OAuth2TokenEndpointConfigurer custom AuthenticationProvider

[jymot]

Expected Behavior
I want to add a custom AuthenticationProviderthrough the authenticationProvider method of OAuth2TokenEndpointConfigurer, and I want to keep the AuthenticationProvider provided by default.

Current Behavior
If I add a new AuthenticationProvider I cannot keep the defaultAuthenticationProvider, because I see the following code from OAuth2TokenEndpointConfigurer

	<B extends HttpSecurityBuilder<B>> void init(B builder) {
		ProviderSettings providerSettings = OAuth2ConfigurerUtils.getProviderSettings(builder);
		this.requestMatcher = new AntPathRequestMatcher(
				providerSettings.getTokenEndpoint(), HttpMethod.POST.name());

		List<AuthenticationProvider> authenticationProviders =
				!this.authenticationProviders.isEmpty() ?
						this.authenticationProviders :
						createDefaultAuthenticationProviders(builder);
		authenticationProviders.forEach(authenticationProvider ->
				builder.authenticationProvider(postProcess(authenticationProvider)));
	}

If this.authenticationProviders is not empty, then the default AuthenticationProvider will not be created.

If I want to achieve my goal, I must manually add the default AuthenticationProvider and my custom implementation together. I think this design is not very flexible.

Context
Is it possible to change the private <B extends HttpSecurityBuilder<B>> List<AuthenticationProvider> createDefaultAuthenticationProviders(B builder) method to public, or add a new method to add the default AuthenticationProviders

[jgrandja]

Closing as duplicate of #417