// GenericAuthFilter.java
// $Id: GenericAuthFilter.java,v 1.19 2007/02/09 22:39:25 ylafon Exp $
// (c) COPYRIGHT MIT and INRIA, 1996.
// Please first read the full copyright statement in file COPYRIGHT.html
package org.w3c.jigsaw.auth;
import java.io.PrintStream;
import java.util.Enumeration;
import java.net.InetAddress;
import org.w3c.tools.resources.Attribute;
import org.w3c.tools.resources.AttributeHolder;
import org.w3c.tools.resources.AttributeRegistry;
import org.w3c.tools.resources.FramedResource;
import org.w3c.tools.resources.InvalidResourceException;
import org.w3c.tools.resources.ProtocolException;
import org.w3c.tools.resources.Resource;
import org.w3c.tools.resources.ResourceFilter;
import org.w3c.tools.resources.ResourceFrame;
import org.w3c.tools.resources.ResourceReference;
import org.w3c.tools.resources.StringArrayAttribute;
import org.w3c.jigsaw.http.Client;
import org.w3c.jigsaw.http.HTTPException;
import org.w3c.jigsaw.http.Reply;
import org.w3c.jigsaw.http.Request;
import org.w3c.jigsaw.http.httpd;
import org.w3c.jigsaw.html.HtmlGenerator;
import org.w3c.tools.codec.Base64Decoder;
import org.w3c.tools.codec.Base64FormatException;
import org.w3c.www.http.HTTP;
import org.w3c.www.http.HttpChallenge;
import org.w3c.www.http.HttpCredential;
import org.w3c.www.http.HttpFactory;
import org.w3c.www.http.HttpReplyMessage;
import org.w3c.www.http.HttpRequestMessage;
import org.w3c.tools.resources.ProtocolException;
/**
* A generic authentication filter.
* This filter will use both IP and basic authentication to try to authenticate
* incomming request. It should not be use for big user's database (typically
* the ones that have more than 1000 entries).
*/
class BasicAuthContextException extends Exception {
BasicAuthContextException (String msg) {
super (msg) ;
}
}
class BasicAuthContext {
String user = null ;
String password = null ;
String cookie = null ;
public String toString() {
return user+":"+password;
}
BasicAuthContext (Request request)
throws BasicAuthContextException, ProtocolException
{
HttpCredential credential = null;
credential = (request.isProxy()
? request.getProxyAuthorization()
: request.getAuthorization());
if ( ! credential.getScheme().equalsIgnoreCase("Basic") ) {
String msg = ("Invalid authentication scheme \""
+ credential.getScheme()
+ " expecting \"Basic\"");
throw new BasicAuthContextException (msg) ;
}
// Decode the credentials:
String decoded = null ;
this.cookie = credential.getAuthParameter("cookie");
try {
Base64Decoder b = new Base64Decoder (cookie) ;
decoded = b.processString() ;
} catch (Base64FormatException e) {
String msg = "Invalid BASE64 encoding of credentials." ;
throw new BasicAuthContextException (msg) ;
}
// Get user and password:
int icolon = decoded.indexOf (':') ;
if ( (icolon > 0) && (icolon+1 < decoded.length()) ) {
// ok, parse was find, check user:
this.user = decoded.substring (0, icolon) ;
this.password = decoded.substring (icolon+1) ;
} else {
String msg = "Invalid credentials syntax in " + decoded ;
throw new BasicAuthContextException (msg) ;
}
}
}
/**
* GenericAuthFilter provides for both IP and basic authentication.
* This is really a first implementation. It looses on several points:
* <ul>
* <li>AuthUser instances, being a subclass of resource dump their classes
* along with their attributes, although here we know that they will all
* be instances of AuthUser.
* <li>The way the ipmatcher is maintained doesn't make much sense.
* <li>The way groups are handled is no good.
* <li>The SimpleResourceStore is not an adequat store for the user database,
* it should rather use the jdbmResourceStore (not written yet).
* </ul>
* However, this provides for the basic functionnalities.
*/
public class GenericAuthFilter extends AuthFilter {
/**
* Attribute index - The list of allowed users.
*/
protected static int ATTR_ALLOWED_USERS = -1 ;
/**
* Attribute index - The list of allowed groups.
*/
protected static int ATTR_ALLOWED_GROUPS = -1 ;
static {
Attribute a = null ;
Class c = null ;
try {
c = Class.forName("org.w3c.jigsaw.auth.GenericAuthFilter");
} catch (Exception ex) {
ex.printStackTrace() ;
System.exit(1) ;
}
// The list of allowed users
a = new StringArrayAttribute("users"
, null
, Attribute.EDITABLE) ;
ATTR_ALLOWED_USERS = AttributeRegistry.registerAttribute(c, a) ;
// The list of allowed groups:
a = new StringArrayAttribute("groups"
, null
, Attribute.EDITABLE);
ATTR_ALLOWED_GROUPS = AttributeRegistry.registerAttribute(c, a) ;
}
/**
* The IPMatcher to match IP templates to user records.
*/
protected IPMatcher ipmatcher = null ;
/**
* The catalog of realms that make our scope.
*/
protected RealmsCatalog catalog = null ;
/**
* Our associated realm.
*/
protected ResourceReference rr_realm = null ;
/**
* The nam of the realm we cache in <code>realm</code>.
*/
protected String loaded_realm = null ;
/**
* The challenge to issue to any client for Basic Authentication.
*/
protected HttpChallenge challenge = null;
/**
* Get a pointer to our realm, and initialize our ipmatcher.
*/
protected synchronized void acquireRealm() {
// Get our catalog:
if ( catalog == null ) {
httpd server = (httpd)
((FramedResource) getTargetResource()).getServer() ;
catalog = server.getRealmsCatalog() ;
}
// Check that our realm name is valid:
String name = getRealm() ;
if ( name == null )
return ;
if ((rr_realm != null) && name.equals(loaded_realm))
return ;
// Load the realm and create the ipmtacher object
rr_realm = catalog.loadRealm(name) ;
if (rr_realm != null) {
try {
AuthRealm realm = (AuthRealm) rr_realm.lock();
Enumeration e = realm.enumerateUserNames() ;
if (e.hasMoreElements()) {
ipmatcher = new IPMatcher() ;
}
while (e.hasMoreElements()) {
String uname = (String) e.nextElement() ;
ResourceReference rr_user = realm.loadUser(uname) ;
try {
AuthUser user = (AuthUser) rr_user.lock();
short ips[][] = user.getIPTemplates() ;
if ( ips != null ) {
for (int i = 0 ; i < ips.length ; i++)
ipmatcher.add(ips[i], rr_user) ;
}
} catch (InvalidResourceException ex) {
System.out.println("Invalid user reference : "+uname);
} finally {
rr_user.unlock();
}
}
} catch (InvalidResourceException ex) {
} finally {
rr_realm.unlock();
}
}
}
/**
* Check that our realm does exist.
* Otherwise we are probably being initialized, and we don't authenticate
* yet.
* @return A boolean <strong>true</strong> if realm can be initialized.
*/
protected synchronized boolean checkRealm() {
acquireRealm() ;
return (ipmatcher != null) ;
}
/**
* Get the list of allowed users.
*/
public String[] getAllowedUsers() {
return (String[]) getValue(ATTR_ALLOWED_USERS, null) ;
}
/**
* Get the list of allowed groups.
*/
public String[] getAllowedGroups() {
return (String[]) getValue(ATTR_ALLOWED_GROUPS, null) ;
}
/**
* Lookup a user by its IP address.
* @param ipaddr The IP address to look for.
* @return An AuthUser instance or <strong>null</strong>.
*/
public synchronized ResourceReference lookupUser (InetAddress ipaddr) {
if ( ipmatcher == null )
acquireRealm() ;
return (ResourceReference) ipmatcher.lookup(ipaddr.getAddress()) ;
}
/**
* Lookup a user by its name.
* @param name The user's name.
* @return An AuthUser instance, or <strong>null</strong>.
*/
public synchronized ResourceReference lookupUser (String name) {
if ( rr_realm == null )
acquireRealm() ;
try {
AuthRealm realm = (AuthRealm) rr_realm.lock();
return realm.loadUser(name) ;
} catch (InvalidResourceException ex) {
return null;
} finally {
rr_realm.unlock();
}
}
/**
* Check the given Basic context against our database.
* @param ctxt The basic auth context to check.
* @return A AuthUser instance if check succeeded, <strong>null</strong>
* otherwise.
*/
protected ResourceReference checkBasicAuth(BasicAuthContext ctxt) {
ResourceReference rr_user = (ResourceReference)lookupUser(ctxt.user) ;
if (rr_user != null) {
try {
AuthUser user = (AuthUser) rr_user.lock();
// This user doesn't even exists !
if ( user == null )
return null ;
// If it has a password check it
if ( ! user.definesAttribute("password") ) {
return rr_user;
} else {
return user.getPassword().equals(ctxt.password)
? rr_user
: null ;
}
} catch (InvalidResourceException ex) {
return null;
} finally {
rr_user.unlock();
}
}
return null;
}
/**
* Is this user allowed in the realm ?
* First check in the list of allowed users (if any), than in the list
* of allowed groups (if any). If no allowed users or allowed groups
* are defined, than simply check for the existence of this user.
* @return A boolean <strong>true</strong> if access allowed.
*/
protected boolean checkUser(AuthUser user) {
String allowed_users[] = getAllowedUsers() ;
// Check in the list of allowed users:
if ( allowed_users != null ) {
for (int i = 0 ; i < allowed_users.length ; i++) {
if (allowed_users[i].equals(user.getName()))
return true ;
}
}
// Check in the list of allowed groups:
String allowed_groups[] = getAllowedGroups() ;
if ( allowed_groups != null ) {
String ugroups[] = user.getGroups() ;
if ( ugroups != null ) {
for (int i = 0 ; i < ugroups.length ; i++) {
for (int j = 0 ; j < allowed_groups.length ; j++) {
if ( allowed_groups[j].equals(ugroups[i]) )
return true ;
}
}
}
}
// If no users or groups specified, return true
if ((allowed_users == null) && (allowed_groups == null))
return true ;
return false ;
}
/**
* Catch set value on the realm, to maintain cached values.
*/
public void setValue(int idx, Object value) {
super.setValue(idx, value);
if ( idx == ATTR_REALM ) {
// Initialize the filter challenge:
challenge = HttpFactory.makeChallenge("Basic");
challenge.setAuthParameter("realm", getRealm());
}
}
/**
* Authenticate the given request.
* We first check for valid authentication information. If no
* authentication is provided, than we try to map the IP address to some
* of the ones we know about. If the IP address is not found, we challenge
* the client for a password.
* <p>If the IP address is found, than either our user entry requires an
* extra password step (in wich case we challenge it), or simple IP
* based authentication is enough, so we allow the request.
* @param request The request to be authentified.
* @exception org.w3c.tools.resources.ProtocolException if authentication
* failed
*/
public void authenticate (Request request)
throws ProtocolException
{
// Are we being edited ?
if ( ! checkRealm() )
return ;
// Internal requests always allowed:
Client client = request.getClient() ;
if ( client == null )
return ;
// Check for User by IP address:
boolean ipchecked = false ;
ResourceReference rr_user = lookupUser(client.getInetAddress());
if (rr_user != null) {
try {
AuthUser user = (AuthUser) rr_user.lock();
if ( user != null ) {
ipchecked = true ;
// Good the user exists, does it need more authentication ?
if ( ! user.definesAttribute("password") &&
checkUser(user)) {
request.setState(STATE_AUTHUSER, user.getName()) ;
request.setState(STATE_AUTHTYPE, "ip");
return ;
}
}
} catch (InvalidResourceException ex) {
//FIXME
} finally {
rr_user.unlock();
}
}
// Check authentication according to auth method:
if ((request.hasAuthorization() && ! request.isProxy())
|| (request.isProxy() && request.hasProxyAuthorization())) {
BasicAuthContext ctxt = null ;
try {
ctxt = new BasicAuthContext(request);
} catch (BasicAuthContextException ex) {
ctxt = null;
}
// Is that user allowed ?
if ( ctxt != null ) {
rr_user = checkBasicAuth(ctxt) ;
if (rr_user != null) {
try {
AuthUser user = (AuthUser) rr_user.lock();
if ((user != null) && checkUser(user)) {
// Check that if IP auth was required,
// it succeeded:
boolean iprequired =
user.definesAttribute("ipaddress") ;
if ( ( ! iprequired) || ipchecked ) {
// Set the request fields, and continue:
request.setState(STATE_AUTHUSER, ctxt.user);
request.setState(STATE_AUTHTYPE, "Basic") ;
return ;
}
}
} catch (InvalidResourceException ex) {
//FIXME
} finally {
rr_user.unlock();
}
}
}
}
// Every possible scheme has failed for this request, emit an error
Reply e = null;
if ( request.isProxy() ) {
e = request.makeReply(HTTP.PROXY_AUTH_REQUIRED);
e.setProxyAuthenticate(challenge);
} else {
e = request.makeReply(HTTP.UNAUTHORIZED);
e.setWWWAuthenticate (challenge);
}
HtmlGenerator g = new HtmlGenerator("Unauthorized");
g.append ("<h1>Unauthorized access</h1>"
+ "<p>You are denied access to this resource.");
e.setStream(g);
throw new HTTPException (e);
}
/**
* Initialize the filter.
*/
public void initialize(Object values[]) {
super.initialize(values) ;
if ( getRealm() != null ) {
// Initialize the filter challenge:
challenge = HttpFactory.makeChallenge("Basic");
challenge.setAuthParameter("realm", getRealm());
}
}
}