added untested LDAP authentication provider

web/src/main/java/lcsb/mapviewer/web/config/LdapAuthenticationProvider.java

+package lcsb.mapviewer.web.config;
+
+import com.unboundid.ldap.sdk.LDAPException;
+import lcsb.mapviewer.common.Configuration;
+import lcsb.mapviewer.model.user.User;
+import lcsb.mapviewer.services.UserDTO;
+import lcsb.mapviewer.services.interfaces.ILdapService;
+import lcsb.mapviewer.services.interfaces.IUserService;
+import org.springframework.security.authentication.AuthenticationProvider;
+import org.springframework.security.authentication.AuthenticationServiceException;
+import org.springframework.security.authentication.BadCredentialsException;
+import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
+import org.springframework.security.core.Authentication;
+import org.springframework.security.core.AuthenticationException;
+import org.springframework.security.core.userdetails.UserDetailsService;
+import org.springframework.security.core.userdetails.UsernameNotFoundException;
+import org.springframework.security.crypto.password.PasswordEncoder;
+import org.springframework.stereotype.Service;
+
+@Service
+public class LdapAuthenticationProvider implements AuthenticationProvider {
+
+  private IUserService userService;
+  private ILdapService ldapService;
+  private UserDetailsService userDetailsService;
+  private PasswordEncoder passwordEncoder;
+
+  public LdapAuthenticationProvider(IUserService userService,
+                                    ILdapService ldapService,
+                                    UserDetailsService userDetailsService,
+                                    PasswordEncoder passwordEncoder) {
+    this.userService = userService;
+    this.ldapService = ldapService;
+    this.userDetailsService = userDetailsService;
+    this.passwordEncoder = passwordEncoder;
+  }
+
+  @Override
+  public Authentication authenticate(Authentication authentication) throws AuthenticationException {
+    String username = authentication.getName().toLowerCase();
+    if (username.isEmpty()) {
+      throw new UsernameNotFoundException("Invalid username.");
+    }
+
+    boolean ldapLoginSuccess;
+    try {
+      ldapLoginSuccess = ldapService.login(username, (String) authentication.getCredentials());
+    } catch (LDAPException e) {
+      throw new AuthenticationServiceException("Connection to LDAP service failed.", e);
+    }
+
+    if (!ldapLoginSuccess) {
+      throw new BadCredentialsException("Invalid credentials or username.");
+    }
+
+    boolean userExistsLocally = userService.getUserByLogin(username) != null;
+    if (!userExistsLocally) {
+      createLocalUser(authentication);
+    }
+
+    return new UsernamePasswordAuthenticationToken(
+      username,
+      authentication.getCredentials(),
+      userDetailsService.loadUserByUsername(username).getAuthorities()
+    );
+  }
+
+  @Override
+  public boolean supports(Class<?> authentication) {
+    if (authentication == null
+        || authentication.getName().isEmpty()
+        || !UsernamePasswordAuthenticationToken.class.isAssignableFrom(authentication)
+        || authentication.getName().equals(Configuration.ANONYMOUS_LOGIN)) {
+      return false;
+    }
+    User user = userService.getUserByLogin(authentication.getName());
+    return user == null || user.isConnectedToLdap();
+  }
+
+  private void createLocalUser(Authentication authentication) {
+    UserDTO userDTO;
+    try {
+      userDTO = ldapService.getUserByLogin(authentication.getName());
+    } catch (LDAPException e) {
+      throw new UsernameNotFoundException("Could not find username in LDAP.", e);
+    }
+    User newUser = new User();
+    newUser.setLogin(userDTO.getLogin());
+    newUser.setCryptedPassword(passwordEncoder.encode((String) authentication.getCredentials()));
+    newUser.setConnectedToLdap(true);
+    newUser.setName(userDTO.getFirstName());
+    newUser.setSurname(userDTO.getLastName());
+    newUser.setEmail(userDTO.getEmail());
+    userService.addUser(newUser);
+    userService.grantDefaultPrivileges(newUser);
+  }
+
+}