s2a: Correct type of exception thrown (#11588)

* throw IllegalArgumentException in ProtoUtil.

* throw exception in TrustManager in more standard way.

* handle IllegalArgumentException in SslContextFactory.

* Don't throw error on unknown TLS version.

Author: rmehta19

s2a/src/main/java/io/grpc/s2a/internal/handshaker/ProtoUtil.java

@@ -27,7 +27,8 @@ final class ProtoUtil {
    *
    * @param tlsVersion the {@link TLSVersion} object to be converted.
    * @return a {@link String} representation of the TLS version.
-   * @throws AssertionError if the {@code tlsVersion} is not one of the supported TLS versions.
+   * @throws IllegalArgumentException if the {@code tlsVersion} is not one of
+   *     the supported TLS versions.
    */
   @VisibleForTesting
   static String convertTlsProtocolVersion(TLSVersion tlsVersion) {
@@ -41,7 +42,7 @@ static String convertTlsProtocolVersion(TLSVersion tlsVersion) {
       case TLS_VERSION_1_0:
         return "TLSv1";
       default:
-        throw new AssertionError(
+        throw new IllegalArgumentException(
             String.format("TLS version %d is not supported.", tlsVersion.getNumber()));
     }
   }
@@ -62,7 +63,11 @@ static ImmutableSet<String> buildTlsProtocolVersionSet(
       }
       if (versionNumber >= minTlsVersion.getNumber()
           && versionNumber <= maxTlsVersion.getNumber()) {
-        tlsVersions.add(convertTlsProtocolVersion(tlsVersion));
+        try {
+          tlsVersions.add(convertTlsProtocolVersion(tlsVersion));
+        } catch (IllegalArgumentException e) {
+          continue;
+        }
       }
     }
     return tlsVersions.build();

s2a/src/main/java/io/grpc/s2a/internal/handshaker/S2ATrustManager.java

@@ -120,10 +120,10 @@ private void checkPeerTrusted(X509Certificate[] chain, boolean isCheckingClientC
     SessionResp resp;
     try {
       resp = stub.send(reqBuilder.build());
-    } catch (IOException | InterruptedException e) {
-      if (e instanceof InterruptedException) {
-        Thread.currentThread().interrupt();
-      }
+    } catch (IOException e) {
+      throw new CertificateException("Failed to send request to S2A.", e);
+    } catch (InterruptedException e) {
+      Thread.currentThread().interrupt();
       throw new CertificateException("Failed to send request to S2A.", e);
     }
     if (resp.hasStatus() && resp.getStatus().getCode() != 0) {

s2a/src/main/java/io/grpc/s2a/internal/handshaker/SslContextFactory.java

@@ -138,11 +138,13 @@ private static void configureSslContextWithClientTlsConfiguration(
           NoSuchAlgorithmException,
           UnrecoverableKeyException {
     sslContextBuilder.keyManager(createKeylessManager(clientTlsConfiguration));
-    ImmutableSet<String> tlsVersions =
+    ImmutableSet<String> tlsVersions;
+    tlsVersions =
         ProtoUtil.buildTlsProtocolVersionSet(
             clientTlsConfiguration.getMinTlsVersion(), clientTlsConfiguration.getMaxTlsVersion());
     if (tlsVersions.isEmpty()) {
-      throw new S2AConnectionException("Set of TLS versions received from S2A server is empty.");
+      throw new S2AConnectionException("Set of TLS versions received from S2A server is"
+        + " empty or not supported.");
     }
     sslContextBuilder.protocols(tlsVersions);
   }

s2a/src/test/java/io/grpc/s2a/internal/handshaker/ProtoUtilTest.java

@@ -46,9 +46,9 @@ public void convertTlsProtocolVersion_success() {
 
   @Test
   public void convertTlsProtocolVersion_withUnknownTlsVersion_fails() {
-    AssertionError expected =
+    IllegalArgumentException expected =
         assertThrows(
-            AssertionError.class,
+            IllegalArgumentException.class,
             () -> ProtoUtil.convertTlsProtocolVersion(TLSVersion.TLS_VERSION_UNSPECIFIED));
     expect.that(expected).hasMessageThat().isEqualTo("TLS version 0 is not supported.");
   }
@@ -79,12 +79,10 @@ public void buildTlsProtocolVersionSet_success() {
 
   @Test
   public void buildTlsProtocolVersionSet_failure() {
-    AssertionError expected =
-        assertThrows(
-            AssertionError.class,
-            () ->
-                ProtoUtil.buildTlsProtocolVersionSet(
-                    TLSVersion.TLS_VERSION_UNSPECIFIED, TLSVersion.TLS_VERSION_1_3));
-    expect.that(expected).hasMessageThat().isEqualTo("TLS version 0 is not supported.");
+    expect
+        .that(
+            ProtoUtil.buildTlsProtocolVersionSet(
+                    TLSVersion.TLS_VERSION_UNSPECIFIED, TLSVersion.TLS_VERSION_1_3))
+        .isEqualTo(ImmutableSet.of("TLSv1", "TLSv1.1", "TLSv1.2", "TLSv1.3"));
   }
 }

s2a/src/test/java/io/grpc/s2a/internal/handshaker/SslContextFactoryTest.java

@@ -142,7 +142,7 @@ public void createForClient_getsBadTlsVersionsFromServer_throwsError() throws Ex
 
     assertThat(expected)
         .hasMessageThat()
-        .contains("Set of TLS versions received from S2A server is empty.");
+        .contains("Set of TLS versions received from S2A server is empty or not supported.");
   }
 
   @Test