Add ServerAuthenticationConverter interface

- Adding an ServerAuthenticationConverter interface
- Retro-fitting ServerOAuth2LoginAuthenticationTokenConverter,
 ServerBearerTokenAuthentivationConverter, ServerFormLoginAuthenticationConverter,
 and ServerHttpBasicAuthenticationConverter to implement ServerAuthenticationConverter
- Deprecate existing AuthenticationWebFilter.setAuthenticationConverter
and add overloaded one which takes ServerAuthenticationConverter

Fixes gh-5338

oauth2/oauth2-client/src/main/java/org/springframework/security/oauth2/client/web/ServerOAuth2LoginAuthenticationTokenConverter.java

@@ -16,8 +16,6 @@
 
 package org.springframework.security.oauth2.client.web;
 
-import java.util.function.Function;
-
 import org.springframework.security.core.Authentication;
 import org.springframework.security.oauth2.client.authentication.OAuth2LoginAuthenticationToken;
 import org.springframework.security.oauth2.client.registration.ReactiveClientRegistrationRepository;
@@ -27,6 +25,7 @@ import org.springframework.security.oauth2.core.endpoint.OAuth2AuthorizationExch
 import org.springframework.security.oauth2.core.endpoint.OAuth2AuthorizationRequest;
 import org.springframework.security.oauth2.core.endpoint.OAuth2AuthorizationResponse;
 import org.springframework.security.oauth2.core.endpoint.OAuth2ParameterNames;
+import org.springframework.security.web.server.authentication.ServerAuthenticationConverter;
 import org.springframework.util.Assert;
 import org.springframework.util.MultiValueMap;
 import org.springframework.web.server.ServerWebExchange;
@@ -34,16 +33,14 @@ import org.springframework.web.util.UriComponentsBuilder;
 
 import reactor.core.publisher.Mono;
 
-
 /**
  * Converts from a {@link ServerWebExchange} to an {@link OAuth2LoginAuthenticationToken} that can be authenticated. The
  * converter does not validate any errors it only performs a conversion.
  * @author Rob Winch
  * @since 5.1
- * @see org.springframework.security.web.server.authentication.AuthenticationWebFilter#setAuthenticationConverter(Function)
+ * @see org.springframework.security.web.server.authentication.AuthenticationWebFilter#setAuthenticationConverter(ServerAuthenticationConverter)
  */
-public class ServerOAuth2LoginAuthenticationTokenConverter implements
-		Function<ServerWebExchange, Mono<Authentication>> {
+public class ServerOAuth2LoginAuthenticationTokenConverter implements ServerAuthenticationConverter {
 
 	static final String AUTHORIZATION_REQUEST_NOT_FOUND_ERROR_CODE = "authorization_request_not_found";
 
@@ -72,7 +69,7 @@ public class ServerOAuth2LoginAuthenticationTokenConverter implements
 	}
 
 	@Override
-	public Mono<Authentication> apply(ServerWebExchange serverWebExchange) {
+	public Mono<Authentication> convert(ServerWebExchange serverWebExchange) {
 		return this.authorizationRequestRepository.removeAuthorizationRequest(serverWebExchange)
 			.switchIfEmpty(oauth2AuthenticationException(AUTHORIZATION_REQUEST_NOT_FOUND_ERROR_CODE))
 			.flatMap(authorizationRequest -> authenticationRequest(serverWebExchange, authorizationRequest));
@@ -97,14 +94,14 @@ public class ServerOAuth2LoginAuthenticationTokenConverter implements
 				})
 				.switchIfEmpty(oauth2AuthenticationException(CLIENT_REGISTRATION_NOT_FOUND_ERROR_CODE))
 				.map(clientRegistration -> {
-					OAuth2AuthorizationResponse authorizationResponse = convert(exchange);
+					OAuth2AuthorizationResponse authorizationResponse = convertResponse(exchange);
 					OAuth2LoginAuthenticationToken authenticationRequest = new OAuth2LoginAuthenticationToken(
 							clientRegistration, new OAuth2AuthorizationExchange(authorizationRequest, authorizationResponse));
 					return authenticationRequest;
 				});
 	}
 
-	private static OAuth2AuthorizationResponse convert(ServerWebExchange exchange) {
+	private static OAuth2AuthorizationResponse convertResponse(ServerWebExchange exchange) {
 		MultiValueMap<String, String> queryParams = exchange.getRequest()
 				.getQueryParams();
 		String redirectUri = UriComponentsBuilder.fromUri(exchange.getRequest().getURI())

oauth2/oauth2-client/src/test/java/org/springframework/security/oauth2/client/web/ServerOAuth2LoginAuthenticationTokenConverterTest.java

@@ -141,6 +141,6 @@ public class ServerOAuth2LoginAuthenticationTokenConverterTest {
 
 	private OAuth2LoginAuthenticationToken applyConverter() {
 		MockServerWebExchange exchange = MockServerWebExchange.from(this.request);
-		return (OAuth2LoginAuthenticationToken) this.converter.apply(exchange).block();
+		return (OAuth2LoginAuthenticationToken) this.converter.convert(exchange).block();
 	}
 }

oauth2/oauth2-resource-server/src/main/java/org/springframework/security/oauth2/server/resource/web/server/ServerBearerTokenAuthenticationConverter.java

@@ -25,11 +25,11 @@ import org.springframework.security.oauth2.core.OAuth2AuthenticationException;
 import org.springframework.security.oauth2.server.resource.BearerTokenAuthenticationToken;
 import org.springframework.security.oauth2.server.resource.BearerTokenError;
 import org.springframework.security.oauth2.server.resource.BearerTokenErrorCodes;
+import org.springframework.security.web.server.authentication.ServerAuthenticationConverter;
 import org.springframework.util.StringUtils;
 import org.springframework.web.server.ServerWebExchange;
 import reactor.core.publisher.Mono;
 
-import java.util.function.Function;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
@@ -41,13 +41,12 @@ import java.util.regex.Pattern;
  * @since 5.1
  * @see <a href="https://tools.ietf.org/html/rfc6750#section-2" target="_blank">RFC 6750 Section 2: Authenticated Requests</a>
  */
-public class ServerBearerTokenAuthenticationConverter implements
-		Function<ServerWebExchange, Mono<Authentication>> {
+public class ServerBearerTokenAuthenticationConverter implements ServerAuthenticationConverter {
 	private static final Pattern authorizationPattern = Pattern.compile("^Bearer (?<token>[a-zA-Z0-9-._~+/]+)=*$");
 
 	private boolean allowUriQueryParameter = false;
 
-	public Mono<Authentication> apply(ServerWebExchange exchange) {
+	public Mono<Authentication> convert(ServerWebExchange exchange) {
 		return Mono.justOrEmpty(this.token(exchange.getRequest()))
 			.map(BearerTokenAuthenticationToken::new);
 	}

oauth2/oauth2-resource-server/src/test/java/org/springframework/security/oauth2/server/resource/web/server/ServerBearerTokenAuthenticationConverterTests.java

@@ -129,6 +129,6 @@ public class ServerBearerTokenAuthenticationConverterTests {
 
 	private BearerTokenAuthenticationToken convertToToken(MockServerHttpRequest request) {
 		MockServerWebExchange exchange = MockServerWebExchange.from(request);
-		return this.converter.apply(exchange).cast(BearerTokenAuthenticationToken.class).block();
+		return this.converter.convert(exchange).cast(BearerTokenAuthenticationToken.class).block();
 	}
 }