Bug 1497487 - Backport bug 767623 to BMO: Use HMAC to generate tokens and sensitive graph filenames

Author: dylanwh

Bugzilla/Token.pm

@@ -20,7 +20,6 @@ use Bugzilla::User;
 use Date::Format;
 use Date::Parse;
 use File::Basename;
-use Digest::MD5 qw(md5_hex);
 use Digest::SHA qw(hmac_sha256_base64);
 use Encode;
 use JSON qw(encode_json decode_json);
@@ -254,15 +253,15 @@ sub issue_hash_token {
     my $user_id = Bugzilla->user->id || remote_ip();
 
     # The concatenated string is of the form
-    # token creation time + site-wide secret + user ID (either ID or remote IP) + data
-    my @args = ($time, Bugzilla->localconfig->{'site_wide_secret'}, $user_id, @$data);
+    # token creation time + user ID (either ID or remote IP) + data
+    my @args = ($time, $user_id, @$data);
 
     my $token = join('*', @args);
-    # Wide characters cause md5_hex() to die.
-    if (Bugzilla->params->{'utf8'}) {
-        utf8::encode($token) if utf8::is_utf8($token);
-    }
-    $token = md5_hex($token);
+    # $token needs to be a byte string.
+    utf8::encode($token);
+    $token = hmac_sha256_base64($token, Bugzilla->localconfig->{'site_wide_secret'});
+    $token =~ s/\+/-/g;
+    $token =~ s/\//_/g;
 
     # Prepend the token creation time, unencrypted, so that the token
     # lifetime can be validated.

reports.cgi

@@ -19,7 +19,7 @@ use Bugzilla::Error;
 use Bugzilla::Status;
 
 use File::Basename;
-use Digest::MD5 qw(md5_hex);
+use Digest::SHA qw(hmac_sha256_base64);
 
 # If we're using bug groups for products, we should apply those restrictions
 # to viewing reports, as well.  Time to check the login in that case.
@@ -90,14 +90,12 @@ else {
     # Filenames must not be guessable as they can point to products
     # you are not allowed to see. Also, different projects can have
     # the same product names.
-    my $key = Bugzilla->localconfig->{'site_wide_secret'};
     my $project = bz_locations()->{'project'} || '';
-    my $image_file =  join(':', ($key, $project, $prod_id, @datasets));
-    # Wide characters cause md5_hex() to die.
-    if (Bugzilla->params->{'utf8'}) {
-        utf8::encode($image_file) if utf8::is_utf8($image_file);
-    }
-    $image_file = md5_hex($image_file) . '.png';
+    my $image_file =  join(':', ($project, $prod_id, @datasets));
+    my $key = Bugzilla->localconfig->{'site_wide_secret'};
+    $image_file = hmac_sha256_base64($image_file, $key) . '.png';
+    $image_file =~ s/\+/-/g;
+    $image_file =~ s/\//_/g;
     trick_taint($image_file);
 
     if (! -e "$graph_dir/$image_file") {