OpenSSH
[Top] [All Lists]

No warning message is displayed for "none" cipher

To: <openssh-unix-dev@mindrot.org>
Subject: No warning message is displayed for "none" cipher
From: "ponraj" <tryponraj@gmail.com>
Date: Fri, 5 Jan 2007 16:52:06 +0530
Delivered-to: sp-com-lists@consult.net
Delivered-to: openssh-unix-dev-list1@securepoint.com
Delivered-to: openssh-unix-dev-tmda@mindrot.org
Delivered-to: openssh-unix-dev@mindrot.org
List-archive: <http://lists.mindrot.org/pipermail/openssh-unix-dev>
List-help: <mailto:openssh-unix-dev-request@mindrot.org?subject=help>
List-id: Development of portable OpenSSH <openssh-unix-dev.mindrot.org>
List-post: <mailto:openssh-unix-dev@mindrot.org>
List-subscribe: <http://lists.mindrot.org/mailman/listinfo/openssh-unix-dev>, <mailto:openssh-unix-dev-request@mindrot.org?subject=subscribe>
List-unsubscribe: <http://lists.mindrot.org/mailman/listinfo/openssh-unix-dev>, <mailto:openssh-unix-dev-request@mindrot.org?subject=unsubscribe>
Reply-to: ponraj <tryponraj@gmail.com>
Sender: openssh-unix-dev-bounces+openssh-unix-dev-list1=securepoint.com@mindrot.org
Hello all,


I tried to connect to the server that supports protocol 1:

# ssh -1 -o "cipher none" remotehost
<No valid SSH1 cipher, using 3des instead>

As per the code in sshconnect1.c, it has to alert the user about "none" cipher 
usage.
try_challenge_response_authentication() {
....
                if (options.cipher == SSH_CIPHER_NONE)
                        logit("WARNING: Encryption is disabled! "
                            "Response will be transmitted in clear text.");
}

try_password_authentication() {
...
        if (options.cipher == SSH_CIPHER_NONE)
                logit("WARNING: Encryption is disabled! Password will be 
transmitted in clear text.");
}

But "none" cipher is skipped during "invalid" cipher testing and the actual 
cipher for the connection is set to default cipher type.If it is the case, I 
would like to know how to alert the user about the "none" cipher usage. If such 
warnings are not required why or for what purpose does the code check the 
"none" cipher usage during password and challenge response authentication ?


regards
Ponraj M
_______________________________________________
openssh-unix-dev mailing list
openssh-unix-dev@mindrot.org
http://lists.mindrot.org/mailman/listinfo/openssh-unix-dev

<Prev in Thread] Current Thread [Next in Thread>