fix: Make it explicit that there is a network call to MDS to get SecureSessionAgentConfig (#1573)

* S2A utility returns S2AConfig. * S2A -> SecureSessionAgent. * getConfig + javadocs. * static create. * typo. * add javadoc. * format.

Author: rmehta19

…ttp/java/com/google/auth/oauth2/S2A.java …ogle/auth/oauth2/SecureSessionAgent.javaoauth2_http/java/com/google/auth/oauth2/S2A.java renamed to oauth2_http/java/com/google/auth/oauth2/SecureSessionAgent.java oauth2_http/java/com/google/auth/oauth2/S2A.java renamed to oauth2_http/java/com/google/auth/oauth2/SecureSessionAgent.java

@@ -58,7 +58,7 @@
  * <p>This is an experimental utility.
  */
 @ThreadSafe
-public final class S2A {
+public class SecureSessionAgent {
  static final String S2A_PLAINTEXT_ADDRESS_JSON_KEY = "plaintext_address";
  static final String S2A_MTLS_ADDRESS_JSON_KEY = "mtls_address";
  static final String S2A_CONFIG_ENDPOINT_POSTFIX =
@@ -72,23 +72,25 @@ public final class S2A {
  private static final String MDS_MTLS_ENDPOINT =
  ComputeEngineCredentials.getMetadataServerUrl() + S2A_CONFIG_ENDPOINT_POSTFIX;
 
- private S2AConfig config;
-
  private transient HttpTransportFactory transportFactory;
 
- S2A(S2A.Builder builder) {
+ SecureSessionAgent(SecureSessionAgent.Builder builder) {
  this.transportFactory = builder.getHttpTransportFactory();
- this.config = getS2AConfigFromMDS();
  }
 
- /** @return the mTLS S2A Address from the mTLS config. */
- public String getMtlsS2AAddress() {
- return config.getMtlsAddress();
+ /**
+ * This method makes a network call to MDS to get the {@link SecureSessionAgentConfig} which
+ * contains the plaintext and mtls address to reach the S2A (Secure Session Agent).
+ *
+ * @return a SecureSessionAgentConfig.
+ */
+ public SecureSessionAgentConfig getConfig() {
+ return getSecureSessionAgentConfigFromMDS();
  }
 
- /** @return the plaintext S2A Address from the mTLS config. */
- public String getPlaintextS2AAddress() {
- return config.getPlaintextAddress();
+ /** @return default instance of SecureSessionAgent */
+ public static SecureSessionAgent create() {
+ return newBuilder().build();
  }
 
  public static Builder newBuilder() {
@@ -110,17 +112,18 @@ public HttpTransportFactory getHttpTransportFactory() {
  return this.transportFactory;
  }
 
- public S2A build() {
- return new S2A(this);
+ public SecureSessionAgent build() {
+ return new SecureSessionAgent(this);
  }
  }
 
  /**
- * Queries the MDS mTLS Autoconfiguration endpoint and returns the {@link S2AConfig}.
+ * Queries the MDS mTLS Autoconfiguration endpoint and returns the {@link
+ * SecureSessionAgentConfig}.
  *
- * <p>Returns {@link S2AConfig}. If S2A is not running, or if any error occurs when making the
- * request to MDS / processing the response, {@link S2AConfig} will be populated with empty
- * addresses.
+ * <p>Returns {@link SecureSessionAgentConfig}. If S2A is not running, or if any error occurs when
+ * making the request to MDS / processing the response, {@link SecureSessionAgentConfig} will be
+ * populated with empty addresses.
  *
  * <p>Users are expected to try to fetch the mTLS-S2A address first (via {@link
  * getMtlsS2AAddress}). If it is empty or they have some problem loading the mTLS-MDS credentials,
@@ -129,9 +132,9 @@ public S2A build() {
  * when talking to the MDS / processing the response or that S2A is not running in the
  * environment; in either case this indicates S2A shouldn't be used.
  *
- * @return the {@link S2AConfig}.
+ * @return the {@link SecureSessionAgentConfig}.
  */
- private S2AConfig getS2AConfigFromMDS() {
+ private SecureSessionAgentConfig getSecureSessionAgentConfigFromMDS() {
  if (transportFactory == null) {
  transportFactory =
  Iterables.getFirst(
@@ -144,9 +147,9 @@ private S2AConfig getS2AConfigFromMDS() {
  request = transportFactory.create().createRequestFactory().buildGetRequest(genericUrl);
  } catch (IOException ignore) {
  /*
- * Return empty addresses in {@link S2AConfig} if error building the GET request.
+ * Return empty addresses in {@link SecureSessionAgentConfig} if error building the GET request.
  */
- return S2AConfig.createBuilder().build();
+ return SecureSessionAgentConfig.createBuilder().build();
  }
 
  request.setParser(new JsonObjectParser(OAuth2Utils.JSON_FACTORY));
@@ -173,14 +176,14 @@ private S2AConfig getS2AConfigFromMDS() {
  HttpResponse response = request.execute();
  InputStream content = response.getContent();
  if (content == null) {
- return S2AConfig.createBuilder().build();
+ return SecureSessionAgentConfig.createBuilder().build();
  }
  responseData = response.parseAs(GenericData.class);
  } catch (IOException ignore) {
  /*
- * Return empty addresses in {@link S2AConfig} once all retries have been exhausted.
+ * Return empty addresses in {@link SecureSessionAgentConfig} once all retries have been exhausted.
  */
- return S2AConfig.createBuilder().build();
+ return SecureSessionAgentConfig.createBuilder().build();
  }
 
  String plaintextS2AAddress = "";
@@ -190,19 +193,19 @@ private S2AConfig getS2AConfigFromMDS() {
  OAuth2Utils.validateString(responseData, S2A_PLAINTEXT_ADDRESS_JSON_KEY, PARSE_ERROR_S2A);
  } catch (IOException ignore) {
  /*
- * Do not throw error because of parsing error, just leave the address as empty in {@link S2AConfig}.
+ * Do not throw error because of parsing error, just leave the address as empty in {@link SecureSessionAgentConfig}.
  */
  }
  try {
  mtlsS2AAddress =
  OAuth2Utils.validateString(responseData, S2A_MTLS_ADDRESS_JSON_KEY, PARSE_ERROR_S2A);
  } catch (IOException ignore) {
  /*
- * Do not throw error because of parsing error, just leave the address as empty in {@link S2AConfig}.
+ * Do not throw error because of parsing error, just leave the address as empty in {@link SecureSessionAgentConfig}.
  */
  }
 
- return S2AConfig.createBuilder()
+ return SecureSessionAgentConfig.createBuilder()
  .setPlaintextAddress(plaintextS2AAddress)
  .setMtlsAddress(mtlsS2AAddress)
  .build();

…va/com/google/auth/oauth2/S2AConfig.java …uth/oauth2/SecureSessionAgentConfig.javaoauth2_http/java/com/google/auth/oauth2/S2AConfig.java renamed to oauth2_http/java/com/google/auth/oauth2/SecureSessionAgentConfig.java oauth2_http/java/com/google/auth/oauth2/S2AConfig.java renamed to oauth2_http/java/com/google/auth/oauth2/SecureSessionAgentConfig.java

@@ -33,7 +33,7 @@
 import com.google.errorprone.annotations.CanIgnoreReturnValue;
 
 /** Holds an mTLS configuration (consists of address of S2A) retrieved from the Metadata Server. */
-final class S2AConfig {
+public class SecureSessionAgentConfig {
  // plaintextAddress is the plaintext address to reach the S2A.
  private final String plaintextAddress;
 
@@ -86,12 +86,12 @@ public Builder setMtlsAddress(String mtlsAddress) {
  return this;
  }
 
- public S2AConfig build() {
- return new S2AConfig(plaintextAddress, mtlsAddress);
+ public SecureSessionAgentConfig build() {
+ return new SecureSessionAgentConfig(plaintextAddress, mtlsAddress);
  }
  }
 
- private S2AConfig(String plaintextAddress, String mtlsAddress) {
+ private SecureSessionAgentConfig(String plaintextAddress, String mtlsAddress) {
  this.plaintextAddress = plaintextAddress;
  this.mtlsAddress = mtlsAddress;
  }

oauth2_http/javatests/com/google/auth/oauth2/MockMetadataServerTransport.java

@@ -291,8 +291,8 @@ private MockLowLevelHttpRequest getMockRequestForMtlsConfig(String url) {
  @Override
  public LowLevelHttpResponse execute() throws IOException {
 
- String metadataRequestHeader = getFirstHeaderValue(S2A.METADATA_FLAVOR);
- if (!S2A.GOOGLE.equals(metadataRequestHeader)) {
+ String metadataRequestHeader = getFirstHeaderValue(SecureSessionAgent.METADATA_FLAVOR);
+ if (!SecureSessionAgent.GOOGLE.equals(metadataRequestHeader)) {
  throw new IOException("Metadata request header not found");
  }
 
@@ -337,6 +337,7 @@ protected boolean isIdentityDocumentUrl(String url) {
  protected boolean isMtlsConfigRequestUrl(String url) {
  return url.equals(
  String.format(
- ComputeEngineCredentials.getMetadataServerUrl() + S2A.S2A_CONFIG_ENDPOINT_POSTFIX));
+ ComputeEngineCredentials.getMetadataServerUrl()
+ + SecureSessionAgent.S2A_CONFIG_ENDPOINT_POSTFIX));
  }
 }

…om/google/auth/oauth2/S2AConfigTest.java …oauth2/SecureSessionAgentConfigTest.javaoauth2_http/javatests/com/google/auth/oauth2/S2AConfigTest.java renamed to oauth2_http/javatests/com/google/auth/oauth2/SecureSessionAgentConfigTest.java oauth2_http/javatests/com/google/auth/oauth2/S2AConfigTest.java renamed to oauth2_http/javatests/com/google/auth/oauth2/SecureSessionAgentConfigTest.java

@@ -37,16 +37,16 @@
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
 
-/** Test cases for {@link S2AConfig}. */
+/** Test cases for {@linkSecureSessionAgentConfig}. */
 @RunWith(JUnit4.class)
-public class S2AConfigTest {
+public class SecureSessionAgentConfigTest {
  private static final String S2A_PLAINTEXT_ADDRESS = "plaintext";
  private static final String S2A_MTLS_ADDRESS = "mtls";
 
  @Test
  public void createS2AConfig_success() {
- S2AConfig config =
- S2AConfig.createBuilder()
+ SecureSessionAgentConfig config =
+ SecureSessionAgentConfig.createBuilder()
  .setPlaintextAddress(S2A_PLAINTEXT_ADDRESS)
  .setMtlsAddress(S2A_MTLS_ADDRESS)
  .build();
@@ -56,7 +56,7 @@ public void createS2AConfig_success() {
 
  @Test
  public void createEmptyS2AConfig_success() {
- S2AConfig config = S2AConfig.createBuilder().build();
+ SecureSessionAgentConfig config = SecureSessionAgentConfig.createBuilder().build();
  assertTrue(config.getPlaintextAddress().isEmpty());
  assertTrue(config.getMtlsAddress().isEmpty());
  }

…ests/com/google/auth/oauth2/S2ATest.java …/auth/oauth2/SecureSessionAgentTest.javaoauth2_http/javatests/com/google/auth/oauth2/S2ATest.java renamed to oauth2_http/javatests/com/google/auth/oauth2/SecureSessionAgentTest.java oauth2_http/javatests/com/google/auth/oauth2/S2ATest.java renamed to oauth2_http/javatests/com/google/auth/oauth2/SecureSessionAgentTest.java

@@ -40,9 +40,9 @@
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
 
-/** Test cases for {@link S2A}. */
+/** Test cases for {@link SecureSessionAgent}. */
 @RunWith(JUnit4.class)
-public class S2ATest {
+public class SecureSessionAgentTest {
 
  private static final String INVALID_JSON_KEY = "invalid_key";
  private static final String S2A_PLAINTEXT_ADDRESS = "plaintext";
@@ -53,15 +53,17 @@ public void getS2AAddress_validAddress() {
  MockMetadataServerTransportFactory transportFactory = new MockMetadataServerTransportFactory();
  transportFactory.transport.setS2AContentMap(
  ImmutableMap.of(
- S2A.S2A_PLAINTEXT_ADDRESS_JSON_KEY,
+ SecureSessionAgent.S2A_PLAINTEXT_ADDRESS_JSON_KEY,
  S2A_PLAINTEXT_ADDRESS,
- S2A.S2A_MTLS_ADDRESS_JSON_KEY,
+ SecureSessionAgent.S2A_MTLS_ADDRESS_JSON_KEY,
  S2A_MTLS_ADDRESS));
  transportFactory.transport.setRequestStatusCode(HttpStatusCodes.STATUS_CODE_OK);
 
- S2A s2aUtils = S2A.newBuilder().setHttpTransportFactory(transportFactory).build();
- String plaintextS2AAddress = s2aUtils.getPlaintextS2AAddress();
- String mtlsS2AAddress = s2aUtils.getMtlsS2AAddress();
+ SecureSessionAgent s2aUtils =
+ SecureSessionAgent.newBuilder().setHttpTransportFactory(transportFactory).build();
+ SecureSessionAgentConfig config = s2aUtils.getConfig();
+ String plaintextS2AAddress = config.getPlaintextAddress();
+ String mtlsS2AAddress = config.getMtlsAddress();
  assertEquals(S2A_PLAINTEXT_ADDRESS, plaintextS2AAddress);
  assertEquals(S2A_MTLS_ADDRESS, mtlsS2AAddress);
  }
@@ -71,16 +73,18 @@ public void getS2AAddress_queryEndpointResponseErrorCode_emptyAddress() {
  MockMetadataServerTransportFactory transportFactory = new MockMetadataServerTransportFactory();
  transportFactory.transport.setS2AContentMap(
  ImmutableMap.of(
- S2A.S2A_PLAINTEXT_ADDRESS_JSON_KEY,
+ SecureSessionAgent.S2A_PLAINTEXT_ADDRESS_JSON_KEY,
  S2A_PLAINTEXT_ADDRESS,
- S2A.S2A_MTLS_ADDRESS_JSON_KEY,
+ SecureSessionAgent.S2A_MTLS_ADDRESS_JSON_KEY,
  S2A_MTLS_ADDRESS));
  transportFactory.transport.setRequestStatusCode(
  HttpStatusCodes.STATUS_CODE_SERVICE_UNAVAILABLE);
 
- S2A s2aUtils = S2A.newBuilder().setHttpTransportFactory(transportFactory).build();
- String plaintextS2AAddress = s2aUtils.getPlaintextS2AAddress();
- String mtlsS2AAddress = s2aUtils.getMtlsS2AAddress();
+ SecureSessionAgent s2aUtils =
+ SecureSessionAgent.newBuilder().setHttpTransportFactory(transportFactory).build();
+ SecureSessionAgentConfig config = s2aUtils.getConfig();
+ String plaintextS2AAddress = config.getPlaintextAddress();
+ String mtlsS2AAddress = config.getMtlsAddress();
  assertTrue(plaintextS2AAddress.isEmpty());
  assertTrue(mtlsS2AAddress.isEmpty());
  }
@@ -90,16 +94,18 @@ public void getS2AAddress_queryEndpointResponseEmpty_emptyAddress() {
  MockMetadataServerTransportFactory transportFactory = new MockMetadataServerTransportFactory();
  transportFactory.transport.setS2AContentMap(
  ImmutableMap.of(
- S2A.S2A_PLAINTEXT_ADDRESS_JSON_KEY,
+ SecureSessionAgent.S2A_PLAINTEXT_ADDRESS_JSON_KEY,
  S2A_PLAINTEXT_ADDRESS,
- S2A.S2A_MTLS_ADDRESS_JSON_KEY,
+ SecureSessionAgent.S2A_MTLS_ADDRESS_JSON_KEY,
  S2A_MTLS_ADDRESS));
  transportFactory.transport.setRequestStatusCode(HttpStatusCodes.STATUS_CODE_OK);
  transportFactory.transport.setEmptyContent(true);
 
- S2A s2aUtils = S2A.newBuilder().setHttpTransportFactory(transportFactory).build();
- String plaintextS2AAddress = s2aUtils.getPlaintextS2AAddress();
- String mtlsS2AAddress = s2aUtils.getMtlsS2AAddress();
+ SecureSessionAgent s2aUtils =
+ SecureSessionAgent.newBuilder().setHttpTransportFactory(transportFactory).build();
+ SecureSessionAgentConfig config = s2aUtils.getConfig();
+ String plaintextS2AAddress = config.getPlaintextAddress();
+ String mtlsS2AAddress = config.getMtlsAddress();
  assertTrue(plaintextS2AAddress.isEmpty());
  assertTrue(mtlsS2AAddress.isEmpty());
  }
@@ -111,13 +117,15 @@ public void getS2AAddress_queryEndpointResponseInvalidPlaintextJsonKey_plaintext
  ImmutableMap.of(
  INVALID_JSON_KEY,
  S2A_PLAINTEXT_ADDRESS,
- S2A.S2A_MTLS_ADDRESS_JSON_KEY,
+ SecureSessionAgent.S2A_MTLS_ADDRESS_JSON_KEY,
  S2A_MTLS_ADDRESS));
  transportFactory.transport.setRequestStatusCode(HttpStatusCodes.STATUS_CODE_OK);
 
- S2A s2aUtils = S2A.newBuilder().setHttpTransportFactory(transportFactory).build();
- String plaintextS2AAddress = s2aUtils.getPlaintextS2AAddress();
- String mtlsS2AAddress = s2aUtils.getMtlsS2AAddress();
+ SecureSessionAgent s2aUtils =
+ SecureSessionAgent.newBuilder().setHttpTransportFactory(transportFactory).build();
+ SecureSessionAgentConfig config = s2aUtils.getConfig();
+ String plaintextS2AAddress = config.getPlaintextAddress();
+ String mtlsS2AAddress = config.getMtlsAddress();
  assertTrue(plaintextS2AAddress.isEmpty());
  assertEquals(S2A_MTLS_ADDRESS, mtlsS2AAddress);
  }
@@ -127,15 +135,17 @@ public void getS2AAddress_queryEndpointResponseInvalidMtlsJsonKey_mtlsEmptyAddre
  MockMetadataServerTransportFactory transportFactory = new MockMetadataServerTransportFactory();
  transportFactory.transport.setS2AContentMap(
  ImmutableMap.of(
- S2A.S2A_PLAINTEXT_ADDRESS_JSON_KEY,
+ SecureSessionAgent.S2A_PLAINTEXT_ADDRESS_JSON_KEY,
  S2A_PLAINTEXT_ADDRESS,
  INVALID_JSON_KEY,
  S2A_MTLS_ADDRESS));
  transportFactory.transport.setRequestStatusCode(HttpStatusCodes.STATUS_CODE_OK);
 
- S2A s2aUtils = S2A.newBuilder().setHttpTransportFactory(transportFactory).build();
- String plaintextS2AAddress = s2aUtils.getPlaintextS2AAddress();
- String mtlsS2AAddress = s2aUtils.getMtlsS2AAddress();
+ SecureSessionAgent s2aUtils =
+ SecureSessionAgent.newBuilder().setHttpTransportFactory(transportFactory).build();
+ SecureSessionAgentConfig config = s2aUtils.getConfig();
+ String plaintextS2AAddress = config.getPlaintextAddress();
+ String mtlsS2AAddress = config.getMtlsAddress();
  assertEquals(S2A_PLAINTEXT_ADDRESS, plaintextS2AAddress);
  assertTrue(mtlsS2AAddress.isEmpty());
  }