Single Sign on not working

Mon Mar 5 09:18:22 EST 2012

Hi

I 'm trying to implement single signon using kerberos+LDAP. I 'm able to
login to servers , but next time also , I 'm asked enter credentials. That
is authentication is working , but single sign on feature is not working .

[root at client ~]# ssh bkurian at ldap2.shadow.com
bkurian at ldap2.shadow.com's password:
Last login: Mon Mar  5 19:39:11 2012 from client.shadow.com
[bkurian at ldap2 ~]$ logout

Connection to ldap2.shadow.com closed.
[root at client ~]# ssh bkurian at ldap2.shadow.com  -vvv
OpenSSH_4.3p2, OpenSSL 0.9.8e-fips-rhel5 01 Jul 2008
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug2: ssh_connect: needpriv 0
debug1: Connecting to ldap2.shadow.com [192.168.122.48] port 22.
debug1: Connection established.
debug1: permanently_set_uid: 0/0
debug1: identity file /root/.ssh/identity type -1
debug1: identity file /root/.ssh/id_rsa type -1
debug1: identity file /root/.ssh/id_dsa type -1
debug1: loaded 3 keys
debug1: Remote protocol version 2.0, remote software version OpenSSH_4.3
debug1: match: OpenSSH_4.3 pat OpenSSH*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_4.3
debug2: fd 3 setting O_NONBLOCK
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug2: kex_parse_kexinit:
diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
debug2: kex_parse_kexinit: ssh-rsa,ssh-dss
debug2: kex_parse_kexinit:
aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,
rijndael-cbc at lysator.liu.se
debug2: kex_parse_kexinit:
aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,
rijndael-cbc at lysator.liu.se
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,hmac-ripemd160,
hmac-ripemd160 at openssh.com,hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,hmac-ripemd160,
hmac-ripemd160 at openssh.com,hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: none,zlib at openssh.com,zlib
debug2: kex_parse_kexinit: none,zlib at openssh.com,zlib
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit: first_kex_follows 0
debug2: kex_parse_kexinit: reserved 0
debug2: kex_parse_kexinit:
diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
debug2: kex_parse_kexinit: ssh-rsa,ssh-dss
debug2: kex_parse_kexinit:
aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,
rijndael-cbc at lysator.liu.se
debug2: kex_parse_kexinit:
aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,
rijndael-cbc at lysator.liu.se
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,hmac-ripemd160,
hmac-ripemd160 at openssh.com,hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,hmac-ripemd160,
hmac-ripemd160 at openssh.com,hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: none,zlib at openssh.com
debug2: kex_parse_kexinit: none,zlib at openssh.com
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit: first_kex_follows 0
debug2: kex_parse_kexinit: reserved 0
debug2: mac_init: found hmac-md5
debug1: kex: server->client aes128-ctr hmac-md5 none
debug2: mac_init: found hmac-md5
debug1: kex: client->server aes128-ctr hmac-md5 none
debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
debug2: dh_gen_key: priv key bits set: 115/256
debug2: bits set: 550/1024
debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
debug3: check_host_in_hostfile: filename /root/.ssh/known_hosts
debug3: check_host_in_hostfile: match line 4
debug3: check_host_in_hostfile: filename /root/.ssh/known_hosts
debug3: check_host_in_hostfile: match line 4
debug1: Host 'ldap2.shadow.com' is known and matches the RSA host key.
debug1: Found key in /root/.ssh/known_hosts:4
debug2: bits set: 528/1024
debug1: ssh_rsa_verify: signature correct
debug2: kex_derive_keys
debug2: set_newkeys: mode 1
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug2: set_newkeys: mode 0
debug1: SSH2_MSG_NEWKEYS received
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug2: service_accept: ssh-userauth
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug2: key: /root/.ssh/identity ((nil))
debug2: key: /root/.ssh/id_rsa ((nil))
debug2: key: /root/.ssh/id_dsa ((nil))
debug1: Authentications that can continue:
publickey,gssapi-with-mic,password
debug3: start over, passed a different list
publickey,gssapi-with-mic,password
debug3: preferred gssapi-with-mic,publickey,keyboard-interactive,password
debug3: authmethod_lookup gssapi-with-mic
debug3: remaining preferred: publickey,keyboard-interactive,password
debug3: authmethod_is_enabled gssapi-with-mic
debug1: Next authentication method: gssapi-with-mic
debug3: Trying to reverse map address 192.168.122.48.
debug1: Unspecified GSS failure.  Minor code may provide more information
No credentials cache found

debug1: Unspecified GSS failure.  Minor code may provide more information
No credentials cache found

debug2: we did not send a packet, disable method
debug3: authmethod_lookup publickey
debug3: remaining preferred: keyboard-interactive,password
debug3: authmethod_is_enabled publickey
debug1: Next authentication method: publickey
debug1: Trying private key: /root/.ssh/identity
debug3: no such identity: /root/.ssh/identity
debug1: Trying private key: /root/.ssh/id_rsa
debug3: no such identity: /root/.ssh/id_rsa
debug1: Trying private key: /root/.ssh/id_dsa
debug3: no such identity: /root/.ssh/id_dsa
debug2: we did not send a packet, disable method
debug3: authmethod_lookup password
debug3: remaining preferred: ,password
debug3: authmethod_is_enabled password
debug1: Next authentication method: password
bkurian at ldap2.shadow.com's password:

*This is how the KDC logs looks like *

Mar 05 19:44:06 kdc.shadow.com krb5kdc[21385](info): AS_REQ (12 etypes {18
17 16 23 1 3 2 11 10 15 12 13}) 192.168.122.48: ISSUE: authtime 1330956846,
etypes {rep=16 tkt=16 ses=16}, bkurian at SHADOW.COM for krbtgt/
SHADOW.COM at SHADOW.COM
Mar 05 19:44:06 kdc.shadow.com krb5kdc[21385](info): TGS_REQ (7 etypes {18
17 16 23 1 3 2}) 192.168.122.48: ISSUE: authtime 1330956846, etypes {rep=16
tkt=16 ses=16}, bkurian at SHADOW.COM for host/ldap2.shadow.com at SHADOW.COM

*This is how the sshd logs of remote server looks like *

Mar  5 19:44:08 ldap2 sshd[2917]: pam_unix(sshd:auth): authentication
failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=client.shadow.com
user=bkurian
Mar  5 19:44:08 ldap2 sshd[2917]: pam_krb5[2917]: TGT verified using key
for 'host/ldap2.shadow.com at SHADOW.COM'
Mar  5 19:44:08 ldap2 sshd[2917]: pam_krb5[2917]: authentication succeeds
for 'bkurian' (bkurian at SHADOW.COM)
Mar  5 19:44:08 ldap2 sshd[2917]: Accepted password for bkurian from
192.168.122.140 port 56598 ssh2
Mar  5 19:44:08 ldap2 sshd[2917]: pam_unix(sshd:session): session opened
for user bkurian by (uid=0)

-- 
Regards

Basil