* isASCII() now only accepts \x0a\x20-\x7e and strings <= 1024 bytes

* isRational() and isSrational() improved to most definitely not accept a
  non-faction value.
* Put all the debugging stufff into a debugging function

diff --git a/includes/Exif.php b/includes/Exif.php
index 593096c..248fcda 100644 (file)
--- a/includes/Exif.php
+++ b/includes/Exif.php
@@ -304,73 +304,65 @@ class Exif {
         * @return bool
         */
        function isByte( $in ) {
-               $fname = 'isByte';
                if ( sprintf('%d', $in) === $in && $in >= 0 && $in <= 255 ) {
-                       wfDebug("Exif::$fname: accepted: '$in' (type: " . gettype( $in ) . ")\n");
+                       $this->debug( $in, __FUNCTION__, true );
                        return true;
                } else {
-                       wfDebug("Exif::$fname: rejected: '$in' (type: " . gettype( $in ) . ")\n");
+                       $this->debug( $in, __FUNCTION__, false );
                        return false;
                }
        }
        
        function isASCII( $in ) {
-               wfDebug("Exif::isASCII: input was '$in'\n");
+               if ( preg_match( "/[^\x0a\x20-\x7e]/", $in ) ) {
+                       $this->debug( $in, __FUNCTION__, 'found a character not in our whitelist' );
+                       return false;
+               }
+               
                if ( preg_match( "/^\s*$/", $in ) ) {
+                       $this->debug( $in, __FUNCTION__, 'input consisted solely of whitespace' );
+                       return false;
+               }
+               
+               if ( strlen($in) > 1024 ) {
+                       $this->debug( $in, __FUNCTION__, 'input was too long' );
                        return false;
                }
+               
                return true;
        }
 
        function isShort( $in ) {
-               $fname = 'isShort';
                if ( sprintf('%d', $in) === $in && $in >= 0 && $in <= 65536 ) {
-                       wfDebug("Exif::$fname: accepted: '$in' (type: " . gettype( $in ) . ")\n");
+                       $this->debug( $in, __FUNCTION__, true );
                        return true;
                } else {
-                       wfDebug("Exif::$fname: rejected: '$in' (type: " . gettype( $in ) . ")\n");
+                       $this->debug( $in, __FUNCTION__, true );
                        return false;
                }
        }
 
        function isLong( $in ) {
-               $fname = 'isLong';
                if ( sprintf('%d', $in) === $in && $in >= 0 && $in <= 4294967296 ) {
-                       wfDebug("Exif::$fname: accepted: '$in' (type: " . gettype( $in ) . ")\n");
+                       $this->debug( $in, __FUNCTION__, true );
                        return true;
                } else {
-                       wfDebug("Exif::$fname: rejected: '$in' (type: " . gettype( $in ) . ")\n");
+                       $this->debug( $in, __FUNCTION__, false );
                        return false;
                }
        }
        
        function isRational( $in ) {
-               $fname = 'isRational';
-               if ( strpos( $in, '/' ) === false ) {
-                       wfDebug("Exif::$fname: fed a non-fraction value: (type: " . gettype( $in ) . "; data: '$in')\n");
-                       return false;
+               if ( preg_match( "/^(\d+)\/(\d+[1-9]|[1-9]\d*)$/", $in, $m ) ) { # Avoid division by zero
+                       return $this->isLong( $m[1] ) && $this->isLong( $m[2] );
                } else {
-                       $a = explode( '/', $in, 2 );
-                       if ( $this->isLong( $a[0] ) && $this->isLong( $a[1] ) ) {
-                               wfDebug("Exif::$fname: accepted: '$in' (type: " . gettype( $in ) . ")\n");
-                               return true;
-                       } else {
-                               wfDebug("Exif::$fname: rejected: '$in' (type: " . gettype( $in ) . ")\n");
-                               return false;
-                       }
+                       $this->debug( $in, __FUNCTION__, 'fed a non-fraction value' );
+                       return false;
                }
        }
 
-       /**
-        * In order not to output binary gibberish such as raw thumbnails we
-        * return false here
-        *
-        * @todo We might actually want to display some of the UNDEFINED
-        *       stuff, but we strip it for now.
-        */
        function isUndefined( $in ) {
-               $fname = 'isUndefined';
-               wfDebug("Exif::$fname: input was '$in'\n");
+               $this->debug( $in, __FUNCTION__ );
                if ( preg_match( "/^\d{4}$/", $in ) ) { // Allow ExifVersion and FlashpixVersion
                        return true;
                } else {
@@ -379,30 +371,21 @@ class Exif {
        }
 
        function isSlong( $in ) {
-               $fname = 'isSlong';
                if ( $this->isLong( abs( $in ) ) ) {
-                       wfDebug("Exif::$fname: accepted: '$in' (type: " . gettype( $in ) . ")\n");
+                       $this->debug( $in, __FUNCTION__, true );
                        return true;
                } else {
-                       wfDebug("Exif::$fname: rejected: '$in' (type: " . gettype( $in ) . ")\n");
+                       $this->debug( $in, __FUNCTION__, false );
                        return false;
                }
        }
 
        function isSrational( $in ) {
-               $fname = 'isSrational';
-               if ( strpos( $in, '/' ) === false ) {
-                        wfDebug("Exif::$fname: fed a non-fraction value: (type: " . gettype( $in ) . "; data: '$in')\n");
-                        return false;
+               if ( preg_match( "/^(\d+)\/(\d+[1-9]|[1-9]\d*)$/", $in, $m ) ) { # Avoid division by zero
+                       return $this->isSlong( $m[0] ) && $this->isSlong( $m[1] );
                } else {
-                       $a = explode( '/', $in, 2 );
-                       if ( $this->isSlong( $a[0] ) && $this->isSlong( $a[1] ) ) {
-                                wfDebug("Exif::$fname: accepted: '$in' (type: " . gettype( $in ) . ")\n");
-                                return true;
-                       } else {
-                               wfDebug("Exif::$fname: rejected: '$in' (type: " . gettype( $in ) . ")\n");
-                               return false;
-                       }
+                       $this->debug( $in, __FUNCTION__, 'fed a non-fraction value' );
+                       return false;
                }
        }
        /**#@-*/
@@ -436,7 +419,8 @@ class Exif {
                        case (string)MW_EXIF_SHORT.','.MW_EXIF_LONG:
                                return $this->isShort( $val ) || $this->isLong( $val );
                        default:
-                               wfDebug( "Exif::validate: The tag \"$tag\" in unrecognized (type: " . gettype( $val ) . "; contents: $val)\n" );
+                               wfDebug( ucfirst( __CLASS__ ) . '::' . __FUNCTION__ .
+                                       ": The tag '$tag' in unknown (type: " . gettype( $val ) . "; content: '$val')\n" );
                                return false;
                }
        }
@@ -754,6 +738,29 @@ class Exif {
        function msg( $tag, $val ) {
                return wfMsg( strtolower("exif-$tag-$val") );
        }
+
+       /**
+        * Conviniance function for debugging output
+        *
+        * @param mixed $in 
+        * @param string $fname
+        * @param mixed $action
+        */
+        function debug( $in, $fname, $action = null ) {
+               $type = gettype( $in );
+               $class = ucfirst( __CLASS__ );
+               if ( $type === 'array' )
+                       $in = print_r( $in, true );
+               
+               if ( $action === true )
+                       wfDebug( "$class::$fname: accepted: '$in' (type: $type)\n");
+               elseif ( $action === false )
+                       wfDebug( "$class::$fname: rejected: '$in' (type: $type)\n");
+               elseif ( $action === null )
+                       wfDebug( "$class::$fname: input was: '$in' (type: $type)\n");
+               else
+                       wfDebug( "$class::$fname: $action (type: $type; content: '$in')\n");
+        }
 }
 
 } // MEDIAWIKI