SASL Server Plugin

[Dan White]

On 11/20/12 10:20 +0530, Mathew iprocessor wrote:
>Hi,
>
>I need to implement SASL in my email client. I downloaded Cyrus-SASL and
>installed it. When the client sends the "UserName" and "Password", my
>server needs to verify the "UserName" and "Password" and Authenticate it.
>The below are some of my doubts, Please clarify.

See:
http://www.cyrussasl.org/docs/cyrus-sasl/2.1.25/programming.php

Within your email client, after you have captured the user's username and
password, you provide a callback to libsasl2 in which you provide that
information to the library, and you will not need to know the details of
how each of the existing mechanisms are implemented, such as PLAIN or
DIGEST-MD5.

>1) The "sasl2-sample-client" and "sasl2-sample-server" in the "bin"
>directories and the "sample-client" and "sample-server" in "sample"
>response are different. Where can I get the source code for
>"sasl2-sample-server"?

There are two sets of sample/client applications distributed within the
/sample directory of the source code. To compile both:

./configure [options]
cd sample
make
make sample-server
make sample-client

>2) Once the "Username" and "Password" is passed from client to server, the
>server needs to verify the "UserName" and "Password" and authenticate the
>client. How to do this in server side? Does "sasl_checkpass" do this or can
>you suggest some other best way to achieve the above?  CAN YOU PROVIDE SOME
>CODE SNIPPETS FOR THIS?

That depends on the mechanism that was negotiated between the client and
the server. For some mechanisms, such as DIGEST-MD5 and SCRAM, the username
and password are not sent over the wire.

For the PLAIN and LOGIN mechanisms (and the older user/pass
style of authentication), where the username and password are sent, then
authentication is performed using the configured 'pwcheck_method'. See:

http://www.cyrussasl.org/docs/cyrus-sasl/2.1.25/options.php

Are you also attempting to write an email server?

>3) I tried testing "sample-client" and "sample-server"  and I get the below
>response, how to solve this?
>
>*Server Terminal:
>*
>
>[root at localhost sample]# ./sample-server -p 8000 -s rcmd -m PLAIN
>Forcing use of mechanism PLAIN
>Sending list of 1 mechanism(s)
>S: UExBSU4=
>Waiting for client mechanism...
>
>*Client Terminal:
>
>*
>
>[root at localhost sample]# ./sample-client -s rcmd -p 8000 -m PLAIN -n
>127.0.0.1
>service=rcmd
>Waiting for mechanism list from server...
>S: UExBSU4*=                                                   Pasted
>server Response*
>recieved 5 byte message
>Forcing use of mechanism PLAIN
>Choosing best mechanism from: PLAIN
>lt-sample-client: SASL Other: No worthy mechs found
>error was SASL(-4): no mechanism available: No worthy mechs found
>lt-sample-client: Starting SASL negotiation: no mechanism available

You may not have the appropriate plugins installed. Use 'pluginviewer' or
'saslpluginviewer' on your system to list the available plugins. If you are
missing PLAIN, then you're likely missing some relevant packages (or you've
compiled something wrong).

-- 
Dan White