Facebook auth on Linux SSL error: weak, ephemeral Diffie-Hellman key

[ZimbiX]

I'm trying to log in to Spotify Linux using Facebook, but I'm seeing the "Spotify desktop client communication failed" error.

This is the URL that fails to load is https://login.spotilocal.com:4371/, which does correctly resolve to 127.0.0.1.

I'm running "stable" Spotify (spotify-client_0.9.17.1.g9b85d43.7-1_amd64) on Ubuntu 15.04.

I read that logging in to Spotify directly using my Facebook credentials can work, but I'm not comfortable doing this - especially given how I saw elsewhere that the credentials are not transmitted directly to Facebook, but via Spotify servers...

Chrome:

Server has a weak, ephemeral Diffie-Hellman public key

ERR_SSL_WEAK_SERVER_EPHEMERAL_DH_KEY

Firefox:

An error occurred during a connection to login.spotilocal.com:4371.

SSL received a weak ephemeral Diffie-Hellman key in Server Key Exchange handshake message.

(Error code: ssl_error_weak_server_ephemeral_dh_key)

The Firefox console shows the error on the requesting page better than Chrome:

[Dreadlord · Accepted solution]

Hello @ZimbiX,

Can you please let me know your Firefox version?

Also can you please try to install the latest non-stable version and let me know if the SSL issue persists?

Alternatively you can go to about:config in firefox and change security.ssl3.dhe_rsa_aes 128/256 to false.

Once you get your autologin.blob just save it ( look for prefs file ) and set security.ssl3.dhe_rsa_aes 128/256 once again. 

If you have any questions, don't hesitate to ask 🙂

[ZimbiX]

Thanks for the suggestions, @Dreadlord. Since posting, I have found and switched to the non-stable version, which has alleviated this particular problem for me. I did look into those settings before deciding to go with the non-stable version, and I'm curious as to if they would have worked.

I'm booting this disk on a different machine today, which must be why it prompted me to re-log in. Do you know how Spotify detects this?

The non-stable is now re-downloading all my offline'd playlists and appears to be effectively duplicating the existing cache, going by the rapidly increasing size of the already large ~/.cache/spotify. Is there a recommended method to safely remove the cache without having to manually reselect the many playlists to download?

Cheers,

-ZimbiX

[Dreadlord]

Hey @ZimbiX,

When you are logging in, Spotify checks your prefs file for autologin credentials.

You can easily see that with 

strace spotify

Spotify opens up prefs file checks for credentials and closes the file.

Example prefs file :

Spoiler

autologin.username="facebook user ID"
autologin.blob="example blob goes there"
app.autostart-configured=true
autologin.canonical_username="your username goes here if you set one"
autologin.saved_credentials="{\"Facebook ID here\":\"example blob goes here"}"
core.clock_delta=3

As for the cache, I haven't checked how it works, but I think there should be a way to do it using symlinks.