[openssl-users] Unable to select NULL or NULL-MD5

[Matt Caswell]

On 29/03/18 00:14, Eric Jacksch wrote:
> Greetings,
> 
> I'm using OpenSSL for testing and recently compiled 1.1.0g and h. I'm
> seeing the same behaviour in both. 
> 
> openssl ciphers -v list the NULL ciphers, but when I try to use NULL or
> NULL-MD5 I get the same result:  No ciphers available.
> 
> I've tried several compile options to no avail.
> 
> Can anyone point me in the right direction?
> 
> Thanks!
> 
> 
> ./openssl s_client -connect x.x.x.x:443 -cipher NULL

Change you cipher list to be `-cipher NULL:@SECLEVEL=0`. If your server
is also running OpenSSL then you'll need to enable it there as well.

The default security level is 1, which disables NULL ciphers amongst
various other things.

Matt





> 
> CONNECTED(00000003)
> 
> 140735917126464:error:141640B5:SSL
> routines:tls_construct_client_hello:no ciphers
> available:ssl/statem/statem_clnt.c:800:
> 
> ---
> 
> no peer certificate available
> 
> ---
> 
> No client certificate CA names sent
> 
> ---
> 
> SSL handshake has read 0 bytes and written 0 bytes
> 
> Verification: OK
> 
> ---
> 
> New, (NONE), Cipher is (NONE)
> 
> Secure Renegotiation IS NOT supported
> 
> Compression: NONE
> 
> Expansion: NONE
> 
> No ALPN negotiated
> 
> SSL-Session:
> 
>     Protocol  : TLSv1.2
> 
>     Cipher    : 0000
> 
>     Session-ID: 
> 
>     Session-ID-ctx: 
> 
>     Master-Key: 
> 
>     PSK identity: None
> 
>     PSK identity hint: None
> 
>     SRP username: None
> 
>     Start Time: 1522278574
> 
>     Timeout   : 7200 (sec)
> 
>     Verify return code: 0 (ok)
> 
>     Extended master secret: no
> 
> ---
> 
> -- 
> Eric Jacksch, CPP, CISM, CISSP
> +1 613 482-7650
> eric at jacksch.com <mailto:eric at jacksch.com>
> Twitter: @EricJacksch
> https://SecurityShelf.com <https://securityshelf.com/>
> 
>