X-Git-Url: https://git.toastfreeware.priv.at/toast/cookiecaptcha.git/blobdiff_plain/2b89cec777f9becfd199d676e757e2c2064bc554..def5670e9b43c6204d0fc36ea236f3b7910bd820:/ConfirmEdit.php

diff --git a/ConfirmEdit.php b/ConfirmEdit.php
index be229cf..f6cab65 100644
--- a/ConfirmEdit.php
+++ b/ConfirmEdit.php
@@ -6,7 +6,7 @@
  * can extend the base to produce their fancy images in place of the
  * text-based test output here.
  *
- * Copyright (C) 2005, 2006 Brion Vibber <brion@pobox.com>
+ * Copyright (C) 2005-2007 Brion Vibber <brion@wikimedia.org>
  * http://www.mediawiki.org/
  *
  * This program is free software; you can redistribute it and/or modify
@@ -79,6 +79,7 @@ $wgCaptchaTriggers['edit']          = false; // Would check on every edit
 $wgCaptchaTriggers['create']		= false; // Check on page creation.
 $wgCaptchaTriggers['addurl']        = true;  // Check on edits that add URLs
 $wgCaptchaTriggers['createaccount'] = true;  // Special:Userlogin&type=signup
+$wgCaptchaTriggers['badlogin']      = true;  // Special:Userlogin after failure
 
 /**
  * You may wish to apply special rules for captcha triggering on some namespaces.
@@ -108,7 +109,7 @@ global $wgCaptchaStorageClass;
 $wgCaptchaStorageClass = 'CaptchaSessionStore';
 
 /**
- * Number of sections a captcha session should last in the data cache
+ * Number of seconds a captcha session should last in the data cache
  * before expiring when managing through CaptchaCacheStore class.
  *
  * Default is a half hour.
@@ -116,6 +117,18 @@ $wgCaptchaStorageClass = 'CaptchaSessionStore';
 global $wgCaptchaSessionExpiration;
 $wgCaptchaSessionExpiration = 30 * 60;
 
+/**
+ * Number of seconds after a bad login that a captcha will be shown to
+ * that client on the login form to slow down password-guessing bots.
+ *
+ * Has no effect if 'badlogin' is disabled in $wgCaptchaTriggers or
+ * if there is not a caching engine enabled.
+ *
+ * Default is five minutes.
+ */
+global $wgCaptchaBadLoginExpiration;
+$wgCaptchaBadLoginExpiration = 5 * 60;
+
 /**
  * Allow users who have confirmed their e-mail addresses to post
  * URL links without being harassed by the captcha.
@@ -127,7 +140,7 @@ $ceAllowConfirmedEmail = false;
  * Regex to whitelist URLs to known-good sites...
  * For instance:
  * $wgCaptchaWhitelist = '#^https?://([a-z0-9-]+\\.)?(wikimedia|wikipedia)\.org/#i';
- * @fixme Use the 'spam-whitelist' thingy instead?
+ * Local admins can define a whitelist under [[MediaWiki:captcha-addurl-whitelist]]
  */
 $wgCaptchaWhitelist = false;
 
@@ -162,6 +175,22 @@ function ceSetup() {
 
 	$wgHooks['UserCreateForm'][] = array( &$wgCaptcha, 'injectUserCreate' );
 	$wgHooks['AbortNewAccount'][] = array( &$wgCaptcha, 'confirmUserCreate' );
+	
+	$wgHooks['LoginAuthenticateAudit'][] = array( &$wgCaptcha, 'triggerUserLogin' );
+	$wgHooks['UserLoginForm'][] = array( &$wgCaptcha, 'injectUserLogin' );
+	$wgHooks['AbortLogin'][] = array( &$wgCaptcha, 'confirmUserLogin' );
+	
+	global $wgGroupPermissions, $wgCaptchaTriggers;
+	if( !$wgGroupPermissions['*']['read'] && $wgCaptchaTriggers['badlogin'] ) {
+		// We need to ensure that the captcha interface is accessible
+		// so that unauthenticated users can actually get in after a
+		// mistaken password typing.
+		global $wgWhitelistRead;
+		$image = Title::makeTitle( NS_SPECIAL, 'Captcha/image' );
+		$help = Title::makeTitle( NS_SPECIAL, 'Captcha/help' );
+		$wgWhitelistRead[] = $image->getPrefixedText();
+		$wgWhitelistRead[] = $help->getPrefixedText();
+	}
 }
 
 /**
@@ -258,6 +287,67 @@ class SimpleCaptcha {
 		return true;
 	}
 
+	/**
+	 * Inject a captcha into the user login form after a failed
+	 * password attempt as a speedbump for mass attacks.
+	 * @fixme if multiple thingies insert a header, could break
+	 * @param SimpleTemplate $template
+	 * @return bool true to keep running callbacks
+	 */
+	function injectUserLogin( &$template ) {
+		if( $this->isBadLoginTriggered() ) {
+			global $wgOut;
+			$template->set( 'header',
+				"<div class='captcha'>" .
+				$wgOut->parse( $this->getMessage( 'badlogin' ) ) .
+				$this->getForm() .
+				"</div>\n" );
+		}
+		return true;
+	}
+	
+	/**
+	 * When a bad login attempt is made, increment an expiring counter
+	 * in the memcache cloud. Later checks for this may trigger a
+	 * captcha display to prevent too many hits from the same place.
+	 * @param User $user
+	 * @param string $password
+	 * @param int $retval authentication return value
+	 * @return bool true to keep running callbacks
+	 */
+	function triggerUserLogin( $user, $password, $retval ) {
+		global $wgCaptchaTriggers, $wgCaptchaBadLoginExpiration, $wgMemc;
+		if( $retval == LoginForm::WRONG_PASS && $wgCaptchaTriggers['badlogin'] ) {
+			$key = $this->badLoginKey();
+			$count = $wgMemc->get( $key );
+			if( !$count ) {
+				$wgMemc->add( $key, 0, $wgCaptchaBadLoginExpiration );
+			}
+			$count = $wgMemc->incr( $key );
+		}
+		return true;
+	}
+	
+	/**
+	 * Check if a bad login has already been registered for this
+	 * IP address. If so, require a captcha.
+	 * @return bool
+	 * @access private
+	 */
+	function isBadLoginTriggered() {
+		global $wgMemc;
+		return intval( $wgMemc->get( $this->badLoginKey() ) ) > 0;
+	}
+	
+	/**
+	 * Internal cache key for badlogin checks.
+	 * @return string
+	 * @access private
+	 */
+	function badLoginKey() {
+		return wfMemcKey( 'captcha', 'badlogin', 'ip', wfGetIP() );
+	}
+	
 	/**
 	 * Check if the submitted form matches the captcha session data provided
 	 * by the plugin when the form was generated.
@@ -390,12 +480,70 @@ class SimpleCaptcha {
 
 	/**
 	 * Filter callback function for URL whitelisting
+	 * @param string url to check
 	 * @return bool true if unknown, false if whitelisted
 	 * @access private
 	 */
 	function filterLink( $url ) {
 		global $wgCaptchaWhitelist;
-		return !( $wgCaptchaWhitelist && preg_match( $wgCaptchaWhitelist, $url ) );
+		$source = wfMsgForContent( 'captcha-addurl-whitelist' );
+
+		$whitelist = wfEmptyMsg( 'captcha-addurl-whitelist', $source ) 
+			? false
+			: $this->buildRegexes( explode( "\n", $source ) );
+
+		$cwl = $wgCaptchaWhitelist !== false ? preg_match( $wgCaptchaWhitelist, $url ) : false;
+		$wl  = $whitelist          !== false ? preg_match( $whitelist, $url )          : false;
+
+		return !( $cwl || $wl );
+	}
+
+	/**
+	 * Build regex from whitelist
+	 * @param string lines from [[MediaWiki:Captcha-addurl-whitelist]]
+	 * @return string Regex or bool false if whitelist is empty
+	 * @access private
+	 */
+	function buildRegexes( $lines ) {
+		# Code duplicated from the SpamBlacklist extension (r19197)
+
+		# Strip comments and whitespace, then remove blanks
+		$lines = array_filter( array_map( 'trim', preg_replace( '/#.*$/', '', $lines ) ) );
+
+		# No lines, don't make a regex which will match everything
+		if ( count( $lines ) == 0 ) {
+			wfDebug( "No lines\n" );
+			return false;
+		} else {
+			# Make regex
+			# It's faster using the S modifier even though it will usually only be run once
+			//$regex = 'http://+[a-z0-9_\-.]*(' . implode( '|', $lines ) . ')';
+			//return '/' . str_replace( '/', '\/', preg_replace('|\\\*/|', '/', $regex) ) . '/Si';
+			$regexes = '';
+			$regexStart = '/http:\/\/+[a-z0-9_\-.]*(';
+			$regexEnd = ')/Si';
+			$regexMax = 4096;
+			$build = false;
+			foreach( $lines as $line ) {
+				// FIXME: not very robust size check, but should work. :)
+				if( $build === false ) {
+					$build = $line;
+				} elseif( strlen( $build ) + strlen( $line ) > $regexMax ) {
+					$regexes .= $regexStart .
+						str_replace( '/', '\/', preg_replace('|\\\*/|', '/', $build) ) .
+						$regexEnd;
+					$build = $line;
+				} else {
+					$build .= '|' . $line;
+				}
+			}
+			if( $build !== false ) {
+				$regexes .= $regexStart .
+					str_replace( '/', '\/', preg_replace('|\\\*/|', '/', $build) ) .
+					$regexEnd;
+			}
+			return $regexes;
+		}
 	}
 
 	/**
@@ -436,6 +584,25 @@ class SimpleCaptcha {
 		}
 		return true;
 	}
+	
+	/**
+	 * Hook for user login form submissions.
+	 * @param User $u
+	 * @param string $message
+	 * @return bool true to continue, false to abort user creation
+	 */
+	function confirmUserLogin( $u, $pass, &$retval ) {
+		if( $this->isBadLoginTriggered() ) {
+			$this->trigger = "post-badlogin login '" . $u->getName() . "'";
+			if( !$this->passCaptcha() ) {
+				$message = wfMsg( 'captcha-badlogin-fail' );
+				// Emulate a bad-password return to confuse the shit out of attackers
+				$retval = LoginForm::WRONG_PASS;
+				return false;
+			}
+		}
+		return true;
+	}
 
 	/**
 	 * Given a required captcha run, test form input for correct
@@ -608,4 +775,4 @@ class CaptchaCacheStore {
 
 } # End invocation guard
 
-?>
+