Beefy Boxes and Bandwidth Generously Provided by pair Networks
There's more than one way to do things

Comment on

( #3333=superdoc: print w/replies, xml ) Need Help??

How are you using SSH with threads?

In my experience it is never safe to use threads (or forks) with any form of SSH if you plan to create a connection before creating child threads, and then using that connection in multiple children.

The reason is that like any well engineered security product, ssh (RFC 4251) will include protection against replay attacks, via some sort of sequence number. If you start an ssh connection in the parent, and then create child threads, then both parent and child will have copies of the connection object, with a sequence number. If both parent and child (or multiple children) then use their connections to talk to the server, then the ssh demon on the server will see the sequence number go backwards which would normally only happen if a cracker was attempting a replay attack, so the server will close or otherwise reject the connection.

In reply to Re: Is Net::SSH::Expect a thread-safe module? by chrestomanci
in thread Is Net::SSH::Expect a thread-safe module? by ashok.g

Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":

  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.
  • Log In?

    What's my password?
    Create A New User
    and all is quiet...

    How do I use this? | Other CB clients
    Other Users?
    Others surveying the Monastery: (6)
    As of 2018-05-27 11:00 GMT
    Find Nodes?
      Voting Booth?