Subject: Re: Publickey subsystem draft

From: Richard Whalen <[email-masked]>
Date: Fri, 5 Sep 2003 14:27:07 -0400

I am looking into implementing the Public-Key Subsystem and I've come across
a bit of a problem that I need to solve before I can continue.

Our implementation is built upon the implementation from SSH.COM.  In this
implementation there is a file that contains a list of the files that
contain the keys, with one key per file.

Implementing the "list" operation is no problem: read the file that contains
the list of key files and then send the information from each key file.

The hard part comes with the "add" and "remove" operations.  Since each key
is stored in a separate file, there needs to be a name for this file.  The
current draft does not contain a "name" for a key that could be used to
specify the file that the key is stored in.

----------------------
Richard Whalen
Process Software
508-879-6994x261

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From: "Dan O'Reilly" <[email-masked]>
Date: Fri, 05 Sep 2003 12:30:05 -0600

Why not use the methodology used by SSH-KEYGEN?  It's simple to implement
and would be in keeping with that used on the server already.

>specify the file that the key is stored in.

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+-------------------------------+----------------------------------------+
| Dan O'Reilly                  |  "There are 10 types of people in this |
| Principal Engineer            |   world: those who understand binary   |
| Process Software              |   and those who don't."                |
| http://www.process.com        |                                        |
+-------------------------------+----------------------------------------+

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From: Joseph Galbraith <[email-masked]>
Date: Fri, 05 Sep 2003 13:47:29 -0600

Our server is file based as well (presence
in the directory authorizes the key for us.)

For add, we autogenerate a name (using the
fingerprint of the key.)

For remove, we iterate through each canidate
file until we find the one that matches, and
then we delete that file.

You'll have to read each key file in the
list file until you find the one that the
user is trying to remove.  I'm not sure whether
you should just remove the entry or whether
you should remove both the entry and the file.

We deliberately avoided assuming a file based
implementation in the draft.  (What if you used
a database to store keys?)

Thanks,

- Joseph

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From: Markus Friedl <[email-masked]>
Date: Wed, 10 Sep 2003 21:44:03 +0200

> and would be in keeping with that used on the server already.

the server does not need to see the private key.

i also think that the server should _never_ see the private key.

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From: "Dan O'Reilly" <[email-masked]>
Date: Wed, 10 Sep 2003 13:49:09 -0600

>i also think that the server should _never_ see the private key.

I agree with you, but I missed the point of your message.

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From: Markus Friedl <[email-masked]>
Date: Wed, 10 Sep 2003 23:42:13 +0200

> I agree with you, but I missed the point of your message.

i obviously missed your point as well, sorry.

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From: "Dan O'Reilly" <[email-masked]>
Date: Wed, 10 Sep 2003 16:01:57 -0600

>i obviously missed your point as well, sorry.

What I was referring to was the idea that the file naming methodology as
used by SSH-KEYGEN on the server system could be used for the files that
will hold the various public keys.

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