Parsing consistency between directives (e.g. 'Port' vs. 'PermitOpen')

Jim Long james at
Sat May 9 13:24:50 AEST 2020

Given that OpenSSH currently accepts the sshd_config syntax:

Port x
Port y
Port z

to bind the SSH daemon to a total of three ports: x, y and z;

What are the ramifications of allowing the 'PermitOpen' directive to
similarly support:

PermitOpen a:b
PermitOpen c:d
PermitOpen e:f

to permit TCP forwarding to three host:port destination pairs: a:b, c:d,
and e:f?

This would permit somewhat more convenient granular control of
sshd_config forwarding privileges, such as altering the example to:

PermitOpen a:b
#PermitOpen c:d
PermitOpen e:f

Thank you for your time.


More information about the openssh-unix-dev mailing list