zlib compression with dbclient

Ari Hyttinen ari.hyttinen at ailocom.com
Tue Nov 8 17:31:37 WST 2005


Only way I could get zlib compression to work with dbclient and OpenSSH 
sshd was to
- either disable "none" compression completely or at least put it after 
"zlib" compression (in common-algo.c)
*and*
- set 'Compression Yes' in OpenSSH sshd_config.

OpenSSH compression default is "delayed", ie to allow compression only 
after authentication, and if I left it to be default, then dbclient with 
"none" compression disabled could not connect at all (as expected).  
With both "zlib" and "none" (no matter the order in common-algo.c), 
dbclient would never switch to using zlib after authenticating with "none".

I looked at trace log "enter buf_compress"/"leave buf_compress" messages 
to determine if compression was actually in use.

So to use zlib compression with dbclient, I had to tweak both OpenSSH 
sshd_config *and* dropbear source.  Am I missing something or is this 
simply an unimplemented feature?

-- 
Ailocom Oy
Ari Hyttinen
mobile: +358-50-4040731
e-mail: ari.hyttinen at ailocom.com




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