spring-security saml2：如何获取当前用户？

我正在使用 spring-security 和 spring-security-saml2-service-provider 版本 5.2.0.RELEASE。我正在尝试在 IDP 身份验证后获取当前断言，以便将其映射到本地系统中的用户。 我使用此代码来获取 Saml2Authentication 对象

@Component
@Log4j
public class EventListener implements ApplicationListener<InteractiveAuthenticationSuccessEvent> {
    @Override
    public void onApplicationEvent(InteractiveAuthenticationSuccessEvent interactiveAuthenticationSuccessEvent) {
        Object principal = interactiveAuthenticationSuccessEvent.getAuthentication().getPrincipal();
        Saml2Authentication authentication = (Saml2Authentication)interactiveAuthenticationSuccessEvent.getAuthentication()

但我无法获取用户。我可以获得 saml2 响应 (authentication.getSaml2Response)，但我不确定如何使用用户 id 获取断言。

真的，我想做从 SAML 响应 (XML) 检索属性和 NameID https://stackoverflow.com/questions/31099829/retrieve-attributes-and-nameid-from-a-saml-response-xml在Java代码中。不确定 spring-security 中是否有什么东西可以帮助我。

Update经过一些工作后，我使用 OpenSAML 库并解析 SAMLv2 响应来获取属性。我不知道这是否是正确的方法

@Override
    public void onApplicationEvent(InteractiveAuthenticationSuccessEvent interactiveAuthenticationSuccessEvent) {
        Saml2Authentication authentication = (Saml2Authentication) interactiveAuthenticationSuccessEvent.getAuthentication();
        try {

            Document messageDoc;
            BasicParserPool basicParserPool = new BasicParserPool();
            basicParserPool.initialize();
            InputStream inputStream = new ByteArrayInputStream(authentication.getSaml2Response().getBytes());
            messageDoc = basicParserPool.parse(inputStream);
            Element messageElem = messageDoc.getDocumentElement();
            Unmarshaller unmarshaller = XMLObjectProviderRegistrySupport.getUnmarshallerFactory().getUnmarshaller(messageElem);
            XMLObject samlObject = unmarshaller.unmarshall(messageElem);
            Response response = (Response) samlObject;
            response.getAssertions().forEach(assertion -> {
                assertion.getAttributeStatements().forEach(attributeStatement ->
                {
                    attributeStatement.getAttributes().forEach(attribute -> {
                        log.error("Names:" + attribute.getName() + getAttributesList(attribute.getAttributeValues()));
                    });
                });
            });
        } catch (Exception e) {
            log.error(e);
        }
    }

    private List<String> getAttributesList(Collection<XMLObject> collection) {
        return collection.stream().map(this::getAttributeValue)
                .collect(Collectors.toList());
    }

    private String getAttributeValue(XMLObject attributeValue) {
        return attributeValue == null ?
                null :
                attributeValue instanceof XSString ?
                        getStringAttributeValue((XSString) attributeValue) :
                        attributeValue instanceof XSAnyImpl ?
                                getAnyAttributeValue((XSAnyImpl) attributeValue) :
                                attributeValue.toString();
    }

    private String getStringAttributeValue(XSString attributeValue) {
        return attributeValue.getValue();
    }

    private String getAnyAttributeValue(XSAnyImpl attributeValue) {
        return attributeValue.getTextContent();
    }

默认情况下，Spring SAML Security 使用主题元素中的 NameID 值来设置“用户名”。如果“瞬态 NameID 格式”，则根据 SAML 规范，对于每个 SSO 流，该值必须是不同/唯一的。

您可以自己实现UserDetailsService它实现了org.springframework.security.saml.userdetails.SAMLUserDetailsService在方法中loadUserBySAML您可以提取 SAML 属性

@Override
public Object loadUserBySAML(SAMLCredential credential) throws UsernameNotFoundException {
  final List<Attribute> attributesFromAttributeStatement = credential.getAttributes();

  final String userName = getUserNameValueFromAttribute(attributesFromAttributeStatement);

  // if needed calculate authorities
  final List<GrantedAuthority> grantedAuthorities = getGrantedAuthorities();
  final User authenticatedUser = new User(userName, "", grantedAuthorities);
  return authenticatedUser;
}