Add string constants for HTTP header names (#956)

* Add string constants for HTTP header names

* revert package-lock changes

* Clarify names

* add CONTENT_TYPE

* Fix formatting

* Move X-FORWARDED-FOR to ProxyHttpHeaders

core/src/main/java/google/registry/flows/EppRequestHandler.java

@@ -25,6 +25,7 @@ import com.google.common.flogger.FluentLogger;
 import com.google.common.net.MediaType;
 import google.registry.model.eppoutput.EppOutput;
 import google.registry.request.Response;
+import google.registry.util.ProxyHttpHeaders;
 import javax.inject.Inject;
 
 /** Handle an EPP request and response. */
@@ -72,7 +73,7 @@ public class EppRequestHandler {
       // See: https://tools.ietf.org/html/rfc5734#section-2
       if (eppOutput.isResponse()
           && eppOutput.getResponse().getResult().getCode() == SUCCESS_AND_CLOSE) {
-        response.setHeader("Epp-Session", "close");
+        response.setHeader(ProxyHttpHeaders.EPP_SESSION, "close");
       }
       // If a login request returns a success, a logged-in header is added to the response to inform
       // the proxy that it is no longer necessary to send the full client certificate to the backend
@@ -80,7 +81,7 @@ public class EppRequestHandler {
       if (eppOutput.isResponse()
           && eppOutput.getResponse().isLoginResponse()
           && eppOutput.isSuccess()) {
-        response.setHeader("Logged-In", "true");
+        response.setHeader(ProxyHttpHeaders.LOGGED_IN, "true");
       }
     } catch (Exception e) {
       logger.atWarning().withCause(e).log("handleEppCommand general exception");

core/src/main/java/google/registry/flows/TlsCredentials.java

@@ -34,6 +34,7 @@ import google.registry.model.registrar.Registrar;
 import google.registry.request.Header;
 import google.registry.util.CidrAddressBlock;
 import google.registry.util.Clock;
+import google.registry.util.ProxyHttpHeaders;
 import java.io.ByteArrayInputStream;
 import java.net.InetAddress;
 import java.security.cert.CertificateException;
@@ -78,9 +79,9 @@ public class TlsCredentials implements TransportCredentials {
   @Inject
   public TlsCredentials(
       @Config("requireSslCertificates") boolean requireSslCertificates,
-      @Header("X-SSL-Certificate") Optional<String> clientCertificateHash,
-      @Header("X-SSL-Full-Certificate") Optional<String> clientCertificate,
-      @Header("X-Forwarded-For") Optional<String> clientAddress,
+      @Header(ProxyHttpHeaders.CERTIFICATE_HASH) Optional<String> clientCertificateHash,
+      @Header(ProxyHttpHeaders.FULL_CERTIFICATE) Optional<String> clientCertificate,
+      @Header(ProxyHttpHeaders.IP_ADDRESS) Optional<String> clientAddress,
       CertificateChecker certificateChecker,
       Clock clock) {
     this.requireSslCertificates = requireSslCertificates;
@@ -328,25 +329,25 @@ public class TlsCredentials implements TransportCredentials {
   public static final class EppTlsModule {
 
     @Provides
-    @Header("X-SSL-Certificate")
+    @Header(ProxyHttpHeaders.CERTIFICATE_HASH)
     static Optional<String> provideClientCertificateHash(HttpServletRequest req) {
       // Note: This header is actually required, we just want to handle its absence explicitly
       // by throwing an EPP exception rather than a generic Bad Request exception.
-      return extractOptionalHeader(req, "X-SSL-Certificate");
+      return extractOptionalHeader(req, ProxyHttpHeaders.CERTIFICATE_HASH);
     }
 
     @Provides
-    @Header("X-SSL-Full-Certificate")
+    @Header(ProxyHttpHeaders.FULL_CERTIFICATE)
     static Optional<String> provideClientCertificate(HttpServletRequest req) {
       // Note: This header is actually required, we just want to handle its absence explicitly
       // by throwing an EPP exception rather than a generic Bad Request exception.
-      return extractOptionalHeader(req, "X-SSL-Full-Certificate");
+      return extractOptionalHeader(req, ProxyHttpHeaders.FULL_CERTIFICATE);
     }
 
     @Provides
-    @Header("X-Forwarded-For")
-    static Optional<String> provideForwardedFor(HttpServletRequest req) {
-      return extractOptionalHeader(req, "X-Forwarded-For");
+    @Header(ProxyHttpHeaders.IP_ADDRESS)
+    static Optional<String> provideIpAddress(HttpServletRequest req) {
+      return extractOptionalHeader(req, ProxyHttpHeaders.IP_ADDRESS);
     }
   }
 }

core/src/test/java/google/registry/flows/EppTestCase.java

@@ -46,6 +46,7 @@ import google.registry.testing.FakeClock;
 import google.registry.testing.FakeHttpSession;
 import google.registry.testing.FakeResponse;
 import google.registry.testing.InjectExtension;
+import google.registry.util.ProxyHttpHeaders;
 import java.util.Map;
 import java.util.Objects;
 import java.util.Optional;
@@ -162,7 +163,8 @@ public class EppTestCase {
     FakeResponse response = executeXmlCommand(input);
 
     // Check that the logged-in header was added to the response
-    assertThat(response.getHeaders()).isEqualTo(ImmutableMap.of("Logged-In", "true"));
+    assertThat(response.getHeaders())
+        .isEqualTo(ImmutableMap.of(ProxyHttpHeaders.LOGGED_IN, "true"));
 
     return verifyAndReturnOutput(
         response.getPayload(), expectedOutput, inputFilename, outputFilename);
@@ -183,7 +185,7 @@ public class EppTestCase {
 
     // Checks that the Logged-In header is not in the response. If testing the login command, use
     // assertLoginCommandAndResponse instead of this method.
-    assertThat(response.getHeaders()).doesNotContainEntry("Logged-In", "true");
+    assertThat(response.getHeaders()).doesNotContainEntry(ProxyHttpHeaders.LOGGED_IN, "true");
 
     return verifyAndReturnOutput(
         response.getPayload(), expectedOutput, inputFilename, outputFilename);

core/src/test/java/google/registry/flows/TlsCredentialsTest.java

@@ -33,6 +33,7 @@ import google.registry.model.registrar.Registrar;
 import google.registry.testing.AppEngineExtension;
 import google.registry.testing.FakeClock;
 import google.registry.util.CidrAddressBlock;
+import google.registry.util.ProxyHttpHeaders;
 import java.util.Optional;
 import javax.servlet.http.HttpServletRequest;
 import org.joda.time.DateTime;
@@ -59,7 +60,7 @@ final class TlsCredentialsTest {
   @Test
   void testProvideClientCertificateHash() {
     HttpServletRequest req = mock(HttpServletRequest.class);
-    when(req.getHeader("X-SSL-Certificate")).thenReturn("data");
+    when(req.getHeader(ProxyHttpHeaders.CERTIFICATE_HASH)).thenReturn("data");
     assertThat(TlsCredentials.EppTlsModule.provideClientCertificateHash(req)).hasValue("data");
   }
 
@@ -128,7 +129,7 @@ final class TlsCredentialsTest {
   @Test
   void testProvideClientCertificate() {
     HttpServletRequest req = mock(HttpServletRequest.class);
-    when(req.getHeader("X-SSL-Full-Certificate")).thenReturn("data");
+    when(req.getHeader(ProxyHttpHeaders.FULL_CERTIFICATE)).thenReturn("data");
     assertThat(TlsCredentials.EppTlsModule.provideClientCertificate(req)).hasValue("data");
   }