Add configuration support for Opaque Token authentication

Closes gh-15872

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/security/oauth2/resource/OAuth2ResourceServerProperties.java

@@ -19,6 +19,8 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.nio.charset.StandardCharsets;
 
+import javax.annotation.PostConstruct;
+
 import org.springframework.boot.context.properties.ConfigurationProperties;
 import org.springframework.boot.context.properties.source.InvalidConfigurationPropertyValueException;
 import org.springframework.core.io.Resource;
@@ -41,6 +43,32 @@ public class OAuth2ResourceServerProperties {
 		return this.jwt;
 	}
 
+	private final OpaqueToken opaqueToken = new OpaqueToken();
+
+	public OpaqueToken getOpaqueToken() {
+		return this.opaqueToken;
+	}
+
+	@PostConstruct
+	public void validate() {
+		if (this.getOpaqueToken().getIntrospectionUri() != null) {
+			if (this.getJwt().getJwkSetUri() != null) {
+				handleError("jwt.jwk-set-uri");
+			}
+			if (this.getJwt().getIssuerUri() != null) {
+				handleError("jwt.issuer-uri");
+			}
+			if (this.getJwt().getPublicKeyLocation() != null) {
+				handleError("jwt.public-key-location");
+			}
+		}
+	}
+
+	private void handleError(String property) {
+		throw new IllegalStateException(
+				"Only one of " + property + " and opaque-token.introspection-uri should be configured.");
+	}
+
 	public static class Jwt {
 
 		/**
@@ -109,4 +137,47 @@ public class OAuth2ResourceServerProperties {
 
 	}
 
+	public static class OpaqueToken {
+
+		/**
+		 * Client id used to authenticate with the token introspection endpoint.
+		 */
+		private String clientId;
+
+		/**
+		 * Client secret used to authenticate with the token introspection endpoint.
+		 */
+		private String clientSecret;
+
+		/**
+		 * OAuth 2.0 endpoint through which token introspection is accomplished.
+		 */
+		private String introspectionUri;
+
+		public String getClientId() {
+			return this.clientId;
+		}
+
+		public void setClientId(String clientId) {
+			this.clientId = clientId;
+		}
+
+		public String getClientSecret() {
+			return this.clientSecret;
+		}
+
+		public void setClientSecret(String clientSecret) {
+			this.clientSecret = clientSecret;
+		}
+
+		public String getIntrospectionUri() {
+			return this.introspectionUri;
+		}
+
+		public void setIntrospectionUri(String introspectionUri) {
+			this.introspectionUri = introspectionUri;
+		}
+
+	}
+
 }

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/security/oauth2/resource/reactive/ReactiveOAuth2ResourceServerAutoConfiguration.java

@@ -27,6 +27,8 @@ import org.springframework.context.annotation.Import;
 import org.springframework.security.config.annotation.web.reactive.EnableWebFluxSecurity;
 import org.springframework.security.oauth2.jwt.ReactiveJwtDecoder;
 import org.springframework.security.oauth2.server.resource.BearerTokenAuthenticationToken;
+import org.springframework.security.oauth2.server.resource.authentication.OAuth2IntrospectionAuthenticationToken;
+import org.springframework.security.oauth2.server.resource.introspection.ReactiveOAuth2TokenIntrospectionClient;
 
 /**
  * {@link EnableAutoConfiguration Auto-configuration} for Reactive OAuth2 resource server
@@ -38,10 +40,24 @@ import org.springframework.security.oauth2.server.resource.BearerTokenAuthentica
 @Configuration(proxyBeanMethods = false)
 @AutoConfigureBefore(ReactiveSecurityAutoConfiguration.class)
 @EnableConfigurationProperties(OAuth2ResourceServerProperties.class)
-@ConditionalOnClass({ EnableWebFluxSecurity.class, BearerTokenAuthenticationToken.class, ReactiveJwtDecoder.class })
+@ConditionalOnClass({ EnableWebFluxSecurity.class })
 @ConditionalOnWebApplication(type = ConditionalOnWebApplication.Type.REACTIVE)
-@Import({ ReactiveOAuth2ResourceServerJwkConfiguration.class,
-		ReactiveOAuth2ResourceServerWebSecurityConfiguration.class })
 public class ReactiveOAuth2ResourceServerAutoConfiguration {
 
+	@Configuration(proxyBeanMethods = false)
+	@ConditionalOnClass({ BearerTokenAuthenticationToken.class, ReactiveJwtDecoder.class })
+	@Import({ ReactiveOAuth2ResourceServerJwkConfiguration.JwtConfiguration.class,
+			ReactiveOAuth2ResourceServerJwkConfiguration.WebSecurityConfiguration.class })
+	static class JwtConfiguration {
+
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	@ConditionalOnClass({ OAuth2IntrospectionAuthenticationToken.class, ReactiveOAuth2TokenIntrospectionClient.class })
+	@Import({ ReactiveOAuth2ResourceServerOpaqueTokenConfiguration.OpaqueTokenIntrospectionClientConfiguration.class,
+			ReactiveOAuth2ResourceServerOpaqueTokenConfiguration.WebSecurityConfiguration.class })
+	static class OpaqueTokenConfiguration {
+
+	}
+
 }

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/security/oauth2/resource/reactive/ReactiveOAuth2ResourceServerJwkConfiguration.java

@@ -20,6 +20,7 @@ import java.security.interfaces.RSAPublicKey;
 import java.security.spec.X509EncodedKeySpec;
 import java.util.Base64;
 
+import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.boot.autoconfigure.security.oauth2.resource.IssuerUriCondition;
@@ -28,13 +29,16 @@ import org.springframework.boot.autoconfigure.security.oauth2.resource.OAuth2Res
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Conditional;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.security.config.web.server.ServerHttpSecurity;
 import org.springframework.security.oauth2.jwt.NimbusReactiveJwtDecoder;
 import org.springframework.security.oauth2.jwt.ReactiveJwtDecoder;
 import org.springframework.security.oauth2.jwt.ReactiveJwtDecoders;
+import org.springframework.security.web.server.SecurityWebFilterChain;
 
 /**
  * Configures a {@link ReactiveJwtDecoder} when a JWK Set URI, OpenID Connect Issuer URI
- * or Public Key configuration is available.
+ * or Public Key configuration is available. Also configures a
+ * {@link SecurityWebFilterChain} if a {@link ReactiveJwtDecoder} bean is found.
  *
  * @author Madhura Bhave
  * @author Artsiom Yudovin
@@ -42,38 +46,56 @@ import org.springframework.security.oauth2.jwt.ReactiveJwtDecoders;
 @Configuration(proxyBeanMethods = false)
 class ReactiveOAuth2ResourceServerJwkConfiguration {
 
-	private final OAuth2ResourceServerProperties.Jwt properties;
+	@Configuration(proxyBeanMethods = false)
+	@ConditionalOnMissingBean(ReactiveJwtDecoder.class)
+	static class JwtConfiguration {
+
+		private final OAuth2ResourceServerProperties.Jwt properties;
+
+		JwtConfiguration(OAuth2ResourceServerProperties properties) {
+			this.properties = properties.getJwt();
+		}
+
+		@Bean
+		@ConditionalOnProperty(name = "spring.security.oauth2.resourceserver.jwt.jwk-set-uri")
+		public ReactiveJwtDecoder jwtDecoder() {
+			return new NimbusReactiveJwtDecoder(this.properties.getJwkSetUri());
+		}
+
+		@Bean
+		@Conditional(KeyValueCondition.class)
+		public NimbusReactiveJwtDecoder jwtDecoderByPublicKeyValue() throws Exception {
+			RSAPublicKey publicKey = (RSAPublicKey) KeyFactory.getInstance("RSA")
+					.generatePublic(new X509EncodedKeySpec(getKeySpec(this.properties.readPublicKey())));
+			return NimbusReactiveJwtDecoder.withPublicKey(publicKey).build();
+		}
+
+		private byte[] getKeySpec(String keyValue) {
+			keyValue = keyValue.replace("-----BEGIN PUBLIC KEY-----", "").replace("-----END PUBLIC KEY-----", "");
+			return Base64.getMimeDecoder().decode(keyValue);
+		}
+
+		@Bean
+		@Conditional(IssuerUriCondition.class)
+		public ReactiveJwtDecoder jwtDecoderByIssuerUri() {
+			return ReactiveJwtDecoders.fromOidcIssuerLocation(this.properties.getIssuerUri());
+		}
 
-	ReactiveOAuth2ResourceServerJwkConfiguration(OAuth2ResourceServerProperties properties) {
-		this.properties = properties.getJwt();
 	}
 
-	@Bean
+	@Configuration(proxyBeanMethods = false)
-	@ConditionalOnProperty(name = "spring.security.oauth2.resourceserver.jwt.jwk-set-uri")
+	@ConditionalOnMissingBean(SecurityWebFilterChain.class)
-	@ConditionalOnMissingBean
+	static class WebSecurityConfiguration {
-	public ReactiveJwtDecoder jwtDecoder() {
-		return new NimbusReactiveJwtDecoder(this.properties.getJwkSetUri());
-	}
 
-	@Bean
+		@Bean
-	@Conditional(KeyValueCondition.class)
+		@ConditionalOnBean(ReactiveJwtDecoder.class)
-	@ConditionalOnMissingBean
+		public SecurityWebFilterChain springSecurityFilterChain(ServerHttpSecurity http,
-	public NimbusReactiveJwtDecoder jwtDecoderByPublicKeyValue() throws Exception {
+				ReactiveJwtDecoder jwtDecoder) {
-		RSAPublicKey publicKey = (RSAPublicKey) KeyFactory.getInstance("RSA")
+			http.authorizeExchange().anyExchange().authenticated().and().oauth2ResourceServer().jwt()
-				.generatePublic(new X509EncodedKeySpec(getKeySpec(this.properties.readPublicKey())));
+					.jwtDecoder(jwtDecoder);
-		return NimbusReactiveJwtDecoder.withPublicKey(publicKey).build();
+			return http.build();
-	}
+		}
 
-	private byte[] getKeySpec(String keyValue) {
-		keyValue = keyValue.replace("-----BEGIN PUBLIC KEY-----", "").replace("-----END PUBLIC KEY-----", "");
-		return Base64.getMimeDecoder().decode(keyValue);
-	}
-
-	@Bean
-	@Conditional(IssuerUriCondition.class)
-	@ConditionalOnMissingBean
-	public ReactiveJwtDecoder jwtDecoderByIssuerUri() {
-		return ReactiveJwtDecoders.fromOidcIssuerLocation(this.properties.getIssuerUri());
 	}
 
 }

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/security/oauth2/resource/reactive/ReactiveOAuth2ResourceServerOpaqueTokenConfiguration.java

@@ -0,0 +1,67 @@
+/*
+ * Copyright 2012-2019 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.boot.autoconfigure.security.oauth2.resource.reactive;
+
+import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
+import org.springframework.boot.autoconfigure.security.oauth2.resource.OAuth2ResourceServerProperties;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.security.config.web.server.ServerHttpSecurity;
+import org.springframework.security.oauth2.server.resource.introspection.NimbusReactiveOAuth2TokenIntrospectionClient;
+import org.springframework.security.oauth2.server.resource.introspection.ReactiveOAuth2TokenIntrospectionClient;
+import org.springframework.security.web.server.SecurityWebFilterChain;
+
+/**
+ * Configures a {@link ReactiveOAuth2TokenIntrospectionClient} when a token introspection
+ * endpoint is available. Also configures a {@link SecurityWebFilterChain} if a
+ * {@link ReactiveOAuth2TokenIntrospectionClient} bean is found.
+ *
+ * @author Madhura Bhave
+ */
+class ReactiveOAuth2ResourceServerOpaqueTokenConfiguration {
+
+	@Configuration(proxyBeanMethods = false)
+	@ConditionalOnMissingBean(ReactiveOAuth2TokenIntrospectionClient.class)
+	static class OpaqueTokenIntrospectionClientConfiguration {
+
+		@Bean
+		@ConditionalOnProperty(name = "spring.security.oauth2.resourceserver.opaque-token.introspection-uri")
+		public NimbusReactiveOAuth2TokenIntrospectionClient oAuth2TokenIntrospectionClient(
+				OAuth2ResourceServerProperties properties) {
+			OAuth2ResourceServerProperties.OpaqueToken opaqueToken = properties.getOpaqueToken();
+			return new NimbusReactiveOAuth2TokenIntrospectionClient(opaqueToken.getIntrospectionUri(),
+					opaqueToken.getClientId(), opaqueToken.getClientSecret());
+		}
+
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	@ConditionalOnMissingBean(SecurityWebFilterChain.class)
+	static class WebSecurityConfiguration {
+
+		@Bean
+		@ConditionalOnBean(ReactiveOAuth2TokenIntrospectionClient.class)
+		public SecurityWebFilterChain springSecurityFilterChain(ServerHttpSecurity http) {
+			http.authorizeExchange().anyExchange().authenticated().and().oauth2ResourceServer().opaqueToken();
+			return http.build();
+		}
+
+	}
+
+}

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/security/oauth2/resource/reactive/ReactiveOAuth2ResourceServerWebSecurityConfiguration.java

@@ -1,44 +0,0 @@
-/*
- * Copyright 2012-2019 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.boot.autoconfigure.security.oauth2.resource.reactive;
-
-import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
-import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
-import org.springframework.context.annotation.Bean;
-import org.springframework.context.annotation.Configuration;
-import org.springframework.security.config.web.server.ServerHttpSecurity;
-import org.springframework.security.oauth2.jwt.ReactiveJwtDecoder;
-import org.springframework.security.web.server.SecurityWebFilterChain;
-
-/**
- * Configures a {@link SecurityWebFilterChain} for Reactive OAuth2 resource server support
- * if a {@link ReactiveJwtDecoder} bean is present.
- *
- * @author Madhura Bhave
- */
-@Configuration(proxyBeanMethods = false)
-@ConditionalOnBean(ReactiveJwtDecoder.class)
-class ReactiveOAuth2ResourceServerWebSecurityConfiguration {
-
-	@Bean
-	@ConditionalOnMissingBean
-	public SecurityWebFilterChain springSecurityFilterChain(ServerHttpSecurity http, ReactiveJwtDecoder jwtDecoder) {
-		http.authorizeExchange().anyExchange().authenticated().and().oauth2ResourceServer().jwt()
-				.jwtDecoder(jwtDecoder);
-		return http.build();
-	}
-
-}

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/security/oauth2/resource/servlet/OAuth2ResourceServerAutoConfiguration.java

@@ -26,9 +26,11 @@ import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.Import;
 import org.springframework.security.oauth2.jwt.JwtDecoder;
 import org.springframework.security.oauth2.server.resource.authentication.JwtAuthenticationToken;
+import org.springframework.security.oauth2.server.resource.authentication.OAuth2IntrospectionAuthenticationToken;
+import org.springframework.security.oauth2.server.resource.introspection.OAuth2TokenIntrospectionClient;
 
 /**
- * {@link EnableAutoConfiguration Auto-configuration} for OAuth resource server support.
+ * {@link EnableAutoConfiguration Auto-configuration} for OAuth2 resource server support.
  *
  * @author Madhura Bhave
  * @since 2.1.0
@@ -36,9 +38,24 @@ import org.springframework.security.oauth2.server.resource.authentication.JwtAut
 @Configuration(proxyBeanMethods = false)
 @AutoConfigureBefore(SecurityAutoConfiguration.class)
 @EnableConfigurationProperties(OAuth2ResourceServerProperties.class)
-@ConditionalOnClass({ JwtAuthenticationToken.class, JwtDecoder.class })
 @ConditionalOnWebApplication(type = ConditionalOnWebApplication.Type.SERVLET)
-@Import({ OAuth2ResourceServerJwtConfiguration.class, OAuth2ResourceServerWebSecurityConfiguration.class })
+
 public class OAuth2ResourceServerAutoConfiguration {
 
+	@Configuration(proxyBeanMethods = false)
+	@ConditionalOnClass({ JwtAuthenticationToken.class, JwtDecoder.class })
+	@Import({ OAuth2ResourceServerJwtConfiguration.JwtDecoderConfiguration.class,
+			OAuth2ResourceServerJwtConfiguration.OAuth2WebSecurityConfigurerAdapter.class })
+	static class JwtConfiguration {
+
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	@ConditionalOnClass({ OAuth2IntrospectionAuthenticationToken.class, OAuth2TokenIntrospectionClient.class })
+	@Import({ OAuth2ResourceServerOpaqueTokenConfiguration.OpaqueTokenIntrospectionClientConfiguration.class,
+			OAuth2ResourceServerOpaqueTokenConfiguration.OAuth2WebSecurityConfigurerAdapter.class })
+	static class OpaqueTokenConfiguration {
+
+	}
+
 }

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/security/oauth2/resource/servlet/OAuth2ResourceServerJwtConfiguration.java

@@ -20,6 +20,7 @@ import java.security.interfaces.RSAPublicKey;
 import java.security.spec.X509EncodedKeySpec;
 import java.util.Base64;
 
+import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.boot.autoconfigure.security.oauth2.resource.IssuerUriCondition;
@@ -28,6 +29,8 @@ import org.springframework.boot.autoconfigure.security.oauth2.resource.OAuth2Res
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Conditional;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.security.config.annotation.web.builders.HttpSecurity;
+import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
 import org.springframework.security.oauth2.jose.jws.SignatureAlgorithm;
 import org.springframework.security.oauth2.jwt.JwtDecoder;
 import org.springframework.security.oauth2.jwt.JwtDecoders;
@@ -35,7 +38,8 @@ import org.springframework.security.oauth2.jwt.NimbusJwtDecoder;
 
 /**
  * Configures a {@link JwtDecoder} when a JWK Set URI, OpenID Connect Issuer URI or Public
- * Key configuration is available.
+ * Key configuration is available. Also configures a {@link WebSecurityConfigurerAdapter}
+ * if a {@link JwtDecoder} bean is found.
  *
  * @author Madhura Bhave
  * @author Artsiom Yudovin
@@ -43,39 +47,59 @@ import org.springframework.security.oauth2.jwt.NimbusJwtDecoder;
 @Configuration(proxyBeanMethods = false)
 class OAuth2ResourceServerJwtConfiguration {
 
-	private final OAuth2ResourceServerProperties.Jwt properties;
+	@Configuration(proxyBeanMethods = false)
+	@ConditionalOnMissingBean(JwtDecoder.class)
+	static class JwtDecoderConfiguration {
+
+		private final OAuth2ResourceServerProperties.Jwt properties;
+
+		JwtDecoderConfiguration(OAuth2ResourceServerProperties properties) {
+			this.properties = properties.getJwt();
+		}
+
+		@Bean
+		@ConditionalOnProperty(name = "spring.security.oauth2.resourceserver.jwt.jwk-set-uri")
+		public JwtDecoder jwtDecoderByJwkKeySetUri() {
+			return NimbusJwtDecoder.withJwkSetUri(this.properties.getJwkSetUri())
+					.jwsAlgorithm(SignatureAlgorithm.from(this.properties.getJwsAlgorithm())).build();
+		}
+
+		@Bean
+		@Conditional(KeyValueCondition.class)
+		public JwtDecoder jwtDecoderByPublicKeyValue() throws Exception {
+			RSAPublicKey publicKey = (RSAPublicKey) KeyFactory.getInstance("RSA")
+					.generatePublic(new X509EncodedKeySpec(getKeySpec(this.properties.readPublicKey())));
+			return NimbusJwtDecoder.withPublicKey(publicKey).build();
+		}
+
+		private byte[] getKeySpec(String keyValue) {
+			keyValue = keyValue.replace("-----BEGIN PUBLIC KEY-----", "").replace("-----END PUBLIC KEY-----", "");
+			return Base64.getMimeDecoder().decode(keyValue);
+		}
+
+		@Bean
+		@Conditional(IssuerUriCondition.class)
+		public JwtDecoder jwtDecoderByIssuerUri() {
+			return JwtDecoders.fromOidcIssuerLocation(this.properties.getIssuerUri());
+		}
 
-	OAuth2ResourceServerJwtConfiguration(OAuth2ResourceServerProperties properties) {
-		this.properties = properties.getJwt();
 	}
 
-	@Bean
+	@Configuration(proxyBeanMethods = false)
-	@ConditionalOnProperty(name = "spring.security.oauth2.resourceserver.jwt.jwk-set-uri")
+	@ConditionalOnMissingBean(WebSecurityConfigurerAdapter.class)
-	@ConditionalOnMissingBean
+	static class OAuth2WebSecurityConfigurerAdapter {
-	public JwtDecoder jwtDecoderByJwkKeySetUri() {
-		return NimbusJwtDecoder.withJwkSetUri(this.properties.getJwkSetUri())
-				.jwsAlgorithm(SignatureAlgorithm.from(this.properties.getJwsAlgorithm())).build();
-	}
 
-	@Bean
+		@Bean
-	@Conditional(KeyValueCondition.class)
+		@ConditionalOnBean(JwtDecoder.class)
-	@ConditionalOnMissingBean
+		public WebSecurityConfigurerAdapter jwtDecoderWebSecurityConfigurerAdapter() {
-	public JwtDecoder jwtDecoderByPublicKeyValue() throws Exception {
+			return new WebSecurityConfigurerAdapter() {
-		RSAPublicKey publicKey = (RSAPublicKey) KeyFactory.getInstance("RSA")
+				@Override
-				.generatePublic(new X509EncodedKeySpec(getKeySpec(this.properties.readPublicKey())));
+				protected void configure(HttpSecurity http) throws Exception {
-		return NimbusJwtDecoder.withPublicKey(publicKey).build();
+					http.authorizeRequests().anyRequest().authenticated().and().oauth2ResourceServer().jwt();
-	}
+				}
+			};
+		}
 
-	private byte[] getKeySpec(String keyValue) {
-		keyValue = keyValue.replace("-----BEGIN PUBLIC KEY-----", "").replace("-----END PUBLIC KEY-----", "");
-		return Base64.getMimeDecoder().decode(keyValue);
-	}
-
-	@Bean
-	@Conditional(IssuerUriCondition.class)
-	@ConditionalOnMissingBean
-	public JwtDecoder jwtDecoderByIssuerUri() {
-		return JwtDecoders.fromOidcIssuerLocation(this.properties.getIssuerUri());
 	}
 
 }

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/security/oauth2/resource/servlet/OAuth2ResourceServerOpaqueTokenConfiguration.java

@@ -0,0 +1,71 @@
+/*
+ * Copyright 2012-2019 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.boot.autoconfigure.security.oauth2.resource.servlet;
+
+import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
+import org.springframework.boot.autoconfigure.security.oauth2.resource.OAuth2ResourceServerProperties;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.security.config.annotation.web.builders.HttpSecurity;
+import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
+import org.springframework.security.oauth2.server.resource.introspection.NimbusOAuth2TokenIntrospectionClient;
+import org.springframework.security.oauth2.server.resource.introspection.OAuth2TokenIntrospectionClient;
+
+/**
+ * Configures a {@link OAuth2TokenIntrospectionClient} when a token introspection endpoint
+ * is available. Also configures a {@link WebSecurityConfigurerAdapter} if a
+ * {@link OAuth2TokenIntrospectionClient} bean is found.
+ *
+ * @author Madhura Bhave
+ */
+@Configuration(proxyBeanMethods = false)
+class OAuth2ResourceServerOpaqueTokenConfiguration {
+
+	@Configuration(proxyBeanMethods = false)
+	@ConditionalOnMissingBean(OAuth2TokenIntrospectionClient.class)
+	static class OpaqueTokenIntrospectionClientConfiguration {
+
+		@Bean
+		@ConditionalOnProperty(name = "spring.security.oauth2.resourceserver.opaque-token.introspection-uri")
+		public NimbusOAuth2TokenIntrospectionClient oAuth2TokenIntrospectionClient(
+				OAuth2ResourceServerProperties properties) {
+			OAuth2ResourceServerProperties.OpaqueToken opaqueToken = properties.getOpaqueToken();
+			return new NimbusOAuth2TokenIntrospectionClient(opaqueToken.getIntrospectionUri(),
+					opaqueToken.getClientId(), opaqueToken.getClientSecret());
+		}
+
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	@ConditionalOnMissingBean(WebSecurityConfigurerAdapter.class)
+	static class OAuth2WebSecurityConfigurerAdapter {
+
+		@Bean
+		@ConditionalOnBean(OAuth2TokenIntrospectionClient.class)
+		public WebSecurityConfigurerAdapter opaqueTokenWebSecurityConfigurerAdapter() {
+			return new WebSecurityConfigurerAdapter() {
+				@Override
+				protected void configure(HttpSecurity http) throws Exception {
+					http.authorizeRequests().anyRequest().authenticated().and().oauth2ResourceServer().opaqueToken();
+				}
+			};
+		}
+
+	}
+
+}

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/security/oauth2/resource/servlet/OAuth2ResourceServerWebSecurityConfiguration.java

@@ -1,45 +0,0 @@
-/*
- * Copyright 2012-2019 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.boot.autoconfigure.security.oauth2.resource.servlet;
-
-import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
-import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
-import org.springframework.context.annotation.Configuration;
-import org.springframework.security.config.annotation.web.builders.HttpSecurity;
-import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
-import org.springframework.security.oauth2.jwt.JwtDecoder;
-
-/**
- * {@link WebSecurityConfigurerAdapter} for OAuth2 resource server support.
- *
- * @author Madhura Bhave
- */
-@Configuration(proxyBeanMethods = false)
-@ConditionalOnMissingBean(WebSecurityConfigurerAdapter.class)
-class OAuth2ResourceServerWebSecurityConfiguration {
-
-	@Configuration(proxyBeanMethods = false)
-	@ConditionalOnBean(JwtDecoder.class)
-	static class OAuth2WebSecurityConfigurerAdapter extends WebSecurityConfigurerAdapter {
-
-		@Override
-		protected void configure(HttpSecurity http) throws Exception {
-			http.authorizeRequests().anyRequest().authenticated().and().oauth2ResourceServer().jwt();
-		}
-
-	}
-
-}

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/security/oauth2/resource/reactive/ReactiveOAuth2ResourceServerAutoConfigurationTests.java

@@ -46,6 +46,10 @@ import org.springframework.security.oauth2.jwt.NimbusReactiveJwtDecoder;
 import org.springframework.security.oauth2.jwt.ReactiveJwtDecoder;
 import org.springframework.security.oauth2.server.resource.BearerTokenAuthenticationToken;
 import org.springframework.security.oauth2.server.resource.authentication.JwtReactiveAuthenticationManager;
+import org.springframework.security.oauth2.server.resource.authentication.OAuth2IntrospectionAuthenticationToken;
+import org.springframework.security.oauth2.server.resource.authentication.OAuth2IntrospectionReactiveAuthenticationManager;
+import org.springframework.security.oauth2.server.resource.introspection.OAuth2TokenIntrospectionClient;
+import org.springframework.security.oauth2.server.resource.introspection.ReactiveOAuth2TokenIntrospectionClient;
 import org.springframework.security.web.server.MatcherSecurityWebFilterChain;
 import org.springframework.security.web.server.SecurityWebFilterChain;
 import org.springframework.security.web.server.authentication.AuthenticationWebFilter;
@@ -204,6 +208,81 @@ class ReactiveOAuth2ResourceServerAutoConfigurationTests {
 				});
 	}
 
+	@Test
+	void autoConfigurationWhenIntrospectionUriAvailableShouldConfigureIntrospectionClient() {
+		this.contextRunner
+				.withPropertyValues(
+						"spring.security.oauth2.resourceserver.opaque-token.introspection-uri=https://check-token.com",
+						"spring.security.oauth2.resourceserver.opaque-token.client-id=my-client-id",
+						"spring.security.oauth2.resourceserver.opaque-token.client-secret=my-client-secret")
+				.run((context) -> {
+					assertThat(context).hasSingleBean(ReactiveOAuth2TokenIntrospectionClient.class);
+					assertFilterConfiguredWithOpaqueTokenAuthenticationManager(context);
+				});
+	}
+
+	@Test
+	void oAuth2TokenIntrospectionClientIsConditionalOnMissingBean() {
+		this.contextRunner
+				.withPropertyValues(
+						"spring.security.oauth2.resourceserver.opaque-token.introspection-uri=https://check-token.com")
+				.withUserConfiguration(OAuth2TokenIntrospectionClientConfig.class)
+				.run((this::assertFilterConfiguredWithOpaqueTokenAuthenticationManager));
+	}
+
+	@Test
+	void autoConfigurationForOpaqueTokenWhenSecurityWebFilterChainConfigPresentShouldNotAddOne() {
+		this.contextRunner
+				.withPropertyValues(
+						"spring.security.oauth2.resourceserver.opaque-token.introspection-uri=https://check-token.com",
+						"spring.security.oauth2.resourceserver.opaque-token.client-id=my-client-id",
+						"spring.security.oauth2.resourceserver.opaque-token.client-secret=my-client-secret")
+				.withUserConfiguration(SecurityWebFilterChainConfig.class).run((context) -> {
+					assertThat(context).hasSingleBean(SecurityWebFilterChain.class);
+					assertThat(context).hasBean("testSpringSecurityFilterChain");
+				});
+	}
+
+	@Test
+	void autoConfigurationWhenIntrospectionUriAvailableShouldBeConditionalOnClass() {
+		this.contextRunner.withClassLoader(new FilteredClassLoader(OAuth2IntrospectionAuthenticationToken.class))
+				.withPropertyValues(
+						"spring.security.oauth2.resourceserver.opaque-token.introspection-uri=https://check-token.com",
+						"spring.security.oauth2.resourceserver.opaque-token.client-id=my-client-id",
+						"spring.security.oauth2.resourceserver.opaque-token.client-secret=my-client-secret")
+				.run((context) -> assertThat(context).doesNotHaveBean(OAuth2TokenIntrospectionClient.class));
+	}
+
+	@Test
+	void autoConfigurationWhenBothJwkSetUriAndTokenIntrospectionUriSetShouldFail() {
+		this.contextRunner
+				.withPropertyValues(
+						"spring.security.oauth2.resourceserver.opaque-token.introspection-uri=https://check-token.com",
+						"spring.security.oauth2.resourceserver.jwt.jwk-set-uri=https://jwk-set-uri.com")
+				.run((context) -> assertThat(context).hasFailed().getFailure().hasMessageContaining(
+						"Only one of jwt.jwk-set-uri and opaque-token.introspection-uri should be configured."));
+	}
+
+	@Test
+	void autoConfigurationWhenBothJwtIssuerUriAndTokenIntrospectionUriSetShouldFail() {
+		this.contextRunner
+				.withPropertyValues(
+						"spring.security.oauth2.resourceserver.opaque-token.introspection-uri=https://check-token.com",
+						"spring.security.oauth2.resourceserver.jwt.issuer-uri=https://jwk-oidc-issuer-location.com")
+				.run((context) -> assertThat(context).hasFailed().getFailure().hasMessageContaining(
+						"Only one of jwt.issuer-uri and opaque-token.introspection-uri should be configured."));
+	}
+
+	@Test
+	void autoConfigurationWhenBothJwtKeyLocationAndTokenIntrospectionUriSetShouldFail() {
+		this.contextRunner
+				.withPropertyValues(
+						"spring.security.oauth2.resourceserver.opaque-token.introspection-uri=https://check-token.com",
+						"spring.security.oauth2.resourceserver.jwt.public-key-location=classpath:public-key-location")
+				.run((context) -> assertThat(context).hasFailed().getFailure().hasMessageContaining(
+						"Only one of jwt.public-key-location and opaque-token.introspection-uri should be configured."));
+	}
+
 	private void assertFilterConfiguredWithJwtAuthenticationManager(AssertableReactiveWebApplicationContext context) {
 		MatcherSecurityWebFilterChain filterChain = (MatcherSecurityWebFilterChain) context
 				.getBean(BeanIds.SPRING_SECURITY_FILTER_CHAIN);
@@ -213,7 +292,18 @@ class ReactiveOAuth2ResourceServerAutoConfigurationTests {
 		ReactiveAuthenticationManager authenticationManager = (ReactiveAuthenticationManager) ReflectionTestUtils
 				.getField(webFilter, "authenticationManager");
 		assertThat(authenticationManager).isInstanceOf(JwtReactiveAuthenticationManager.class);
+	}
 
+	private void assertFilterConfiguredWithOpaqueTokenAuthenticationManager(
+			AssertableReactiveWebApplicationContext context) {
+		MatcherSecurityWebFilterChain filterChain = (MatcherSecurityWebFilterChain) context
+				.getBean(BeanIds.SPRING_SECURITY_FILTER_CHAIN);
+		Stream<WebFilter> filters = filterChain.getWebFilters().toStream();
+		AuthenticationWebFilter webFilter = (AuthenticationWebFilter) filters
+				.filter((f) -> f instanceof AuthenticationWebFilter).findFirst().orElse(null);
+		ReactiveAuthenticationManager authenticationManager = (ReactiveAuthenticationManager) ReflectionTestUtils
+				.getField(webFilter, "authenticationManager");
+		assertThat(authenticationManager).isInstanceOf(OAuth2IntrospectionReactiveAuthenticationManager.class);
 	}
 
 	private String cleanIssuerPath(String issuer) {
@@ -269,13 +359,23 @@ class ReactiveOAuth2ResourceServerAutoConfigurationTests {
 
 	}
 
+	@Configuration(proxyBeanMethods = false)
+	static class OAuth2TokenIntrospectionClientConfig {
+
+		@Bean
+		public ReactiveOAuth2TokenIntrospectionClient decoder() {
+			return mock(ReactiveOAuth2TokenIntrospectionClient.class);
+		}
+
+	}
+
 	@Configuration(proxyBeanMethods = false)
 	static class SecurityWebFilterChainConfig {
 
 		@Bean
-		SecurityWebFilterChain testSpringSecurityFilterChain(ServerHttpSecurity http, ReactiveJwtDecoder decoder) {
+		SecurityWebFilterChain testSpringSecurityFilterChain(ServerHttpSecurity http) {
 			http.authorizeExchange().pathMatchers("/message/**").hasRole("ADMIN").anyExchange().authenticated().and()
-					.oauth2ResourceServer().jwt().jwtDecoder(decoder);
+					.httpBasic();
 			return http.build();
 		}
 

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/security/oauth2/resource/servlet/OAuth2ResourceServerAutoConfigurationTests.java

@@ -43,6 +43,8 @@ import org.springframework.security.config.BeanIds;
 import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
 import org.springframework.security.oauth2.jwt.JwtDecoder;
 import org.springframework.security.oauth2.server.resource.authentication.JwtAuthenticationToken;
+import org.springframework.security.oauth2.server.resource.authentication.OAuth2IntrospectionAuthenticationToken;
+import org.springframework.security.oauth2.server.resource.introspection.OAuth2TokenIntrospectionClient;
 import org.springframework.security.oauth2.server.resource.web.BearerTokenAuthenticationFilter;
 import org.springframework.security.web.FilterChainProxy;
 import org.springframework.security.web.SecurityFilterChain;
@@ -221,6 +223,68 @@ class OAuth2ResourceServerAutoConfigurationTests {
 				.run((context) -> assertThat(getBearerTokenFilter(context)).isNull());
 	}
 
+	@Test
+	void autoConfigurationWhenIntrospectionUriAvailableShouldConfigureIntrospectionClient() {
+		this.contextRunner
+				.withPropertyValues(
+						"spring.security.oauth2.resourceserver.opaque-token.introspection-uri=https://check-token.com",
+						"spring.security.oauth2.resourceserver.opaque-token.client-id=my-client-id",
+						"spring.security.oauth2.resourceserver.opaque-token.client-secret=my-client-secret")
+				.run((context) -> {
+					assertThat(context).hasSingleBean(OAuth2TokenIntrospectionClient.class);
+					assertThat(getBearerTokenFilter(context)).isNotNull();
+				});
+	}
+
+	@Test
+	void oAuth2TokenIntrospectionClientIsConditionalOnMissingBean() {
+		this.contextRunner
+				.withPropertyValues(
+						"spring.security.oauth2.resourceserver.opaque-token.introspection-uri=https://check-token.com")
+				.withUserConfiguration(OAuth2TokenIntrospectionClientConfig.class)
+				.run((context) -> assertThat(getBearerTokenFilter(context)).isNotNull());
+	}
+
+	@Test
+	void autoConfigurationWhenIntrospectionUriAvailableShouldBeConditionalOnClass() {
+		this.contextRunner.withClassLoader(new FilteredClassLoader(OAuth2IntrospectionAuthenticationToken.class))
+				.withPropertyValues(
+						"spring.security.oauth2.resourceserver.opaque-token.introspection-uri=https://check-token.com",
+						"spring.security.oauth2.resourceserver.opaque-token.client-id=my-client-id",
+						"spring.security.oauth2.resourceserver.opaque-token.client-secret=my-client-secret")
+				.run((context) -> assertThat(context).doesNotHaveBean(OAuth2TokenIntrospectionClient.class));
+	}
+
+	@Test
+	void autoConfigurationWhenBothJwkSetUriAndTokenIntrospectionUriSetShouldFail() {
+		this.contextRunner
+				.withPropertyValues(
+						"spring.security.oauth2.resourceserver.opaque-token.introspection-uri=https://check-token.com",
+						"spring.security.oauth2.resourceserver.jwt.jwk-set-uri=https://jwk-set-uri.com")
+				.run((context) -> assertThat(context).hasFailed().getFailure().hasMessageContaining(
+						"Only one of jwt.jwk-set-uri and opaque-token.introspection-uri should be configured."));
+	}
+
+	@Test
+	void autoConfigurationWhenBothJwtIssuerUriAndTokenIntrospectionUriSetShouldFail() {
+		this.contextRunner
+				.withPropertyValues(
+						"spring.security.oauth2.resourceserver.opaque-token.introspection-uri=https://check-token.com",
+						"spring.security.oauth2.resourceserver.jwt.issuer-uri=https://jwk-oidc-issuer-location.com")
+				.run((context) -> assertThat(context).hasFailed().getFailure().hasMessageContaining(
+						"Only one of jwt.issuer-uri and opaque-token.introspection-uri should be configured."));
+	}
+
+	@Test
+	void autoConfigurationWhenBothJwtKeyLocationAndTokenIntrospectionUriSetShouldFail() {
+		this.contextRunner
+				.withPropertyValues(
+						"spring.security.oauth2.resourceserver.opaque-token.introspection-uri=https://check-token.com",
+						"spring.security.oauth2.resourceserver.jwt.public-key-location=classpath:public-key-location")
+				.run((context) -> assertThat(context).hasFailed().getFailure().hasMessageContaining(
+						"Only one of jwt.public-key-location and opaque-token.introspection-uri should be configured."));
+	}
+
 	private Filter getBearerTokenFilter(AssertableWebApplicationContext context) {
 		FilterChainProxy filterChain = (FilterChainProxy) context.getBean(BeanIds.SPRING_SECURITY_FILTER_CHAIN);
 		List<SecurityFilterChain> filterChains = filterChain.getFilterChains();
@@ -278,4 +342,15 @@ class OAuth2ResourceServerAutoConfigurationTests {
 
 	}
 
+	@Configuration(proxyBeanMethods = false)
+	@EnableWebSecurity
+	static class OAuth2TokenIntrospectionClientConfig {
+
+		@Bean
+		public OAuth2TokenIntrospectionClient decoder() {
+			return mock(OAuth2TokenIntrospectionClient.class);
+		}
+
+	}
+
 }

spring-boot-project/spring-boot-docs/src/main/asciidoc/spring-boot-features.adoc

@@ -3801,8 +3801,8 @@ In other words, the two configurations in the following example use the Google p
 [[boot-features-security-oauth2-server]]
 ==== Resource Server
 If you have `spring-security-oauth2-resource-server` on your classpath, Spring Boot can
-set up an OAuth2 Resource Server as long as a JWK Set URI or OIDC Issuer URI is specified,
+set up an OAuth2 Resource Server. For JWT configuration, a JWK Set URI or OIDC Issuer URI
-as shown in the following examples:
+needs to be specified, as shown in the following examples:
 
 [source,properties,indent=0]
 ----
@@ -3825,7 +3825,20 @@ The same properties are applicable for both servlet and reactive applications.
 Alternatively, you can define your own `JwtDecoder` bean for servlet applications
 or a `ReactiveJwtDecoder` for reactive applications.
 
+In cases where opaque tokens are used instead of JWTs, you can configure the following properties
+to validate tokens via introspection:
 
+[source,properties,indent=0]
+----
+	spring.security.oauth2.resourceserver.opaque-token.introspection-uri=https://example.com/check-token
+	spring.security.oauth2.resourceserver.opaque-token.client-id=my-client-id
+	spring.security.oauth2.resourceserver.opaque-token.client-secret-my-client-secret
+----
+
+Again, the same properties are applicable for both servlet and reactive applications.
+
+Alternatively, you can define your own `OAuth2TokenIntrospectionClient` bean for servlet applications
+or a `ReactiveOAuth2TokenIntrospectionClient` for reactive applications.
 
 ==== Authorization Server
 Currently, Spring Security does not provide support for implementing an OAuth 2.0