[Bug]: Streaming handshake fails when pointing to local Restreamer container.

[ZacharyPlayss]

Version

3.1.2

Environment that reproduces the issue

I'm running Restreamer in a docker container.

For the streampack side I use the "camera demo" defaults (with change of the endpoint ofcourse)

RTMP/SRT/... Server

RTMP

Audio configuration

Default demo configuration

Video configuration

Default demo configuration

Is it reproducible in the demos application?

Yes

Reproduction steps

1. Run the camera stream demo.
2. Run Restreamer in docker as provided here : Restreamer
3. Enable RTMP in Restreamer and copy the endpoint into the demo project.
4. Try to stream.

here is a sample docker compose you can use to recreate the config.

services:
  restreamer:
    image: datarhei/restreamer:latest
    container_name: restreamer
    restart: always
    ports:
      - "8080:8080"
      - "8181:8181"
      - "1935:1935" 
      - "6000:6000/udp"
    environment:
      - RS_TOKEN=mytoken 
      - RS_USERNAME=admin
      - RS_PASSWORD=1234
    volumes:
      - ./config:/core/config
      - ./data:/core/data

visit localhost:8080/ui for on screen config for RTMP streams.

Expected result

Succesfull livestream to restreamer

Actual result

Error pop up containing "Handshake failed: S2 and C1 must have the same random sequence"

Additional context

I'm not to sure wheter this is on the packages end or on Restreamer's end.

Relevant logs output

E  startStream failed
                                                                                                    java.lang.IllegalArgumentException: Handshake failed: S2 and C1 must have the same random sequence
                                                                                                    	at io.github.komedia.komuxer.rtmp.util.Handshake.startClient$rtmp_debug(Handshake.kt:66)
                                                                                                    	at io.github.komedia.komuxer.rtmp.util.Handshake$startClient$1.invokeSuspend(Unknown Source:14)
                                                                                                    	at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:34)
                                                                                                    	at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:100)
                                                                                                    	at kotlinx.coroutines.internal.LimitedDispatcher$Worker.run(LimitedDispatcher.kt:124)
                                                                                                    	at kotlinx.coroutines.scheduling.TaskImpl.run(Tasks.kt:89)
                                                                                                    	at kotlinx.coroutines.scheduling.CoroutineScheduler.runSafely(CoroutineScheduler.kt:586)
                                                                                                    	at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.executeTask(CoroutineScheduler.kt:820)
                                                                                                    	at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.runWorker(CoroutineScheduler.kt:717)
                                                                                                    	at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.run(CoroutineScheduler.kt:704)
2026-02-12 14:43:23.210  8869-8869  PreviewFragment         io....thibaultbee.streampack.sample  E  Error: Oops, startStream: Handshake failed: S2 and C1 must have the same random sequence

[ThibaultBee]

Hi,

Thanks for your wll documented issue.

The exception is raised here: https://github.com/ThibaultBee/krtmp/blob/6e7c96e676f22c363072e08b5337baeea097df1b/rtmp/src/commonMain/kotlin/io/github/thibaultbee/krtmp/rtmp/util/Handshake.kt#L66

The reason is that S2 payload must be equals to C1 which is not the case here.

Now, of course I could remove the require.
But if you look at the RTMP spec, chapter 5.2.4. C2 and S2 Format.
It says about S2 payload:

Random echo (1528 bytes): This field MUST contain the random data
field sent by the peer in S1 (for C2) or S2 (for C1). Either peer
can use the time and time2 fields together with the current
timestamp as a quick estimate of the bandwidth and/or latency of
the connection, but this is unlikely to be useful.

I believe the error to be in Restreamer side. Probably here. Could you add an issue there?

[ZacharyPlayss]

Hi,

Thanks for the quick response.
Following your provided documents it makes a lot of sense.

However I tried this exact config using version 3.0.2 of your package which works fine. I assume this package just doesn't have that specific requirement yet?

I'll also create an issue on Restreamer side for this btw.

[ThibaultBee]

However I tried this exact config using version 3.0.2 of your package which works fine. I assume this package just doesn't have that specific requirement yet?

I completely changed the RTMP implementation between 3.0 and 3.1. It might be a stricter than before.

[ZacharyPlayss]

Ahhh okay!

I'll try to get things sorted on restreamers side then, thanks for the information and help!

[ThibaultBee]

Could you link the Restreamer issue to this thread?

[ThibaultBee]

This issue is not directly related to this project.
Please reopen it if you feel this is an issue that shoud be fixed here.