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Raviteja Daggupati
Raviteja Daggupati

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Implementing One-Time Token Authentication with Spring Security

#springboot #springsecurity #java #authentication

In today's digital landscape, providing secure and user-friendly authentication methods is crucial. One such method gaining popularity is One-Time Token (OTT) authentication, often implemented as "magic links" sent via email. Spring Security 6.4.0 provides robust built-in support for OTT authentication, including ready-to-use implementations. In this comprehensive guide, we'll explore how to implement secure OTT authentication using both built-in solutions and custom implementations.

Understanding One-Time Tokens vs. One-Time Passwords

Before diving into implementation, it's important to understand that One-Time Tokens (OTT) differ from One-Time Passwords (OTP). While OTP systems typically require initial setup and rely on external tools for password generation, OTT systems are simpler from a user perspective - they receive a unique token (usually via email) that they can use to authenticate.

Key differences include:

  • OTT doesn't require initial user setup
  • Tokens are generated and delivered by your application
  • Each token is typically valid for a single use and expires after a set time

Available Built-in Implementations

Spring Security provides two implementations of OneTimeTokenService:

  1. InMemoryOneTimeTokenService:

    • Stores tokens in memory
    • Ideal for development and testing
    • Not suitable for production or clustered environments
    • Tokens are lost on application restart

  2. JdbcOneTimeTokenService:

    • Stores tokens in a database
    • Suitable for production use
    • Works in clustered environments
    • Persistent storage with automatic cleanup

Using InMemoryOneTimeTokenService

Here's how to implement the simpler in-memory solution:

@Configuration @EnableWebSecurity public class SecurityConfig { @Bean public SecurityFilterChain filterChain(HttpSecurity http) throws Exception { http .authorizeHttpRequests(auth -> auth .requestMatchers("/login/**", "/ott/**").permitAll() .anyRequest().authenticated() ) .formLogin(Customizer.withDefaults()) .oneTimeTokenLogin(Customizer.withDefaults()); // Uses InMemoryOneTimeTokenService by default return http.build(); } }
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Using JdbcOneTimeTokenService

For production environments, use the JDBC implementation:

@Configuration @EnableWebSecurity public class SecurityConfig { @Autowired JdbcTemplate jdbcTemplate; @Bean public OneTimeTokenService oneTimeTokenService() { return new JdbcOneTimeTokenService(jdbcTemplate); } @Bean public SecurityFilterChain filterChain(HttpSecurity http) throws Exception { http .authorizeHttpRequests(auth -> auth .requestMatchers("/login/**", "/ott/**").permitAll() .anyRequest().authenticated() ) .formLogin(Customizer.withDefaults()) .oneTimeTokenLogin(Customizer.withDefaults()); return http.build(); } }
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Required table structure for JdbcOneTimeTokenService:

CREATE TABLE one_time_tokens ( token_value VARCHAR(255) PRIMARY KEY, username VARCHAR(255) NOT NULL, issued_at TIMESTAMP NOT NULL, expires_at TIMESTAMP NOT NULL, used BOOLEAN NOT NULL );
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Custom Implementation

For more control over the token generation and validation process, you can create a custom implementation:

1. Token Entity and Repository 

@Entity @Table(name = "one_time_tokens") public class OneTimeToken { @Id @GeneratedValue private Long id; private String tokenValue; private String username; private LocalDateTime createdAt; private LocalDateTime expiresAt; private boolean used; // Getters and setters omitted for brevity } @Repository public interface OneTimeTokenRepository extends JpaRepository<OneTimeToken, Long> { Optional<OneTimeToken> findByTokenValueAndUsedFalse(String tokenValue); void deleteByExpiresAtBefore(LocalDateTime dateTime); }
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2. Custom Token Service 

@Service @Transactional public class PersistentOneTimeTokenService implements OneTimeTokenService { private static final int TOKEN_VALIDITY_MINUTES = 15; @Autowired private OneTimeTokenRepository tokenRepository; @Override public OneTimeToken generate(GenerateOneTimeTokenRequest request) { String tokenValue = UUID.randomUUID().toString(); LocalDateTime now = LocalDateTime.now(); OneTimeToken token = new OneTimeToken(); token.setTokenValue(tokenValue); token.setUsername(request.getUsername()); token.setCreatedAt(now); token.setExpiresAt(now.plusMinutes(TOKEN_VALIDITY_MINUTES)); token.setUsed(false); return return new DefaultOneTimeToken(token.getTokenValue(),token.getUsername(), Instant.now()); } @Override public Authentication consume(ConsumeOneTimeTokenRequest request) { OneTimeToken token = tokenRepository.findByTokenValueAndUsedFalse(request.getTokenValue()) .orElseThrow(() -> new BadCredentialsException("Invalid or expired token")); if (token.getExpiresAt().isBefore(LocalDateTime.now())) { throw new BadCredentialsException("Token has expired"); } token.setUsed(true); tokenRepository.save(token); UserDetails userDetails = loadUserByUsername(token.getUsername()); return new UsernamePasswordAuthenticationToken( userDetails, null, userDetails.getAuthorities()); } }
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Implementing Token Delivery

Spring Security doesn't handle token delivery, so you'll need to implement it:

@Component public class EmailMagicLinkHandler implements OneTimeTokenGenerationSuccessHandler { @Autowired private JavaMailSender mailSender; private final OneTimeTokenGenerationSuccessHandler redirectHandler = new RedirectOneTimeTokenGenerationSuccessHandler("/ott/check-email"); @Override public void handle(HttpServletRequest request, HttpServletResponse response, OneTimeToken token) throws IOException, ServletException { String magicLink = UriComponentsBuilder.fromHttpUrl(UrlUtils.buildFullRequestUrl(request)) .replacePath(request.getContextPath()) .replaceQuery(null) .fragment(null) .path("/login/ott") .queryParam("token", token.getTokenValue()) .toUriString(); SimpleMailMessage message = new SimpleMailMessage(); message.setTo(getUserEmail(token.getUsername())); message.setSubject("Your Sign-in Link"); message.setText("Click here to sign in: " + magicLink); mailSender.send(message); redirectHandler.handle(request, response, token); } }
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Customizing URLs and Pages

Spring Security provides several customization options:

@Configuration @EnableWebSecurity public class SecurityConfig { @Bean public SecurityFilterChain filterChain(HttpSecurity http) throws Exception { http .formLogin(Customizer.withDefaults()) .oneTimeTokenLogin(ott -> ott .generateTokenUrl("/custom/generate-token") // Custom token generation URL .submitPageUrl("/custom/submit-token") // Custom token submission page .showDefaultSubmitPage(false) // Disable default submit page ); return http.build(); } }
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Production Considerations

When deploying OTT authentication in production:

  1. Choose the Right Implementation

    • Use JdbcOneTimeTokenService or custom implementation for production
    • InMemoryOneTimeTokenService should only be used for development/testing

  2. Configure Email Delivery

 spring.mail.host=smtp.your-provider.com spring.mail.port=587 spring.mail.username=your-username spring.mail.password=your-password spring.mail.properties.mail.smtp.auth=true spring.mail.properties.mail.smtp.starttls.enable=true
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  1. Security Best Practices
    • Set appropriate token expiration times (15 minutes recommended)
    • Implement rate limiting for token generation
    • Use HTTPS for all endpoints
    • Monitor failed authentication attempts
    • Ensure tokens are single-use and invalidated immediately after use
    • Implement automatic cleanup of expired tokens
    • Use secure random token generation to prevent guessing

How It Works

  1. User requests a token by submitting their email address
  2. System generates a secure token and sends a magic link via email
  3. User clicks the link and is redirected to the token submission page
  4. System validates the token and authenticates the user if valid

Conclusion

Spring Security's OTT support provides a robust foundation for implementing secure, user-friendly authentication. Whether you choose the built-in implementations or create a custom solution, you can offer your users a passwordless login option while maintaining high security standards.

When implementing OTT authentication, remember to:

  • Choose the appropriate implementation for your environment
  • Implement secure token delivery
  • Configure proper token expiration
  • Follow security best practices
  • Create user-friendly error handling and redirects
  • Implement proper email templating for a professional look

By following this guide, you can implement a secure and user-friendly OTT authentication system that meets your application's needs while leveraging Spring Security's robust security features.

Reference: https://docs.spring.io/spring-security/reference/servlet/authentication/onetimetoken.html

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