Move HeaderUtils#getMostRecentyProxy to RemoteAddressFilter

service/src/main/java/org/whispersystems/textsecuregcm/filters/RemoteAddressFilter.java

@@ -5,17 +5,20 @@
 
 package org.whispersystems.textsecuregcm.filters;
 
+import com.google.common.annotations.VisibleForTesting;
+import java.io.IOException;
+import java.util.Optional;
+import javax.annotation.Nullable;
 import javax.servlet.Filter;
 import javax.servlet.FilterChain;
 import javax.servlet.ServletException;
 import javax.servlet.ServletRequest;
 import javax.servlet.ServletResponse;
 import javax.servlet.http.HttpServletRequest;
+import org.apache.commons.lang3.StringUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
-import org.whispersystems.textsecuregcm.util.HeaderUtils;
 import org.whispersystems.textsecuregcm.util.HttpServletRequestUtil;
-import java.io.IOException;
 
 /**
  * Sets a {@link HttpServletRequest} attribute (that will also be available as a
@@ -47,7 +50,7 @@ public class RemoteAddressFilter implements Filter {
         remoteAddress = HttpServletRequestUtil.getRemoteAddress(httpServletRequest);
       } else {
         final String forwardedFor = httpServletRequest.getHeader(com.google.common.net.HttpHeaders.X_FORWARDED_FOR);
-        remoteAddress = HeaderUtils.getMostRecentProxy(forwardedFor)
+        remoteAddress = getMostRecentProxy(forwardedFor)
             .orElseGet(() -> HttpServletRequestUtil.getRemoteAddress(httpServletRequest));
       }
 
@@ -59,4 +62,25 @@ public class RemoteAddressFilter implements Filter {
 
     chain.doFilter(request, response);
   }
+
+  /**
+   * Returns the most recent proxy in a chain described by an {@code X-Forwarded-For} header.
+   *
+   * @param forwardedFor the value of an X-Forwarded-For header
+   * @return the IP address of the most recent proxy in the forwarding chain, or empty if none was found or
+   * {@code forwardedFor} was null
+   * @see <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/X-Forwarded-For">X-Forwarded-For - HTTP |
+   * MDN</a>
+   */
+  @VisibleForTesting
+  static Optional<String> getMostRecentProxy(@Nullable final String forwardedFor) {
+    return Optional.ofNullable(forwardedFor)
+        .map(ff -> {
+          final int idx = forwardedFor.lastIndexOf(',') + 1;
+          return idx < forwardedFor.length()
+              ? forwardedFor.substring(idx).trim()
+              : null;
+        })
+        .filter(StringUtils::isNotBlank);
+  }
 }

service/src/main/java/org/whispersystems/textsecuregcm/util/HeaderUtils.java

@@ -12,8 +12,6 @@ import java.nio.charset.StandardCharsets;
 import java.util.Base64;
 import java.util.Optional;
 import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
-import org.apache.commons.lang3.StringUtils;
 import org.whispersystems.textsecuregcm.auth.ExternalServiceCredentials;
 
 public final class HeaderUtils {
@@ -47,28 +45,6 @@ public final class HeaderUtils {
     return TIMESTAMP_HEADER + ":" + System.currentTimeMillis();
   }
 
-  /**
-   * Returns the most recent proxy in a chain described by an {@code X-Forwarded-For} header.
-   *
-   * @param forwardedFor the value of an X-Forwarded-For header
-   *
-   * @return the IP address of the most recent proxy in the forwarding chain, or empty if none was found or
-   * {@code forwardedFor} was null
-   *
-   * @see <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/X-Forwarded-For">X-Forwarded-For - HTTP | MDN</a>
-   */
-  @Nonnull
-  public static Optional<String> getMostRecentProxy(@Nullable final String forwardedFor) {
-    return Optional.ofNullable(forwardedFor)
-        .map(ff -> {
-          final int idx = forwardedFor.lastIndexOf(',') + 1;
-          return idx < forwardedFor.length()
-              ? forwardedFor.substring(idx).trim()
-              : null;
-        })
-        .filter(StringUtils::isNotBlank);
-  }
-
   /**
    * Parses a Base64-encoded value of the `Authorization` header
    * in the form of `Basic dXNlcm5hbWU6cGFzc3dvcmQ=`.

service/src/test/java/org/whispersystems/textsecuregcm/filters/RemoteAddressFilterTest.java

@@ -5,18 +5,24 @@
 
 package org.whispersystems.textsecuregcm.filters;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.params.provider.Arguments.arguments;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 import com.google.common.net.HttpHeaders;
+import java.util.Optional;
+import java.util.stream.Stream;
 import javax.servlet.FilterChain;
 import javax.servlet.ServletRequest;
 import javax.servlet.ServletResponse;
 import javax.servlet.http.HttpServletRequest;
 import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
 import org.junit.jupiter.params.provider.CsvSource;
+import org.junit.jupiter.params.provider.MethodSource;
 
 class RemoteAddressFilterTest {
 
@@ -57,4 +63,23 @@ class RemoteAddressFilterTest {
     verify(filterChain).doFilter(any(ServletRequest.class), any(ServletResponse.class));
   }
 
+  @SuppressWarnings("OptionalUsedAsFieldOrParameterType")
+  @ParameterizedTest
+  @MethodSource("argumentsForGetMostRecentProxy")
+  void getMostRecentProxy(final String forwardedFor, final Optional<String> expectedMostRecentProxy) {
+    assertEquals(expectedMostRecentProxy, RemoteAddressFilter.getMostRecentProxy(forwardedFor));
+  }
+
+  private static Stream<Arguments> argumentsForGetMostRecentProxy() {
+    return Stream.of(
+        arguments(null, Optional.empty()),
+        arguments("", Optional.empty()),
+        arguments("    ", Optional.empty()),
+        arguments("203.0.113.195,", Optional.empty()),
+        arguments("203.0.113.195, ", Optional.empty()),
+        arguments("203.0.113.195", Optional.of("203.0.113.195")),
+        arguments("203.0.113.195, 70.41.3.18, 150.172.238.178", Optional.of("150.172.238.178"))
+    );
+  }
+
 }

service/src/test/java/org/whispersystems/textsecuregcm/util/HeaderUtilsTest.java

@@ -1,37 +0,0 @@
-/*
- * Copyright 2021 Signal Messenger, LLC
- * SPDX-License-Identifier: AGPL-3.0-only
- */
-
-package org.whispersystems.textsecuregcm.util;
-
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.params.provider.Arguments.arguments;
-
-import java.util.Optional;
-import java.util.stream.Stream;
-import org.junit.jupiter.params.ParameterizedTest;
-import org.junit.jupiter.params.provider.Arguments;
-import org.junit.jupiter.params.provider.MethodSource;
-
-class HeaderUtilsTest {
-
-    @SuppressWarnings("OptionalUsedAsFieldOrParameterType")
-    @ParameterizedTest
-    @MethodSource("argumentsForGetMostRecentProxy")
-    void getMostRecentProxy(final String forwardedFor, final Optional<String> expectedMostRecentProxy) {
-      assertEquals(expectedMostRecentProxy, HeaderUtils.getMostRecentProxy(forwardedFor));
-    }
-
-    private static Stream<Arguments> argumentsForGetMostRecentProxy() {
-      return Stream.of(
-          arguments(null, Optional.empty()),
-          arguments("", Optional.empty()),
-          arguments("    ", Optional.empty()),
-          arguments("203.0.113.195,", Optional.empty()),
-          arguments("203.0.113.195, ", Optional.empty()),
-          arguments("203.0.113.195", Optional.of("203.0.113.195")),
-          arguments("203.0.113.195, 70.41.3.18, 150.172.238.178", Optional.of("150.172.238.178"))
-      );
-    }
-}