spring-security-adfs-saml2

Spring Security module for service provider (Sp) to authenticate against identity provider's (IdP) ADFS using SAML2 protocol.

How this module is configured:-

• HTTP-Redirect binding for sending SAML messages to IdP.
• Handles Sp servers doing SSL termination.
• Default authentication method is user/password using IdP's form login page.
• Default signature algorithm is SHA256withRSA.
• Default digest algorithm is SHA-256.

Tested against Sp's environments:-

• Local Tomcat server without SSL termination.
• Azure Tomcat server with SSL termination.

Tested against IdP's environments:-

• ADFS 2.0 - Windows Server 2008 R2.
• ADFS 2.1 - Windows Server 2012.

Maven Dependency

<dependency>
  <groupId>com.github.choonchernlim</groupId>
  <artifactId>spring-security-adfs-saml2</artifactId>
  <version>0.9.0</version>
</dependency>

Prerequisites

• Java 8.
• Both Sp and IdP must use HTTPS protocol.
• Java’s default keysize is limited to 128-bit key due to US export laws and a few countries’ import laws. So, Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files must be installed to allow larger key size, such as 256-bit key.
• Keystore contains the following:-
  • (REQUIRED) Sp's public/private keys - to generate digital signature before sending SAML messages to IdP.
  • (OPTIONAL) IdP's public certificate - to verify IdP's SAML messages to prevent man-in-the-middle attack. This certificate can also be stored under JDK's cacerts.
• To generate Sp's public/private keys:-

keytool -genkeypair \
 -v \
 -keystore /path/to/keystore.jks \
 -storepass mystorepass \
 -alias myapp \
 -dname 'CN=[COMMON-NAME], OU=[ORGANIZATION-UNIT], O=[ORGANIZATION-NAME], L=[CITY-NAME], ST=[STATE-NAME], C=[COUNTRY]' \
 -keypass mykeypass \
 -keyalg RSA \
 -keysize 2048 \
 -sigalg SHA256withRSA

• To import IdP's public certificate into keystore:-

keytool -importcert \
  -file idp-adfs-server.crt \
  -keystore /path/to/keystore.jks \
  -alias idp-adfs-server \
  -storepass mystorepass

Usage

Simplest Configuration

If you are configuring for one IDP server, the easiest approach is to hardcode all the SAML config in the @Configuration file.

// Create a Java-based Spring configuration that extends SAMLWebSecurityConfigurerAdapter.
@Configuration
@EnableWebSecurity
class AppSecurityConfig extends SAMLWebSecurityConfigurerAdapter {

    // See `SAMLConfigBean Properties` section below for more info. 
    @Override
    protected SAMLConfigBean samlConfigBean() {
        return new SAMLConfigBeanBuilder()
                .withIdpServerName("idp-server")
                .withSpServerName("sp-server")
                .withSpContextPath("/app")
                .withKeystoreResource(new DefaultResourceLoader().getResource("classpath:keystore.jks"))
                .withKeystorePassword("storepass")
                .withKeystoreAlias("alias")
                .withKeystorePrivateKeyPassword("keypass")
                .withSuccessLoginDefaultUrl("/")
                .withSuccessLogoutUrl("/goodbye")
                .withStoreCsrfTokenInCookie(true)
                .build();
    }

    // This configuration is not needed if your signature algorithm is SHA256withRSA and 
    // digest algorithm is SHA-256. However, if you are using different algorithm(s), then
    // add this bean with the correct algorithms.
    @Bean
    public static SAMLBootstrap samlBootstrap() {
        return new DefaultSAMLBootstrap("RSA",
                                        SignatureConstants.ALGO_ID_SIGNATURE_RSA_SHA512,
                                        SignatureConstants.ALGO_ID_DIGEST_SHA512);
    }

    // call `samlizedConfig(http)` first to decorate `http` with SAML configuration
    // before configuring app specific HTTP security
    @Override
    protected void configure(final HttpSecurity http) throws Exception {
        samlizedConfig(http)
                .authorizeRequests().antMatchers("/admin/**").hasRole("ADMIN")
                .anyRequest().authenticated();
    }

    // call `samlizedConfig(web)` first to decorate `web` with SAML configuration 
    // before configuring app specific web security
    @Override
    public void configure(final WebSecurity web) throws Exception {
        samlizedConfig(web).ignoring().antMatchers("/resources/**");
    }
}

Customizing SSL Verification

By default, the keystore file serves 2 purposes:-

• Acts as a keystore, containing app's public/private key.
• Acts as a truststore, containing IdP's certificate with public key.

If the keystore does not contain IdP's certificate, the SSL verification will fail with the following error when attempting to retrieve IdP's metadata:-

PKIX path construction failed for untrusted credential: [subjectName='CN=idp.server.com,OU=IDP,C=US']: unable to find valid certification path to requested target
I/O exception (javax.net.ssl.SSLPeerUnverifiedException) caught when processing request: SSL peer failed hostname validation for name: null
Error retrieving metadata from https://idp.server.com/federationmetadata/2007-06/federationmetadata.xml

If you store the IdP's certificate under JDK's truststore (ie: cacerts) and you want the SSL verification to rely on that file, do this:-

@Configuration
@EnableWebSecurity
class AppSecurityConfig extends SAMLWebSecurityConfigurerAdapter {

    @Override
    protected SAMLConfigBean samlConfigBean() {
        return new SAMLConfigBeanBuilder()
                // ... other configurations
                .withUseJdkCacertsForSslVerification(true)
                .build();
    }

    ...
}

Environment Properties Driven Configuration

If you don't want to use @Profile to configure environment-specific security, you may pass the configuration values through environment properties.

To prevent lifecycle loading or circular dependency issues, instead of autowiring Environment into the concrete class, use the given autowired applicationContext to get hold of the Spring bean.

@Configuration
@EnableWebSecurity
class AppSecurityConfig extends SAMLWebSecurityConfigurerAdapter {

    @Override
    protected SAMLConfigBean samlConfigBean() {
        final Environment env = applicationContext.getBean(Environment.class);
        
        return new SAMLConfigBeanBuilder()
                .withIdpServerName(env.getProperty("idpServerName"))
                .withSpServerName(env.getProperty("spServerName"))
                .withSpContextPath(env.getProperty("spContextPath"))
                .withKeystoreResource(new DefaultResourceLoader().getResource(env.getProperty("keystoreResource")))
                .withKeystorePassword(env.getProperty("keystorePassword"))
                .withKeystoreAlias(env.getProperty("keystoreAlias"))
                .withKeystorePrivateKeyPassword(env.getProperty("keystorePrivateKeyPassword"))
                .withSuccessLoginDefaultUrl(env.getProperty("successLoginDefaultUrl"))
                .withSuccessLogoutUrl(env.getProperty("successLogoutUrl"))
                .withStoreCsrfTokenInCookie(env.getProperty("storeCsrfTokenInCookie"))
                .build();
    }

    ...
}

Database Driven Configuration

You may also configure SAMLConfigBean by retrieving the configuration values from database.

Let's assume you have the following Spring JPA repository:-

public interface SecurityConfigRepository extends JpaRepository<SecurityConfigEntity, Long> {
    SecurityConfigEntity findByEnvironment(String environment);
}

To prevent lifecycle loading or circular dependency issues, instead of autowiring SecurityConfigRepository into the concrete class, use the given autowired applicationContext to get hold of the Spring repository bean.

@Configuration
@EnableWebSecurity
class AppSecurityConfig extends SAMLWebSecurityConfigurerAdapter {

    @Override
    protected SAMLConfigBean samlConfigBean() {
        final SecurityConfigRepository repository = applicationContext.getBean(SecurityConfigRepository.class);
        final SecurityConfigEntity entity = repository.findByEnvironment("dev");
        
        return new SAMLConfigBeanBuilder()
                .withIdpServerName(entity.getIdpServerName())
                .withSpServerName(entity.getSpServerName())
                .withSpContextPath(entity.getSpContextPath())
                .withKeystoreResource(new DefaultResourceLoader().getResource(entity.getKeystoreResource()))
                .withKeystorePassword(entity.getKeystorePassword())
                .withKeystoreAlias(entity.getKeystoreAlias())
                .withKeystorePrivateKeyPassword(entity.getKeystorePrivateKeyPassword())
                .withSuccessLoginDefaultUrl(entity.getSuccessLoginDefaultUrl())
                .withSuccessLogoutUrl(entity.getSuccessLogoutUrl())
                .withStoreCsrfTokenInCookie(entity.getStoreCsrfTokenInCookie())
                .build();
    }

    ...
}

Mocking Security by Hardcoding a Given User for Rapid App Development

@Override
protected void configure(final HttpSecurity http) throws Exception {
    // `CurrentUser` must extend `User`
    final CurrentUser currentUser = new CurrentUser("First name", "Last Name", "ROLE_ADMIN");

    mockSecurity(http, currentUser)
               .authorizeRequests().antMatchers("/admin/**").hasRole("ADMIN")
               .anyRequest().authenticated();
}

SAMLConfigBean Properties

SAMLConfigBean stores app-specific security configuration.

Property	Required?	Description
idpServerName	Yes	IdP server name. Used for retrieving IdP metadata using HTTPS. If IdP link is https://idp-server/adfs/ls, value should be idp-server.
spServerName	Yes	Sp server name. Used for generating correct SAML endpoints in Sp metadata to handle servers doing SSL termination. If Sp link is https://sp-server:8443/myapp, value should be sp-server.
spHttpsPort	No	Sp HTTPS port. Used for generating correct SAML endpoints in Sp metadata to handle servers doing SSL termination. If Sp link is https://sp-server:8443/myapp, value should be 8443. Default is 443.
spContextPath	No	Sp context path. Used for generating correct SAML endpoints in Sp metadata to handle servers doing SSL termination. If Sp link is https://sp-server:8443/myapp, value should be /myapp. Default is ''.
keystoreResource	Yes	App's keystore containing its public/private key and ADFS' certificate with public key.
keystorePassword	Yes	Password to access app's keystore.
keystoreAlias	Yes	Alias of app's public/private key pair.
keystorePrivateKeyPassword	Yes	Password to access app's private key.
successLoginDefaultUrl	Yes	Where to redirect user on successful login if no saved request is found in the session.
successLogoutUrl	Yes	Where to redirect user on successful logout.
failedLoginDefaultUrl	No	Where to redirect user on failed login. This value is set to null, which returns 401 error code on failed login. But, in theory, this will never be used because IdP will handled the failed login on IdP login page. Default is '', which return 401 error code.
storeCsrfTokenInCookie	No	Whether to store CSRF token in cookie named XSRF-TOKEN and expecting CSRF token to be set using header named X-XSRF-TOKEN to cater single-page app using frameworks like React and AngularJS. Default is false.
samlUserDetailsService	No	For configuring user details and authorities. When set, userDetails will be set as principal. Default is null.
authnContexts	No	Determine what authentication methods to use. To use the order of authentication methods defined by IdP, set as empty set. To enable Windows Integrated Auth (WIA), use CustomAuthnContext.WINDOWS_INTEGRATED_AUTHN_CTX. Default is AuthnContext.PASSWORD_AUTHN_CTX where IdP login page is displayed to obtain user/password.
useJdkCacertsForSslVerification	No	When performing IdP's SSL verification, find IdP's certs under JDK's cacerts instead of app's keystore file. Default is false.

Important SAML Endpoints

There are several SAML processing endpoints, but these are the ones you probably care:-

Endpoint	Description
/saml/login	Initiates login process between Sp and IdP. Upon successful login, user will be redirected to SAMLConfigBean.successLoginDefaultUrl.
/saml/logout	Initiates logout process between Sp and IdP. Upon successful logout, user will be redirected to SAMLConfigBean.successLogoutUrl.
/saml/metadata	Returns Sp metadata. IdP may need this link to register Sp on ADFS.

Relevant Links

• Travis CI Reports
• Maven Site

Learn about my pains and lessons learned while building this module.

• Replacing SHA-1 with SHA-256 on Signature and Digest Algorithms
• Handling IdP’s Public Certificate When Loading Metadata Over HTTPS
• Configuring Binding for Sending SAML Messages to IdP
• Java + SAML: Illegal Key Size