Add support for OAuth 2.0 Token Exchange Grant

Issue spring-projectsgh-60

Author: sjohnr

Diff for: docs/modules/ROOT/pages/protocol-endpoints.adoc

@@ -261,8 +261,8 @@ The supported https://datatracker.ietf.org/doc/html/rfc6749#section-1.3[authoriz
 
 `OAuth2TokenEndpointFilter` is configured with the following defaults:
 
-* `*AuthenticationConverter*` -- A `DelegatingAuthenticationConverter` composed of `OAuth2AuthorizationCodeAuthenticationConverter`, `OAuth2RefreshTokenAuthenticationConverter`, `OAuth2ClientCredentialsAuthenticationConverter`, and `OAuth2DeviceCodeAuthenticationConverter`.
-* `*AuthenticationManager*` -- An `AuthenticationManager` composed of `OAuth2AuthorizationCodeAuthenticationProvider`, `OAuth2RefreshTokenAuthenticationProvider`, `OAuth2ClientCredentialsAuthenticationProvider`, and `OAuth2DeviceCodeAuthenticationProvider`.
+* `*AuthenticationConverter*` -- A `DelegatingAuthenticationConverter` composed of `OAuth2AuthorizationCodeAuthenticationConverter`, `OAuth2RefreshTokenAuthenticationConverter`, `OAuth2ClientCredentialsAuthenticationConverter`, `OAuth2DeviceCodeAuthenticationConverter`, and `OAuth2TokenExchangeAuthenticationConverter`.
+* `*AuthenticationManager*` -- An `AuthenticationManager` composed of `OAuth2AuthorizationCodeAuthenticationProvider`, `OAuth2RefreshTokenAuthenticationProvider`, `OAuth2ClientCredentialsAuthenticationProvider`, `OAuth2DeviceCodeAuthenticationProvider`, and `OAuth2TokenExchangeAuthenticationProvider`.
 * `*AuthenticationSuccessHandler*` -- An `OAuth2AccessTokenResponseAuthenticationSuccessHandler`.
 * `*AuthenticationFailureHandler*` -- An `OAuth2ErrorAuthenticationFailureHandler`.
 

Diff for: oauth2-authorization-server/src/main/java/org/springframework/security/oauth2/server/authorization/aot/hint/OAuth2AuthorizationServerBeanRegistrationAotProcessor.java

@@ -43,6 +43,8 @@
 import org.springframework.security.oauth2.core.oidc.user.OidcUserAuthority;
 import org.springframework.security.oauth2.core.user.DefaultOAuth2User;
 import org.springframework.security.oauth2.core.user.OAuth2UserAuthority;
+import org.springframework.security.oauth2.server.authorization.authentication.OAuth2ActorAuthenticationToken;
+import org.springframework.security.oauth2.server.authorization.authentication.OAuth2CompositeAuthenticationToken;
 import org.springframework.security.oauth2.server.authorization.jackson2.OAuth2AuthorizationServerJackson2Module;
 import org.springframework.security.oauth2.server.authorization.settings.OAuth2TokenFormat;
 import org.springframework.security.web.authentication.WebAuthenticationDetails;
@@ -109,7 +111,9 @@ private void registerHints(RuntimeHints hints) {
 							TypeReference.of(OidcIdToken.class),
 							TypeReference.of(AbstractOAuth2Token.class),
 							TypeReference.of(OidcUserInfo.class),
+							TypeReference.of(OAuth2ActorAuthenticationToken.class),
 							TypeReference.of(OAuth2AuthorizationRequest.class),
+							TypeReference.of(OAuth2CompositeAuthenticationToken.class),
 							TypeReference.of(AuthorizationGrantType.class),
 							TypeReference.of(OAuth2AuthorizationResponseType.class),
 							TypeReference.of(OAuth2TokenFormat.class)
@@ -150,8 +154,12 @@ private void registerHints(RuntimeHints hints) {
 					loadClass("org.springframework.security.jackson2.UserMixin"));
 			this.reflectionHintsRegistrar.registerReflectionHints(hints.reflection(),
 					loadClass("org.springframework.security.jackson2.SimpleGrantedAuthorityMixin"));
+			this.reflectionHintsRegistrar.registerReflectionHints(hints.reflection(),
+					loadClass("org.springframework.security.oauth2.server.authorization.jackson2.OAuth2ActorAuthenticationTokenMixin"));
 			this.reflectionHintsRegistrar.registerReflectionHints(hints.reflection(),
 					loadClass("org.springframework.security.oauth2.server.authorization.jackson2.OAuth2AuthorizationRequestMixin"));
+			this.reflectionHintsRegistrar.registerReflectionHints(hints.reflection(),
+					loadClass("org.springframework.security.oauth2.server.authorization.jackson2.OAuth2CompositeAuthenticationTokenMixin"));
 			this.reflectionHintsRegistrar.registerReflectionHints(hints.reflection(),
 					loadClass("org.springframework.security.oauth2.server.authorization.jackson2.OAuth2TokenFormatMixin"));
 

Diff for: oauth2-authorization-server/src/main/java/org/springframework/security/oauth2/server/authorization/authentication/OAuth2ActorAuthenticationToken.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright 2020-2024 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.security.oauth2.server.authorization.authentication;
+
+import java.io.Serializable;
+import java.util.Collections;
+
+import org.springframework.security.authentication.AbstractAuthenticationToken;
+import org.springframework.security.core.Authentication;
+import org.springframework.util.Assert;
+
+/**
+ * An {@link Authentication} implementation used for the OAuth 2.0 Token Exchange Grant
+ * to represent an actor in a composite token (e.g. the "delegation" use case).
+ *
+ * @author Steve Riesenberg
+ * @since 1.3
+ * @see OAuth2CompositeAuthenticationToken
+ */
+public class OAuth2ActorAuthenticationToken extends AbstractAuthenticationToken implements Serializable {
+
+	private final String name;
+
+	public OAuth2ActorAuthenticationToken(String name) {
+		super(Collections.emptyList());
+		Assert.hasText(name, "name cannot be empty");
+		this.name = name;
+	}
+
+	@Override
+	public Object getPrincipal() {
+		return this.name;
+	}
+
+	@Override
+	public Object getCredentials() {
+		return null;
+	}
+}

Diff for: oauth2-authorization-server/src/main/java/org/springframework/security/oauth2/server/authorization/authentication/OAuth2CompositeAuthenticationToken.java

@@ -0,0 +1,69 @@
+/*
+ * Copyright 2020-2024 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.security.oauth2.server.authorization.authentication;
+
+import java.io.Serializable;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+import org.springframework.security.authentication.AbstractAuthenticationToken;
+import org.springframework.security.core.Authentication;
+import org.springframework.util.Assert;
+
+/**
+ * An {@link Authentication} implementation used for the OAuth 2.0 Token Exchange Grant
+ * to represent the principal in a composite token (e.g. the "delegation" use case).
+ *
+ * @author Steve Riesenberg
+ * @since 1.3
+ * @see OAuth2TokenExchangeAuthenticationToken
+ */
+public class OAuth2CompositeAuthenticationToken extends AbstractAuthenticationToken implements Serializable {
+
+	private final Authentication subject;
+
+	private final List<Authentication> actors;
+
+	public OAuth2CompositeAuthenticationToken(Authentication subject, List<Authentication> actors) {
+		super(subject != null ? subject.getAuthorities() : null);
+		Assert.notNull(subject, "subject cannot be null");
+		Assert.notNull(actors, "actors cannot be null");
+		this.subject = subject;
+		this.actors = Collections.unmodifiableList(new ArrayList<>(actors));
+		setDetails(subject.getDetails());
+		setAuthenticated(subject.isAuthenticated());
+	}
+
+	@Override
+	public Object getPrincipal() {
+		return this.subject.getPrincipal();
+	}
+
+	@Override
+	public Object getCredentials() {
+		return null;
+	}
+
+	public Authentication getSubject() {
+		return this.subject;
+	}
+
+	public List<Authentication> getActors() {
+		return this.actors;
+	}
+}