DTLS Handshake seems to fail when connecting Android/Linux about libdatachannel HOT 5 CLOSED

I updated libjuce from current master and it fixed the problem.
Linux to Android (when android is answering) is working.
Android to Android is working too.

This may be my build specific issue(I build libdatachannel/juice in my project build environment) but I will mention:
I have noticed that libjuice has a call to "getrandom" in random.c
getrandom() is not available on old androids (I target API 21) I believe it was added in API 28.
proper/safe random number generation is obviously out of scope of our debug/testing so I just replaced "static int random_bytes(void *buf, size_t size)" body with:
char ptr = (char)buf;
for (int i = 0; i < size; ++i)
ptr[i] = rand();
You may want to add some ifdef android there or something (with something better than what I did obviously :-)

Thank you for your great work!
I find libjuice and libdatachannel to be very useful components. I have experience working with other ICE libraries(nice/pjnath etc) and this one seems to be the easiest to work with.
The part that you can libjuice instead of libnice is just fantastic (libnice is OK but it requires all the gobject/glib etc stuff which are just too big for small libraries/projects)
Having webrtc.datachannel capability without full WebRTC behemoth library is a great benefit.

from libdatachannel.

Thanks for the logs, looking at them it seems the DTLS handshake failure is not the root of the problem. It actually looks like Android does not receive what is sent by Linux after ICE is connected when it is the answerer (so when it is in the ICE controlled role), in particular it never receives the DTLS server hello. So my guess is this is probably an Android-specific issue with ICE.

I recently merged some minor fixes in libjuice, and I just added error checking on send since it was missing. Could you please retry with the current master? (Don't forget to update the submodules)

If it still doesn't work, the log might give us more information about the issue.

from libdatachannel.

I used the https://github.com/paullouisageneau/libdatachannel/tree/usrsctp-fix-notifications branch. Is it already merged to master ? As without this fix, I get the problem of len(messages)>65k...
I will update libjuice from it's own git master repo, rebuild and see if it fixes it.
If the problem still happens I will update to libdatachannel to master branch and check again.
I will report back my findings.

from libdatachannel.

Don't worry, it's merged to master. Updating libjuice on its own should work too!

from libdatachannel.

Thanks for your very positive feedback, I'm glad the libraries are useful for you! The usage simplicity was indeed the main goal so it's cool to have achieved it in some extend.

It's great it works now, I don't exactly know what the problem was on Android but that's for the better.

Rather than replacing random_bytes(), I think you could get away with changing #if defined(__linux__) to #if defined(__linux__) && !defined(__ANDROID__) here:
https://github.com/paullouisageneau/libjuice/blob/7cd5e53d54f83048122e14a6cc52f6ac38b7a98c/src/random.c#L27
This will output a failing random_bytes() instead and juice_random will fallback on random() which should be available on Android.

from libdatachannel.