feat: add self signed jwt support

dependencies.properties

@@ -34,7 +34,7 @@ version.io_grpc=1.37.0
 #   2) Replace all characters which are neither alphabetic nor digits with the underscore ('_') character
 maven.com_google_api_grpc_proto_google_common_protos=com.google.api.grpc:proto-google-common-protos:2.0.1
 maven.com_google_api_grpc_grpc_google_common_protos=com.google.api.grpc:grpc-google-common-protos:2.0.1
-maven.com_google_auth_google_auth_library_oauth2_http=com.google.auth:google-auth-library-oauth2-http:0.24.0
+maven.com_google_auth_google_auth_library_oauth2_http=com.google.auth:google-auth-library-oauth2-http:0.27.0
 maven.com_google_auth_google_auth_library_credentials=com.google.auth:google-auth-library-credentials:1.0.0
 maven.io_opencensus_opencensus_api=io.opencensus:opencensus-api:0.28.0
 maven.io_opencensus_opencensus_contrib_grpc_metrics=io.opencensus:opencensus-contrib-grpc-metrics:0.28.0

gax/src/main/java/com/google/api/gax/core/GoogleCredentialsProvider.java

@@ -56,6 +56,9 @@ public abstract class GoogleCredentialsProvider implements CredentialsProvider {
   @BetaApi
   public abstract List<String> getJwtEnabledScopes();
 
+  @BetaApi
+  public abstract boolean getUseJwtAccessWithScope();
+
   @VisibleForTesting
   @Nullable
   abstract GoogleCredentials getOAuth2Credentials();
@@ -91,12 +94,19 @@ public Credentials getCredentials() throws IOException {
     if (credentials.createScopedRequired()) {
       credentials = credentials.createScoped(getScopesToApply());
     }
+
+    if (getUseJwtAccessWithScope() && credentials instanceof ServiceAccountCredentials) {
+      // See https://google.aip.dev/auth/4111 for self signed JWT.
+      ServiceAccountCredentials serviceAccount = (ServiceAccountCredentials) credentials;
+      return serviceAccount.createWithUseJwtAccessWithScope(true);
+    }
     return credentials;
   }
 
   public static Builder newBuilder() {
     return new AutoValue_GoogleCredentialsProvider.Builder()
-        .setJwtEnabledScopes(ImmutableList.<String>of());
+        .setJwtEnabledScopes(ImmutableList.<String>of())
+        .setUseJwtAccessWithScope(false);
   }
 
   public abstract Builder toBuilder();
@@ -134,9 +144,18 @@ public abstract static class Builder {
     @BetaApi
     public abstract List<String> getJwtEnabledScopes();
 
+    /** Whether self signed JWT with scopes should be used for service account credentials. */
+    @BetaApi
+    public abstract Builder setUseJwtAccessWithScope(boolean val);
+
+    /** The UseJwtAccessWithScope value previously provided. */
+    @BetaApi
+    public abstract boolean getUseJwtAccessWithScope();
+
     public GoogleCredentialsProvider build() {
       setScopesToApply(ImmutableList.copyOf(getScopesToApply()));
       setJwtEnabledScopes(ImmutableList.copyOf(getJwtEnabledScopes()));
+      setUseJwtAccessWithScope(getUseJwtAccessWithScope());
       return autoBuild();
     }
 

gax/src/test/java/com/google/api/gax/core/GoogleCredentialsProviderTest.java

@@ -30,6 +30,7 @@
 package com.google.api.gax.core;
 
 import static com.google.common.truth.Truth.assertThat;
+import static org.junit.Assert.assertTrue;
 
 import com.google.auth.Credentials;
 import com.google.auth.oauth2.ServiceAccountCredentials;
@@ -43,15 +44,18 @@
 
 @RunWith(JUnit4.class)
 public class GoogleCredentialsProviderTest {
+  ServiceAccountCredentials CreateServiceAccountCredentials() {
+    return ServiceAccountCredentials.newBuilder()
+        .setClientId("fake-client-id")
+        .setClientEmail("fake@example.com")
+        .setPrivateKeyId("fake-private-key")
+        .setPrivateKey(Mockito.mock(PrivateKey.class))
+        .build();
+  }
+
   @Test
   public void serviceAccountReplacedWithJwtTokens() throws Exception {
-    ServiceAccountCredentials serviceAccountCredentials =
-        ServiceAccountCredentials.newBuilder()
-            .setClientId("fake-client-id")
-            .setClientEmail("fake@example.com")
-            .setPrivateKeyId("fake-private-key")
-            .setPrivateKey(Mockito.mock(PrivateKey.class))
-            .build();
+    ServiceAccountCredentials serviceAccountCredentials = CreateServiceAccountCredentials();
 
     GoogleCredentialsProvider provider =
         GoogleCredentialsProvider.newBuilder()
@@ -71,13 +75,7 @@ public void serviceAccountReplacedWithJwtTokens() throws Exception {
 
   @Test
   public void noJwtWithoutScopeMatch() throws Exception {
-    ServiceAccountCredentials serviceAccountCredentials =
-        ServiceAccountCredentials.newBuilder()
-            .setClientId("fake-client-id")
-            .setClientEmail("fake@example.com")
-            .setPrivateKeyId("fake-private-key")
-            .setPrivateKey(Mockito.mock(PrivateKey.class))
-            .build();
+    ServiceAccountCredentials serviceAccountCredentials = CreateServiceAccountCredentials();
 
     GoogleCredentialsProvider provider =
         GoogleCredentialsProvider.newBuilder()
@@ -100,4 +98,30 @@ public void noJwtWithoutScopeMatch() throws Exception {
         .isEqualTo(serviceAccountCredentials.getPrivateKey());
     assertThat(serviceAccountCredentials2.getScopes()).containsExactly("scope1", "scope2");
   }
+
+  @Test
+  public void useJwtAccessWithScope() throws Exception {
+    ServiceAccountCredentials serviceAccountCredentials = CreateServiceAccountCredentials();
+
+    GoogleCredentialsProvider provider =
+        GoogleCredentialsProvider.newBuilder()
+            .setScopesToApply(ImmutableList.of("scope1", "scope2"))
+            .setOAuth2Credentials(serviceAccountCredentials)
+            .setUseJwtAccessWithScope(true)
+            .build();
+
+    Credentials credentials = provider.getCredentials();
+    assertThat(credentials).isInstanceOf(ServiceAccountCredentials.class);
+
+    ServiceAccountCredentials serviceAccountCredentials2 = (ServiceAccountCredentials) credentials;
+    assertThat(serviceAccountCredentials2.getClientId())
+        .isEqualTo(serviceAccountCredentials.getClientId());
+    assertThat(serviceAccountCredentials2.getClientEmail())
+        .isEqualTo(serviceAccountCredentials.getClientEmail());
+    assertThat(serviceAccountCredentials2.getPrivateKeyId())
+        .isEqualTo(serviceAccountCredentials.getPrivateKeyId());
+    assertThat(serviceAccountCredentials2.getPrivateKey())
+        .isEqualTo(serviceAccountCredentials.getPrivateKey());
+    assertTrue(serviceAccountCredentials2.getUseJwtAccessWithScope());
+  }
 }