[tor-relays] failed setup of obfs4 on relay

[teor]

> On 31 Mar 2018, at 04:03, <jackoreamnos at tutanota.com> <jackoreamnos at tutanota.com> wrote:
> 
> Alright, problem solved although I don't understand why.  Hope someone can educate me:
> 
> What I did.
> (1) Turned on Log debug stderr in torrc, and I could see obfs4 loading correctly.
> (2) Then I realized obfs4 writes to a file to help people construct the bridgeline for tow browser in pt_state/obfs4_bridgeline.txt
> 
> The format is like:
> Bridge obfs4 <IP ADDRESS>:<PORT> <FINGERPRINT> cert=[scrubbed] iat-mode=[scrubbed]
> 
> Which is different from the bridge line I used by hand, i.e. has FINGERPRINT, has cert=? and iat-mode=?.  
> These extra bits made all the difference, but why?

Tor can't connect to an obfs4 bridge without its certificate.
The encryption just won't work.

iat-mode controls some other protocol details.

T