linux-hardened/scripts/extract-sys-certs.pl
Kamil Rytarowski cb77f0d623 scripts: Switch to more portable Perl shebang
The default NetBSD package manager is pkgsrc and it installs Perl
along other third party programs under custom and configurable prefix.
The default prefix for binary prebuilt packages is /usr/pkg, and the
Perl executable lands in /usr/pkg/bin/perl.

This change switches "/usr/bin/perl" to "/usr/bin/env perl" as it's
the most portable solution that should work for almost everybody.
Perl's executable is detected automatically.

This change switches -w option passed to the executable with more
modern "use warnings;" approach. There is no functional change to the
default behavior.

While there, drop "require 5" from scripts/namespace.pl (Perl from 1994?).

Signed-off-by: Kamil Rytarowski <n54@gmx.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2017-05-14 11:20:44 +09:00

158 lines
3.7 KiB
Perl
Executable file

#!/usr/bin/env perl
#
use warnings;
use strict;
use Math::BigInt;
use Fcntl "SEEK_SET";
die "Format: $0 [-s <systemmap-file>] <vmlinux-file> <keyring-file>\n"
if ($#ARGV != 1 && $#ARGV != 3 ||
$#ARGV == 3 && $ARGV[0] ne "-s");
my $sysmap = "";
if ($#ARGV == 3) {
shift;
$sysmap = $ARGV[0];
shift;
}
my $vmlinux = $ARGV[0];
my $keyring = $ARGV[1];
#
# Parse the vmlinux section table
#
open FD, "objdump -h $vmlinux |" || die $vmlinux;
my @lines = <FD>;
close(FD) || die $vmlinux;
my @sections = ();
foreach my $line (@lines) {
chomp($line);
if ($line =~ /\s*([0-9]+)\s+(\S+)\s+([0-9a-f]+)\s+([0-9a-f]+)\s+([0-9a-f]+)\s+([0-9a-f]+)\s+2[*][*]([0-9]+)/
) {
my $seg = $1;
my $name = $2;
my $len = Math::BigInt->new("0x" . $3);
my $vma = Math::BigInt->new("0x" . $4);
my $lma = Math::BigInt->new("0x" . $5);
my $foff = Math::BigInt->new("0x" . $6);
my $align = 2 ** $7;
push @sections, { name => $name,
vma => $vma,
len => $len,
foff => $foff };
}
}
print "Have $#sections sections\n";
#
# Try and parse the vmlinux symbol table. If the vmlinux file has been created
# from a vmlinuz file with extract-vmlinux then the symbol table will be empty.
#
open FD, "nm $vmlinux 2>/dev/null |" || die $vmlinux;
@lines = <FD>;
close(FD) || die $vmlinux;
my %symbols = ();
my $nr_symbols = 0;
sub parse_symbols(@) {
foreach my $line (@_) {
chomp($line);
if ($line =~ /([0-9a-f]+)\s([a-zA-Z])\s(\S+)/
) {
my $addr = "0x" . $1;
my $type = $2;
my $name = $3;
$symbols{$name} = $addr;
$nr_symbols++;
}
}
}
parse_symbols(@lines);
if ($nr_symbols == 0 && $sysmap ne "") {
print "No symbols in vmlinux, trying $sysmap\n";
open FD, "<$sysmap" || die $sysmap;
@lines = <FD>;
close(FD) || die $sysmap;
parse_symbols(@lines);
}
die "No symbols available\n"
if ($nr_symbols == 0);
print "Have $nr_symbols symbols\n";
die "Can't find system certificate list"
unless (exists($symbols{"__cert_list_start"}) &&
exists($symbols{"system_certificate_list_size"}));
my $start = Math::BigInt->new($symbols{"__cert_list_start"});
my $end;
my $size;
my $size_sym = Math::BigInt->new($symbols{"system_certificate_list_size"});
open FD, "<$vmlinux" || die $vmlinux;
binmode(FD);
my $s = undef;
foreach my $sec (@sections) {
my $s_name = $sec->{name};
my $s_vma = $sec->{vma};
my $s_len = $sec->{len};
my $s_foff = $sec->{foff};
my $s_vend = $s_vma + $s_len;
next unless ($start >= $s_vma);
next if ($start >= $s_vend);
die "Certificate list size was not found on the same section\n"
if ($size_sym < $s_vma || $size_sym > $s_vend);
die "Cert object in multiple sections: ", $s_name, " and ", $s->{name}, "\n"
if ($s);
my $size_off = $size_sym -$s_vma + $s_foff;
my $packed;
die $vmlinux if (!defined(sysseek(FD, $size_off, SEEK_SET)));
sysread(FD, $packed, 8);
$size = unpack 'L!', $packed;
$end = $start + $size;
printf "Have %u bytes of certs at VMA 0x%x\n", $size, $start;
die "Cert object partially overflows section $s_name\n"
if ($end > $s_vend);
$s = $sec;
}
die "Cert object not inside a section\n"
unless ($s);
print "Certificate list in section ", $s->{name}, "\n";
my $foff = $start - $s->{vma} + $s->{foff};
printf "Certificate list at file offset 0x%x\n", $foff;
die $vmlinux if (!defined(sysseek(FD, $foff, SEEK_SET)));
my $buf = "";
my $len = sysread(FD, $buf, $size);
die "$vmlinux" if (!defined($len));
die "Short read on $vmlinux\n" if ($len != $size);
close(FD) || die $vmlinux;
open FD, ">$keyring" || die $keyring;
binmode(FD);
$len = syswrite(FD, $buf, $size);
die "$keyring" if (!defined($len));
die "Short write on $keyring\n" if ($len != $size);
close(FD) || die $keyring;