[Pkg-openssl-devel] Bug#891570: Bug#891570: [Bug#891570: SSL connect attempt failed error:141A90B5:SSL routines:ssl_cipher_list_to_bytes:no ciphers available

[Kurt Roeckx]

On Tue, Feb 27, 2018 at 09:39:11PM +0100, Sebastian Andrzej Siewior wrote:
> control: clone -1 -2
> control: reassign -2 libio-socket-ssl-perl 2.056-1
> control: severity -2 normal
> control: tags -2 patch
> 
> On 2018-02-27 21:52:23 [+0800], 積丹尼 Dan Jacobson wrote:
> > Here is all you need to reproduce it:
> > 
> > $ mech-dump https://mbasic.facebook.com/
> > POST https://mbasic.facebook.com/login.php?refsrc=https%3A%2F%2Fmbasic.facebook.com%2F&lwv=100&refid=8
> > 
> > Now  upgrade libssl1.1:amd64 1.1.0g-2 1.1.1~~pre1-1
> > 
> > $ mech-dump https://mbasic.facebook.com/
> > Error GETing https://mbasic.facebook.com/: Can't connect to mbasic.facebook.com:443 (SSL connect attempt failed error:141A90B5:SSL routines:ssl_cipher_list_to_bytes:no ciphers available) at /usr/bin/mech-dump line 68.
> > $ dlocate mech-dump
> > libwww-mechanize-perl: /usr/bin/mech-dump
> 
> Thank you. This was helpfull.
> The problem is that libio-socket-ssl-perl has a predefined cipher list
> which does not include any TLS1.3 cipher (yes, it has its own). The
> patch attached adds TLS1.3 cipher which means that it is possible to
> negotiate a TLS1.3 connection if the remote side supports it.
> 
> I cloned the bug and hope that openssl falls back to TLS1.2 only
> connection if the ciphers are missing especially if the remote side does
> not support 1.3. Lets see about that…

I wasn't exactly expecting this problem, I would have expected a
different error message as mentioned in the blog:
139998555496896:error:141A90B5:SSL routines:ssl_cipher_list_to_bytes:no ciphers available:ssl/statem/statem_clnt.c:3720:No ciphers enabled for max supported SSL/TLS version

But note that we're actually changing that behaviour in
https://github.com/openssl/openssl/pull/5392

That said, in general I think it's a bad idea for applications and
libraries to override the defaults. OpenSSL has sane defaults, and
if you want to exclude some ciphers I suggest you start from
DEFAULT and remove some and not create your own list of which one
you want to support.

> +	'TLS13-CHACHA20-POLY1305-SHA256',
> +	'TLS13-AES-256-GCM-SHA384',
> +	'TLS13-AES-128-GCM-SHA256',
> +	'TLS13-AES-128-CCM-8-SHA256',
> +	'TLS13-AES-128-CCM-SHA256',

You probably don't want the CCM ones by default.


Kurt