[stunnel-users] Compression (zlib) does not work under windows

Thu Jun 9 20:54:17 CEST 2005

Hello,

Enabling zlib compression in stunnel (versions 4.06 - 4.10) does not work under windows.  I have tried a combination of the following, all of which have failed in either two ways.  The first way being disconnection with the following messages in the stunnel console:

2005.06.09 11:43:10 LOG7[4072:3088]: SSL alert (write): fatal: decompression failure
2005.06.09 11:43:10 LOG3[4072:3088]: SSL_read: 1408F06B: error:1408F06B:SSL routines:SSL3_GET_RECORD:bad decompression

Or stunnel crashes all together.

Here are the following combinations I've used with stunnel and openssl.

stunnel 4.06 w/ all zlib binary openssl libraries
stunnel 4.07 w/ all zlib binary enabled openssl libraries
stunnel 4.08 w/ all zlib binary enabled openssl libraries
stunnel 4.09 w/ all zlib enabled openssl libraries
stunnel 4.10 w/ all zlib enabled openssl libraries

stunnel 4.06 w/ custom compiled openssl 0.9.7g w/ zlib library under vc++
stunnel 4.07 w/ custom compiled openssl 0.9.7g  w/ zlib library under vc++
stunnel 4.08 w/ custom compiled openssl 0.9.7g  w/ zlib library under vc++
stunnel 4.09 w/ custom compiled openssl 0.9.7g  w/ zlib library under vc++
stunnel 4.10 w/ custom compiled openssl 0.9.7g  w/ zlib library under vc++

Under linux, using stunnel as a client, compression works correctly.

On the server I have tried stunnel versions:

stunnel 4.06 w/ zlib openssl 0.9.7g and openssl 0.9.7f
stunnel 4.09 w/ zlib openssl 0.9.7g and openssl 0.9.7f
stunnel 4.10 w/ zlib openssl 0.9.7g and openssl 0.9.7f

Any help would be appreciated.  We offer stunnel connections as a service to our clients to reduce the overhead of NNTP traffic and we would very much like to get compression working.

Thanks for your time,
Ben