backdoor by authorized_keys2 leftovers

Darren Tucker dtucker at
Fri May 20 11:05:05 EST 2011

On 16/05/11 1:14 PM, Damien Miller wrote:
> On Mon, 16 May 2011, Damien Miller wrote:
>> AuthorizedKeysFile .ssh/authorized_keys
>> AuthorizedKeysFile .ssh/authorized_keys .ssh/authorized_keys2
>> AuthorizedKeysFile /etc/ssh/authorized_keys/keys_%u .ssh/authorized_keys
>> So maybe all-keys-on-one-line is better.
> Here's a diff that implements this:

Diff looks mostly OK, however I suggest the following:
  - all-one-line as mentioned earlier
  - continue to accept authorized_keys2 in sshd_config and stash in 
  - when the config file parsing is done, if it's set append the value 
of authorized_keys2 to the authorized_keys_files array.  This should be 
equivalent to the current behaviour (maybe log a deprecation warning or 
  - explicitly set AuthorizedKeysFile in the shipped sshd_config without 
authorized_keys2 (similar to the Protocol 1 deprecation).

This should mean new installs won't look at authorized_keys2, but the 
behaviour of existing installs won't change during an upgrade.

Darren Tucker (dtucker at
GPG key 8FF4FA69 / D9A3 86E9 7EEE AF4B B2D4  37C9 C982 80C7 8FF4 FA69
     Good judgement comes with experience. Unfortunately, the experience
usually comes from bad judgement.

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