Merge "Add version to ChronologyProtector key"

[lhc/web/wiklou.git] / includes / Block.php

diff --git a/includes/Block.php b/includes/Block.php
index 9d3a2f9..66b9ff0 100644 (file)
--- a/includes/Block.php
+++ b/includes/Block.php
@@ -1467,9 +1467,55 @@ class Block {
                }
 
                // Set the cookie. Reformat the MediaWiki datetime as a Unix timestamp for the cookie.
-               $cookieValue = $setEmpty ? '' : $this->getId();
-               $expiryValue = DateTime::createFromFormat( "YmdHis", $expiryTime );
-               $response->setCookie( 'BlockID', $cookieValue, $expiryValue->format( "U" ) );
+               $cookieValue = $setEmpty ? '' : $this->getCookieValue();
+               $expiryValue = DateTime::createFromFormat( 'YmdHis', $expiryTime )->format( 'U' );
+               $cookieOptions = [ 'httpOnly' => false ];
+               $response->setCookie( 'BlockID', $cookieValue, $expiryValue, $cookieOptions );
+       }
+
+       /**
+        * Get the BlockID cookie's value for this block. This is usually the block ID concatenated
+        * with an HMAC in order to avoid spoofing (T152951), but if wgSecretKey is not set will just
+        * be the block ID.
+        * @return string The block ID, probably concatenated with "!" and the HMAC.
+        */
+       public function getCookieValue() {
+               $config = RequestContext::getMain()->getConfig();
+               $id = $this->getId();
+               $secretKey = $config->get( 'SecretKey' );
+               if ( !$secretKey ) {
+                       // If there's no secret key, don't append a HMAC.
+                       return $id;
+               }
+               $hmac = MWCryptHash::hmac( $id, $secretKey, false );
+               $cookieValue =  $id . '!' . $hmac;
+               return $cookieValue;
+       }
+
+       /**
+        * Get the stored ID from the 'BlockID' cookie. The cookie's value is usually a combination of
+        * the ID and a HMAC (see Block::setCookie), but will sometimes only be the ID.
+        * @param string $cookieValue The string in which to find the ID.
+        * @return integer|null The block ID, or null if the HMAC is present and invalid.
+        */
+       public static function getIdFromCookieValue( $cookieValue ) {
+               // Extract the ID prefix from the cookie value (may be the whole value, if no bang found).
+               $bangPos = strpos( $cookieValue, '!' );
+               $id = ( $bangPos === false ) ? $cookieValue : substr( $cookieValue, 0, $bangPos );
+               // Get the site-wide secret key.
+               $config = RequestContext::getMain()->getConfig();
+               $secretKey = $config->get( 'SecretKey' );
+               if ( !$secretKey ) {
+                       // If there's no secret key, just use the ID as given.
+                       return $id;
+               }
+               $storedHmac = substr( $cookieValue, $bangPos + 1 );
+               $calculatedHmac = MWCryptHash::hmac( $id, $secretKey, false );
+               if ( $calculatedHmac === $storedHmac ) {
+                       return $id;
+               } else {
+                       return null;
+               }
        }
 
        /**