any body tell me how to authenticate client with freeRADIUS

DEAR FELLOWS!

i want to configure radiusd.conf for using with my own client program using md5 , when i authenticate a user with a shared secret according in rfc's. the following error occurs.
please tell me if any entry has to be written in "radiusd.conf" file.

Thank you.
problem details printed by the radiusd -X
================================
rad_recv: Access-Request packet from host 127.0.0.1:1025, id=220, length=56
User-Name = "root"
User-Password = "\305\371s\243\264\353\\\236_\254\323x=\005ta"
NAS-IP-Address = 255.255.255.255
NAS-Port = 10
modcall: entering group authorize for request 0
modcall[authorize]: module "preprocess" returns ok for request 0
modcall[authorize]: module "chap" returns noop for request 0
modcall[authorize]: module "eap" returns noop for request 0
rlm_realm: No '@' in User-Name = "root", looking up realm NULL
rlm_realm: No such realm "NULL"
modcall[authorize]: module "suffix" returns noop for request 0
users: Matched DEFAULT at 152
modcall[authorize]: module "files" returns ok for request 0
modcall[authorize]: module "mschap" returns noop for request 0
modcall: group authorize returns ok for request 0
rad_check_password: Found Auth-Type System
auth: type "System"
modcall: entering group authenticate for request 0
rlm_unix: [root]: invalid password
modcall[authenticate]: module "unix" returns reject for request 0
modcall: group authenticate returns reject for request 0
auth: Failed to validate the user.
WARNING: Unprintable characters in the password. ? Double-check the shared secret on the server and the NAS!
Delaying request 0 for 1 seconds
Finished request 0
Going to the next request
--- Walking the entire request list ---
Waking up in 1 seconds...
--- Walking the entire request list ---
Waking up in 1 seconds...
--- Walking the entire request list ---
Sending Access-Reject of id 220 to 127.0.0.1:1025
Waking up in 4 seconds...
--- Walking the entire request list ---
Cleaning up request 0 ID 220 with timestamp 3c6335b4

i want to configure my radiusd.conf file for using with md5
i mean that i want to write client in c language to send freeRADIUS
a Request Packet in which i send Authenticator which is the output from
md5 one way hash function.

i want to configure radiusd.conf file to use with md5 authenticaiton
in which i want to send username password and secret(encrypted).

plz send me radiusd.conf file which is configured for md5 or tell me the main changes i have to made for all that work.

this time when i authenticate with freeRADIUS and error log generated
rad_recv: Access-Request packet from host 127.0.0.1:1025, id=220, length=56
User-Name = "root"
User-Password = "\305\371s\243\264\353\\\236_\254\323x=\005ta"
NAS-IP-Address = 255.255.255.255
NAS-Port = 10
modcall: entering group authorize for request 0
modcall[authorize]: module "preprocess" returns ok for request 0
modcall[authorize]: module "chap" returns noop for request 0
modcall[authorize]: module "eap" returns noop for request 0
rlm_realm: No '@' in User-Name = "root", looking up realm NULL
rlm_realm: No such realm "NULL"
modcall[authorize]: module "suffix" returns noop for request 0
users: Matched DEFAULT at 152
modcall[authorize]: module "files" returns ok for request 0
modcall[authorize]: module "mschap" returns noop for request 0
modcall: group authorize returns ok for request 0
rad_check_password: Found Auth-Type System
auth: type "System"
modcall: entering group authenticate for request 0
rlm_unix: [root]: invalid password
modcall[authenticate]: module "unix" returns reject for request 0
modcall: group authenticate returns reject for request 0
auth: Failed to validate the user.
WARNING: Unprintable characters in the password. ? Double-check the shared secret on the server and the NAS!
Delaying request 0 for 1 seconds
Finished request 0
Going to the next request
--- Walking the entire request list ---
Waking up in 1 seconds...
--- Walking the entire request list ---
Waking up in 1 seconds...
--- Walking the entire request list ---
Sending Access-Reject of id 220 to 127.0.0.1:1025
Waking up in 4 seconds...
--- Walking the entire request list ---
Cleaning up request 0 ID 220 with timestamp 3c6335b4

---------------------------------------------------

tell me why this error is occuring

plz tell me the attributes that must be present in radius-access-request
to authenticate a user using eap-message attribute of the radius packet.

thank you in anticipation.