[Dovecot] authentication to IMAP

[punit_j]

HI All,

Is there a way to do admin authentication for a normal user in dovecot IMAP ? I have a user using PAM to store password in /etc/shadow file. I need to authenticate the user in IMAP using that password. I tried using : -

I tried all combinations as below

[root at mail ~]# cat /etc/shadow| grep -i ajay
ajay.lal:CM730q8foSA9A:13545:0:99999:7:::
[root at mail ~]# telnet 0 143
Trying 0.0.0.0...
Connected to 0 (0.0.0.0).
Escape character is '^]'.
* OK dovecot ready.
a1 login ajay.lal CM730q8foSA9A
a1 NO Authentication failed.
a1 login ajay.lal "{crypt}CM730q8foSA9A"
a1 NO Authentication failed.

Also i tried 
[root at mail ~]# perl -MMIME::Base64 -e 'print encode_base64("\0ajay.lal\0{crypt}CM730q8foSA9A");'
AGFqYXkubGFsAHtjcnlwdH1DTTczMHE4Zm9TQTlB

[root at mail ~]# telnet 0 143
Trying 0.0.0.0...
Connected to 0 (0.0.0.0).
Escape character is '^]'.
* OK dovecot ready.
a1 AUTHENTICATE PLAIN
+
AGFqYXkubGFsAHtjcnlwdH1DTTczMHE4Zm9TQTlB
a1 NO Authentication failed.


My dovecot server does PLAIN authentication as can 
auth_mechanisms = plain

Is there a way to do PLAIN auth with crypt password or any means of doing admin authentication on behalf of normal user ?

Regards,
Punit