feat(auth): allow limiting header authentication to list of configured IP addresses

README.md

@@ -617,7 +617,7 @@ The username field can be any string field, the roles field has to be a JSON arr
 
 ### Header configuration (reverse proxy)
 
-To enable Header authentification in the application, you'll have to configure the header that will resolve users & groups:
+To enable Header authentication in the application, you'll have to configure the header that will resolve users & groups:
 
 ```yaml
 akhq:
@@ -627,6 +627,7 @@ akhq:
       user-header: x-akhq-user # mandatory (the header name that will contain username)
       groups-header: x-akhq-group # optional (the header name that will contain groups separated by groups-header-separator)
       groups-header-separator: , # optional (separator, defaults to ',')
+      ip-patterns: [0.0.0.0] # optional (Java regular expressions for matching trusted IP addresses, '0.0.0.0' matches all addresses)
       users: # optional, the users list to allow, if empty we only rely on `groups-header`
         - username: header-user # username matching the `user-header` value
           groups: # list of group for current users
@@ -636,10 +637,11 @@ akhq:
             - admin
 ```
 
-* The `user-header` is mandatory in order to map the user with `users` list or to display the user on the ui if no `users` is provided.
-* The `groups-header` is optional and can be used in order to inject a list of groups for all the users. This list will be merged with `groups` for the current users.
-* The `groups-header-separator` is optional and can be used to customize group separator used when parsing `groups-header` header, defaults to `,`.
-* The `users` is a list of allowed users.
+* `user-header` is mandatory in order to map the user with `users` list or to display the user on the ui if no `users` is provided.
+* `groups-header` is optional and can be used in order to inject a list of groups for all the users. This list will be merged with `groups` for the current users.
+* `groups-header-separator` is optional and can be used to customize group separator used when parsing `groups-header` header, defaults to `,`.
+* `ip-patterns` limits the IP addresses that header authentication will accept, given as a list of Java regular expressions, omit or set to `[0.0.0.0]` to allow all addresses
+* `users` is a list of allowed users.
 
 ### External roles and attributes mapping
 

application.example.yml

@@ -14,7 +14,7 @@ micronaut:
         groups:
           enabled: true
           base: "dc=example,dc=com"
-    # OIDC authentification configuration
+    # OIDC authentication configuration
     oauth2:
       enabled: true
       clients:
@@ -265,6 +265,7 @@ akhq:
       user-header: x-akhq-user # mandatory (the header name that will contain username)
       groups-header: x-akhq-group # optional (the header name that will contain groups separated by groups-header-separator)
       groups-header-separator: , # optional (separator, defaults to ',')
+      ip-patterns: [127.0.0.*] # optional (Java regular expressions for matching trusted IP addresses, '0.0.0.0' matches all addresses)
       users: # optional, the users list to allow, if empty we only rely on `groups-header`
         - username: header-user # username matching the `user-header` value
           groups: # list of group for current users

src/main/java/org/akhq/configs/HeaderAuth.java

@@ -1,9 +1,11 @@
 package org.akhq.configs;
 
 import io.micronaut.context.annotation.ConfigurationProperties;
+import io.micronaut.security.config.SecurityConfigurationProperties;
 import lombok.Data;
 
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 
 @Data
@@ -13,6 +15,7 @@ public class HeaderAuth {
     String groupsHeader;
     String groupsHeaderSeparator = ",";
     List<Users> users;
+    List<String> ipPatterns = Collections.singletonList(SecurityConfigurationProperties.ANYWHERE);
 
     @Data
     public static class Users {

src/main/java/org/akhq/modules/HeaderAuthenticationFetcher.java

@@ -7,6 +7,7 @@
 import io.micronaut.security.authentication.AuthenticationUserDetailsAdapter;
 import io.micronaut.security.authentication.Authenticator;
 import io.micronaut.security.authentication.UserDetails;
+import io.micronaut.security.config.SecurityConfigurationProperties;
 import io.micronaut.security.filters.AuthenticationFetcher;
 import io.micronaut.security.token.config.TokenConfiguration;
 import io.reactivex.Flowable;
@@ -15,11 +16,14 @@
 import org.akhq.utils.ClaimProvider;
 import org.reactivestreams.Publisher;
 
+import java.net.InetSocketAddress;
 import java.util.Arrays;
 import java.util.List;
 import java.util.Optional;
+import java.util.regex.Pattern;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
+import javax.annotation.PostConstruct;
 import javax.inject.Inject;
 import javax.inject.Singleton;
 
@@ -39,6 +43,16 @@ public class HeaderAuthenticationFetcher implements AuthenticationFetcher {
     @Inject
     TokenConfiguration configuration;
 
+    private List<Pattern> ipPatternList;
+
+    @PostConstruct
+    public void init() {
+        this.ipPatternList = headerAuth.getIpPatterns()
+            .stream()
+            .map(Pattern::compile)
+            .collect(Collectors.toList());
+    }
+
     @Override
     public Publisher<Authentication> fetchAuthentication(HttpRequest<?> request) {
         Optional<String> userHeaders = headerAuth.getUserHeader() != null ?
@@ -49,6 +63,29 @@ public Publisher<Authentication> fetchAuthentication(HttpRequest<?> request) {
             return Publishers.empty();
         }
 
+        if (!ipPatternList.isEmpty()) {
+            InetSocketAddress socketAddress = request.getRemoteAddress();
+            //noinspection ConstantConditions https://github.com/micronaut-projects/micronaut-security/issues/186
+            if (socketAddress == null) {
+                log.debug("Request remote address was not found. Skipping header authentication.");
+                return Publishers.empty();
+            }
+
+            if (socketAddress.getAddress() == null) {
+                log.debug("Could not resolve the InetAddress. Skipping header authentication.");
+                return Publishers.empty();
+            }
+
+            String hostAddress = socketAddress.getAddress().getHostAddress();
+            if (ipPatternList.stream().noneMatch(pattern ->
+                pattern.pattern().equals(SecurityConfigurationProperties.ANYWHERE) ||
+                    pattern.matcher(hostAddress).matches())) {
+                log.warn("None of the IP patterns [{}] matched the host address [{}]. Skipping header authentication.", headerAuth.getIpPatterns(), hostAddress);
+                return Publishers.empty();
+            }
+            log.debug("One or more of the IP patterns matched the host address [{}]. Continuing request processing.", hostAddress);
+        }
+
         Optional<String> groupHeaders = headerAuth.getGroupsHeader() != null ?
             request.getHeaders().get(headerAuth.getGroupsHeader(), String.class) :
             Optional.empty();

src/test/java/org/akhq/controllers/HeaderAuthControllerTest.java

@@ -10,6 +10,7 @@
 import javax.inject.Inject;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
 
 class HeaderAuthControllerTest extends AbstractTest {
     @Inject
@@ -89,4 +90,25 @@ void invalidUser() {
             assertEquals(3, result.getRoles().size());
         }
     }
+
+    @MicronautTest(environments = "header-ip-disallow")
+    public static class UntrustedIp extends AbstractTest {
+        @Inject
+        @Client("/")
+        protected RxHttpClient client;
+
+        @Test
+        void invalidIp() {
+            AkhqController.AuthUser result = client.toBlocking().retrieve(
+                HttpRequest
+                    .GET("/api/me")
+                    .header("x-akhq-user", "header-user")
+                    .header("x-akhq-group", "limited,extra"),
+                AkhqController.AuthUser.class
+            );
+
+            assertNull(result.getUsername());
+            assertNull(result.getRoles());
+        }
+    }
 }

src/test/resources/application-header-ip-disallow.yml

@@ -0,0 +1,7 @@
+akhq:
+  security:
+    header-auth:
+      user-header: x-akhq-user
+      groups-header: x-akhq-group
+      ip-patterns: ["none"]
+    default-group: invalid-group