a proxy for multiple sasl instances

[Chentao Credungtao]

Hi,

I need to set up Postfix authentication against multiple (3) OpenLDAP 
servers.

I managed to run 3 instances of SASL, each one authenticating against 
one of the 3 servers :

First instance, authenticating against the first LDAP server (example.com) :
# testsaslauthd -f /var/run/saslauthd-com/mux -u john.doe at example.com -p 
password1
0: OK "Success."

Second instance, authenticating against the second LDAP server 
(example.net) :
# testsaslauthd -f /var/run/saslauthd-net/mux -u jane.doe at example.net -p 
password2
0: OK "Success."

Third instance, authenticating against the third LDAP server (example.org) :
# testsaslauthd -f /var/run/saslauthd-org/mux -u jimmy.doe at example.org 
-p password3
0: OK "Success."

The problem : it seems Postfix can only authenticate against one running 
instance of SASL.


Is it possible to set up some kind of a SASL proxy, that forwards each 
authentication-request to another SASL instance, depending on the e-mail 
domain ?
Something like :

# testsaslauthd -f /var/run/saslauthd-proxy/mux -u john.doe at example.com 
-p password1
==> should be forwarded to /var/run/saslauthd-com

# testsaslauthd -f /var/run/saslauthd-proxy/mux -u jane.doe at example.net 
-p password2
==> should be forwarded to /var/run/saslauthd-net

# testsaslauthd -f /var/run/saslauthd-proxy/mux -u jimmy.doe at example.org 
-p password2
==> should be forwarded to /var/run/saslauthd-org

Thanks (any other idea to approach this problem is welcome)

Chen