use warnings;
use Getopt::Long ();
+use Term::ANSIColor ();
our $VERSION = '0.01';
+# CONSTANTS/VARIABLES
+
+# Regex to catch compiler commands.
+my $cc_regex = qr/(?:[a-z0-9_]+-(?:linux|kfreebsd)-gnu(?:eabi|eabihf)?-)?
+ (?:(?<!\.)cc|gcc|g\+\+|c\+\+)
+ (?:-[\d.]+)?/x;
+# Regex to catch (GCC) compiler warnings.
+my $warning_regex = qr/^(.+?):([0-9]+):[0-9]+: warning: (.+?) \[(.+?)\]$/;
+
+# Expected (hardening) flags. All flags are used as regexps.
+my @cflags = (
+ '-g',
+ '-O(?:2|3)',
+);
+my @cflags_format = (
+ '-Wformat',
+ '-Wformat-security',
+ '-Werror=format-security',
+);
+my @cflags_fortify = (
+ # fortify needs at least -O1, but -O2 is recommended anyway
+);
+my @cflags_stack = (
+ '-fstack-protector',
+ '--param=ssp-buffer-size=4',
+);
+my @cflags_pie = (
+ '-fPIE',
+);
+my @cppflags = ();
+my @cppflags_fortify = (
+ '-D_FORTIFY_SOURCE=2',
+);
+my @ldflags = ();
+my @ldflags_relro = (
+ '-Wl,(-z,)?relro',
+);
+my @ldflags_bindnow = (
+ '-Wl,(-z,)?now',
+);
+my @ldflags_pie = (
+ '-fPIE',
+ '-pie',
+);
+# Renaming rules for the output so the regex parts are not visible.
+my %flag_renames = (
+ '-O(?:2|3)' => '-O2',
+ '-Wl,(-z,)?relro' => '-Wl,-z,relro',
+ '-Wl,(-z,)?now' => '-Wl,-z,now',
+);
+
+
+# FUNCTIONS
+
+sub error_flags {
+ my ($message, $missing_flags_ref, $flag_renames_ref, $line) = @_;
+
+ # Rename flags if requested.
+ my @missing_flags = map {
+ (exists $flag_renames_ref->{$_})
+ ? $flag_renames_ref->{$_}
+ : $_
+ } @{$missing_flags_ref};
+
+ my $flags = join ' ', @missing_flags;
+ printf "%s (%s)%s %s",
+ error_color($message, 'red'), $flags, error_color(':', 'yellow'),
+ $line;
+}
+sub error_non_verbose_build {
+ my ($line) = @_;
+
+ printf "%s%s %s",
+ error_color('NONVERBOSE BUILD', 'red'),
+ error_color(':', 'yellow'),
+ $line;
+}
+sub error_color {
+ my ($message, $color) = @_;
+
+ # Use colors when writing to a terminal.
+ if (-t STDOUT) {
+ return Term::ANSIColor::colored($message, $color);
+ } else {
+ return $message;
+ }
+}
+
+sub any_flags_used {
+ my ($line, @flags) = @_;
+
+ foreach my $flag (@flags) {
+ return 1 if $line =~ /\s$flag(?:\s|\\|$)/;
+ }
+
+ return 0;
+}
+sub all_flags_used {
+ my ($line, $missing_flags_ref, @flags) = @_;
+
+ my @missing_flags = ();
+ foreach my $flag (@flags) {
+ if ($line !~ /\s$flag(?:\s|\\|$)/) {
+ push @missing_flags, $flag;
+ }
+ }
+
+ if (scalar @missing_flags == 0) {
+ return 1;
+ }
+
+ @{$missing_flags_ref} = @missing_flags;
+ return 0;
+}
+
+# Modifies $missing_flags_ref array.
+sub pic_pie_conflict {
+ my ($line, $pie, $missing_flags_ref, @flags_pie) = @_;
+
+ return 0 if not $pie;
+ return 0 if not any_flags_used($line, ('-fPIC', '-fpic'));
+
+ my %flags = map { $_ => 1 } @flags_pie;
+
+ # Remove all PIE flags from @missing_flags as they are not required with
+ # -fPIC.
+ my @result = grep {
+ not exists $flags{$_}
+ } @{$missing_flags_ref};
+ @{$missing_flags_ref} = @result;
+
+ # We got a conflict when no flags are left, thus only PIE flags were
+ # missing. If other flags were missing abort because the conflict is not
+ # the problem.
+ return scalar @result == 0;
+}
+
+sub is_non_verbose_build {
+ my ($line, $next_line, $skip_ref) = @_;
+
+ if (not ($line =~ /^checking if you want to see long compiling messages\.\.\. no/
+ or $line =~ /^\s*\[?(?:CC|CCLD|CXX|CXXLD|LD)\]?\s+(.+?)$/
+ or $line =~ /^\s*(?:C|c)ompiling\s+(.+?)(?:\.\.\.)?$/
+ or $line =~ /^\s*(?:B|b)uilding (?:program|shared library)\s+(.+?)$/
+ or $line =~ /^\s*\[[\d ]+%\] Building (?:C|CXX) object (.+?)$/)) {
+ return 0;
+ }
+
+ my $file = $1;
+
+ # On the first pass we only check if this line is verbose or not.
+ return 1 if not defined $next_line;
+
+ # Second pass, we have access to the next line.
+ ${$skip_ref} = 0;
+
+ # CMake and other build systems print the non-verbose messages also when
+ # building verbose. If a compiler and the file name occurs in the next
+ # line, treat it as verbose build.
+ if (defined $file) {
+ # Get filename, we can't use the complete path as only parts of it are
+ # used in the real compiler command.
+ $file =~ m{/([a-zA-Z0-9._-]+)$};
+ $file = $1;
+
+ if ($next_line =~ /\Q$file\E/ and $next_line =~ /$cc_regex/) {
+ # We still have to skip the current line as it doesn't contain any
+ # compiler commands.
+ ${$skip_ref} = 1;
+ return 0;
+ }
+ }
+
+ return 1;
+}
+
+
+# MAIN
+
+# Hardening options. Not all architectures support all hardening options.
+my $harden_format = 1;
+my $harden_fortify = 1;
+my $harden_stack = 1;
+my $harden_relro = 1;
+my $harden_bindnow = 0;
+my $harden_pie = 0;
+
# Parse command line arguments.
my $option_help = 0;
my $option_version = 0;
+my $option_all = 0;
+my $option_arch = undef;
if (not Getopt::Long::GetOptions(
'help|h|?' => \$option_help,
'version' => \$option_version,
+ # Hardening options.
+ 'pie' => \$harden_pie,
+ 'bindnow' => \$harden_bindnow,
+ 'all' => \$option_all,
+ # Misc.
+ 'arch' => \$option_arch,
)) {
require Pod::Usage;
Pod::Usage::pod2usage(2);
exit 0;
}
+if ($option_all) {
+ $harden_pie = 1;
+ $harden_bindnow = 1;
+}
+
+# Final exit code.
+my $exit = 0;
+
+# Input lines, contain only the lines with compiler commands.
+my @input = ();
+
+my $start = 0;
+my $continuation = 0;
+my $complete_line = undef;
+while (my $line = <>) {
+ # We skip over unimportant lines at the beginning to prevent false
+ # positives.
+ $start = 1 if $line =~ /^dpkg-buildpackage:/;
+ next if not $start;
+
+ # Detect architecture automatically unless overridden.
+ if (not $option_arch
+ and $line =~ /^dpkg-buildpackage: host architecture (.+)$/) {
+ $option_arch = $1;
+ }
+
+ # Ignore compiler warnings for now.
+ next if $line =~ /$warning_regex/;
+
+ # Remove all ANSI color sequences which are sometimes used in non-verbose
+ # builds.
+ $line = Term::ANSIColor::colorstrip($line);
+ # Also strip '\0xf' (delete previous character), used by Elink's build
+ # system.
+ $line =~ s/\x0f//g;
+ # And "ESC(B" which seems to be used on armhf and hurd (not sure what it
+ # does).
+ $line =~ s/\033\(B//g;
+
+ # Check if this line indicates a non verbose build.
+ my $non_verbose = is_non_verbose_build($line);
+
+ # One line may contain multiple commands (";"). Treat each one as single
+ # line.
+ my @line = split /(?<!\\);/, $line;
+ foreach $line (@line) {
+ # Add newline, drop all other whitespace at the end of a line.
+ $line =~ s/\s+$//;
+ $line .= "\n";
+
+ if ($continuation) {
+ $continuation = 0;
+
+ # Join lines, but leave the "\" in place so it's clear where the
+ # original line break was.
+ chomp $complete_line;
+ $complete_line .= ' ' . $line;
+ }
+ # Line continuation, line ends with "\".
+ if ($line =~ /\\\s*$/) {
+ $continuation = 1;
+ # Start line continuation.
+ if (not defined $complete_line) {
+ $complete_line = $line;
+ }
+ next;
+ }
+
+ if (not $continuation) {
+ # Use the complete line if a line continuation occurred.
+ if (defined $complete_line) {
+ $line = $complete_line;
+ $complete_line = undef;
+ }
+
+ # Ignore lines with no compiler commands.
+ next if $line !~ /\b$cc_regex(?:\s|\\)/ and not $non_verbose;
+
+ # Ignore false positives.
+ #
+ # `./configure` output.
+ next if not $non_verbose and $line =~ /^checking /;
+ next if $line =~ /^\s*(?:C\s+)?
+ (?:C|c)ompiler[\s.]*:\s+
+ $cc_regex
+ (?:\s-std=[a-z0-9:+]+)?\s*$
+ /x
+ or $line =~ /^\s*(?:- )?(?:CC|CXX)\s*=\s*$cc_regex\s*$/
+ or $line =~ /^\s*-- Check for working (?:C|CXX) compiler: /
+ or $line =~ /^\s*(?:echo )?Using [A-Z_]+\s*=\s*/;
+ # Debian buildd output.
+ next if $line =~ /^\s*Depends: .*?$cc_regex.*?$/
+ and $line !~ /\s-./; # option, prevent false negatives
+
+
+ push @input, $line;
+ }
+ }
+}
+
+if (scalar @input == 0) {
+ print "No compiler commands!\n";
+ $exit |= 1;
+ exit $exit;
+}
+
+# Option or auto detected.
+if ($option_arch) {
+ # The following was partially copied from dpkg-dev 1.16.1.2
+ # (/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.
+
+ require Dpkg::Arch;
+ my ($abi, $os, $cpu) = Dpkg::Arch::debarch_to_debtriplet($option_arch);
+
+ # Disable unsupported hardening options.
+ if ($cpu =~ /^(ia64|alpha|mips|mipsel|hppa)$/ or $option_arch eq 'arm') {
+ $harden_stack = 0;
+ }
+ if ($cpu =~ /^(ia64|hppa|avr32)$/) {
+ $harden_relro = 0;
+ $harden_bindnow = 0;
+ }
+}
+
+# Check if additional hardening options were used. Used to ensure they are
+# used for the complete build.
+foreach my $line (@input) {
+ $harden_pie = 1 if any_flags_used($line, @cflags_pie, @ldflags_pie);
+ $harden_bindnow = 1 if any_flags_used($line, @ldflags_bindnow);
+}
+
+# Check the specified hardening options, same order as dpkg-buildflags.
+if ($harden_pie) {
+ @cflags = (@cflags, @cflags_pie);
+ @ldflags = (@ldflags, @ldflags_pie);
+}
+if ($harden_stack) {
+ @cflags = (@cflags, @cflags_stack);
+}
+if ($harden_fortify) {
+ @cflags = (@cflags, @cflags_fortify);
+ @cppflags = (@cppflags, @cppflags_fortify);
+}
+if ($harden_format) {
+ @cflags = (@cflags, @cflags_format);
+}
+if ($harden_relro) {
+ @ldflags = (@ldflags, @ldflags_relro);
+}
+if ($harden_bindnow) {
+ @ldflags = (@ldflags, @ldflags_bindnow);
+}
+
+for (my $i = 0; $i < scalar @input; $i++) {
+ my $line = $input[$i];
+
+ my $skip = 0;
+ if (is_non_verbose_build($line, $input[$i + 1], \$skip)) {
+ error_non_verbose_build($line);
+ $exit |= 1 << 2;
+ next;
+ }
+ # Even if it's a verbose build, we might have to skip this line.
+ next if $skip;
+
+
+ # Is this a compiler or linker command?
+ my $compiler = 1;
+ my $linker = 0;
+
+ # Linker commands.
+ if ($line =~ m{\s-o # -o
+ [\s\\]*\s+ # possible line continuation
+ (?:[/.A-Za-z0-9~_-]+/)? # path to file
+ [A-Za-z0-9~_-]+ # binary name (no dots!)
+ (?:[0-9.]*\.so[0-9.]*[a-z]? # library (including version)
+ |\.la
+ |\.cgi)? # CGI binary
+ (?:\s|\\|$) # end of file name
+ }x
+ or $line =~ /^libtool: link: /
+ or $line =~ m{\s*/bin/bash .+?libtool\s+(.+?\s+)?--mode=(re)?link}) {
+ $compiler = 0;
+ $linker = 1;
+ }
+
+ # If there are source files then it's compiling/linking in one step and we
+ # must check both.
+ if ($line =~ /\.(?:c|cc|cpp)\b/) {
+ $compiler = 1;
+ }
+
+ # Check hardening flags.
+ my @missing;
+ if ($compiler and not all_flags_used($line, \@missing, @cflags)
+ # Libraries linked with -fPIC don't have to (and can't) be linked
+ # with -fPIE as well. It's no error if only PIE flags are missing.
+ and not pic_pie_conflict($line, $harden_pie, \@missing, @cflags_pie)) {
+ error_flags('CFLAGS missing', \@missing, \%flag_renames, $line);
+ $exit |= 1 << 3;
+ }
+ if ($compiler and not all_flags_used($line, \@missing, @cppflags)) {
+ error_flags('CPPFLAGS missing', \@missing, \%flag_renames, $line);
+ $exit |= 1 << 3;
+ }
+ if ($linker and not all_flags_used($line, \@missing, @ldflags)
+ # Same here, -fPIC conflicts with -fPIE.
+ and not pic_pie_conflict($line, $harden_pie, \@missing, @ldflags_pie)) {
+ error_flags('LDFLAGS missing', \@missing, \%flag_renames, $line);
+ $exit |= 1 << 3;
+ }
+}
+
+exit $exit;
+
__END__
B<blhc> [-h -? --help]
+B<blhc> [--pie] [--bindnow] [--all]
+
--help available options
--version version number and license
+ --pie force +pie check
+ --bindnow force +bindbow check
+ --all force +all (+pie, +bindnow) check
+ --arch set architecture (autodetected)
=head1 DESCRIPTION
Print version number and license.
+=item B<--pie>
+
+Force check for all +pie hardening flags. By default it's auto detected.
+
+=item B<--bindnow>
+
+Force check for all +bindnow hardening flags. By default it's auto detected.
+
+=item B<--all>
+
+Force check for all +all (+pie, +bindnow) hardening flags. By default it's
+auto detected.
+
+=item B<--arch>
+
+Set the specific architecture (e.g. amd64, armel, etc.), automatically
+disables hardening flags not available on this architecture. Is detected
+automatically if dpkg-buildpackage is used.
+
+=back
+
+Auto detection only works if at least one command uses the required hardening
+flag (e.g. -fPIE). Then it's required for all other commands as well.
+
+=head1 EXIT STATUS
+
+The exit status is a "bit mask", each listed status is ORed when the error
+condition occurs to get the result.
+
+=over 8
+
+=item B<0>
+
+Success.
+
+=item B<1>
+
+No compiler commands were found.
+
+=item B<2>
+
+Invalid arguments/options given to blhc.
+
+=item B<4>
+
+Non verbose build.
+
+=item B<8>
+
+Missing hardening flags.
+
=back
=head1 AUTHOR
ruderich.org/simon / blhc / blhc.git / blobdiff