We have an Ubuntu 10.04 server. How can I set it so that new files created (or copied) over SFTP or SSH have g+rw and g+rwx permissions (where appropriate)?
I'm also using setgid (chmod g+s) so that they inherit the proper group owner.
In /etc/ssh/sshd_config, you can pass a flag and value in (-u 0002) like the following to set the umask value:
Subsystem sftp /usr/lib/openssh/sftp-server -u 0002
Append the -u 0002 to the existing Subsystem sftp line of the configuration file.
Afterwards, you will need to restart ssh for the changes to take effect:
service ssh restart
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This only applies to newer versions of OpenSSH, but should be the preferred solution where possible. – Andrew B Jan 12 '13 at 6:27
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2This only works if you need more restrictive permissions than what is set by the client, not more loose. – Joost Aug 19 '15 at 18:52
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As Joost said, this doesn't help to force group-write permissions. I would help to forbid group-write. – flight Sep 10 '15 at 15:46
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According to recent documentation, the same options can be used with
Subsystem sftp internal-sftp. – underscore_d Oct 9 '15 at 12:27
In /etc/ssh/sshd_config, change the following:
Subsystem sftp /usr/lib/openssh/sftp-server
to:
Subsystem sftp /bin/sh -c 'umask 0002; exec /usr/libexec/openssh/sftp-server'
Soure: http://jeff.robbins.ws/articles/setting-the-umask-for-sftp-transactions
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1It's better to put an
execbefore the final/usr/.../sftp-server, so that you won't have uselessshprocesses lying around. – grawity Jun 13 '10 at 20:32 -
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2Yes, umasks are octal. That doesn't mean you need three leading zeroes - one is enough. (In fact, the
umaskcommand doesn't need any leading zeroes, it always reads the argument as an octal number.) ... But on the second thought, maybe0002is clearer to understand. – grawity Jun 19 '10 at 20:52 -
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