/*
 * @(#)ConfigFile.java	1.18 03/12/19
 *
 * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
 
package com.sun.security.auth.login;

import javax.security.auth.AuthPermission;
import javax.security.auth.login.AppConfigurationEntry;
import java.io.*;
import java.util.*;
import java.net.URL;
import java.text.MessageFormat;
import sun.security.util.ResourcesMgr;
import sun.security.util.PropertyExpander;

/**
 * This class represents a default implementation for
 * <code>javax.security.auth.login.Configuration</code>.
 *
 * <p> This object stores the runtime login configuration representation,
 * and is the amalgamation of multiple static login
 * configurations that resides in files.
 * The algorithm for locating the login configuration file(s) and reading their
 * information into this <code>Configuration</code> object is:
 *
 * <ol>
 * <li>
 *   Loop through the <code>java.security.Security</code> properties,
 *   <i>login.config.url.1</i>, <i>login.config.url.2</i>, ...,
 *   <i>login.config.url.X</i>.  These properties are set
 *   in the Java security properties file, which is located in the file named
 *   &lt;JAVA_HOME&gt;/lib/security/java.security, where &lt;JAVA_HOME&gt;
 *   refers to the directory where the JDK was installed.
 *   Each property value specifies a <code>URL</code> pointing to a
 *   login configuration file to be loaded.  Read in and load
 *   each configuration.
 *
 * <li>
 *   The <code>java.lang.System</code> property
 *   <i>java.security.auth.login.config</i>
 *   may also be set to a <code>URL</code> pointing to another
 *   login configuration file
 *   (which is the case when a user uses the -D switch at runtime).
 *   If this property is defined, and its use is allowed by the
 *   security property file (the Security property,
 *   <i>policy.allowSystemProperty</i> is set to <i>true</i>),
 *   also load that login configuration.
 *
 * <li>
 *   If the <i>java.security.auth.login.config</i> property is defined using
 *   "==" (rather than "="), then ignore all other specified
 *   login configurations and only load this configuration.
 *
 * <li>
 *   If no system or security properties were set, try to read from the file,
 *   ${user.home}/.java.login.config, where ${user.home} is the value
 *   represented by the "user.home" System property.
 * </ol>
 * 
 * <p> The configuration syntax supported by this implementation
 * is exactly that syntax specified in the
 * <code>javax.security.auth.login.Configuration</code> class.
 * 
 * @version 1.6, 01/14/00
 * @see javax.security.auth.login.LoginContext
 */
public class ConfigFile extends javax.security.auth.login.Configuration {

    private StreamTokenizer st;
    private int lookahead;
    private int linenum;
    private HashMap configuration;
    private boolean expandProp = true;
    private boolean testing = false;

    /**
     * Create a new <code>Configuration</code> object.
     */
    public ConfigFile() {
	String expandProperties = (String)
	    java.security.AccessController.doPrivileged
	    (new java.security.PrivilegedAction() {
	    public Object run() {
		return System.getProperty("policy.expandProperties");
	    }
	});

	if ("false".equals(expandProperties))
	    expandProp = false;

	try {
	    init();
	} catch (IOException ioe) {
	    throw (SecurityException)
		new SecurityException(ioe.getMessage()).initCause(ioe);
	}
    }

    /**
     * Read and initialize the entire login Configuration.
     *
     * <p>
     *
     * @exception IOException if the Configuration can not be initialized. <p>
     * @exception SecurityException if the caller does not have permission
     *				to initialize the Configuration.
     */
    private void init() throws IOException {

	boolean initialized = false;
	FileReader fr = null;
	String sep = File.separator;

	// new configuration
	HashMap newConfig = new HashMap();

	String allowSys = java.security.Security.getProperty
						("policy.allowSystemProperty");

	if ("true".equalsIgnoreCase(allowSys)) {
	    String extra_config = System.getProperty
					("java.security.auth.login.config");
	    if (extra_config != null) {
		boolean overrideAll = false;
		if (extra_config.startsWith("=")) {
		    overrideAll = true;
		    extra_config = extra_config.substring(1);
		}
		try {
		    extra_config = PropertyExpander.expand(extra_config);
		} catch (PropertyExpander.ExpandException peee) {
		    MessageFormat form = new MessageFormat
			(ResourcesMgr.getString
				("Unable to properly expand config",
				"sun.security.util.AuthResources"));
		    Object[] source = {extra_config};
		    throw new IOException(form.format(source));
		}

		URL configURL = null;
		try {
		    configURL = new URL(extra_config);
		} catch (java.net.MalformedURLException mue) {
		    File configFile = new File(extra_config);
		    if (configFile.exists()) {
			configURL = new URL("file:" +
					configFile.getCanonicalPath());
		    } else {
			MessageFormat form = new MessageFormat
			    (ResourcesMgr.getString
				("extra_config (No such file or directory)",
				"sun.security.util.AuthResources"));
			Object[] source = {extra_config};
			throw new IOException(form.format(source));
		    }
		}

		if (testing)
		    System.out.println("reading "+configURL);
		init(configURL, newConfig);
		initialized = true;
		if (overrideAll) {
		    if (testing)
			System.out.println("overriding other policies!");
		}
	    }
	}

	int n = 1;
	String config_url;
	while ((config_url = java.security.Security.getProperty
					("login.config.url."+n)) != null) {
	    try {
		config_url = PropertyExpander.expand
			(config_url).replace(File.separatorChar, '/');
		if (testing)
			System.out.println("\tReading config: " + config_url);
		init(new URL(config_url), newConfig);
		initialized = true;
	    } catch (PropertyExpander.ExpandException peee) {
		MessageFormat form = new MessageFormat
			(ResourcesMgr.getString
				("Unable to properly expand config",
				"sun.security.util.AuthResources"));
		Object[] source = {config_url};
		throw new IOException(form.format(source));
	    }
	    n++;
	}

	if (initialized == false && n == 1 && config_url == null) {

	    // get the config from the user's home directory
	    if (testing)
		System.out.println("\tReading Policy " +
				"from ~/.java.login.config");
	    config_url = System.getProperty("user.home");
	    try {
		init(new URL("file:" + config_url +
			File.separatorChar + ".java.login.config"),
		    newConfig);
	    } catch (IOException ioe) {
		throw new IOException(ResourcesMgr.getString
			("Unable to locate a login configuration",
			"sun.security.util.AuthResources"));
	    }
	}

	configuration = newConfig;
    }

    private void init(URL config, HashMap newConfig) throws IOException {
	InputStreamReader isr
		= new InputStreamReader(getInputStream(config), "UTF-8");
	readConfig(isr, newConfig);
	isr.close();
    }

    /**
     * Retrieve an entry from the Configuration using an application name
     * as an index.
     *
     * <p>
     *
     * @param applicationName the name used to index the Configuration.
     * @return an array of AppConfigurationEntries which correspond to
     *		the stacked configuration of LoginModules for this
     *		application, or null if this application has no configured
     *		LoginModules.
     */
    public AppConfigurationEntry[] getAppConfigurationEntry
    (String applicationName) {

	LinkedList list = null;
	synchronized (configuration) {
	    list = (LinkedList)configuration.get(applicationName);
	}

	if (list == null || list.size() == 0)
	    return null;

	AppConfigurationEntry[] entries =
				new AppConfigurationEntry[list.size()];
	Iterator iterator = list.iterator();
	for (int i = 0; iterator.hasNext(); i++) {
	    AppConfigurationEntry e = (AppConfigurationEntry)iterator.next();
	    entries[i] = new AppConfigurationEntry(e.getLoginModuleName(),
						e.getControlFlag(),
						e.getOptions());
	}
	return entries;
    }

    /**
     * Refresh and reload the Configuration by re-reading all of the
     * login configurations.
     *
     * <p>
     *
     * @exception SecurityException if the caller does not have permission
     *				to refresh the Configuration.
     */
    public synchronized void refresh() {

	java.lang.SecurityManager sm = System.getSecurityManager();
	if (sm != null)
	    sm.checkPermission(new AuthPermission("refreshLoginConfiguration"));

	java.security.AccessController.doPrivileged
	    (new java.security.PrivilegedAction() {
	    public Object run() {
		try {
		    init();
		} catch (java.io.IOException ioe) {
		    throw new SecurityException(ioe.getLocalizedMessage());
		}
		return null;
	    }
	});
    }

    private void readConfig(Reader reader, HashMap newConfig)
	throws IOException {

	int linenum = 1;
 
	if (!(reader instanceof BufferedReader))
	    reader = new BufferedReader(reader);
 
	st = new StreamTokenizer(reader);
	st.quoteChar('"');
	st.wordChars('$', '$');
	st.wordChars('_', '_');
	st.wordChars('-', '-');
	st.lowerCaseMode(false);
	st.slashSlashComments(true);
	st.slashStarComments(true);
	st.eolIsSignificant(true);
 
	lookahead = nextToken();
	while (lookahead != StreamTokenizer.TT_EOF) {
 
	    if (testing)
		System.out.print("\tReading next config entry: ");
	    parseLoginEntry(newConfig);
	}
    }

    private void parseLoginEntry(HashMap newConfig) throws IOException {
 
	String appName;
	String moduleClass;
	String sflag;
	AppConfigurationEntry.LoginModuleControlFlag controlFlag;
	LinkedList configEntries = new LinkedList();
 
	// application name
	appName = st.sval;
	lookahead = nextToken();
 
	if (testing)
	    System.out.println("appName = " + appName);
 
	match("{");
 
	// get the modules
	while (peek("}") == false) {
	    HashSet argSet = new HashSet();
 
	    // get the module class name
	    moduleClass = match("module class name");
 
	    // controlFlag (required, optional, etc)
	    sflag = match("controlFlag");
	    if (sflag.equalsIgnoreCase("REQUIRED"))
		controlFlag =
			AppConfigurationEntry.LoginModuleControlFlag.REQUIRED;
	    else if (sflag.equalsIgnoreCase("REQUISITE"))
		controlFlag =
			AppConfigurationEntry.LoginModuleControlFlag.REQUISITE;
	    else if (sflag.equalsIgnoreCase("SUFFICIENT"))
		controlFlag =
			AppConfigurationEntry.LoginModuleControlFlag.SUFFICIENT;
	    else if (sflag.equalsIgnoreCase("OPTIONAL"))
		controlFlag =
			AppConfigurationEntry.LoginModuleControlFlag.OPTIONAL;
	    else {
		MessageFormat form = new MessageFormat(ResourcesMgr.getString
			("Configuration Error:\n\tInvalid control flag, flag",
			"sun.security.util.AuthResources"));
		Object[] source = {sflag};
		throw new IOException(form.format(source));
	    }
 
	    // get the args
	    HashMap options = new HashMap();
	    String key;
	    String value;
	    while (peek(";") == false) {
		key = match("option key");
		match("=");
		try {
		    value = expand(match("option value"));
		} catch (PropertyExpander.ExpandException peee) {
		    throw new IOException(peee.getLocalizedMessage());
		}
		options.put(key, value);
	    }
 
	    lookahead = nextToken();
 
	    // create the new element
	    if (testing) {
		System.out.print("\t\t" + moduleClass + ", " + sflag);
		java.util.Iterator i = options.keySet().iterator();
		while (i.hasNext()) {
		    key = (String)i.next();
		    System.out.print(", " +
					key +
					"=" +
					(String)options.get(key));
		}
		System.out.println("");
	    }
	    AppConfigurationEntry entry = new AppConfigurationEntry
							(moduleClass,
							controlFlag,
							options);
	    configEntries.add(entry);
	}

	match("}");
	match(";");
 
	// add this configuration entry
	if (newConfig.containsKey(appName)) {
	    MessageFormat form = new MessageFormat(ResourcesMgr.getString
		("Configuration Error:\n\t" +
			"Can not specify multiple entries for appName",
		"sun.security.util.AuthResources"));
	    Object[] source = {appName};
	    throw new IOException(form.format(source));
	}
	newConfig.put(appName, configEntries);
	if (testing)
	    System.out.println("\t\t***Added entry for " +
				appName + " to overall configuration***");
    }

    private String match(String expect) throws IOException {
 
	String value = null;
 
	switch(lookahead) {
	case StreamTokenizer.TT_EOF:
 
	    MessageFormat form1 = new MessageFormat(ResourcesMgr.getString
		("Configuration Error:\n\texpected [expect], " +
			"read [end of file]",
		"sun.security.util.AuthResources"));
	    Object[] source1 = {expect};
	    throw new IOException(form1.format(source1));
 
	case '"':
	case StreamTokenizer.TT_WORD:

	    if (expect.equalsIgnoreCase("module class name") ||
		expect.equalsIgnoreCase("controlFlag") ||
		expect.equalsIgnoreCase("option key") ||
		expect.equalsIgnoreCase("option value")) {
		value = st.sval;
		lookahead = nextToken();
	    } else {
		MessageFormat form = new MessageFormat(ResourcesMgr.getString
			("Configuration Error:\n\tLine line: " +
				"expected [expect], found [value]",
			"sun.security.util.AuthResources"));
		Object[] source = {new Integer(linenum), expect, st.sval};
		throw new IOException(form.format(source));
	    }
	    break;
 
	case '{':
 
	    if (expect.equalsIgnoreCase("{")) {
		lookahead = nextToken();
	    } else {
		MessageFormat form = new MessageFormat(ResourcesMgr.getString
			("Configuration Error:\n\tLine line: expected [expect]",
			"sun.security.util.AuthResources"));
		Object[] source = {new Integer(linenum), expect, st.sval};
		throw new IOException(form.format(source));
	    }
	    break;

	case ';':

	    if (expect.equalsIgnoreCase(";")) {
		lookahead = nextToken();
	    } else {
		MessageFormat form = new MessageFormat(ResourcesMgr.getString
			("Configuration Error:\n\tLine line: expected [expect]",
			"sun.security.util.AuthResources"));
		Object[] source = {new Integer(linenum), expect, st.sval};
		throw new IOException(form.format(source));
	    }
	    break;
 
	case '}':
 
	    if (expect.equalsIgnoreCase("}")) {
		lookahead = nextToken();
	    } else {
		MessageFormat form = new MessageFormat(ResourcesMgr.getString
			("Configuration Error:\n\tLine line: expected [expect]",
			"sun.security.util.AuthResources"));
		Object[] source = {new Integer(linenum), expect, st.sval};
		throw new IOException(form.format(source));
	    }
	    break;

	case '=':

	    if (expect.equalsIgnoreCase("=")) {
		lookahead = nextToken();
	    } else {
		MessageFormat form = new MessageFormat(ResourcesMgr.getString
			("Configuration Error:\n\tLine line: expected [expect]",
			"sun.security.util.AuthResources"));
		Object[] source = {new Integer(linenum), expect, st.sval};
		throw new IOException(form.format(source));
	    }
	    break;
 
	default:
	    MessageFormat form = new MessageFormat(ResourcesMgr.getString
			("Configuration Error:\n\tLine line: " +
				"expected [expect], found [value]",
			"sun.security.util.AuthResources"));
	    Object[] source = {new Integer(linenum), expect, st.sval};
	    throw new IOException(form.format(source));
	}
	return value;
    }

    private boolean peek(String expect) {
	boolean found = false;
 
	switch (lookahead) {
	case ',':
	    if (expect.equalsIgnoreCase(","))
		found = true;
	    break;
	case ';':
	    if (expect.equalsIgnoreCase(";"))
		found = true;
	    break;
	case '{':
	    if (expect.equalsIgnoreCase("{"))
		found = true;
	    break;
	case '}':
	    if (expect.equalsIgnoreCase("}"))
		found = true;
	    break;
	default:
	}
	return found;
    }

    private int nextToken() throws IOException {
	int tok;
	while ((tok = st.nextToken()) == StreamTokenizer.TT_EOL) {
	    linenum++;
	}
	return tok;
    }

    /*
     * Fast path reading from file urls in order to avoid calling
     * FileURLConnection.connect() which can be quite slow the first time
     * it is called. We really should clean up FileURLConnection so that
     * this is not a problem but in the meantime this fix helps reduce
     * start up time noticeably for the new launcher. -- DAC
     */
    private InputStream getInputStream(URL url) throws IOException {
	if ("file".equals(url.getProtocol())) {
	    String path = url.getFile().replace('/', File.separatorChar);
	    return new FileInputStream(path);
	} else {
	    return url.openStream();
	}
    }

    private String expand(String value)
	throws PropertyExpander.ExpandException, IOException {

	if ("".equals(value)) {
	    return value;
	}

	if (expandProp) {

	    String s = PropertyExpander.expand(value);

	    if (s == null || s.length() == 0) {
		MessageFormat form = new MessageFormat(ResourcesMgr.getString
			("Configuration Error:\n\tLine line: " +
			"system property [value] expanded to empty value",
			"sun.security.util.AuthResources"));
		Object[] source = {new Integer(linenum), value};
		throw new IOException(form.format(source));
	    }
	    return s;
	} else {
	    return value;
	}
    }
}