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Fix potential shell injection issues and fix handling of filenames containing special characters #8

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Fix potential shell injection issues and fix handling of filenames containing special characters #8

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713d10a
Fixed shell injection vulnerabilities and handling of unusual filenames
DemiMarie Apr 30, 2015
9021e78
Removed last use of backticks
DemiMarie Apr 30, 2015
68e3e9c
Deleted unnecessary push
DemiMarie Apr 30, 2015
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92 changes: 57 additions & 35 deletions lib/Module/Signature.pm
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Original file line number Diff line number Diff line change
Expand Up @@ -150,8 +150,13 @@ sub _verify {

sub _has_gpg {
my $gpg = _which_gpg() or return;
`$gpg --version` =~ /GnuPG.*?(\S+)\s*$/m or return;
return $1;
local *HANDLE;
open HANDLE, $gpg, '--version';
while (<HANDLE>) {
/GnuPG.*?(\S+)\s*$/m;
return $1 if ($1);
}
return;
}

sub _fullcheck {
Expand Down Expand Up @@ -231,7 +236,11 @@ sub _which_gpg {
return $which_gpg if $which_gpg;

for my $gpg_bin ('gpg', 'gpg2', 'gnupg', 'gnupg2') {
my $version = `$gpg_bin --version 2>&1`;
my $D;
open $D, '-|', $gpg_bin, qw(--version --logger-fd 1) or
my @list = <$D>;
close $D;
my $version = join '', @list;
if( $version && $version =~ /GnuPG/ ) {
$which_gpg = $gpg_bin;
return $which_gpg;
Expand Down Expand Up @@ -269,8 +278,11 @@ sub _verify_gpg {
system @cmd;
}
else {
my $cmd = join ' ', @cmd;
$output = `$cmd`;
my $handle;
open $handle, '-|', @cmd;
my @list = <$handle>;
close $handle;
$output = join('', @list);
}
unlink $fh->filename;

Expand All @@ -291,6 +303,9 @@ sub _keyserver {
my $scheme = 'x-hkp';
$scheme = 'hkp' if $version ge '1.2.0';

if ($KeyServerPort ~= tr/0-9//dr) {
die "Invalid keyserver port: $KeyServerPort";
}
return "$scheme://$KeyServer:$KeyServerPort";
}

Expand All @@ -308,8 +323,8 @@ sub _verify_crypt_openpgp {

if ($rv->{Validity}) {
warn 'Signature made ', scalar localtime($rv->{Signature}->timestamp),
' using key ID ', substr(uc(unpack('H*', $rv->{Signature}->key_id)), -8), "\n",
"Good signature from \"$rv->{Validity}\"\n" if $Verbose;
' using key ID ', substr(uc(unpack('H*', $rv->{Signature}->key_id)), -8), "\n",
"Good signature from \"$rv->{Validity}\"\n" if $Verbose;
}
else {
warn "Cannot verify signature; public key not found\n";
Expand All @@ -324,15 +339,15 @@ sub _read_sigfile {
my $well_formed;

local *D;
open D, "< $sigfile" or die "Could not open $sigfile: $!";
open D, '<', $sigfile or die "Could not open $sigfile: $!";

if ($] >= 5.006 and <D> =~ /\r/) {
close D;
open D, '<', $sigfile or die "Could not open $sigfile: $!";
binmode D, ':crlf';
} else {
close D;
open D, "< $sigfile" or die "Could not open $sigfile: $!";
open D, '<', $sigfile or die "Could not open $sigfile: $!";
}

my $begin = "-----BEGIN PGP SIGNED MESSAGE-----\n";
Expand Down Expand Up @@ -363,8 +378,8 @@ sub _compare {
}
else {
local (*D, *S);
open S, "< $SIGNATURE" or die "Could not open $SIGNATURE: $!";
open D, "| diff -u $SIGNATURE -" or (warn "Could not call diff: $!", return SIGNATURE_MISMATCH);
open S, '<', $SIGNATURE or die "Could not open $SIGNATURE: $!";
open D, "|-", @('diff', '-u', $SIGNATURE) or (warn "Could not call diff: $!", return SIGNATURE_MISMATCH);
while (<S>) {
print D $_ if (1 .. /^-----BEGIN PGP SIGNED MESSAGE-----/);
print D if (/^Hash: / .. /^$/);
Expand Down Expand Up @@ -419,29 +434,35 @@ sub _sign_gpg {
my $gpg = _which_gpg();

local *D;
my $set_key = '';
$set_key = "--default-key $AUTHOR" if($AUTHOR);
open D, "| $gpg $set_key --clearsign >> $sigfile.tmp" or die "Could not call $gpg: $!";
print D $plaintext;
close D;

(-e "$sigfile.tmp" and -s "$sigfile.tmp") or do {
unlink "$sigfile.tmp";
die "Cannot find $sigfile.tmp, signing aborted.\n";
my $tempfile = $sigfile . '.tmp';
{
my $D;
my @set_key = ($gpg, '--clearsign', '-o', $tempfile);
my @empty = ();
@set_key = ('--default-key', $AUTHOR) if($AUTHOR);
open $D, "|-", @empty, @set_key or die "Could not call $gpg: $!";
print $D $plaintext;
my $status = close $D;
}

(-e $tempfile and -s $tempfile) or do {
unlink $tempfile;
die "Cannot find $tempfile, signing aborted.\n";
};

open D, "< $sigfile.tmp" or die "Cannot open $sigfile.tmp: $!";

open S, "> $sigfile" or do {
unlink "$sigfile.tmp";
my $D;
open $D, "<", $tempfile or die "Cannot open $tempfile: $!";
my $S;
open $S, '>', $sigfile or do {
unlink $tempfile;
die "Could not write to $sigfile: $!";
};

print S $Preamble;
print S <D>;
print $S $Preamble;
print $S <D>;

close S;
close D;
close $S;
close $D;

unlink("$sigfile.tmp");

Expand All @@ -450,20 +471,21 @@ sub _sign_gpg {
# This doesn't work because the output from verify goes to STDERR.
# If I try to redirect it using "--logger-fd 1" it just hangs.
# WTF?
my @verify = `$gpg --batch --verify $SIGNATURE`;
while (@verify) {
open $D, '|-', $gpg, qw(--batch --verify --logger-fd 1), $SIGNATURE;
while (<$D>) {
if (/key ID ([0-9A-F]+)$/) {
$key_id = $1;
} elsif (/signature from "(.+)"$/) {
$key_name = $1;
}
}

close $D;
my $found_name;
my $found_key;
if (defined $key_id && defined $key_name) {
my $keyserver = _keyserver($version);
while (`$gpg --batch --keyserver=$keyserver --search-keys '$key_name'`) {
open $D, $gpg, '--batch', "--keyserver=$keyserver", '--search-keys', $key_name;
while (<$D>) {
if (/^\(\d+\)/) {
$found_name = 0;
} elsif ($found_name) {
Expand All @@ -478,7 +500,7 @@ sub _sign_gpg {
next;
}
}

close $D;
unless ($found_key) {
_warn_non_public_signature($key_name);
}
Expand Down Expand Up @@ -513,7 +535,7 @@ sub _sign_crypt_openpgp {


local *D;
open D, "> $sigfile" or die "Could not write to $sigfile: $!";
open D, '>', $sigfile or die "Could not write to $sigfile: $!";
print D $Preamble;
print D $signature;
close D;
Expand Down Expand Up @@ -615,7 +637,7 @@ sub _mkdigest_files {
}
else {
local *F;
open F, "< $file" or die "Cannot open $file for reading: $!";
open F, '<', $file or die "Cannot open $file for reading: $!";
if (-B $file) {
binmode(F);
$obj->addfile(*F);
Expand Down