GUAC-586: Associate unique identifier with each AuthenticationProvider.

extensions/guacamole-auth-jdbc/modules/guacamole-auth-jdbc-mysql/src/main/java/net/sourceforge/guacamole/net/auth/mysql/MySQLAuthenticationProvider.java

@@ -192,6 +192,11 @@ public class MySQLAuthenticationProvider implements AuthenticationProvider {
 
     }
 
+    @Override
+    public String getIdentifier() {
+        return "mysql";
+    }
+
     @Override
     public AuthenticatedUser authenticateUser(Credentials credentials)
             throws GuacamoleException {

extensions/guacamole-auth-jdbc/modules/guacamole-auth-jdbc-postgresql/src/main/java/org/glyptodon/guacamole/auth/postgresql/PostgreSQLAuthenticationProvider.java

@@ -192,6 +192,11 @@ public class PostgreSQLAuthenticationProvider implements AuthenticationProvider
 
     }
 
+    @Override
+    public String getIdentifier() {
+        return "postgresql";
+    }
+
     @Override
     public AuthenticatedUser authenticateUser(Credentials credentials)
             throws GuacamoleException {

extensions/guacamole-auth-ldap/src/main/java/net/sourceforge/guacamole/net/auth/ldap/LDAPAuthenticationProvider.java

@@ -74,6 +74,11 @@ public class LDAPAuthenticationProvider extends SimpleAuthenticationProvider {
         environment = new LocalEnvironment();
     }
 
+    @Override
+    public String getIdentifier() {
+        return "ldap";
+    }
+
     // Courtesy of OWASP: https://www.owasp.org/index.php/Preventing_LDAP_Injection_in_Java
     private static String escapeLDAPSearchFilter(String filter) {
         StringBuilder sb = new StringBuilder();

extensions/guacamole-auth-noauth/src/main/java/net/sourceforge/guacamole/net/auth/noauth/NoAuthenticationProvider.java

@@ -122,6 +122,11 @@ public class NoAuthenticationProvider extends SimpleAuthenticationProvider {
         environment = new LocalEnvironment();
     }
 
+    @Override
+    public String getIdentifier() {
+        return "noauth";
+    }
+
     /**
      * Retrieves the configuration file, as defined within guacamole.properties.
      *