okhttp: enable TLS 1.3 on Android, retain TLS 1.2-only for desktop JVM

bengtsson1-flir · web-flow · commit f43013161b3c · 2026-05-01T06:55:43.000-07:00
The ConnectionSpec used by OkHttpChannelBuilder had TLS 1.3 explicitly disabled since Dec 2020 due to a Conscrypt/SunJSSE incompatibility. However, this incompatibility does not affect Android. The previous code applied the TLS 1.2-only restriction unconditionally to all platforms. Regulatory impact: TLS 1.2 is classified as a legacy mechanism in ENISA Agreed Cryptographic Mechanisms v2.0 (April 2025), with TLS 1.3 listed as the recommended protocol. This limitation has been forcing all downstream components using grpc-okhttp on Android to operate with a legacy protocol, creating compliance friction with the EU Radio Equipment Directive (RED) and EU Cyber Resilience Act (CRA) certification requirements. Fixes: #7431 (Android only) Fixes: #7765 (Android only)
diff --git a/okhttp/src/main/java/io/grpc/okhttp/OkHttpChannelBuilder.java b/okhttp/src/main/java/io/grpc/okhttp/OkHttpChannelBuilder.java
@@ -116,17 +116,26 @@ private enum NegotiationType {
               CipherSuite.TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,
               CipherSuite.TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,
               CipherSuite.TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256,
-              CipherSuite.TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
-
-              // TLS 1.3 does not work so far. See issues:
-              // https://github.com/grpc/grpc-java/issues/7765
-              //
-              // TLS 1.3
-              //CipherSuite.TLS_AES_128_GCM_SHA256,
-              //CipherSuite.TLS_AES_256_GCM_SHA384,
-              //CipherSuite.TLS_CHACHA20_POLY1305_SHA256
-              )
-          .tlsVersions(/*TlsVersion.TLS_1_3,*/ TlsVersion.TLS_1_2)
+              CipherSuite.TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256,
+              CipherSuite.TLS_AES_128_GCM_SHA256,
+              CipherSuite.TLS_AES_256_GCM_SHA384,
+              CipherSuite.TLS_CHACHA20_POLY1305_SHA256)
+          .tlsVersions(TlsVersion.TLS_1_3, TlsVersion.TLS_1_2)
+          .supportsTlsExtensions(true)
+          .build();
+
+  // @VisibleForTesting
+  static final ConnectionSpec INTERNAL_LEGACY_CONNECTION_SPEC =
+      new ConnectionSpec.Builder(ConnectionSpec.MODERN_TLS)
+          .cipherSuites(
+              // The following items should be sync with Netty's Http2SecurityUtil.CIPHERS.
+              CipherSuite.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
+              CipherSuite.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
+              CipherSuite.TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,
+              CipherSuite.TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,
+              CipherSuite.TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256,
+              CipherSuite.TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256)
+          .tlsVersions(TlsVersion.TLS_1_2)
           .supportsTlsExtensions(true)
           .build();
 
@@ -184,7 +193,7 @@ public static OkHttpChannelBuilder forTarget(String target, ChannelCredentials c
   private SSLSocketFactory sslSocketFactory;
   private final boolean freezeSecurityConfiguration;
   private HostnameVerifier hostnameVerifier;
-  private ConnectionSpec connectionSpec = INTERNAL_DEFAULT_CONNECTION_SPEC;
+  private ConnectionSpec connectionSpec = initialConnectionSpec();
   private NegotiationType negotiationType = NegotiationType.TLS;
   private long keepAliveTimeNanos = KEEPALIVE_TIME_NANOS_DISABLED;
   private long keepAliveTimeoutNanos = DEFAULT_KEEPALIVE_TIMEOUT_NANOS;
@@ -199,6 +208,12 @@ public static OkHttpChannelBuilder forTarget(String target, ChannelCredentials c
    */
   private final boolean useGetForSafeMethods = false;
 
+  private static ConnectionSpec initialConnectionSpec() {
+    return (OkHttpProtocolNegotiator.get() instanceof OkHttpProtocolNegotiator.AndroidNegotiator)
+        ? INTERNAL_DEFAULT_CONNECTION_SPEC
+        : INTERNAL_LEGACY_CONNECTION_SPEC;
+  }
+
   private OkHttpChannelBuilder(String host, int port) {
     this(GrpcUtil.authorityFromHostAndPort(host, port));
   }
diff --git a/okhttp/src/main/java/io/grpc/okhttp/OkHttpProtocolNegotiator.java b/okhttp/src/main/java/io/grpc/okhttp/OkHttpProtocolNegotiator.java
@@ -122,7 +122,6 @@ public String getSelectedProtocol(SSLSocket socket) {
     return platform.getSelectedProtocol(socket);
   }
 
-  @VisibleForTesting
   static final class AndroidNegotiator extends OkHttpProtocolNegotiator {
     // setUseSessionTickets(boolean)
     private static final OptionalMethod<Socket> SET_USE_SESSION_TICKETS =
diff --git a/okhttp/src/main/java/io/grpc/okhttp/SslSocketFactoryServerCredentials.java b/okhttp/src/main/java/io/grpc/okhttp/SslSocketFactoryServerCredentials.java
@@ -41,7 +41,7 @@ static final class ServerCredentials extends io.grpc.ServerCredentials {
     private final ConnectionSpec connectionSpec;
 
     ServerCredentials(SSLSocketFactory factory) {
-      this(factory, OkHttpChannelBuilder.INTERNAL_DEFAULT_CONNECTION_SPEC);
+      this(factory, OkHttpChannelBuilder.INTERNAL_LEGACY_CONNECTION_SPEC);
     }
 
     ServerCredentials(SSLSocketFactory factory, ConnectionSpec connectionSpec) {

Original file line number	Diff line number	Diff line change
`@@ -122,7 +122,6 @@ public String getSelectedProtocol(SSLSocket socket) {`
`122`	`122`	`return platform.getSelectedProtocol(socket);`
`123`	`123`	`}`
`124`	`124`
`125`		`- @VisibleForTesting`
`126`	`125`	`static final class AndroidNegotiator extends OkHttpProtocolNegotiator {`
`127`	`126`	`// setUseSessionTickets(boolean)`
`128`	`127`	`private static final OptionalMethod<Socket> SET_USE_SESSION_TICKETS =`
Original file line number	Diff line number	Diff line change
`@@ -41,7 +41,7 @@ static final class ServerCredentials extends io.grpc.ServerCredentials {`
`41`	`41`	`private final ConnectionSpec connectionSpec;`
`42`	`42`
`43`	`43`	`ServerCredentials(SSLSocketFactory factory) {`
`44`		`- this(factory, OkHttpChannelBuilder.INTERNAL_DEFAULT_CONNECTION_SPEC);`
	`44`	`+ this(factory, OkHttpChannelBuilder.INTERNAL_LEGACY_CONNECTION_SPEC);`
`45`	`45`	`}`
`46`	`46`
`47`	`47`	`ServerCredentials(SSLSocketFactory factory, ConnectionSpec connectionSpec) {`