Subject: Re: Authentication issue

Re: Authentication issue

From: Dan Fandrich <dan_at_coneharvesters.com>
Date: Mon, 20 Jul 2015 23:36:16 +0200

On Fri, Jul 17, 2015 at 04:18:06PM +0530, Kishore Av wrote:
> Thanks for response,
> I already tried userauth_list and it returns NULL.
> Based on your explanation i comes to know that, ssh server should be configured
> as none. It seems server issue.

While it may appear that 'ssh <IP address>' is connecting without
authentication, there are several ways that ssh could be silently
authenticating without requiring a password and without you realizing it (e.g.
Kerberos, private key, ssh-agent). If you give the -v option on the OpenSSH
client command-line, it will show you the steps it is going to authenticate the
connection. There's a good chance that it's not actually unauthenticated. In
today's world, there are few instances where that's a good idea.

>
> Thanks
> Kishore
>
> On 17-Jul-2015 2:47 pm, "Peter Stuge" <peter_at_stuge.se> wrote:
>
> Kishore Av wrote:
> > I could able to connect ssh server only with username and without
> > providing the password manually.
>
> Did you study the protocol specification?
>
> RFC 4252 5.2.  The "none" Authentication Request
>
>    A client may request a list of authentication 'method name' values
>    that may continue by using the "none" authentication 'method name'.
>
>
> > Is there a way to connect that server through libssh2 ?
>
> As I wrote, the libssh2 API matches the protocol API closely.
>
>
> > If so, which API can be used to connect?
>
> Did you study the library API documentation?
>
> /* libssh2_userauth_list
>  *
>  * List authentication methods
>  * Will yield successful login if "none" happens to be allowable for this
> user
>
>
>
> //Peter
> _______________________________________________
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>

> _______________________________________________
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Received on 2015-07-20