Prelim proof-of-concept testing captcha extension framework.

Not a real captcha, not expected to be robust against real spammers yet!
2024-11-11 17:00:49 +00:00 · 2005-09-30 09:21:02 +00:00 · 2005-09-30 09:21:02 +00:00 · 75483a0771
commit 75483a0771
1 changed files with 167 additions and 0 deletions
--- a/ConfirmEdit.php
+++ b/ConfirmEdit.php
@ -0,0 +1,167 @@
+<?php
+
+# Prelim in-progress code. Proof of concept for framework, not
+# intended as a real production captcha system!
+
+# Loader for spam blacklist feature
+# Include this from LocalSettings.php
+
+if ( defined( 'MEDIAWIKI' ) ) {
+
+global $wgExtensionFunctions, $wgHooks, $wgGroupPermissions;
+
+$wgExtensionFunctions[] = 'ceSetup';
+
+$wgHooks['EditFilter'][] = 'ceConfirmEditLinks';
+
+$wgGroupPermissions['*'        ]['skipcaptcha'] = false;
+$wgGroupPermissions['user'     ]['skipcaptcha'] = false;
+$wgGroupPermissions['bot'      ]['skipcaptcha'] = true; // registered bots
+$wgGroupPermissions['sysop'    ]['skipcaptcha'] = true;
+
+/**
+ * Allow users who have confirmed their e-mail addresses to post
+ * URL links without being harassed by the captcha.
+ */
+global $ceAllowConfirmedEmail;
+$ceAllowConfirmedEmail = false;
+
+/**
+ * Set up message strings for captcha utilities.
+ */
+function ceSetup() {
+	global $wgMessageCache;
+	$wgMessageCache->addMessage('captcha-short', "Your edit includes new URL links; as a protection
+		against automated spam, you'll need to enter the answer to this
+		simple arithmetic test:" );
+	SpecialPage::addPage( new SpecialPage( 'Captcha', false,
+		/*listed*/ false, /*function*/ false, /*file*/ false ) );
+}
+
+/**
+ * Entry point for Special:Captcha
+ */
+function wfSpecialCaptcha( $par = null ) {
+	switch( $par ) {
+	case "image":
+		return ceShowImage();
+	case "help":
+	default:
+		return ceShowHelp();
+	}
+}
+
+function ceConfirmEditLinks( &$editPage, $newtext, $section ) {
+	$oldtext = ceLoadText( $editPage, $section );
+	
+	$oldLinks = ceFindLinks( $oldtext );
+	$newLinks = ceFindLinks( $newtext );
+	
+	$addedLinks = array_diff( $newLinks, $oldLinks );
+	$numLinks = count( $addedLinks );
+	
+	/*
+	var_dump( $oldtext );
+	var_dump( $newtext );
+	var_dump( $oldLinks );
+	var_dump( $newLinks );
+	var_dump( $addedLinks );
+	die( '---' );
+	*/
+	
+	if( $numLinks > 0 ) {
+		wfDebug( "ConfirmEdit found $numLinks new links...\n" );
+		if( ceKeyMatch() ) {
+			wfDebug( "ConfirmEdit given proper key from form, passing.\n" );
+			return true;
+		} else {
+			wfDebug( "ConfirmEdit missing form key, prompting.\n" );
+			$editPage->showEditForm( 'ceFormCallback' );
+			return false;
+		}
+	} else {
+		wfDebug( "ConfirmEdit: no new links.\n" );
+		return true;
+	}
+}
+
+function ceKeyMatch() {
+	global $wgUser;
+	if( $wgUser->isAllowed( 'skipcaptcha' ) ) {
+		wfDebug( "ConfirmEdit: user group allows skipping captcha\n" );
+		return true;
+	}
+
+	global $wgEmailAuthentication, $ceAllowConfirmedEmail;
+	if( $wgEmailAuthentication && $ceAllowConfirmedEmail &&
+		$wgUser->isEmailConfirmed() ) {
+		wfDebug( "ConfirmEdit: user has confirmed mail, skippng captcha\n" );
+		return true;
+	}
+	
+	if( !isset( $_SESSION['ceAnswerVar'] ) ) {
+		wfDebug( "ConfirmEdit no session captcha key set, this is new visitor.\n" );
+		return false;
+	}
+	global $wgRequest;
+	return $wgRequest->getVal( $_SESSION['ceAnswerVar'] ) == $_SESSION['ceAnswer'];
+}
+
+function ceFormCallback( &$out ) {
+	$source = 'ceSource' . mt_rand();
+	$dest = 'ceConfirm' . mt_rand();
+	
+	$a = mt_rand(0, 100);
+	$b = mt_rand(0, 10);
+	$op = mt_rand(0, 1) ? '+' : '-';
+	
+	$test = "$a $op $b";
+	$answer = ($op == '+') ? ($a + $b) : ($a - $b);
+	$_SESSION['ceAnswer'] = $answer;
+	$_SESSION['ceAnswerVar'] = $dest;
+	
+	
+	$out->addWikiText( wfMsg( "captcha-short" ) );	
+	$out->addHTML( <<<END
+		<p><span id="$source">$test</span> = <input name="$dest" id="$dest" /></p>
+END
+		);
+}
+
+function ceLoadText( $editPage, $section ) {
+	$rev = Revision::newFromTitle( $editPage->mTitle );
+	if( is_null( $rev ) ) {
+		return "";
+	} else {
+		$text = $rev->getText();
+		if( $section != '' ) {
+			return Article::getSection( $text, $section );
+		} else {
+			return $text;
+		}
+	}
+}
+
+function ceFindLinks( $text ) {
+	$regex = '/((?:' . HTTP_PROTOCOLS . ')' . EXT_LINK_URL_CLASS . '+)/';
+	
+	if( preg_match_all( $regex, $text, $matches, PREG_PATTERN_ORDER ) ) {
+		return $matches[1];
+	} else {
+		return array();
+	}
+}
+
+function ceShowHelp() {
+	global $wgOut, $ceAllowConfirmedEmail;
+	$wgOut->setPageTitle( 'Captcha help' );
+	$wgOut->addWikiText( <<<END
+So what's this wacky captcha thing about?
+
+It's your enemy. It's here to kill you. RUN WHILE YOU STILL CAN
+END
+		);
+}
+
+} # End invocation guard
+?>