Lightopenid even lighter below 10KB

lightopenid.php

<?php
	class LightOpenID {
		public $returnUrl, $required = array( ), $optional = array( ), $verify_peer = null, $capath = null, $cainfo = null;
		private $identity, $claimed_id;
		protected $server, $version, $trustRoot, $aliases, $identifier_select = false, $ax = false, $sreg = false, $data;
		function __construct( ) {
			$this->trustRoot = ( !empty( $_SERVER[ 'HTTPS' ] ) ? 'https' : 'http' ) . '://' . $_SERVER[ 'HTTP_HOST' ];
			$uri             = rtrim( preg_replace( '#((?<=\?)|&)openid\.[^&]+#', '', $_SERVER[ 'REQUEST_URI' ] ), '?' );
			$this->returnUrl = $this->trustRoot . $uri;
			$this->data      = $_POST + $_GET;
		}
		function __set( $name, $value ) {
			switch ( $name ) {
				case 'identity':
					if ( strlen( $value = trim( (String) $value ) ) ) {
						if ( preg_match( '#^xri:/*#i', $value, $m ) )
							$value = substr( $value, strlen( $m[ 0 ] ) );
						elseif ( !preg_match( '/^(?:[=@+\$!\(]|https?:)/i', $value ) )
							$value = "http://$value";
						if ( preg_match( '#^https?://[^/]+$#i', $value, $m ) )
							$value .= '/';
					}
					$this->$name = $this->claimed_id = $value;
					break;
				case 'realm':
					$this->trustRoot = trim( $value );
			}
		}
		function __get( $name ) {
			switch ( $name ) {
				case 'identity':
					return $this->claimed_id;
				case 'trustRoot':
				case 'realm':
					return $this->trustRoot;
				case 'mode':
					return empty( $this->data[ 'openid_mode' ] ) ? null : $this->data[ 'openid_mode' ];
			}
		}
		protected function request_curl( $url, $method = 'GET', $params = array( ) ) {
			$params = http_build_query( $params, '', '&' );
			$c      = curl_init( $url . ( $method == 'GET' && $params ? '?' . $params : '' ) );
			curl_setopt( $c, CURLOPT_FOLLOWLOCATION, true );
			curl_setopt( $c, CURLOPT_HEADER, false );
			curl_setopt( $c, CURLOPT_SSL_VERIFYPEER, false );
			curl_setopt( $c, CURLOPT_RETURNTRANSFER, true );
			curl_setopt( $c, CURLOPT_HTTPHEADER, array(
				 'Accept: application/xrds+xml, */*' 
			) );
			if ( $this->verify_peer !== null ) {
				curl_setopt( $c, CURLOPT_SSL_VERIFYPEER, $this->verify_peer );
				if ( $this->capath )
					curl_setopt( $c, CURLOPT_CAPATH, $this->capath );
				if ( $this->cainfo )
					curl_setopt( $c, CURLOPT_CAINFO, $this->cainfo );
			}
			if ( $method == 'POST' ) {
				curl_setopt( $c, CURLOPT_POST, true );
				curl_setopt( $c, CURLOPT_POSTFIELDS, $params );
			} elseif ( $method == 'HEAD' ) {
				curl_setopt( $c, CURLOPT_HEADER, true );
				curl_setopt( $c, CURLOPT_NOBODY, true );
			} else
				curl_setopt( $c, CURLOPT_HTTPGET, true );
			$res = curl_exec( $c );
			if ( $method == 'HEAD' ) {
				$headers = array( );
				foreach ( explode( "\n", $res ) as $header ) {
					$pos              = strpos( $header, ':' );
					$name             = strtolower( trim( substr( $header, 0, $pos ) ) );
					$headers[ $name ] = trim( substr( $header, $pos + 1 ) );
				}
				$effective_url = curl_getinfo( $c, CURLINFO_EFFECTIVE_URL );
				if ( $effective_url != $url )
					$this->identity = $this->claimed_id = $effective_url;
				return $headers;
			}
			if ( curl_errno( $c ) )
				throw new ErrorException( curl_error( $c ), curl_errno( $c ) );
			return $res;
		}
		protected function request( $url, $method = 'GET', $params = array( ) ) {
			return $this->request_curl( $url, $method, $params );
		}
		protected function build_url( $url, $parts ) {
			if ( isset( $url[ 'query' ], $parts[ 'query' ] ) )
				$parts[ 'query' ] = $url[ 'query' ] . '&' . $parts[ 'query' ];
			$url = $parts + $url;
			$url = $url[ 'scheme' ] . '://' . ( empty( $url[ 'username' ] ) ? '' : ( empty( $url[ 'password' ] ) ? "{$url['username']}@" : "{$url['username']}:{$url['password']}@" ) ) . $url[ 'host' ] . ( empty( $url[ 'port' ] ) ? '' : ":{$url['port']}" ) . ( empty( $url[ 'path' ] ) ? '' : $url[ 'path' ] ) . ( empty( $url[ 'query' ] ) ? '' : "?{$url['query']}" ) . ( empty( $url[ 'fragment' ] ) ? '' : "#{$url['fragment']}" );
			return $url;
		}
		protected function htmlTag( $content, $tag, $attrName, $attrValue, $valueName ) {
			preg_match_all( "#<{$tag}[^>]*$attrName=['\"].*?$attrValue.*?['\"][^>]*$valueName=['\"](.+?)['\"][^>]*/?>#i", $content, $matches1 );
			preg_match_all( "#<{$tag}[^>]*$valueName=['\"](.+?)['\"][^>]*$attrName=['\"].*?$attrValue.*?['\"][^>]*/?>#i", $content, $matches2 );
			$result = array_merge( $matches1[ 1 ], $matches2[ 1 ] );
			return empty( $result ) ? false : $result[ 0 ];
		}
		function discover( $url ) {
			if ( !$url )
				throw new ErrorException( 'No identity supplied.' );
			if ( !preg_match( '#^https?:#', $url ) )
				$url = "https://xri.net/$url";
			$originalUrl = $url;
			$yadis       = true;
			for ( $i = 0; $i < 5; $i++ ) {
				if ( $yadis ) {
					$headers = $this->request( $url, 'HEAD' );
					$next    = false;
					if ( isset( $headers[ 'x-xrds-location' ] ) ) {
						$url  = $this->build_url( parse_url( $url ), parse_url( trim( $headers[ 'x-xrds-location' ] ) ) );
						$next = true;
					}
					if ( isset( $headers[ 'content-type' ] ) && ( strpos( $headers[ 'content-type' ], 'application/xrds+xml' ) !== false || strpos( $headers[ 'content-type' ], 'text/xml' ) !== false ) ) {
						$content = $this->request( $url, 'GET' );
						preg_match_all( '#<Service.*?>(.*?)</Service>#s', $content, $m );
						foreach ( $m[ 1 ] as $content ) {
							$content = ' ' . $content;
							$ns      = preg_quote( 'http://specs.openid.net/auth/2.0/' );
							if ( preg_match( '#<Type>\s*' . $ns . '(server|signon)\s*</Type>#s', $content, $type ) ) {
								if ( $type[ 1 ] == 'server' )
									$this->identifier_select = true;
								preg_match( '#<URI.*?>(.*)</URI>#', $content, $server );
								preg_match( '#<(Local|Canonical)ID>(.*)</\1ID>#', $content, $delegate );
								if ( empty( $server ) )
									return false;
								$this->ax   = (bool) strpos( $content, '<Type>http://openid.net/srv/ax/1.0</Type>' );
								$this->sreg = strpos( $content, '<Type>http://openid.net/sreg/1.0</Type>' ) || strpos( $content, '<Type>http://openid.net/extensions/sreg/1.1</Type>' );
								$server     = $server[ 1 ];
								if ( isset( $delegate[ 2 ] ) )
									$this->identity = trim( $delegate[ 2 ] );
								$this->version = 2;
								$this->server  = $server;
								return $server;
							}
						}
					}
				}
			}
			throw new ErrorException( 'Endless redirection!' );
		}
		protected function axParams( ) {
			$params = array( );
			if ( $this->required || $this->optional ) {
				$params[ 'openid.ns.ax' ]   = 'http://openid.net/srv/ax/1.0';
				$params[ 'openid.ax.mode' ] = 'fetch_request';
				$this->aliases              = array( );
				$counts                     = array( );
				$required                   = array( );
				$optional                   = array( );
				foreach ( array(
					 'required',
					'optional' 
				) as $type ) {
					foreach ( $this->$type as $alias => $field ) {
						if ( is_int( $alias ) )
							$alias = strtr( $field, '/', '_' );
						$this->aliases[ $alias ] = 'http://axschema.org/' . $field;
						if ( empty( $counts[ $alias ] ) )
							$counts[ $alias ] = 0;
						$counts[ $alias ] += 1;
						${$type}[ ] = $alias;
					}
				}
				foreach ( $this->aliases as $alias => $ns )
					$params[ 'openid.ax.type.' . $alias ] = $ns;
				foreach ( $counts as $alias => $count )
					if ( $count == 1 )
						continue;
				$params[ 'openid.ax.count.' . $alias ] = $count;
				if ( $required )
					$params[ 'openid.ax.required' ] = implode( ',', $required );
				if ( $optional )
					$params[ 'openid.ax.if_available' ] = implode( ',', $optional );
			}
			return $params;
		}
		function validate( ) {
			$this->claimed_id = isset( $this->data[ 'openid_claimed_id' ] ) ? $this->data[ 'openid_claimed_id' ] : $this->data[ 'openid_identity' ];
			$params           = array(
				 'openid.assoc_handle' => $this->data[ 'openid_assoc_handle' ],
				'openid.signed' => $this->data[ 'openid_signed' ],
				'openid.sig' => $this->data[ 'openid_sig' ] 
			);
			if ( isset( $this->data[ 'openid_ns' ] ) )
				$params[ 'openid.ns' ] = 'http://specs.openid.net/auth/2.0';
			elseif ( isset( $this->data[ 'openid_claimed_id' ] ) && $this->data[ 'openid_claimed_id' ] != $this->data[ 'openid_identity' ] )
				$this->returnUrl .= ( strpos( $this->returnUrl, '?' ) ? '&' : '?' ) . 'openid.claimed_id=' . $this->claimed_id;
			if ( $this->data[ 'openid_return_to' ] != $this->returnUrl )
				return false;
			$server = $this->discover( $this->claimed_id );
			foreach ( explode( ',', $this->data[ 'openid_signed' ] ) as $item ) {
				$value                       = $this->data[ 'openid_' . str_replace( '.', '_', $item ) ];
				$params[ 'openid.' . $item ] = get_magic_quotes_gpc() ? stripslashes( $value ) : $value;
			}
			$params[ 'openid.mode' ] = 'check_authentication';
			$res                     = $this->request( $server, 'POST', $params );
			return preg_match( '/is_valid\s*:\s*true/i', $res );
		}
		protected function authUrl_v2( $identifier_select ) {
			$params = array(
				 'openid.ns' => 'http://specs.openid.net/auth/2.0',
				'openid.mode' => 'checkid_setup',
				'openid.return_to' => $this->returnUrl,
				'openid.realm' => $this->trustRoot 
			);
			if ( $this->ax )
				$params += $this->axParams();
			if ( !$this->ax && !$this->sreg )
				$params += $this->axParams();
			if ( $identifier_select )
				$params[ 'openid.identity' ] = $params[ 'openid.claimed_id' ] = 'http://specs.openid.net/auth/2.0/identifier_select';
			else {
				$params[ 'openid.identity' ]   = $this->identity;
				$params[ 'openid.claimed_id' ] = $this->claimed_id;
			}
			return $this->build_url( parse_url( $this->server ), array(
				 'query' => http_build_query( $params, '', '&' ) 
			) );
		}
		function authUrl( $identifier_select = null ) {
			if ( !$this->server )
				$this->discover( $this->identity );
			if ( $this->version == 2 ) {
				if ( $identifier_select === null ) {
					return $this->authUrl_v2( $this->identifier_select );
				}
				return $this->authUrl_v2( $identifier_select );
			}
		}
	}