Configuration

Paramiko does not itself leverage OpenSSH-style config file directives, but it does implement a parser for the format, which users can honor themselves (and is used by higher-level libraries, such as Fabric).

The API for this is SSHConfig, which loads SSH config files from disk, file-like object, or string and exposes a “look up a hostname, get a dict of applicable keywords/values back” functionality.

As with OpenSSH’s own support, this dict will contain values from across the parsed file, depending on the order in which keywords were encountered and how specific or generic the Host or Match directives were.

Keywords currently supported

The following is an alphabetical list of which ssh_config directives Paramiko interprets during the parse/lookup process (as above, actual SSH connections do not reference parsed configs). Departures from OpenSSH’s implementation (e.g. to support backwards compat with older Paramiko releases) are included. A keyword by itself means no known departures.

  • AddressFamily: used when looking up the local hostname for purposes of expanding the %l/%L tokens (this is actually a minor value-add on top of OpenSSH, which doesn’t actually honor this setting when expanding %l).

  • CanonicalDomains

    New in version 2.7.

  • CanonicalizeFallbackLocal: when no, triggers raising of CouldNotCanonicalize for target hostnames which do not successfully canonicalize.

    New in version 2.7.

  • CanonicalizeHostname: along with the other Canonicaliz* settings (sans CanonicalizePermittedCNAMEs, which is not yet implemented), enables hostname canonicalization, insofar as calling SSHConfig.lookup with a given hostname will return a canonicalized copy of the config data, including an updated HostName value.

    New in version 2.7.

  • CanonicalizeMaxDots

    New in version 2.7.

  • Host

  • HostName: used in %h token expansion

  • Match: fully supported, with the following caveats:

    • You must have the optional dependency Invoke installed; see the installation docs (in brief: install paramiko[invoke] or paramiko[all]).

    • As usual, connection-time information is not present during config lookup, and thus cannot be used to determine matching. This primarily impacts Match user, which can match against loaded User values but has no knowledge about connection-time usernames.

    New in version 2.7.

  • Port: supplies potential values for %p token expansion.

  • ProxyCommand: see our ProxyCommand class for an easy way to honor this keyword from a config you’ve parsed.

    • Honors token expansion.

    • When a lookup would result in an effective ProxyCommand none, Paramiko (as of 1.x-2.x) strips it from the resulting dict entirely. A later major version may retain the "none" marker for clarity’s sake.

  • User: supplies potential values for %u token expansion.

Expansion tokens

We support most SSH config expansion tokens where possible, so when they are present in a config file source, the result of a SSHConfig.lookup will contain the expansions/substitutions (based on the rest of the config or properties of the local system).

Specifically, we are known to support the below, where applicable (e.g. as in OpenSSH, %L works in ControlPath but not elsewhere):

  • %d

  • %h

  • %l

  • %L

  • %n

  • %p

  • %r

  • %u: substitutes the configured User value, or the local user (as seen by getpass.getuser) if not specified.

In addition, we extend OpenSSH’s tokens as follows:

  • ~ is treated like %d (expands to the local user’s home directory path) when expanding ProxyCommand values, since ProxyCommand does not natively support %d for some reason.

config module API documentation

Mostly of interest to contributors; see previous section for behavioral details.

Configuration file (aka ssh_config) support.