GUACAMOLE-1855: Merge configuration options for bypassing MFA based on client address.

extensions/guacamole-auth-totp/pom.xml

@@ -177,6 +177,14 @@
             <version>2.1.1</version>
             <scope>provided</scope>
         </dependency>
+        
+        <!-- Library for unified IPv4/6 parsing and validation -->
+        <dependency>
+            <groupId>com.github.seancfoley</groupId>
+            <artifactId>ipaddress</artifactId>
+            <version>5.5.0</version>
+            <scope>provided</scope>
+        </dependency>
 
     </dependencies>
 

extensions/guacamole-auth-totp/src/main/java/org/apache/guacamole/auth/totp/conf/ConfigurationService.java

@@ -20,10 +20,14 @@
 package org.apache.guacamole.auth.totp.conf;
 
 import com.google.inject.Inject;
+import inet.ipaddr.IPAddress;
+import java.util.Collections;
+import java.util.List;
 import org.apache.guacamole.GuacamoleException;
 import org.apache.guacamole.GuacamoleServerException;
 import org.apache.guacamole.environment.Environment;
 import org.apache.guacamole.properties.EnumGuacamoleProperty;
+import org.apache.guacamole.properties.IPAddressListProperty;
 import org.apache.guacamole.properties.IntegerGuacamoleProperty;
 import org.apache.guacamole.properties.StringGuacamoleProperty;
 import org.apache.guacamole.totp.TOTPGenerator;
@@ -88,6 +92,36 @@ public class ConfigurationService {
         public String getName() { return "totp-mode"; }
 
     };
+    
+    /**
+     * A property that contains a list of IP addresses and/or subnets for which
+     * MFA via the TOTP module should be bypassed. Users logging in from addresses
+     * contained in this list will not be prompted for a second authentication
+     * factor. If this property is empty or not defined, and the TOTP module
+     * is installed, all users will be prompted for MFA.
+     */
+    private static final IPAddressListProperty TOTP_BYPASS_HOSTS =
+            new IPAddressListProperty() {
+                
+        @Override
+        public String getName() { return "totp-bypass-hosts"; }
+                
+    };
+    
+    /**
+     * A property that contains a list of IP addresses and/or subnets for which
+     * MFA via the TOTP module should explicitly be enabled. If this property is defined,
+     * and the TOTP module is installed, users logging in from hosts contained
+     * in this list will be prompted for MFA, and users logging in from all
+     * other hosts will not be prompted for MFA.
+     */
+    private static final IPAddressListProperty TOTP_ENFORCE_HOSTS =
+            new IPAddressListProperty() {
+    
+        @Override
+        public String getName() { return "totp-enforce-hosts"; }
+                
+    };
 
     /**
      * Returns the human-readable name of the entity issuing user accounts. If
@@ -158,5 +192,39 @@ public class ConfigurationService {
     public TOTPGenerator.Mode getMode() throws GuacamoleException {
         return environment.getProperty(TOTP_MODE, TOTPGenerator.Mode.SHA1);
     }
+    
+    /**
+     * Return the list of IP addresses and/or subnets for which MFA authentication via the
+     * TOTP module should be bypassed, allowing users from those addresses to log in
+     * without the MFA requirement.
+     * 
+     * @return
+     *     A list of IP addresses and/or subnets for which MFA authentication
+     *     should be bypassed.
+     * 
+     * @throws GuacamoleException 
+     *     If guacamole.properties cannot be parsed, or an invalid IP address
+     *     or subnet is specified.
+     */
+    public List<IPAddress> getBypassHosts() throws GuacamoleException {
+        return environment.getProperty(TOTP_BYPASS_HOSTS, Collections.emptyList());
+    }
+    
+    /**
+     * Return the list of IP addresses and/or subnets for which MFA authentication via the TOTP
+     * module should be explicitly enabled, requiring users logging in from hosts specified in
+     * the list to complete MFA.
+     * 
+     * @return
+     *     A list of IP addresses and/or subnets for which MFA authentication
+     *     should be explicitly enabled.
+     * 
+     * @throws GuacamoleException 
+     *     If guacamole.properties cannot be parsed, or an invalid IP address
+     *     or subnet is specified.
+     */
+    public List<IPAddress> getEnforceHosts() throws GuacamoleException {
+        return environment.getProperty(TOTP_ENFORCE_HOSTS, Collections.emptyList());
+    }
 
 }

extensions/guacamole-auth-totp/src/main/java/org/apache/guacamole/auth/totp/user/UserVerificationService.java

@@ -22,9 +22,12 @@ package org.apache.guacamole.auth.totp.user;
 import com.google.common.io.BaseEncoding;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import inet.ipaddr.IPAddress;
+import inet.ipaddr.IPAddressString;
 import java.security.InvalidKeyException;
 import java.util.Collections;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import javax.servlet.http.HttpServletRequest;
@@ -44,6 +47,7 @@ import org.apache.guacamole.net.auth.User;
 import org.apache.guacamole.net.auth.UserContext;
 import org.apache.guacamole.net.auth.UserGroup;
 import org.apache.guacamole.net.auth.credentials.CredentialsInfo;
+import org.apache.guacamole.properties.IPAddressListProperty;
 import org.apache.guacamole.totp.TOTPGenerator;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -311,6 +315,45 @@ public class UserVerificationService {
     public void verifyIdentity(UserContext context,
             AuthenticatedUser authenticatedUser) throws GuacamoleException {
 
+        // Pull the original HTTP request used to authenticate
+        Credentials credentials = authenticatedUser.getCredentials();
+        HttpServletRequest request = credentials.getRequest();
+        
+        // Get the current client address
+        IPAddress clientAddr = new IPAddressString(request.getRemoteAddr()).getAddress();
+
+        // Ignore anonymous users
+        if (authenticatedUser.getIdentifier().equals(AuthenticatedUser.ANONYMOUS_IDENTIFIER))
+            return;
+        
+        // Pull address lists to check from configuration. Note that the enforce
+        // list will override the bypass list, which means that, if the client
+        // address happens to be in both lists, Duo MFA will be enforced.
+        List<IPAddress> bypassAddresses = confService.getBypassHosts();
+        List<IPAddress> enforceAddresses = confService.getEnforceHosts();
+        
+        // Check the bypass list for the client address, and set the enforce
+        // flag to the opposite.
+        boolean enforceHost = !(IPAddressListProperty.addressListContains(bypassAddresses, clientAddr));
+        
+        // Only continue processing if the list is not empty
+        if (!enforceAddresses.isEmpty()) {
+            
+            // If client address is not available or invalid, MFA will
+            // be enforced.
+            if (clientAddr == null || !clientAddr.isIPAddress())
+                enforceHost = true;
+            
+            // Check the enforce list and set the flag if the client address
+            // is found in the list.
+            else
+                enforceHost = IPAddressListProperty.addressListContains(enforceAddresses, clientAddr);
+        }
+            
+        // If the enforce flag is not true, bypass TOTP MFA.
+        if (!enforceHost)
+            return;
+        
         // Ignore anonymous users
         String username = authenticatedUser.getIdentifier();
         if (username.equals(AuthenticatedUser.ANONYMOUS_IDENTIFIER))
@@ -325,10 +368,6 @@ public class UserVerificationService {
         if (key == null)
             return;
 
-        // Pull the original HTTP request used to authenticate
-        Credentials credentials = authenticatedUser.getCredentials();
-        HttpServletRequest request = credentials.getRequest();
-
         // Retrieve TOTP from request
         String code = request.getParameter(AuthenticationCodeField.PARAMETER_NAME);