make ssh connections via paramiko more configurable

[totaam]

Issue migrated from trac ticket # 2567

component: network | priority: major | resolution: fixed

2020-01-27 17:13:25: antoine created the issue

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OpenSSH supports configuration options, both in its config file and using the command line.
We should provide a similar way of setting options:

• reading the openssh ssh_config if present
• handling options in URL strings

See also:

• SSHFP with paramiko #2097 SSHFP with paramiko
• paramiko should honour ssh config IdentityFile #2282 honour ssh config IdentityFile
• paramiko support for .ssh/config #1937 paramiko support for .ssh/config

[totaam]

2020-01-27 17:14:08: antoine changed status from new to assigned

[totaam]

2020-01-27 17:14:08: antoine edited the issue description

[totaam]

2020-01-27 18:08:16: antoine changed status from assigned to closed

[totaam]

2020-01-27 18:08:16: antoine set resolution to fixed

[totaam]

2020-01-27 18:08:16: antoine edited the issue description

[totaam]

2020-01-27 18:08:16: antoine commented

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Done in r25103.

Self-explanatory examples (add --debug=ssh for debugging):

xpra attach ssh://localhost/ --ssh=paramiko:verify-hostkey=no,auth=none+password

xpra attach ssh://localhost/ --ssh=paramiko:verify-hostkey=yes,verifyhostkeydns=yes,auth=agent+key

xpra attach ssh://localhost/ --ssh=paramiko:verifyhostkeydns=no,auth=password,numberofpasswordprompts=5

[totaam]

2020-02-06 13:00:58: antoine changed status from closed to reopened

[totaam]

2020-02-06 13:00:58: antoine removed resolution (was fixed)

[totaam]

2020-02-06 13:00:58: antoine commented

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Let's also make it possible to specify the keyfile to use.

[totaam]

2020-02-08 05:36:31: antoine changed status from reopened to closed

[totaam]

2020-02-08 05:36:31: antoine set resolution to fixed

[totaam]

2020-02-08 05:36:31: antoine commented

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As of r25180, we can also specify paramiko attributes on the URI, including the key:

XPRA_SSH_DEFAULT_KEYFILES="" xpra attach "ssh://localhost/?key=$HOME/.ssh/id_rsa&auth=key"

The same options can still be specified as a general paramiko attribute:

XPRA_SSH_DEFAULT_KEYFILES="" xpra attach "ssh://localhost/" --ssh="paramiko:key=/home/antoine/.ssh/id_rsa,auth=key"

The new XPRA_SSH_DEFAULT_KEYFILES env var is used in these examples to disable the default ssh key locations.

-Important*: the old URI format ssh:host/DISPLAY is no longer supported. Parsing such strings was becoming increasingly unwieldy.

See also #2582.

[totaam]

2020-02-12 14:49:00: antoine commented

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r25180 caused a regression when there is no host config, fixed in r25214