1
0
Fork 0
mirror of https://github.com/perlbot/perlbuut synced 2025-06-07 17:25:41 -04:00
perlbuut/lib/eval.pl

439 lines
12 KiB
Perl
Executable file

#!/usr/bin/env perl
#use lib '/home/ryan/perl5/lib/perl5/i686-linux';
#use lib '/home/ryan/perl5/lib/perl5';
use strict;
use Data::Dumper;
use Scalar::Util; #Required by Data::Dumper
use BSD::Resource;
use File::Glob;
use POSIX;
use List::Util qw/reduce/;
use Cwd;
use FindBin;
# Modules expected by many evals, load them now to avoid typing in channel
use Encode qw/encode decode/;
use IO::String;
use File::Slurper qw/read_text/;
# save the old stdout, we're going to clobber it soon. STDOUT
my $oldout;
my $outbuffer = "";
open($oldout, ">&STDOUT") or die "Can't dup STDOUT: $!";
open(my $stdh, ">", \$outbuffer)
or die "Can't dup to buffer: $!";
select($stdh);
$|++;
#*STDOUT = $stdh;
sub get_seccomp {
use Linux::Seccomp ':all';
my $seccomp = Linux::Seccomp->new(SCMP_ACT_KILL);
##### set seccomp
#
# Rules should only allow:
# 1. open as read
# 2. write to stderr/stdout
# 3. exit
# 4. close file handle
# 5. random syscall
# 6. read
# 7. seek
# 8. fstat/fcntl
# 9. brk
# 10.
my $rule_add = sub {
my $name = shift;
$seccomp->rule_add(SCMP_ACT_ALLOW, syscall_resolve_name($name), @_);
};
$rule_add->(write => [0, '==', 2]); # STDERR
$rule_add->(write => [0, '==', 1]); # STDOUT
#mmap(NULL, 2112544, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 7, 0) = 0x7efedad0e000
#mprotect(0x7efedad12000, 2093056, PROT_NONE) = 0
#mmap(0x7efedaf11000, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 7, 0x3000) = 0x7efedaf11000
## MMAP? I don't know what it's being used for exactly. I'll leave it out and see what happens
# Used when loading executable code. Might need to figure out what to do to make it more secure?
# also seems to be used when freeing/allocating large blocks of memory, as you'd expect
$rule_add->(mmap => );
$rule_add->(munmap => );
$rule_add->(mremap => );
$rule_add->(mprotect =>);
# Allow select, might need to have some kind of restriction on it? probably fine
$rule_add->(select => );
# These are the allowed modes on open, allow that to work in any combo
my ($O_DIRECTORY, $O_CLOEXEC, $O_NOCTTY) = (00200000, 02000000, 00000400);
my @allowed_open_modes = (&POSIX::O_RDONLY, &POSIX::O_NONBLOCK, $O_DIRECTORY, $O_CLOEXEC, $O_NOCTTY);
# this annoying bitch of code is because Algorithm::Permute doesn't work with newer perls
# Also this ends up more efficient. We skip 0 because it's redundant
for my $b (1..(2**@allowed_open_modes) - 1) {
my $q = 1;
my $mode = 0;
#printf "%04b: ", $b;
do {
if ($q & $b) {
my $r = int(log($q)/log(2)+0.5); # get the thing
$mode |= $allowed_open_modes[$r];
#print "$r";
}
$q <<= 1;
} while ($q <= $b);
$rule_add->(open => [1, '==', $mode]);
$rule_add->(openat => [2, '==', $mode]);
#print " => $mode\n";
}
# 4352 ioctl(4, TCGETS, 0x7ffd10963820) = -1 ENOTTY (Inappropriate ioctl for device)
$rule_add->(ioctl => [1, '==', 0x5401]); # This happens on opened files for some reason? wtf
my @blind_syscalls = qw/read exit exit_group brk lseek fstat fcntl stat rt_sigaction rt_sigprocmask geteuid getuid getcwd close getdents getgid getegid getgroups lstat nanosleep getrlimit/;
for my $syscall (@blind_syscalls) {
$rule_add->($syscall);
}
$seccomp->load unless -e './noseccomp';
}
no warnings;
# This sub is defined here so that it is defined before the 'use charnames'
# command. This causes extremely strange interactions that result in the
# deparse output being much longer than it should be.
sub deparse_perl_code {
my( $code ) = @_;
my $sub;
{
no strict; no warnings; no charnames;
$sub = eval "use $]; sub{ $code\n }";
}
if( $@ ) { print STDOUT "Error: $@"; return }
my $dp = B::Deparse->new("-p", "-q", "-x7");
my $ret = $dp->coderef2text($sub);
$ret =~ s/\{//;
$ret =~ s/package (?:\w+(?:::)?)+;//;
$ret =~ s/ no warnings;//;
$ret =~ s/\s+/ /g;
$ret =~ s/\s*\}\s*$//;
$ret =~ s/\s*\$\^H\{[^}]+\}(\s+=\s+[^;]+;?)?\s*//g;
$ret =~ s/\s*BEGIN\s*\{\s*[^}]*\s*\}\s*/ /;
print STDOUT $ret;
}
eval "use utf8; \$\343\201\257 = 42; 'ש' =~ /([\p{Bidi_Class:L}\p{Bidi_Class:R}])/"; # attempt to automatically load the utf8 libraries.
eval "use utf8; [ 'ß' =~ m/^\Qss\E\z/i ? 'True' : 'False' ];"; # Try to grab some more utf8 libs
eval "use utf8; [CORE::fc '€']";
use charnames qw(:full);
use PerlIO;
use PerlIO::scalar;
use Text::ParseWords;
eval {"\N{SPARKLE}"}; # force loading of some of the charnames stuff
# Required for perl_deparse
use B::Deparse;
## Javascript Libs
#BEGIN{ eval "use JavaScript::V8; require JSON::XS; JavaScript::V8::Context->new()->eval('1')"; }
#my $JSENV_CODE = do { local $/; open my $fh, "deps/env.js"; <$fh> };
#require 'bytes_heavy.pl';
use Tie::Hash::NamedCapture;
{#no warnings 'constant';
uc "\x{666}"; #Attempt to load unicode libraries.
lc "JONQUIÉRE";
}
binmode STDOUT, ":utf8"; # Enable utf8 output.
#BEGIN{ eval "use PHP::Interpreter;"; }
# Evil Ruby stuff
#BEGIN{ eval "use Inline::Ruby qw/rb_eval/;"; }
#BEGIN { $SIG{SEGV} = sub { die "Segmentation Fault\n"; } } #Attempt to override the handler Ruby installs.
# # Evil K20 stuff
# BEGIN {
# local $@;
# eval "use Language::K20;";
# unless( $@ ) {
# Language::K20::k20eval( "2+2\n" ); # This eval loads the dynamic components before the chroot.
# # Note that k20eval always tries to output to stdout so we
# # must end the command with a \n to prevent this output.
# }
# }
#
# BEGIN { chdir "var/"; $0="../$0"; } # CHDIR to stop inline from creating stupid _Inline directories everywhere
# # Inline::Lua doesn't seem to provide an eval function. SIGH.
# BEGIN { eval 'use Inline Lua => "function lua_eval(str) return loadstring(str) end";'; }
# BEGIN { chdir ".."; $0=~s/^\.\.\/// } # Assume our earlier chdir succeded. Yay!
# # Evil python stuff
# BEGIN { eval "use Inline::Python qw/py_eval/;"; }
# # Evil J stuff
# BEGIN { eval "use Jplugin;"; }
use Carp::Heavy;
use Storable qw/nfreeze/; nfreeze([]); #Preload Nfreeze since it's loaded on demand
my $code = do { local $/; <STDIN> };
# Close every other filehandle we may have open
# this is probably legacy code at this point since it was used
# inside the original bb2 which forked to execute this code.
opendir my $dh, "/proc/self/fd" or die $!;
while(my $fd = readdir($dh)) { next unless $fd > 2; POSIX::close($fd) }
# Get the nobody uid before we chroot.
my $nobody_uid = getpwnam("nobody");
die "Error, can't find a uid for 'nobody'. Replace with someone who exists" unless $nobody_uid;
# Set the CPU LIMIT.
# Do this before the chroot because some of the other
# setrlimit calls will prevent chroot from working
# however at the same time we need to preload an autload file
# that chroot will prevent, so do it here.
setrlimit(RLIMIT_CPU, 10,10);
# Root Check
if( $< != 0 )
{
die "Not root, can't chroot or take other precautions, dying\n";
}
# The chroot section
chdir($FindBin::Bin."/../jail") or die "Jail not made, see bin/makejail.sh";
# redirect STDIN to /dev/null, to avoid warnings in convoluted cases.
open STDIN, '<', '/dev/null' or die "Can't open /dev/null: $!";
chroot(".") or die $!;
# Here's where we actually drop our root privilege
$)="$nobody_uid $nobody_uid";
$(=$nobody_uid;
$<=$>=$nobody_uid;
POSIX::setgid($nobody_uid); #We just assume the uid is the same as the gid. Hot.
die "Failed to drop to nobody"
if $> != $nobody_uid
or $< != $nobody_uid;
my $kilo = 1024;
my $meg = $kilo * $kilo;
my $limit = 300 * $meg;
(
setrlimit(RLIMIT_VMEM, 1.5*$limit, 1.5*$limit)
and
setrlimit(RLIMIT_DATA, $limit, $limit )
and
setrlimit(RLIMIT_STACK, $limit, $limit )
and
setrlimit(RLIMIT_NPROC, 1,1)
and
setrlimit(RLIMIT_NOFILE, 20,20)
and
setrlimit(RLIMIT_OFILE, 20,20)
and
setrlimit(RLIMIT_OPEN_MAX,20,20)
and
setrlimit(RLIMIT_LOCKS, 0,0)
and
setrlimit(RLIMIT_AS,$limit,$limit)
and
setrlimit(RLIMIT_MEMLOCK,100,100)
and
setrlimit(RLIMIT_CPU, 10, 10)
)
or die "Failed to set rlimit: $!";
%ENV=();
#setrlimit(RLIMIT_MSGQUEUE,100,100);
die "Failed to drop root: $<" if $< == 0;
# close STDIN;
# Setup SECCOMP for us
get_seccomp();
$code =~ s/^\s*(\w+)\s*//
or die "Failed to parse code type! $code";
my $type = $1;
# Chomp code..
$code =~ s/\s*$//;
# Choose which type of evaluation to perform
# will probably be a dispatch table soon.
if( $type eq 'perl' or $type eq 'pl' ) {
perl_code($code);
}
elsif( $type eq 'deparse' ) {
deparse_perl_code($code);
}
# elsif( $type eq 'javascript' ) {
# javascript_code($code);
# }
# elsif( $type eq 'php' ) {
# php_code($code);
# }
# elsif( $type eq 'k20' ) {
# k20_code($code);
# }
# elsif( $type eq 'rb' or $type eq 'ruby' ) {
# ruby_code($code);
# }
# elsif( $type eq 'py' or $type eq 'python' ) {
# python_code($code);
# }
# elsif( $type eq 'lua' ) {
# lua_code($code);
# }
# elsif( $type eq 'j' ) {
# j_code($code);
# }
# *STDOUT = $oldout;
close($stdh);
select(STDOUT);
print($outbuffer);
exit;
#-----------------------------------------------------------------------------
# Evaluate the actual code
#-----------------------------------------------------------------------------
sub perl_code {
my( $code ) = @_;
local $@;
local @INC = map {s|/home/ryan||r} @INC;
local $_;
my $ret;
my @os = qw/aix bsdos darwin dynixptx freebsd haiku linux hpux irix next openbsd dec_osf svr4 sco_sv unicos unicosmk solaris sunos MSWin32 MSWin16 MSWin63 dos os2 cygwin VMS vos os390 os400 posix-bc riscos amigaos xenix/;
{
local $^O = $os[rand()*@os];
no strict; no warnings; package main;
$code = "use $]; use feature qw/postderef refaliasing lexical_subs postderef_qq signatures/; use experimental 'declared_refs'; $code";
$ret = eval $code;
}
local $Data::Dumper::Terse = 1;
local $Data::Dumper::Quotekeys = 0;
local $Data::Dumper::Indent = 0;
local $Data::Dumper::Useqq = 1;
my $out = ref($ret) ? Dumper( $ret ) : "" . $ret;
print $out unless $outbuffer;
if( $@ ) { print "ERROR: $@" }
}
# sub javascript_code {
# my( $code ) = @_;
# local $@;
#
# my $js = JavaScript::V8::Context->new;
#
# # Set up the Environment for ENVJS
# $js->bind("print", sub { print @_ } );
# $js->bind("write", sub { print @_ } );
#
# # for( qw/log debug info warn error/ ) {
# # $js->eval("Envjs.$_=function(x){}");
# # }
#
# # $js->eval($JSENV_CODE) or die $@;
#
# $code =~ s/(["\\])/\\$1/g;
# my $rcode = qq{write(eval("$code"))};
#
#
#
# my $out = eval { $js->eval($rcode) };
#
# if( $@ ) { print "ERROR: $@"; }
# else { print encode_json $out }
# }
#
# sub ruby_code {
# my( $code ) = @_;
# local $@;
#
# print rb_eval( $code );
# }
#
# sub php_code {
# my( $code ) = @_;
# local $@;
#
# #warn "PHP - [$code]";
#
# my $php = PHP::Interpreter->new;
#
# $php->set_output_handler(\ my $output );
#
# $php->eval("$code;");
#
# print $php->get_output;
#
# #warn "ENDING";
#
# if( $@ ) { print "ERROR: $@"; }
# }
#
# sub k20_code {
# my( $code ) = @_;
#
# $code =~ s/\r?\n//g;
#
#
# Language::K20::k20eval( '."\\\\r ' . int(rand(2**31)) . '";' . "\n"); # set random seed
#
# Language::K20::k20eval( $code );
# }
#
# sub python_code {
# my( $code ) = @_;
#
# py_eval( $code, 2 );
# }
#
# sub lua_code {
# my( $code ) = @_;
#
# #print lua_eval( $code )->();
#
# my $ret = lua_eval( $code );
#
# print ref $ret ? $ret->() : $ret;
# }
#
# sub j_code {
# my( $code ) = @_;
#
# Jplugin::jplugin( $code );
# }