Public key format problems

[Ryan Moore]

I'm trying to get SSH1 RSA-key authentication to work. But the file
format the Multinet server wants seems very different than what my client
is generating. The client I'm trying to use is SecureCRT from VanDyke
Software. I've asked it to generate an RSA keypair. The public key it
generated looks like this:

---- BEGIN SSH2 PUBLIC KEY ----
Subject: rmoore
Comment: "***@rsa-work"
ModBitSize: 1024
AAAAB3NzaC1yc2EAAAADAQABAAAAgQDVJK7ZwyVo4AEa+MHQqP0LMuGhIjipat2AIuh7
GPxwWdB1YSjDbuLhSGrKjYfD74JmUUCEpmzqnOd6tLhH+LHa0PI5QSpR6hH/7MXa0y7A
2Rg0EjqLgzdY9lTMsamKUhrB5K3umwvyaMbJu+UMNx3M8stXLPrc6EkjXqndYyoM+w==
---- END SSH2 PUBLIC KEY ----

Now I go over to my VMS server and it wants something in the
authorized_keys file which gives the number of bits, the exponent, and
the modulus of the key. And it looks like all those things are suppsed to
be numbers. I certainly don't see a number in the above generated key.

How do I convert the above key into something the SSH1 server will
consume? So far the SSH1 server is not interested in doing an RSA
authenticated connection.

Eventually we're going to get SSH2 going, and I'm fearing I'm going to
have the same type of problem for that eventually. Here's an example of
my SSH2 DSS key... how do I convert this so Multinet can use it?

---- BEGIN SSH2 PUBLIC KEY ----
Subject: rmoore
Comment: "***@work"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---- END SSH2 PUBLIC KEY ----

-Ryan

[t***@hivemind.org]

Hi,

Post by Ryan Moore
Eventually we're going to get SSH2 going, and I'm fearing I'm going to
have the same type of problem for that eventually. Here's an example of
my SSH2 DSS key... how do I convert this so Multinet can use it?

With SSH2, I've just been trying to do the very same thing. As far as I
can tell, that is the correct format - at least, I tried copying the
public key file as-is from SecureCRT:

(1) Copy it to the [.SSH2] subdirectory of the SYS$LOGIN of the user
you want to be able to authenticate as with that key, say as filename
KEY.PUB. Perhaps use an FTP ASCII transfer to ensure newlines get
handled correctly.

(2) Create file [.SSH2]AUTHORIZATION with line:
KEY KEY.PUB

(3) Ensure your SSHD2_CONFIG. is set up to allow public key
authentication - may be default, but "AllowedAuthentications publickey"
may be appropriate.

However, while this approach has worked for me under VMS 8.3 Alpha with
TCPIP services 5.6, under VMS 7.3 VAX with TCPware 5.7-2, so it might
work for you, it did *not* work for me on the latest MultiNet 5.1 under
VMS 8.3 Alpha.

I yesterday posted a load of debugging info on comp.os.vms under
subject "MultiNet 5.1 public key authentication fails on PuTTY,
SecureCRT" - it seems to come down to the server accepting the key as
valid, then rejecting the signature performed by the client. A
SecureCRT dialog reports: "The server recognized your public key... but
none of the known signature mechanisms were accepted." However,
authentication from an OpenSSH client works fine!

(I can repost client and server debugging logs and keys here if anyone
would be interested - the local news server doesn't carry this group so
I didn't find it until this morning.)

Regards,