later. Keep it in sync.
+ # The following was partially copied from dpkg-dev 1.19.5
+ # (/usr/share/perl5/Dpkg/Vendor/Debian.pm, _add_build_flags()),
+ # copyright Raphaël Hertzog <hertzog@debian.org>, Guillem Jover
+ # <guillem@debian.org>, Kees Cook <kees@debian.org>, Canonical, Ltd.
+ # licensed under GPL version 2 or later. Keep it in sync.
require Dpkg::Arch;
my ($os, $cpu);
}
my %builtin_pie_arch = map { $_ => 1 } qw(
- amd64 arm64 armel armhf i386 kfreebsd-amd64 kfreebsd-i386
- mips mipsel mips64el ppc64el s390x sparc sparc64
+ amd64
+ arm64
+ armel
+ armhf
+ hurd-i386
+ i386
+ kfreebsd-amd64
+ kfreebsd-i386
+ mips
+ mipsel
+ mips64el
+ powerpc
+ ppc64
+ ppc64el
+ riscv64
+ s390x
+ sparc
+ sparc64
);
# Disable unsupported hardening options.
and is_non_verbose_build($line, \$skip,
\@input, $i, $parallel)) {
if (not $option_buildd) {
- error_non_verbose_build($line);
+ error_non_verbose_build($line, $input_number[$i]);
$exit |= $exit_code{non_verbose_build};
} else {
$statistics{commands_nonverbose}++;
# Check hardening flags.
my @missing;
- if ($compile and not all_flags_used($line, \@missing, @cflags)
+ if ($compile and (not all_flags_used($line, \@missing, @cflags)
+ or (($harden_stack or $harden_stack_strong)
+ and cflags_stack_broken($line, \@missing,
+ $harden_stack_strong)))
# Libraries linked with -fPIC don't have to (and can't) be
# linked with -fPIE as well. It's no error if only PIE flags
# are missing.
# Assume dpkg-buildflags returns the correct flags.
and index($line, '`dpkg-buildflags --get CFLAGS`') == -1) {
if (not $option_buildd) {
- error_flags('CFLAGS missing', \@missing, \%flag_renames, $input[$i]);
+ error_flags('CFLAGS missing', \@missing, \%flag_renames,
+ $input[$i], $input_number[$i]);
$exit |= $exit_code{flags_missing};
} else {
$statistics{compile_missing}++;
# Assume dpkg-buildflags returns the correct flags.
and index($line, '`dpkg-buildflags --get CXXFLAGS`') == -1) {
if (not $option_buildd) {
- error_flags('CXXFLAGS missing', \@missing, \%flag_renames, $input[$i]);
+ error_flags('CXXFLAGS missing', \@missing, \%flag_renames,
+ $input[$i], $input_number[$i]);
$exit |= $exit_code{flags_missing};
} else {
$statistics{compile_cpp_missing}++;
# Assume dpkg-buildflags returns the correct flags.
and index($line, '`dpkg-buildflags --get CPPFLAGS`') == -1) {
if (not $option_buildd) {
- error_flags('CPPFLAGS missing', \@missing, \%flag_renames, $input[$i]);
+ error_flags('CPPFLAGS missing', \@missing, \%flag_renames,
+ $input[$i], $input_number[$i]);
$exit |= $exit_code{flags_missing};
} else {
$statistics{preprocess_missing}++;
# Assume dpkg-buildflags returns the correct flags.
and index($line, '`dpkg-buildflags --get LDFLAGS`') == -1) {
if (not $option_buildd) {
- error_flags('LDFLAGS missing', \@missing, \%flag_renames, $input[$i]);
+ error_flags('LDFLAGS missing', \@missing, \%flag_renames,
+ $input[$i], $input_number[$i]);
$exit |= $exit_code{flags_missing};
} else {
$statistics{link_missing}++;
=back
+=item B<--debian>
+
+Apply Debian-specific settings. At the moment this only disables checking for
+PIE which is automatically applied by Debian's GCC and no longer requires a
+compiler command line argument.
+
=item B<--color>
Use colored (ANSI) output for warning messages.
+=item B<--line-numbers>
+
+Display line numbers.
+
=item B<--ignore-arch> I<arch>
Ignore build logs from architectures matching I<arch>. I<arch> is a string.
pbuilder path/to/package.dsc | tee path/log/file
blhc path/to/file || echo flags missing
+Assume this build log was created on a Debian system and thus don't warn about
+missing PIE flags if the current architecture injects them automatically (this
+is enabled in buildd mode per default). C<--arch> is necessary if the build
+log contains no architecture information as written by dpkg-buildpackage.
+
+ blhc --debian --all --arch=amd64 path/to/log/file
+
=head1 BUILDD TAGS
The following tags are used in I<--buildd> mode. In braces the additional data
=head1 LICENSE AND COPYRIGHT
-Copyright (C) 2012-2017 by Simon Ruderich
+Copyright (C) 2012-2019 by Simon Ruderich
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