[stunnel-users] stunnel patch to support URL lookups for parameters (take 2)
dan.jakubiec at gmail.com
Wed Dec 13 21:04:56 CET 2006
Attached is a patch which extends the "connect=" and "CApath=" options
to allow these parameters to be obtained dynamically at connect-time
via a URL lookup, rather than statically from the stunnel
configuration file. It is a generalization of an earlier patch to
4.04 submitted by Jan Piet-Mens which does something similar using
LDAP lookups. Feedback is appreciated!
Here is a summary of the functionality, along with some notes:
1. The patch was written to allow stunnel to dynamically route and
authenticate incoming connections based on parameters found in the
2. Routing and authentication information is obtained by issuing a URL
lookup, so the information can be obtained from a variety of local or
3. It is particularly useful in high-volume, load-balancing scenarios
where many copies of stunnel are running on multiple front-end
servers. It allows the destination socket and client certificate
verification info to be obtained on-the-fly from a centralized
4. Although primarily intended for use with HTTP, this patch uses the
libcurl URL library and should work with all of its supported
protocols: HTTP, HTTPS, FTP, FTPS, TFTP, DICT, TELNET, LDAP or FILE.
As a brief example, an end-user might configure their stunnel as follows:
cert = id.pem
verify = 2
CApath = ca_dir
CAlookup = http://database.stunnel.org/map_client.php?hash=%h
accept = 50000
connect = @http://database.stunnel.org/map_client.php?common_name=%n
In this scenario, an incoming stunnel connection would obtain it's
connect info from database.stunnel.org by sending an HTTP request and
passing the common name found in the client certificate. Similarly,
the client's certificate would be verified using CA certificates
obtained via HTTP lookup to the same host.
Comments are appreciated.
-------------- next part --------------
A non-text attachment was scrubbed...
Size: 21633 bytes
Desc: not available
More information about the stunnel-users