#!/usr/bin/perl
# Build log hardening check, checks build logs for missing hardening flags.
# Copyright (C) 2012 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
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see .
use strict;
use warnings;
use Getopt::Long ();
use Term::ANSIColor ();
our $VERSION = '0.01';
# FUNCTIONS
sub error_flags {
my ($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'),
$line;
}
sub error_color {
my ($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'));
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;
}
# CONSTANTS/VARIABLES
# 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',
'-O2',
'-fstack-protector',
'--param=ssp-buffer-size=4',
'-Wformat',
'-Wformat-security',
'-Werror=format-security',
);
my @cflags_pie = (
'-fPIE',
);
my @cppflags = (
'-D_FORTIFY_SOURCE=2',
);
my @ldflags = (
'-Wl,(-z,)?relro',
);
my @ldflags_pie = (
'-fPIE',
'-pie',
);
my @ldflags_bindnow = (
'-Wl,(-z,)?now',
);
# All (hardening) flags.
my @flags = (@cflags, @cflags_pie,
@cppflags,
@ldflags, @ldflags_pie, @ldflags_bindnow);
# Renaming rules for the output so the regex parts are not visible.
my %flag_renames = (
'-Wl,(-z,)?relro' => '-Wl,-z,relro',
'-Wl,(-z,)?now' => '-Wl,-z,now',
);
# MAIN
# Additional hardening options.
my $pie = 0;
my $bindnow = 0;
# Parse command line arguments.
my $option_all = 0;
my $option_help = 0;
my $option_version = 0;
if (not Getopt::Long::GetOptions(
'help|h|?' => \$option_help,
'version' => \$option_version,
'pie' => \$pie,
'bindnow' => \$bindnow,
'all' => \$option_all,
)) {
require Pod::Usage;
Pod::Usage::pod2usage(2);
}
if ($option_help) {
require Pod::Usage;
Pod::Usage::pod2usage(1);
}
if ($option_version) {
print "blhc $VERSION Copyright (C) 2012 Simon Ruderich
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see .
";
exit 0;
}
if ($option_all) {
$pie = 1;
$bindnow = 1;
}
# Final exit code.
my $exit = 0;
# Input lines, contain only the lines with compiler commands.
my @input = ();
my $continuation = 0;
while (my $line = <>) {
# Ignore compiler warnings for now.
next if $line =~ /$warning_regex/;
# One line may contain multiple commands (";"). Treat each one as single
# line.
my @line = split /(? [-h -? --help]
B [--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
=head1 DESCRIPTION
blhc is a small tool which checks build logs for missing hardening flags and
other important warnings. It's licensed under the GPL 3 or later.
=head1 OPTIONS
=over 8
=item B<-h -? --help>
Print available options.
=item B<--version>
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.
=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>
Missing hardening flags.
=back
=head1 AUTHOR
Simon Ruderich, Esimon@ruderich.orgE
=head1 COPYRIGHT AND LICENSE
Copyright (C) 2012 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
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see .
=cut