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Bug 589092 - SSH originating host check fails if specified symbolically and no PTR record
Summary: SSH originating host check fails if specified symbolically and no PTR record
Alias: None
Product: Red Hat Enterprise Linux 5
Classification: Red Hat
Component: openssh
Version: 5.4
Hardware: All
OS: Linux
Target Milestone: rc
: ---
Assignee: Jan F. Chadima
QA Contact: BaseOS QE Security Team
Depends On:
TreeView+ depends on / blocked
Reported: 2010-05-05 11:31 UTC by David Tonhofer
Modified: 2010-05-12 06:41 UTC (History)
0 users

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Last Closed: 2010-05-12 05:28:32 UTC
Target Upstream Version:

Attachments (Terms of Use)

Description David Tonhofer 2010-05-05 11:31:00 UTC
Description of problem:

In $USER/.ssh/authorized_keys, a login for $USER is permitted with an originating host check:

no-pty,permitopen="",from="" ssh-rsa AAAAB....

A login from a remote machine fails however. The sshd log says:

"Authentication tried for $USER with correct key but not from a permitted host (host=, ip=

There might be a problem with the IP address comparison function?

Replacing the symbolic hostname with the IP address makes things work:

no-pty,permitopen="",from="" ssh-rsa AAAAB

A login from a remote machine succeeds. The sshd log says:

"Accepted publickey for $USER from port 59015 ssh2"

However, login from other machines specified using the symbolic name _do_ succeed. has no PTR record yet though. So I suppose that is the problem.

In which case, the logline is misleading and should read "no PTR record available for verification"...


Version-Release number of selected component (if applicable):

How reproducible:

Comment 1 Jan F. Chadima 2010-05-12 05:28:32 UTC
There is an intentional test of the reverse lookup.

Comment 2 David Tonhofer 2010-05-12 06:41:10 UTC

Makes sense. Still, in that case the error message in the log should be clearer. 

"but not from a permitted host (host=, ip="

does not make much sense, "no PTR record available for verification" would be clearer.

Best regards,

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