sftp vfs support not using key-based authentication

[mith brown]

Hi,

I've been able to successfully use key-based authentication using the FISH protocol (I just run: cd sh://centos in mc's command line and it would work). centos is described in my ~/.ssh/config as follows:

Host centos
    HostName 192.168.1.239
    IdentityFile ~/.ssh/centos
    User centos

and it successfully logs in when I provide it with the Host in my ~/.ssh/config file without prompting me for a name or password.

However, the same is not true when I select SFTP instead (cd sftp://centos) and it requests a password, so it looks like the SFTP VFS is not processing all the lines in ~/.ssh/config.

I checked and noticed this ticket upstream - https://www.midnight-commander.org/ticket/3238 - that says that they resolved this issue in 4.8.15. However, on 4.8.15 on Ubuntu 16.04, I still have this problem. I downloaded and installed from source code (v4.8.17) and indeed the issue was fixed in upstream.

I am using the latest version of mc on Ubuntu. Here are the package details:

$ apt policy mc
mc:
  Installed: 3:4.8.15-2
  Candidate: 3:4.8.15-2
  Version table:
 *** 3:4.8.15-2 500
        500 http://au.archive.ubuntu.com/ubuntu xenial/universe amd64 Packages
        100 /var/lib/dpkg/status

Thanks.

[Yury V. Zaytsev (zyv)]

Well, I'm not sure how we can help you. There is an option to install from source, or else unofficial binary packages are provided here: http://www.midnight-commander.org/wiki/Binaries . It is way to hard to backport fixes to 4.8.15, and the other problem is you need to identify them in the first place. I would say the only reasonable strategy would be to request a backport of the complete package, but I'd suggest you to wait with filling a bug for that until 4.8.18 is released and gets into Ubuntu.

[mith brown (mthbrown)]

Thanks Yury. The actual patch that fixes the issue is over here - https://www.midnight-commander.org/attachment/ticket/3581/mc-3581-sftpsfs-fix-bad-pointer-arithmetic-in-config_parser.patch - and it was marked is fixed in 4.8.16 (https://www.midnight-commander.org/wiki/NEWS-4.8.16) as part of the patch related to 3851.

I can live with my compiled version for the time being.

Any idea when 4.8.18 will be released?

Thanks.

[Yury V. Zaytsev (zyv)]

> Any idea when 4.8.18 will be released?

I hope to start tomorrow and be done by Monday. I'm not sure how long it will take after that for it to appear in Ubuntu so that a backport can be requested, but I would say a couple of months is not an unreasonable estimate, because it has to go through Debian unstable first anyways.

> The actual patch that fixes the issue is over here

I see, if you are confident, you can try Ubuntu SRU process, I've done this a couple of times in the past and it works, but it's sometimes ends up taking months, which is why I'd say backport is a more interesting alternative.