#632 User authentication (#773)

* #632 User authentication

The hardest part is done, integrate with Karaf's JAAS implementation.
Next step: implement a servlet filter that uses it

* #632 User authentication

* #632 User authentication (WTF)

core/roboconf-dm-rest-commons/pom.xml

@@ -86,7 +86,13 @@
   			<artifactId>roboconf-dm</artifactId>
   			<version>${project.version}</version>
   			<scope>test</scope>
-		</dependency>	
+		</dependency>
+
+		<dependency>
+			<groupId>org.mockito</groupId>
+			<artifactId>mockito-core</artifactId>
+			<scope>test</scope>
+		</dependency>
 	</dependencies>
 
 	<build>

core/roboconf-dm-rest-commons/src/main/java/net/roboconf/dm/rest/commons/UrlConstants.java

@@ -36,4 +36,7 @@ public interface UrlConstants {
 	String TARGETS = "targets";
 	String PREFERENCES = "preferences";
 	String SCHEDULER = "scheduler";
+	String AUTHENTICATION = "auth";
+
+	String SESSION_ID = "sid";
 }

core/roboconf-dm-rest-commons/src/main/java/net/roboconf/dm/rest/commons/security/AuthenticationManager.java

@@ -0,0 +1,250 @@
+/**
+ * Copyright 2017 Linagora, Université Joseph Fourier, Floralis
+ *
+ * The present code is developed in the scope of the joint LINAGORA -
+ * Université Joseph Fourier - Floralis research program and is designated
+ * as a "Result" pursuant to the terms and conditions of the LINAGORA
+ * - Université Joseph Fourier - Floralis research program. Each copyright
+ * holder of Results enumerated here above fully & independently holds complete
+ * ownership of the complete Intellectual Property rights applicable to the whole
+ * of said Results, and may freely exploit it in any manner which does not infringe
+ * the moral rights of the other copyright holders.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.roboconf.dm.rest.commons.security;
+
+import java.io.IOException;
+import java.util.Date;
+import java.util.UUID;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.logging.Logger;
+
+import javax.security.auth.callback.Callback;
+import javax.security.auth.callback.CallbackHandler;
+import javax.security.auth.callback.NameCallback;
+import javax.security.auth.callback.PasswordCallback;
+import javax.security.auth.callback.UnsupportedCallbackException;
+import javax.security.auth.login.LoginContext;
+import javax.security.auth.login.LoginException;
+
+/**
+ * A class in charge of managing authentication and sessions.
+ * <p>
+ * Authentication is delegated to various implementations.
+ * By default, it is handled by Karaf's JAAS implementation, but it is possible
+ * to override it by using {@link #setAuthService(IAuthService)}. You will HAVE
+ * TO use this method if you run the REST services outside Karaf.
+ * </p>
+ * <p>
+ * When the authentication succeeds, a token is generated by this class
+ * (a random UUID in fact). The token is stored by this class and associated
+ * with the login time.
+ * </p>
+ * <p>
+ * Since sessions can be limited in time (depending on admin preferences),
+ * we can verify on every action that the session is still valid.
+ * </p>
+ * <p>
+ * To prevent "man in the middle" "attacks, authentication should be
+ * used along with HTTPS.
+ * </p>
+ *
+ * @author Vincent Zurczak - Linagora
+ */
+public class AuthenticationManager {
+
+	private final ConcurrentHashMap<String,Long> tokenToLoginTime = new ConcurrentHashMap<> ();
+	private final Logger logger = Logger.getLogger( getClass().getName());
+	private final String realm;
+
+	private IAuthService authService;
+
+
+	/**
+	 * @author Vincent Zurczak - Linagora
+	 */
+	public static enum REST_ROLES {
+		ADM, TPL_RW, APP_RW, APP_R
+	}
+
+
+
+	/**
+	 * Constructor.
+	 * @param realm
+	 */
+	public AuthenticationManager( String realm ) {
+		this.realm = realm;
+		this.authService = new KarafAuthService();
+		this.authService.setRealm( this.realm );
+	}
+
+
+	/**
+	 * @param authenticater the authService to set
+	 */
+	public void setAuthService( IAuthService authService ) {
+		this.authService = authService;
+		authService.setRealm( this.realm );
+	}
+
+
+	/**
+	 * Authenticates a user and creates a new session.
+	 * @param user a user name
+	 * @param pwd a pass word
+	 * @return a token if authentication worked, null if it failed
+	 */
+	public String login( String user, String pwd ) {
+
+		String token = null;
+		try {
+			this.authService.authenticate( user, pwd );
+
+			token = UUID.randomUUID().toString();
+			Long now = new Date().getTime();
+			this.tokenToLoginTime.put( token, now );
+
+		} catch( LoginException e ) {
+			this.logger.severe( "Invalid login attempt by user " + user );
+		}
+
+		return token;
+	}
+
+
+	/**
+	 * Determines whether a session is valid.
+	 * @param token a token
+	 * @param validityPeriod the validity period for a session (in seconds, < 0 for unbound)
+	 * @return true if the session is valid, false otherwise
+	 */
+	public boolean isSessionValid( final String token, long validityPeriod ) {
+
+		boolean valid = false;
+		Long loginTime = null;
+		if( token != null )
+			loginTime = this.tokenToLoginTime.get( token );
+
+		if( validityPeriod < 0 ) {
+			valid = loginTime != null;
+
+		} else if( loginTime != null ) {
+			long now = new Date().getTime();
+			valid = (now - loginTime) <= validityPeriod * 1000;
+
+			// Invalid sessions should be deleted
+			if( ! valid )
+				logout( token );
+		}
+
+		return valid;
+	}
+
+
+	/**
+	 * Invalidates a session.
+	 * <p>
+	 * No error is thrown if the session was already invalid.
+	 * </p>
+	 *
+	 * @param token a token (can be null)
+	 */
+	public void logout( String token ) {
+		if( token != null )
+			this.tokenToLoginTime.remove( token );
+	}
+
+
+	/**
+	 * An abstraction to manage authentication.
+	 * @author Vincent Zurczak - Linagora
+	 */
+	public interface IAuthService {
+
+		/**
+		 * Authenticates someone by user and password.
+		 * @param user a user name
+		 * @param pwd a password
+		 * @throws LoginException if authentication failed
+		 */
+		void authenticate( String user, String pwd ) throws LoginException;
+
+		/**
+		 * Sets the REALM to use.
+		 * @param realm a realm name
+		 */
+		void setRealm( String realm );
+	}
+
+
+	/**
+	 * Authentication managed by Apache Karaf.
+	 * <p>
+	 * Karaf uses JAAS and by default supports several login modules
+	 * (properties files, databases, LDAP, etc).
+	 * </p>
+	 * @author Vincent Zurczak - Linagora
+	 */
+	public static class KarafAuthService implements IAuthService {
+		private String realm;
+
+
+		@Override
+		public void authenticate( String user, String pwd ) throws LoginException {
+			LoginContext loginCtx = new LoginContext( this.realm, new RoboconfCallbackHandler( user, pwd ));
+			loginCtx.login();
+		}
+
+		@Override
+		public void setRealm( String realm ) {
+			this.realm = realm;
+		}
+	}
+
+
+	/**
+	 * A callback handler for JAAS.
+	 * @author Vincent Zurczak - Linagora
+	 */
+	static final class RoboconfCallbackHandler implements CallbackHandler {
+		private final String username, password;
+
+
+		/**
+		 * Constructor.
+		 * @param username
+		 * @param password
+		 */
+		public RoboconfCallbackHandler( String username, String password ) {
+			this.username = username;
+			this.password = password;
+		}
+
+
+		@Override
+		public void handle( Callback[] callbacks ) throws IOException, UnsupportedCallbackException {
+
+			for( Callback callback : callbacks ) {
+				if (callback instanceof NameCallback )
+					((NameCallback) callback).setName( this.username );
+				else if( callback instanceof PasswordCallback )
+					((PasswordCallback) callback).setPassword( this.password.toCharArray());
+				else
+					throw new UnsupportedCallbackException( callback );
+			}
+		}
+	}
+}