Can't use private key to login into server

[ksham]

I can log into my server using putty, however I cannot login using SecureCRT.

I exported the key using "Putty Key Generator" -> Conversions -> "Export Open SSH Key"

My servers /var/log/auth.log shows this when I try to login:

Jul 3 16:59:38 servername sshd[24327]: error: bad sig size 32 32
Jul 3 16:59:38 servername sshd[24327]: fatal: mm_answer_sign: key_sign failed


Any insight would be great!

[rtb]

Hi ksham,

Thanks for the post. The unknown details are greater than the known details, so it is hard to provide any insight.

My guess is that the problem lies in the SSH2 transport negotiation. I would check differences in the cipher, MAC and key exchange algorithms chosen when connecting with SecureCRT vs. putty.

In SecureCRT, you can see the negotiation details by selecting Trace Options from the File menu, disconnecting and reconnecting your session.

Once you know what the differences are, you can configure the cipher, MAC and key exchange algorithms in the Connection / SSH2 and Connection / SSH2 / Advanced categories in the Session Options dialog. You have to be disconnected to make any changes to the options.