That is the output after input rsa

console# configure

console(config)# crypto key pubkey-chain ssh

console(config-pubkey-chain)# user-key support2 rsa

console(config-pubkey-key)# key-string rsa  <-- press enter and then copy and paste the pub key

AAAAB3NzaC1yc2EAAAABIwAAAQEAynwu0QyOUdDn0Xn/RZlfSJ3SvPmRDVO7xqGNImTmGQQvwjcIpcqFNHfH6U0yBPjYeq81BFyyffSUCalM/Jl+9aAF7RJL3qJTkB8KnMG4FAv58C8VEvJdjpuKTvNUB09SvdajGVMSJT....==

<--- press enter x 2

02-Jan-2000 15:17:57 %SSHD-E-ERROR: SSH error: buffer_get_string: Bad string length -1362722816

02-Jan-2000 15:17:57 %SSHD-E-ERROR: SSH error: key_from_blob: invalid key type.

02-Jan-2000 15:17:57 %SSHD-E-ERROR: SSH error: key_read: key_from_blob rsaAAAAB3NzaC1yc2EAAAABIwAAAQEAynwu0QyOUdDn0Xn/RZlfSJ3SvP... failed

Invalid key string

Did you know why?  Thanks!

Finally I successful created.  That should be by

console(config-pubkey-chain)# user-key user rsa

console(config-pubkey-key)# key-string  <-- start place the pub key from here

Thanks for advise.

But new question comes out is why is still need to ask me username and password?

and

Is it either "ip ssh pubkey-auth" or "ip ssh server" is support?

Following is part of my config for reference

=======================

aaa authentication enable default line

aaa authentication login default local

line ssh

password 60b6be022be2346a7be1b63107626fdf encrypted

exit

username admin password 60b6be022be2346a7be163107626fdf level 15 encrypted

username user password 60b6be022be2346a7be1b63107626fdf level 15 encrypted

ip ssh server

ip ssh pubkey-auth

crypto key pubkey-chain ssh

user-key support2 rsa

key-string row AAAAB3NzaC1yc2EAAAABIwAAAQEAzwV4m/Lr/1D8

key-string row +YWbYspkDOCtWm778afFsmFp5C4ScPorD1+sPGBT

key-string row M8KBreOdRu8xiy1UNcmstTtXMafyCPTUZhd9CfCt

key-string row 9lfEgOf6DNJ0eKkJdaonWlV4+QWZaeTN

key-string row NCqbug4q4Oi6XhJJYi3/KGH+d1feGn5thxal8vMR

key-string row ZLktisvCqr+V5A9XhEWdp1o5ct73tToy0ExHHaWY

key-string row 5OCAwIYKMkadHBc6ugsDggUpDrYm/RGGuvZnAno7

key-string row 8SEunsSIbaBXpscwCmjF4PPYfo1Ej/T95fNo6qlF

key-string row 40JQigwSr4a2dpW96ho1i9saf0SBFDvnAXH1cVJD

key-string row 4DLVfGSfIxrVadp27w==

exit

exit

=============================

Hello,

After enabled ip ssh pubkey-auth

Login using the public key pre-imported

========================================

[user@testdellsw ~]$ ssh 192.168.168.1

User Name:user

Password:***********

========================================

If that user did not have correct private key on hand

=======================================

[noprivkey@testdellsw ~]# ssh 192.168.168.1

Permission denied (publickey).

=======================================

That why asking why still require input username and password even owned correct private key?

and

Is it either "ip ssh pubkey-auth" or "ip ssh server" is support?

Thanks!

Hello,

Just updated some config with

-------

aaa authentication enable default line

aaa authentication enable user none

aaa authentication login default local

aaa authentication login user none

------

This time the result is user just require input their username and no need to enter password .  But it seems just by pass username called user to bypass input the password

Following is running ssh with debug for reference:

-------OpenSSH_5.3p1, OpenSSL 1.0.0-fips 29 Mar 2010

debug1: Reading configuration data /etc/ssh/ssh_config

debug1: Applying options for *

debug1: Connecting to 192.168.168.1 [192.168.168.1] port 22.

debug1: Connection established.

debug1: identity file /home/user/.ssh/identity type -1

debug1: identity file /home/user/.ssh/id_rsa type 1

debug1: identity file /home/user/.ssh/id_dsa type -1

debug1: Remote protocol version 2.0, remote software version OpenSSH_3.4p1.RL

debug1: match: OpenSSH_3.4p1.RL pat OpenSSH_3.*

debug1: Enabling compatibility mode for protocol 2.0

debug1: Local version string SSH-2.0-OpenSSH_5.3

debug1: SSH2_MSG_KEXINIT sent

debug1: SSH2_MSG_KEXINIT received

debug1: kex: server->client aes128-cbc hmac-md5 none

debug1: kex: client->server aes128-cbc hmac-md5 none

debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent

debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP

debug1: SSH2_MSG_KEX_DH_GEX_INIT sent

debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY

debug1: Host '192.168.168.1' is known and matches the RSA host key.

debug1: Found key in /home/user/.ssh/known_hosts:1

debug1: ssh_rsa_verify: signature correct

debug1: SSH2_MSG_NEWKEYS sent

debug1: expecting SSH2_MSG_NEWKEYS

debug1: SSH2_MSG_NEWKEYS received

debug1: SSH2_MSG_SERVICE_REQUEST sent

debug1: SSH2_MSG_SERVICE_ACCEPT received

debug1: Authentications that can continue: publickey

debug1: Next authentication method: publickey

debug1: Trying private key: /home/user/.ssh/identity

debug1: Offering public key: /home/user/.ssh/id_rsa

debug1: Server accepts key: pkalg ssh-rsa blen 277

debug1: read PEM private key done: type RSA

debug1: Authentication succeeded (publickey).

debug1: channel 0: new [client-session]

debug1: Entering interactive session.

debug1: Sending environment.

debug1: Sending env LANG = en_US.UTF-8

----------

Hello,

Please check the following output for any idea for this question.

******************************

console# show authentication methods

Login Authentication Method Lists

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

Default             : Local

user                  : None

Enable  Authentication Method Lists

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

Default             : Line

user                  : None

Line           Login Method List         Enable Method List

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

Console        Default                   Default

Telnet         Default                   Default

SSH            Default                   Default

http                : Local

https               : Local

dot1x               :

************************************

Thanks!

What currently result is:

- The user did not with correct public/private key pair will not allow to login

- When user have correct public/private key pair.  It can login to non privileged level

- If I remove "ip ssh pubkey-auth",  Every body can login without username or password.  And entry to no privileged level

- No need to input password after input >enable

What updated code now

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

aaa authentication enable default line

aaa authentication enable user none

aaa authentication login default local

aaa authentication login user none

line ssh

login authentication user

enable authentication user

password 60b6be022be2346a7be1b63107626fdf encrypted

exit

username user password d41d8cd98f00b204e9800998ecf8427e level 15 encrypted

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

console# show authentication methods

Login Authentication Method Lists

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

Default             : Local

user            : None

Enable  Authentication Method Lists

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

Default             : Line

user            : None

Line           Login Method List         Enable Method List

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

Console        Default                   Default

Telnet         Default                   Default

SSH            user                  user

http                : Local

https               : Local

dot1x               :

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

thanks for advise

Yes, it nearly to what I expected.  Just see what is it possible can config like

- The user can directly entry to enable privileged level after login?  Rather than I need to enter "enable" after access

- How can I keep other user can login by their username and password thru ssh?

-------------------- part of config -----------------------------------

aaa authentication enable default line

aaa authentication enable user none

aaa authentication login default local

aaa authentication login user none

line ssh

login authentication user

enable authentication user

password 60b6be022be2346a7be1b63107626fdf encrypted

exit

username user password d41d8cd98f00b204e9800998ecf8427e level 15 encrypted

ip ssh server

ip ssh pubkey-auth

crypto key pubkey-chain ssh

user-key user rsa

key-string row AAAAB3NzaC1yc2EAAAABIwAAAQEAtYX/x5cDBPkD

key-string row q6s2U0jIh908qlg/NFqR4EJWbrIZSpfIExGc4dET

key-string row L7RCP0W2cLet9uG891cLiN6rOoGfRBLiai5SSqKE

key-string row z/aEJrnRe7AjHPVK60tQRPH7pQCVDoJW

key-string row Q6zyJzo7ensi9PgSu6rzIuSLB8V7DJ8D/tjQtomD

key-string row KTTP2LTo4io3qOnxD9dsNmc/bZqo5i8B6YGbeIM8

key-string row AVtdvLBFHwuqryarqx3L62n8alV6vpnoUJYFCXwI

key-string row yPEcUd9JoYLljdT80fNjh44ePNJeO6hUaJ7Hr8Fn

key-string row jhchCaGFhotlWbYCLBVJh5uKUeBmXw7Ju9GwezGX

key-string row CwbNpwgNDFtgnvfwXQ==

exit

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

Thanks!

Once you have the RSA key associated with the user - you turn on the key checking by issuing:

conf

ip ssh pub-key auth

 

you shouldn't be prompted for a password after typing in the user name.

Of course you need the private key sent via whatever ssh client you are using.. that's a whole other wormhole.