#cd /usr/src/redhat/SOURCES/srp-2.2.1/telnet
#make；make install

# description: The SRP Telnet server
serves Telnet connections.
# It uses SRP for authentication.
service telnet {
socket_type = stream
wait = no
user = root
server = /usr/local/sbin/telnetd
log_on_success += DURATION USERID
log_on_failure += USERID
nice = 10
disable = no }

#killall -USR1 xinetd

auth required /lib/security/pam_listfile.so item=user sense=deny file=/etc/telnetusers onerr=succeed
auth required /lib/security/pam_stack.so service=srp-telnet
auth required /lib/security/pam_shells.so
account required /lib/security/pam_stack.so service=srp-telnet
session required /lib/security/pam_stack.so service=srp-telnet

$/usr/local/bin/telnet localhost 23
Trying 127.0.0.1...
Connected to localhost.intevo.com (127.0.0.1).
Escape character is '^]'.
[ Trying SRP ... ]
SRP Username (root): cao
[ Using 1024-bit modulus for 'cao' ]
SRP Password:
[ SRP authentication successful ]
[ Input is now decrypted with type CAST128_CFB64 ]
[ Output is now encrypted with type CAST128_CFB64 ]
Last login: Tue Dec 21 09:30:08 from cao.net