# Build log hardening check, checks build logs for missing hardening flags.
-# Copyright (C) 2012-2013 Simon Ruderich
+# Copyright (C) 2012-2018 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 = '0.04';
+our $VERSION = '0.07';
# CONSTANTS/VARIABLES
my $cc_regex = qr/
(?<!\s-) # ignore options, e.g. "-c++" [sic!] (used by swig)
(?<!\.) # ignore file names, e.g. "test.gcc"
- (?:cc|gcc|g\+\+|c\+\+)
+ (?:cc|gcc|g\+\+|c\+\+|gfortran|mpicc|mpicxx|mpifort)
(?:-[\d.]+)? # version suffix, e.g. "gcc-4.6"
/x;
# Full regex which matches the complete compiler name. Used in a few places to
# prevent false negatives.
+my $cc_regex_full_prefix = qr/
+ [a-z0-9_]+-(?:linux-|kfreebsd-)?gnu(?:eabi|eabihf)?
+ /x;
my $cc_regex_full = qr/
- (?:[a-z0-9_]+-(?:linux-|kfreebsd-)?gnu(?:eabi|eabihf)?-)?
+ (?:$cc_regex_full_prefix-)?
$cc_regex
/x;
# Regex to check if a line contains a compiler command.
/x;
# Regex to catch (GCC) compiler warnings.
my $warning_regex = qr/^(.+?):(\d+):\d+: warning: (.+?) \[(.+?)\]$/;
+# Regex to catch libtool commands and not lines which show commands executed
+# by libtool (e.g. libtool: link: ...).
+my $libtool_regex = qr/\blibtool\s.*--mode=/;
+my $libtool_link_regex = qr/\blibtool: link: /;
# List of source file extensions which require preprocessing.
my @source_preprocess_compile_cpp = (
# Objective-C++
qw( mm M ),
);
+my @source_preprocess_compile_fortran = (
+ # Fortran
+ qw( F FOR fpp FPP FTN F90 F95 F03 F08 ),
+);
my @source_preprocess_compile = (
# C
qw( c ),
# (Objective-)C++
@source_preprocess_compile_cpp,
# Fortran
- qw( F FOR fpp FPP FTN F90 F95 F03 F08 ),
+ @source_preprocess_compile_fortran,
);
my @source_preprocess_no_compile = (
# Assembly
qw( mii ),
);
my @source_no_preprocess_compile_ada = (
+ # Ada source
+ qw( ada ),
# Ada body
qw( adb ),
- # If you add another file, fix use of @source_no_preprocess_compile_ada
- # below (search for $compile_ada).
+);
+my @source_no_preprocess_compile_fortran = (
+ # Fortran
+ qw( f for ftn f90 f95 f03 f08 ),
);
my @source_no_preprocess_compile = (
# C
# Objective-C
qw( mi ),
# Fortran
- qw( f for ftn f90 f95 f03 f08 ),
+ @source_no_preprocess_compile_fortran,
# Ada
@source_no_preprocess_compile_ada,
);
+my @source_no_preprocess_no_compile_ada = (
+ # Ada specification
+ qw( ads ),
+);
my @source_no_preprocess_no_compile = (
# Assembly
qw( s ),
- # Ada specification
- qw( ads ),
+ # Ada
+ @source_no_preprocess_no_compile_ada,
);
my @source_no_preprocess = (
@source_no_preprocess_compile,
@source_preprocess_compile_cpp,
@source_no_preprocess_compile_cpp,
);
+my %extensions_ada = map { $_ => 1 } (
+ @source_no_preprocess_compile_ada,
+ @source_no_preprocess_no_compile_ada,
+);
+my %extensions_fortran = map { $_ => 1 } (
+ @source_no_preprocess_compile_fortran,
+ @source_preprocess_compile_fortran,
+);
my %extensions_object = map { $_ => 1 } (
@object,
);
# real regexps below for better execution speed).
my @def_cflags = (
'-g',
- '-O(?:2|3)',
+ '-O(?:2|3)', # keep at index 1, search for @def_cflags_debug to change it
+);
+my @def_cflags_debug = (
+ # These flags indicate a debug build which disables checks for -O2.
+ '-O0',
+ '-Og',
);
my @def_cflags_format = (
'-Wformat(?:=2)?', # -Wformat=2 implies -Wformat, accept it too
'-fstack-protector',
'--param[= ]ssp-buffer-size=4',
);
+my @def_cflags_stack_strong = (
+ '-fstack-protector-strong',
+);
my @def_cflags_pie = (
'-fPIE',
);
my @def_cppflags = ();
my @def_cppflags_fortify = (
'-D_FORTIFY_SOURCE=2', # must be first, see cppflags_fortify_broken()
- # If you add another flag fix hack below (search for "Hack to fix").
+ # If you add another flag fix hack below (search for "Hack to fix") and
+ # $def_cppflags_fortify[0].
);
my @def_cppflags_fortify_bad = (
# These flags may overwrite -D_FORTIFY_SOURCE=2.
\@def_cflags_format,
\@def_cflags_fortify,
\@def_cflags_stack,
+ \@def_cflags_stack_strong,
\@def_cflags_pie,
\@def_cxxflags,
\@def_cppflags,
# References to all used flags.
my @flag_refs_all = (
@flag_refs,
+ \@def_cflags_debug,
\@def_cppflags_fortify_bad,
\@def_ldflags_pic,
);
}
sub is_non_verbose_build {
- my ($line, $next_line, $skip_ref) = @_;
+ my ($line, $skip_ref, $input_ref, $line_offset, $line_count) = @_;
+
+ if ($line =~ /$libtool_regex/o) {
+ # libtool's --silent hides the real compiler flags.
+ if ($line =~ /\s--silent/) {
+ return 1;
+ # If --silent is not present, skip this line as some compiler flags
+ # might be missing (e.g. -fPIE) which are handled correctly by libtool
+ # internally. libtool displays the real compiler command on the next
+ # line, so the flags are checked as usual.
+ } else {
+ ${$skip_ref} = 1;
+ return 0;
+ }
+ }
if (not (index($line, 'checking if you want to see long compiling messages... no') == 0
or $line =~ /^\s*\[?(?:CC|CCLD|C\+\+|CXX|CXXLD|LD|LINK)\]?\s+(.+?)$/
return 0 if $line =~ /^\s*C\+\+.+?:\s+(?:yes|no)\s*$/;
return 0 if $line =~ /^\s*C\+\+ Library: stdc\+\+$/;
# "Compiling" non binary files.
- return 0 if $line =~ /^\s*Compiling \S+\.(?:py|el)['"]?(?:\.\.\.)?$/;
+ return 0 if $line =~ /^\s*Compiling \S+\.(?:py|el)['"]?\s*(?:\.\.\.)?$/;
# "Compiling" with no file name.
if ($line =~ /^\s*[Cc]ompiling\s+(.+?)(?:\.\.\.)?$/) {
# $file_extension_regex may need spaces around the filename.
my $file = $1;
# On the first pass we only check if this line is verbose or not.
- return 1 if not defined $next_line;
+ return 1 if not defined $input_ref;
- # Second pass, we have access to the next line.
+ # Second pass, we have access to the next lines.
${$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.
+ # lines, 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.
$file =~ m{/([^/\s]+)$};
$file = $1;
- if (index($next_line, $file) != -1 and $next_line =~ /$cc_regex/o) {
- # Not a non-verbose line, but we still have to skip the current line
- # as it doesn't contain any compiler commands.
- ${$skip_ref} = 1;
- return 0;
+ for (my $i = 1; $i <= $line_count; $i++) {
+ my $next_line = $input_ref->[$line_offset + $i];
+ last unless defined $next_line;
+
+ if (index($next_line, $file) != -1 and $next_line =~ /$cc_regex/o) {
+ # Not a non-verbose line, but we still have to skip the
+ # current line as it doesn't contain any compiler commands.
+ ${$skip_ref} = 1;
+ return 0;
+ }
}
}
return 1;
}
-# Remove @flags from $flag_refs_ref, and $flag_renames_ref.
+# Remove @flags from $flag_refs_ref, uses $flag_renames_ref as reference.
sub remove_flags {
my ($flag_refs_ref, $flag_renames_ref, @flags) = @_;
my $option_all = 0;
my $option_arch = undef;
my $option_buildd = 0;
+my $option_debian = 0;
$option_color = 0;
if (not Getopt::Long::GetOptions(
'help|h|?' => \$option_help,
'color' => \$option_color,
'arch=s' => \$option_arch,
'buildd' => \$option_buildd,
+ 'debian' => \$option_debian,
)) {
require Pod::Usage;
Pod::Usage::pod2usage(2);
}
if ($option_version) {
print <<"EOF";
-blhc $VERSION Copyright (C) 2012-2013 Simon Ruderich
+blhc $VERSION Copyright (C) 2012-2018 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 $harden_format = 1;
my $harden_fortify = 1;
my $harden_stack = 1;
+ my $harden_stack_strong = 1;
my $harden_relro = 1;
my $harden_bindnow = $option_bindnow; # defaults to 0
my $harden_pie = $option_pie; # defaults to 0
# Does this build log use ada? Ada also uses gcc as compiler but uses
- # different CFLAGS. But only perform ada checks if an ada compiler used
+ # different CFLAGS. But only perform ada checks if an ada compiler is used
# for performance reasons.
my $ada = 0;
+ # Fortran also requires different CFLAGS.
+ my $fortran = 0;
+
+ # Number of parallel jobs to prevent false positives when detecting
+ # non-verbose builds. As not all jobs declare the number of parallel jobs
+ # use a large enough default.
+ my $parallel = 10;
+
+ # Don't check for PIE flags if automatically applied by the compiler. Only
+ # used in buildd and Debian mode.
+ my $disable_harden_pie = 0;
+ if ($option_debian) {
+ $disable_harden_pie = 1;
+ }
while (my $line = <$fh>) {
# Detect architecture automatically unless overridden. For buildd logs
#
# Packages which were built before 1.16.1 but used their own hardening
# flags are not checked.
+ #
+ # Strong stack protector is used since dpkg 1.17.11.
+ #
+ # Recent GCC versions automatically use PIE (only on supported
+ # architectures) and dpkg respects this properly since 1.18.15 and
+ # doesn't pass PIE flags manually.
if ($option_buildd
and index($line, 'Toolchain package versions: ') == 0) {
require Dpkg::Version;
- if (not $line =~ /\bdpkg-dev_(\S+)/
- or Dpkg::Version::version_compare($1, '1.16.1') < 0) {
+
+ my $disable = 1;
+ my $disable_strong = 1;
+
+ if ($line =~ /\bdpkg-dev_(\S+)/) {
+ if (Dpkg::Version::version_compare($1, '1.16.1') >= 0) {
+ $disable = 0;
+ }
+ if (Dpkg::Version::version_compare($1, '1.17.11') >= 0) {
+ $disable_strong = 0;
+ }
+ if (Dpkg::Version::version_compare($1, '1.18.15') >= 0) {
+ $disable_harden_pie = 1;
+ }
+ }
+
+ if ($disable) {
$harden_format = 0;
$harden_fortify = 0;
$harden_stack = 0;
$harden_bindnow = 0;
$harden_pie = 0;
}
+ if ($disable_strong) {
+ $harden_stack_strong = 0;
+ }
}
# The following two versions of CMake in Debian obeyed CPPFLAGS, but
if ($line =~ /\bgnat\b/) {
$ada = 1;
}
+ # Fortran compiler.
+ if ($line =~ /\bgfortran\b/) {
+ $fortran = 1;
+ }
+ }
+
+ # This flags is not always available, but if it is use it.
+ if ($line =~ /^DEB_BUILD_OPTIONS=.*\bparallel=(\d+)/) {
+ $parallel = $1;
}
# We skip over unimportant lines at the beginning of the log to
}
}
+ next if $line =~ /^\s*#/;
# Ignore compiler warnings for now.
next if $line =~ /$warning_regex/o;
}
# Check if this line indicates a non verbose build.
- $non_verbose |= is_non_verbose_build($line);
+ my $skip = 0;
+ $non_verbose |= is_non_verbose_build($line, \$skip);
+ next if $skip;
# One line may contain multiple commands (";"). Treat each one as
# single line. parse_line() is slow, only use it when necessary.
next if not $before =~ /$cc_regex_normal/o
and not $after =~ /$cc_regex_normal/o;
}
+ # Ignore false positives caused by gcc -v. It outputs a line
+ # looking like a normal compiler line but which is sometimes
+ # missing hardening flags, although the normal compiler line
+ # contains them.
+ next if $line =~ m{^\s+/usr/lib/gcc/$cc_regex_full_prefix/
+ [0-9.]+/cc1(?:plus)?}xo;
+ # Ignore false positive with `rm` which may remove files which
+ # look like a compiler executable thus causing the line to be
+ # 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+};
# Check if additional hardening options were used. Used to ensure
# they are used for the complete build.
# Option or auto detected.
if ($arch) {
- # The following was partially copied from dpkg-dev 1.17.1
- # (/usr/share/perl5/Dpkg/Vendor/Debian.pm, add_hardening_flags()),
+ # The following was partially copied from dpkg-dev 1.18.24
+ # (/usr/share/perl5/Dpkg/Vendor/Debian.pm, _add_hardening_flags()),
# copyright Raphaƫl Hertzog <hertzog@debian.org>, Kees Cook
# <kees@debian.org>, Canonical, Ltd. licensed under GPL version 2 or
# later. Keep it in sync.
require Dpkg::Arch;
- my ($abi, $os, $cpu) = Dpkg::Arch::debarch_to_debtriplet($arch);
+ my ($os, $cpu);
+ # Recent dpkg versions use a quadruplet for arch. Support both.
+ eval {
+ (undef, undef, $os, $cpu) = Dpkg::Arch::debarch_to_debtuple($arch);
+ };
+ if ($@) {
+ (undef, $os, $cpu) = Dpkg::Arch::debarch_to_debtriplet($arch);
+ }
+
+ my %builtin_pie_arch = map { $_ => 1 } qw(
+ amd64 arm64 armel armhf i386 kfreebsd-amd64 kfreebsd-i386
+ mips mipsel mips64el ppc64el s390x sparc sparc64
+ );
# Disable unsupported hardening options.
- if ($os !~ /^(?:linux|knetbsd|hurd)$/ or
- $cpu =~ /^(?:hppa|mips|mipsel|avr32)$/) {
+ if ($os !~ /^(?:linux|kfreebsd|knetbsd|hurd)$/
+ or $cpu =~ /^(?:hppa|avr32)$/) {
$harden_pie = 0;
}
- if ($cpu =~ /^(?:ia64|alpha|mips|mipsel|hppa|arm64)$/
- or $arch eq 'arm') {
+ if ($cpu =~ /^(?:ia64|alpha|hppa|nios2)$/ or $arch eq 'arm') {
$harden_stack = 0;
+ $harden_stack_strong = 0;
}
if ($cpu =~ /^(?:ia64|hppa|avr32)$/) {
$harden_relro = 0;
$harden_bindnow = 0;
}
+
+ if ($disable_harden_pie and exists $builtin_pie_arch{$arch}) {
+ $harden_pie = 0;
+ }
}
# Default values.
@cxxflags = (@cxxflags, @def_cflags_pie);
@ldflags = (@ldflags, @def_ldflags_pie);
}
- if ($harden_stack) {
+ if ($harden_stack_strong) {
+ @cflags = (@cflags, @def_cflags_stack_strong);
+ @cxxflags = (@cxxflags, @def_cflags_stack_strong);
+ } elsif ($harden_stack) {
@cflags = (@cflags, @def_cflags_stack);
@cxxflags = (@cxxflags, @def_cflags_stack);
}
@ldflags = (@ldflags, @def_ldflags_bindnow);
}
- # Stores normal CFLAGS when @cflags_ada are temporarily used.
- my @cflags_backup;
- # Ada CFLAGS, only set if ada is used.
- my @cflags_ada;
# Ada doesn't support format hardening flags, see #680117 for more
- # information. Filter them out if ada is used.
- if ($ada and $harden_format) {
- @cflags_ada = grep {
+ # information. Same for fortran. Filter them out if either language is
+ # used.
+ my @cflags_backup;
+ my @cflags_noformat;
+ if (($ada or $fortran) and $harden_format) {
+ @cflags_noformat = grep {
my $ok = 1;
foreach my $flag (@def_cflags_format) {
$ok = 0 if $_ eq $flag;
my $skip = 0;
if ($input_nonverbose[$i]
- and is_non_verbose_build($line, $input[$i + 1], \$skip)) {
+ and is_non_verbose_build($line, \$skip,
+ \@input, $i, $parallel)) {
if (not $option_buildd) {
error_non_verbose_build($line);
$exit |= $exit_code{non_verbose_build};
# is_non_verbose_build()).
next if $skip;
+ my $orig_line = $line;
+
# Remove everything until and including the compiler command. Makes
# checks easier and faster.
$line =~ s/^.*?$cc_regex//o;
}
# These file types require preprocessing.
if (extension_found(\%extensions_preprocess, @extensions)) {
- $preprocess = 1;
+ # Prevent false positives with "libtool: link: g++ -include test.h
+ # .." compiler lines.
+ if ($orig_line !~ /$libtool_link_regex/o) {
+ $preprocess = 1;
+ }
}
if (not $flag_preprocess) {
}
my $compile_cpp = 0;
- my $compile_ada = 0;
+ my $restore_cflags = 0;
# Assume CXXFLAGS are required when a C++ file is specified in the
# compiler line.
if ($compile
$compile_cpp = 1;
# Ada needs special CFLAGS, use them if only ada files are compiled.
} elsif ($ada
- and $compile
- and array_equal(\@extensions,
- \@source_no_preprocess_compile_ada)) {
- $compile_ada = 1;
+ and extension_found(\%extensions_ada, @extensions)) {
+ $restore_cflags = 1;
+ $preprocess = 0; # Ada uses no CPPFLAGS
@cflags_backup = @cflags;
- @cflags = @cflags_ada;
+ @cflags = @cflags_noformat;
+ # Same for fortran.
+ } elsif ($fortran
+ and extension_found(\%extensions_fortran, @extensions)) {
+ $restore_cflags = 1;
+ @cflags_backup = @cflags;
+ @cflags = @cflags_noformat;
}
if ($option_buildd) {
$statistics{link}++ if $link;
}
+ # Check if there are flags indicating a debug build. If that's true,
+ # skip the check for -O2. This prevents fortification, but that's fine
+ # for a debug build.
+ if (any_flags_used($line, @def_cflags_debug)) {
+ remove_flags([\@cflags], \%flag_renames, $def_cflags[1]);
+ remove_flags([\@cppflags], \%flag_renames, $def_cppflags_fortify[0]);
+ }
+
# Check hardening flags.
my @missing;
if ($compile and not all_flags_used($line, \@missing, @cflags)
}
# Restore normal CFLAGS.
- if ($compile_ada) {
+ if ($restore_cflags) {
@cflags = @cflags_backup;
}
}
=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.
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) 2012-2013 by Simon Ruderich
+Copyright (C) 2012-2018 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