Feature/make OIDC generic

[yoh1496]

This PR contains below features.

Generic OpenID Connect Plugin

• Added OIDCTokenHandler class.

  • With OIDCTokenHandler class, you can parse id_token (JWT).
  • OIDCTokenHandler.createFromOIDCConfigurationURL loads IdP configuration from specified OpenID Connect Discovery 1.0 configuration endpoint ( https://openid.net/specs/openid-connect-registration-1_0.html ) and initialize OIDCTokenHandler.
  • This class tires to parse id_token with io.jsonwebtoken.

• Added OIDCAuthPluginBase class.

  • This class is abstract. By inheriting and overriding this class, you can customize how AuthenticatedIdentity is generated and how AuthPlugin verifies passed client_id is trusted.

• Added GenericOIDCAuthPlugin class.

  • Sub-class of OIDCAuthPluginBase.

• Added OIDCPluginLoader class

  • This implements AuthPlugin interface.
  • Load properties file and initialize multiple instances.

Test codes

This PR contains some test codes.

• Initializing OIDCTokenHandler test with OpenID Connect Discovery configuration URL mock.
• Verifing valid id_token and invalid id_token.

[tochi-y]

@yoh1496 Thanks for your modification. I'm in the middle of a review, but I'd like to leave a comment. Action is not required.

[tochi-y]

Due to an existing OidcPluginException problem, the exception information is not chained here. We would like to deal with it in the future. I will create an issue.

[tochi-y]

@yoh1496 I added comments. Please check them, thanks.

[tochi-y]

Can you extract a private method from line 53 to line 86? The following code is for example.

    private Properties loadConfigurationFile() {
        String configFilename = System.getProperty("io.personium.configurationFile",
                "personium-unit-config.properties");
        try {
            return loadFromClasspath(configFilename);
        } catch (IOException e) {
            log.info("IOException while loading: " + configFilename, e);
        }
        try {
            return loadFromLocalfile(configFilename);
        } catch (IOException e) {
            log.info("IOException while loading: " + configFilename, e);
        }
        log.info("Properties file cannot be loaded: " + configFilename);
    }

[tochi-y]

Can you write the method name according to the content?

[yoh1496]

Thank you for merging.

By the way, can the argument key of Property.getProperty takes regular expression?

-                String accountNameKey = props.getProperty(propPrefix + ".accountNameKey", "username");
+                String accountNameKey = props.getProperty(propPrefix + "\\.accountNameKey$", "username");

You applied this change like above, is that correct?

[tochi-y]

@yoh1496 Thank you for pointing it out. I also noticed that mistake and corrected it with the next commit.
5f249d1