1 files changed, 70 insertions, 0 deletions
diff --git a/www/rt42/files/patch-lib_RT_Util.pm b/www/rt42/files/patch-lib_RT_Util.pm
new file mode 100644
index 000000000000..4784c49008bd
--- /dev/null
+++ b/www/rt42/files/patch-lib_RT_Util.pm
@@ -0,0 +1,70 @@
+--- lib/RT/Util.pm.orig	2016-06-08 21:49:02 UTC
++++ lib/RT/Util.pm
+@@ -54,6 +54,8 @@ use warnings;
+ use base 'Exporter';
+ our @EXPORT = qw/safe_run_child mime_recommended_filename/;
+ 
++use Encode qw/encode/;
++
+ sub safe_run_child (&) {
+     my $our_pid = $$;
+ 
+@@ -150,6 +152,58 @@ sub assert_bytes {
+ }
+ 
+ 
++=head2 C<constant_time_eq($a, $b)>
++
++Compares two strings for equality in constant-time. Replacement for the C<eq>
++operator designed to avoid timing side-channel vulnerabilities. Returns zero
++or one.
++
++This is intended for use in cryptographic subsystems for comparing well-formed
++data such as hashes - not for direct use with user input or as a general
++replacement for the C<eq> operator.
++
++The two string arguments B<MUST> be of equal length. If the lengths differ,
++this function will call C<die()>, as proceeding with execution would create
++a timing vulnerability. Length is defined by characters, not bytes.
++
++This code has been tested to do what it claims. Do not change it without
++thorough statistical timing analysis to validate the changes.
++
++Added to resolve CVE-2017-5361
++
++For more on timing attacks, see this Wikipedia article:
++B<https://en.wikipedia.org/wiki/Timing_attack>
++
++=cut
++
++sub constant_time_eq {
++    my ($a, $b) = @_;
++
++    my $result = 0;
++
++    # generic error message avoids potential information leaks
++    my $generic_error = "Cannot compare values";
++    die $generic_error unless defined $a and defined $b;
++    die $generic_error unless length $a == length $b;
++    die $generic_error if ref($a) or ref($b);
++
++    for (my $i = 0; $i < length($a); $i++) {
++        my $a_char = substr($a, $i, 1);
++        my $b_char = substr($b, $i, 1);
++
++        # encode() is set to die on malformed
++        my @a_octets = unpack("C*", encode('UTF-8', $a_char, Encode::FB_CROAK));
++        my @b_octets = unpack("C*", encode('UTF-8', $b_char, Encode::FB_CROAK));
++        die $generic_error if (scalar @a_octets) != (scalar @b_octets);
++
++        for (my $j = 0; $j < scalar @a_octets; $j++) {
++            $result |= $a_octets[$j] ^ $b_octets[$j];
++        }
++    }
++    return 0 + not $result;
++}
++
++
+ RT::Base->_ImportOverlays();
+ 
+ 1;