Hi,
I’ve tried to compile the app and see what the issue is. Indeed, as mentioned in Syncthing lite no longer works.... it’s the TLSV1_ALERT_PROTOCOL_VERSION error.
I’ll see if that can be bumped to TLSv1.3 somehow. But my first attempt to compile on modern Android Studio failed for hours, not being able to fix all issues (hundreds of errors). I’ve now managed to get a working APK on Android studio dated back to Dec’2018.
Another thing that’s making me feel uncomfortable is, I’ve switched in a repo for the now officially unavailable ANKO dependency that still hosts it.
maven { url “https://artifactory.appodeal.com/appodeal-public/” }
Maybe a coincidential sighting, but after my first build where all those modules associated with it were loaded into the Android java buildEnv by gradle, I’ve noticed this running process on my build machine:
C:\WINDOWS\explorer.exe /factory,{75dff2b7-6936-4c06-a8bb-676a7b00b24b} -Embedding
If you put the string into Google, there are warnings that this may be an exploit indicator, as Explorer.exe is running below the “svchost.exe” process. Oh my 
.
If someone is reading this and likes to help me migrating the kotlin project and dependencies to a recent Android Studio build, we could work together. Please contact me. I’ve already re-written some classes to build using currently supported dependencies, like AppIntro (continued in a fork on github) and sf4j.
As well if anyone has a hint for me, how that “old java 1.8 compiled thingy” using gradle 4.6 could get TLS v1.3 activated.
failed to connect to DeviceAddress(deviceId=DeviceId(deviceId=RF2FVSV), instanceId=null, address=relay://services.ff3l.net:22067, producer=UNKNOWN, score=2108, lastModified=Tue Jul 01 10:23:34 GMT 2025)
javax.net.ssl.SSLHandshakeException: Read error: ssl=0x76a898c39858: Failure in SSL library, usually a protocol error
error:1000042e:SSL routines:OPENSSL_internal:TLSV1_ALERT_PROTOCOL_VERSION (external/boringssl/src/ssl/tls_record.cc:592 0x76aa28cb8c60:0x00000003)
at com.android.org.conscrypt.SSLUtils.toSSLHandshakeException(SSLUtils.java:356)
at com.android.org.conscrypt.ConscryptEngine.convertException(ConscryptEngine.java:1127)
at com.android.org.conscrypt.ConscryptEngine.unwrap(ConscryptEngine.java:912)
at com.android.org.conscrypt.ConscryptEngine.unwrap(ConscryptEngine.java:740)
at com.android.org.conscrypt.ConscryptEngine.unwrap(ConscryptEngine.java:705)
at com.android.org.conscrypt.ConscryptEngineSocket$SSLInputStream.processDataFromSocket(ConscryptEngineSocket.java:896)
at com.android.org.conscrypt.ConscryptEngineSocket$SSLInputStream.-$$Nest$mprocessDataFromSocket(Unknown Source:0)
at com.android.org.conscrypt.ConscryptEngineSocket.doHandshake(ConscryptEngineSocket.java:236)
at com.android.org.conscrypt.ConscryptEngineSocket.startHandshake(ConscryptEngineSocket.java:218)
at com.android.org.conscrypt.ConscryptEngineSocket.waitForHandshake(ConscryptEngineSocket.java:609)
at com.android.org.conscrypt.ConscryptEngineSocket.-$$Nest$mwaitForHandshake(Unknown Source:0)
at com.android.org.conscrypt.ConscryptEngineSocket$SSLInputStream.read(ConscryptEngineSocket.java:833)
at java.io.DataInputStream.readFully(DataInputStream.java:203)
at java.io.DataInputStream.readInt(DataInputStream.java:394)
at net.syncthing.java.bep.connectionactor.HelloMessageHandler.receiveHelloMessage(HelloMessageHandler.kt:63)
at net.syncthing.java.bep.connectionactor.ConnectionActor$createInstance$1$invokeSuspend$$inlined$use$lambda$1$2.invokeSuspend(Instance.kt:50)
at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:32)
at kotlinx.coroutines.DispatchedTask$DefaultImpls.run(Dispatched.kt:235)
at kotlinx.coroutines.DispatchedContinuation.run(Dispatched.kt:81)
at kotlinx.coroutines.scheduling.Task.run(Tasks.kt:94)
at kotlinx.coroutines.scheduling.CoroutineScheduler.runSafely(CoroutineScheduler.kt:586)
at kotlinx.coroutines.scheduling.CoroutineScheduler.access$runSafely(CoroutineScheduler.kt:60)
at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.run(CoroutineScheduler.kt:732)
Caused by: javax.net.ssl.SSLProtocolException: Read error: ssl=0x76a898c39858: Failure in SSL library, usually a protocol error
error:1000042e:SSL routines:OPENSSL_internal:TLSV1_ALERT_PROTOCOL_VERSION (external/boringssl/src/ssl/tls_record.cc:592 0x76aa28cb8c60:0x00000003)
at com.android.org.conscrypt.NativeCrypto.ENGINE_SSL_read_direct(Native Method)
at com.android.org.conscrypt.NativeSsl.readDirectByteBuffer(NativeSsl.java:570)
at com.android.org.conscrypt.ConscryptEngine.readPlaintextDataDirect(ConscryptEngine.java:1088)
at com.android.org.conscrypt.ConscryptEngine.readPlaintextData(ConscryptEngine.java:1072)
at com.android.org.conscrypt.ConscryptEngine.unwrap(ConscryptEngine.java:869)
... 20 more
. Depending on how much I succeed with reviving syncthing-lite, there’ll maybe also a git repo fork.
. But I can now connect successfully to an old syncthing v1.13.1 node.
, idk why.
But thank you for spearheading the diagnosis. Your efforts are greatly appreciated for looking into it though. It would be cool if syncthing lite was re-born.
