http://www.perlmonks.org?node_id=1012789

anshumangoyal has asked for the wisdom of the Perl Monks concerning the following question:

I am facing issue with Net::SCP::Expect while performing SCP. It sometimes dies saying 
The authenticity of host can't be established.
RSA Fingerprint is XXXX
Are you Sure Yes/No

[download]
I want to check how Net::SCP::Expect can perform no host checking and just do an SCP. Is there any way to do that?

Replies are listed 'Best First'.
Re: Net::SCP::Expect RSA Fingerprint Problem
by salva (Canon) on Jan 11, 2013 at 08:28 UTC
    If the option StrictHostKeyChecking=no is passed to OpenSSH ssh client and no key exists on the known_hosts file for the target host, it will accept as good (and remembered for future connections) the first one received from the remote host.

    Though, I don't see how extra options for ssh can be passed through Net::SCP::Expect.

    Anyway, you can use Net::OpenSSH instead: 

    $ssh = Net::OpenSSH->new($host,
                         user => $user, password => $password,
                         master_opts => [-o => 'StrictHostKeyChecking=
+no']);

$ssh->scp_put(...);
$ssh->scp_get(...);

    [download]

    Note that disabling strict host key checking has some security implications that you should be aware of.

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[d/l]
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      Even Net::SCP::Expect has this option. This is how you pass this: 
          my $scp_exp = Net::SCP::Expect->new(
                                         host     => $host,
                                         user     => $user,
                                         password => $pass,
                                         timeout  => undef,
                                         auto_yes => 1,
                                         recursive => 1,
                                         option => 'StrictHostKeyCheck
+ing=no'
    );

      [download]
      Thanks for the Great Help. This worked like a charm!!
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[d/l]
        I must admit I do like to see feedback from the original question poster indicating which solution to the problem actually worked for them. Thanks for updating us.
        A Monk aims to give answers to those who have none, and to learn from those who know more.
[reply]
        How can I give the options 'StrictHostKeyChecking=no' and 'UserKnownHostsFile=/dev/null'? auto_yes => 1 is working only with option => 'StrictHostKeyChecking=no'.
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Re: Net::SCP::Expect RSA Fingerprint Problem
by quester (Vicar) on Jan 11, 2013 at 06:47 UTC

    You could try auto_yes if you just want to answer every question coming from scp with a yes...

    Net::SCP::Expect->new(auto_yes=>1,...)

    [download]
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[d/l]
      This is my Code: 
          my $scp_exp = Net::SCP::Expect->new(
        host     => $host,
        user     => $user,
        password => $pass,
        timeout  => undef,
        auto_yes => 1
    );

      [download]
      Still I am getting this error. Dont know what all is happening.
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[d/l]

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