Configuration.php

<?php
 
/**
 * Configuration of SimpleSAMLphp
 *
 * @author Andreas Aakre Solberg, UNINETT AS. <andreas.solberg@uninett.no>
 * @package simpleSAMLphp
 * @version $Id$
 */
class SimpleSAML_Configuration {

	/**
	 * A default value which means that the given option is required.
	 */
	const REQUIRED_OPTION = '___REQUIRED_OPTION___';


	/**
	 * Associative array with mappings from instance-names to configuration objects.
	 */
	private static $instance = array();


	/**
	 * Configration directories.
	 *
	 * This associative array contains the mappings from configuration sets to
	 * configuration directories.
	 */
	private static $configDirs = array();


	/**
	 * Cache of loaded configuration files.
	 *
	 * The index in the array is the full path to the file.
	 */
	private static $loadedConfigs = array();


	/**
	 * The configuration array.
	 */
	private $configuration;


	/**
	 * The location which will be given when an error occurs.
	 */
	private $location;


	/**
	 * The file this configuration was loaded from.
	 */
	private $filename = NULL;



	/**
	 * Initializes a configuration from the given array.
	 *
	 * @param array $config  The configuration array.
	 * @param string $location  The location which will be given when an error occurs.
	 */
	public function __construct($config, $location) {
		assert('is_array($config)');
		assert('is_string($location)');

		$this->configuration = $config;
		$this->location = $location;
	}


	/**
	 * Load the given configuration file.
	 *
	 * @param string $filename  The full path of the configuration file.
	 * @return SimpleSAML_Configuration  The configuration file. An exception will be thrown if the
	 *                                   configuration file is missing.
	 */
	private static function loadFromFile($filename) {
		assert('is_string($filename)');

		if (array_key_exists($filename, self::$loadedConfigs)) {
			return self::$loadedConfigs[$filename];
		}

		if (!file_exists($filename)) {
			throw new Exception('Missing configuration file: ' . $filename);
		}

		$config = 'UNINITIALIZED';

		/* The file initializes a variable named '$config'. */
		require_once($filename);

		/* Check that $config is initialized to an array. */
		if (!is_array($config)) {
			throw new Exception('Invalid configuration file: ' . $filename);
		}

		if (array_key_exists('override.host', $config)) {
			$host = SimpleSAML_Utilities::getSelfHost();
			if (array_key_exists($host, $config['override.host'])) {
				$ofs = $config['override.host'][$host];
				foreach (SimpleSAML_Utilities::arrayize($ofs) AS $of) {
					$overrideFile = dirname($filename) . '/' . $of;
					if (!file_exists($overrideFile)) {
						throw new Exception('Config file [' . $filename . '] requests override for host ' . $host . ' but file does not exists [' . $of . ']');
					}
					require($overrideFile);
				}
			}
		}

		$cfg = new SimpleSAML_Configuration($config, $filename);
		$cfg->filename = $filename;

		self::$loadedConfigs[$filename] = $cfg;

		return $cfg;
	}


	/**
	 * Set the directory for configuration files for the given configuration set.
	 *
	 * @param string $path  The directory which contains the configuration files.
	 * @param string $configSet  The configuration set. Defaults to 'simplesaml'.
	 */
	public static function setConfigDir($path, $configSet = 'simplesaml') {
		assert('is_string($path)');
		assert('is_string($configSet)');

		self::$configDirs[$configSet] = $path;
	}


	/**
	 * Load a configuration file from a configuration set.
	 *
	 * @param string $filename  The name of the configuration file.
	 * @param string $configSet  The configuration set. Optional, defaults to 'simplesaml'.
	 */
	public static function getConfig($filename = 'config.php', $configSet = 'simplesaml') {
		assert('is_string($filename)');
		assert('is_string($configSet)');

		if (!array_key_exists($configSet, self::$configDirs)) {
			throw new Exception('Configuration set \'' . $configSet . '\' not initialized.');
		}

		$dir = self::$configDirs[$configSet];
		$filePath = $dir . '/' . $filename;
		return self::loadFromFile($filePath);
	}


	/**
	 * Loads a configuration from the given array.
	 *
	 * @param array $config  The configuration array.
	 * @param string $location  The location which will be given when an error occurs. Optional.
	 * @return SimpleSAML_Configuration  The configuration object.
	 */
	public static function loadFromArray($config, $location = '[ARRAY]') {
		assert('is_array($config)');
		assert('is_string($location)');

		return new SimpleSAML_Configuration($config, $location);
	}


	/**
	 * Get a configuration file by its instance name.
	 *
	 * This function retrieves a configuration file by its instance name. The instance
	 * name is initialized by the init function, or by copyFromBase function.
	 *
	 * If no configuration file with the given instance name is found, an exception will
	 * be thrown.
	 *
	 * @param string $instancename  The instance name of the configuration file. Depreceated.
	 * @return SimpleSAML_Configuration  The configuration object.
	 */
	public static function getInstance($instancename = 'simplesaml') {
		assert('is_string($instancename)');

		if ($instancename === 'simplesaml') {
			return self::getConfig();
		}

		if (!array_key_exists($instancename, self::$instance)) 
			throw new Exception('Configuration with name ' . $instancename . ' is not initialized.');
		return self::$instance[$instancename];
	}


	/**
	 * Initialize a instance name with the given configuration file.
	 *
	 * @see setConfigDir()
	 * @depreceated  This function is superseeded by the setConfigDir function.
	 */
	public static function init($path, $instancename = 'simplesaml', $configfilename = 'config.php') {
		assert('is_string($path)');
		assert('is_string($instancename)');
		assert('is_string($configfilename)');

		if ($instancename === 'simplesaml') {
			/* For backwards compatibility. */
			self::setConfigDir($path, 'simplesaml');
		}

		/* Check if we already have loaded the given config - return the existing instance if we have. */
		if(array_key_exists($instancename, self::$instance)) {
			return self::$instance[$instancename];
		}

		self::$instance[$instancename] = self::loadFromFile($path . '/' . $configfilename);
	}


	/**
	 * Load a configuration file which is located in the same directory as this configuration file.
	 *
	 * @see getConfig()
	 * @depreceated  This function is superseeded by the getConfig() function.
	 */
	public function copyFromBase($instancename, $filename) {
		assert('is_string($instancename)');
		assert('is_string($filename)');
		assert('$this->filename !== NULL');

		/* Check if we already have loaded the given config - return the existing instance if we have. */
		if(array_key_exists($instancename, self::$instance)) {
			return self::$instance[$instancename];
		}

		$dir = dirname($this->filename);

		if ($instancename === 'simplesaml') {
			/* For backwards compatibility. */
			self::setConfigDir($path, 'simplesaml');
		}

		self::$instance[$instancename] = self::loadFromFile($dir . '/' . $filename);
		return self::$instance[$instancename];
	}


	public function getVersion($verbose = FALSE) {
		return 'trunk post-1.3';
	}


	/** 
	 * Retrieve a configuration option set in config.php.
	 *
	 * @param $name  Name of the configuration option.
	 * @param $default  Default value of the configuration option. This parameter will default to NULL if not
	 *                  specified. This can be set to SimpleSAML_Configuration::REQUIRED_OPTION, which will
	 *                  cause an exception to be thrown if the option isn't found.
	 * @return  The configuration option with name $name, or $default if the option was not found.
	 */
	public function getValue($name, $default = NULL) {

		/* Return the default value if the option is unset. */
		if (!array_key_exists($name, $this->configuration)) {
			if($default === self::REQUIRED_OPTION) {
				throw new Exception($this->location . ': Could not retrieve the required option ' .
					var_export($name, TRUE));
			}
			return $default;
		}

		return $this->configuration[$name];
	}
	
	public function getBaseURL() {
		if (preg_match('/^\*(.*)$/', $this->getValue('baseurlpath', ''), $matches)) {
			return SimpleSAML_Utilities::getFirstPathElement(false) . $matches[1];
		}
		return $this->getValue('baseurlpath', '');
	}


	/**
	 * This function resolves a path which may be relative to the
	 * simpleSAMLphp base directory.
	 *
	 * The path will never end with a '/'.
	 *
	 * @param $path  The path we should resolve. This option may be NULL.
	 * @return $path if $path is an absolute path, or $path prepended with
	 *         the base directory of this simpleSAMLphp installation. We
	 *         will return NULL if $path is NULL.
	 */
	public function resolvePath($path) {
		if($path === NULL) {
			return NULL;
		}

		assert('is_string($path)');

		/* Prepend path with basedir if it doesn't start with
                 * a slash. We assume getBaseDir ends with a slash.
		 */
		if ($path[0] !== '/') $path = $this->getBaseDir() . $path;

		/* Remove trailing slashes. */
		while (substr($path, -1) === '/') {
			$path = substr($path, 0, -1);
		}

		return $path;
	}


	/**
	 * Retrieve a path configuration option set in config.php.
	 * The function will always return an absolute path unless the
	 * option is not set. It will then return the default value.
	 *
	 * It checks if the value starts with a slash, and prefixes it
	 * with the value from getBaseDir if it doesn't.
	 *
	 * @param $name Name of the configuration option.
	 * @param $default Default value of the configuration option. 
	 * 		This parameter will default to NULL if not specified.
	 * @return The path configuration option with name $name, or $default if
	 *  the option was not found.
	 */
	public function getPathValue($name, $default = NULL) {

		/* Return the default value if the option is unset. */
		if (!array_key_exists($name, $this->configuration)) {
			$path = $default;
		} else {
			$path = $this->configuration[$name];
		}

		return $this->resolvePath($path) . '/';
	}


	/** 
	 * Retrieve the base directory for this simpleSAMLphp installation.
	 * This function first checks the 'basedir' configuration option. If
	 * this option is undefined or NULL, then we fall back to looking at
	 * the current filename.
	 *
	 * @return The absolute path to the base directory for this simpleSAMLphp
	 *  installation. This path will always end with a slash.
	 */
	public function getBaseDir() {
		/* Check if a directory is configured in the configuration
		 * file.
		 */
		$dir = $this->getValue('basedir');
		if($dir !== NULL) {
			/* Add trailing slash if it is missing. */
			if(substr($dir, -1) !== '/') {
				$dir .= '/';
			}

			return $dir;
		}

		/* The directory wasn't set in the configuration file. Our
		 * path is <base directory>/lib/SimpleSAML/Configuration.php
		 */

		$dir = __FILE__;
		assert('basename($dir) === "Configuration.php"');

		$dir = dirname($dir);
		assert('basename($dir) === "SimpleSAML"');

		$dir = dirname($dir);
		assert('basename($dir) === "lib"');

		$dir = dirname($dir);

		/* Add trailing slash. */
		$dir .= '/';

		return $dir;
	}


	/**
	 * This function retrieves a boolean configuration option.
	 *
	 * An exception will be thrown if this option isn't a boolean, or if this option isn't found, and no
	 * default value is given.
	 *
	 * @param $name  The name of the option.
	 * @param $default  A default value which will be returned if the option isn't found. The option will be
	 *                  required if this parameter isn't given. The default value can be any value, including
	 *                  NULL.
	 * @return  The option with the given name, or $default if the option isn't found and $default is specified.
	 */
	public function getBoolean($name, $default = self::REQUIRED_OPTION) {
		assert('is_string($name)');

		$ret = $this->getValue($name, $default);

		if($ret === $default) {
			/* The option wasn't found, or it matches the default value. In any case, return
			 * this value.
			 */
			return $ret;
		}

		if(!is_bool($ret)) {
			throw new Exception($this->location . ': The option ' . var_export($name, TRUE) .
				' is not a valid boolean value.');
		}

		return $ret;
	}


	/**
	 * This function retrieves a string configuration option.
	 *
	 * An exception will be thrown if this option isn't a string, or if this option isn't found, and no
	 * default value is given.
	 *
	 * @param $name  The name of the option.
	 * @param $default  A default value which will be returned if the option isn't found. The option will be
	 *                  required if this parameter isn't given. The default value can be any value, including
	 *                  NULL.
	 * @return  The option with the given name, or $default if the option isn't found and $default is specified.
	 */
	public function getString($name, $default = self::REQUIRED_OPTION) {
		assert('is_string($name)');

		$ret = $this->getValue($name, $default);

		if($ret === $default) {
			/* The option wasn't found, or it matches the default value. In any case, return
			 * this value.
			 */
			return $ret;
		}

		if(!is_string($ret)) {
			throw new Exception($this->location . ': The option ' . var_export($name, TRUE) .
				' is not a valid string value.');
		}

		return $ret;
	}


	/**
	 * Retrieve a configuration option with one of the given values.
	 *
	 * This will check that the configuration option matches one of the given values. The match will use
	 * strict comparison. An exception will be thrown if it does not match.
	 *
	 * The option can be mandatory or optional. If no default value is given, it will be considered to be
	 * mandatory, and an exception will be thrown if it isn't provided. If a default value is given, it
	 * is considered to be optional, and the default value is returned. The default value is automatically
	 * included in the list of allowed values.
	 *
	 * @param $name  The name of the option.
	 * @param $allowedValues  The values the option is allowed to take, as an array.
	 * @param $default  The default value which will be returned if the option isn't found. If this parameter
	 *                  isn't given, the option will be considered to be mandatory. The default value can be
	 *                  any value, including NULL.
	 * @return  The option with the given name, or $default if the option isn't found adn $default is given.
	 */
	public function getValueValidate($name, $allowedValues, $default = self::REQUIRED_OPTION) {
		assert('is_string($name)');
		assert('is_array($allowedValues)');

		$ret = $this->getValue($name, $default);
		if($ret === $default) {
			/* The option wasn't found, or it matches the default value. In any case, return
			 * this value.
			 */
			return $ret;
		}

		if(!in_array($ret, $allowedValues, TRUE)) {
			$strValues = array();
			foreach($allowedValues as $av) {
				$strValues[] = var_export($av, TRUE);
			}
			$strValues = implode(', ', $strValues);

			throw new Exception($this->location . ': Invalid value given for the option ' .
				var_export($name, TRUE) . '. It should have one of the following values: ' .
				$strValues . '; but it had the following value: ' . var_export($ret, TRUE));
		}

		return $ret;
	}


	/**
	 * This function retrieves an array configuration option.
	 *
	 * An exception will be thrown if this option isn't an array, or if this option isn't found, and no
	 * default value is given.
	 *
	 * @param string $name  The name of the option.
	 * @param mixed$default  A default value which will be returned if the option isn't found. The option will be
	 *                       required if this parameter isn't given. The default value can be any value, including
	 *                       NULL.
	 * @return mixed  The option with the given name, or $default if the option isn't found and $default is specified.
	 */
	public function getArray($name, $default = self::REQUIRED_OPTION) {
		assert('is_string($name)');

		$ret = $this->getValue($name, $default);

		if ($ret === $default) {
			/* The option wasn't found, or it matches the default value. In any case, return
			 * this value.
			 */
			return $ret;
		}

		if (!is_array($ret)) {
			throw new Exception($this->location . ': The option ' . var_export($name, TRUE) .
				' is not an array.');
		}

		return $ret;
	}


	/**
	 * Retrieve list of options.
	 *
	 * This function returns the name of all options which are defined in this
	 * configuration file, as an array of strings.
	 *
	 * @return array  Name of all options defined in this configuration file.
	 */
	public function getOptions() {

		return array_keys($this->configuration);
	}

}

?>