[openssl-users] Existing connections on certification expires

Robert Moskowitz rgm at htt-consult.com
Mon Aug 28 13:26:22 UTC 2017

On 08/28/2017 09:07 AM, Viktor Dukhovni wrote:
> On Mon, Aug 28, 2017 at 06:13:51AM -0400, Robert Moskowitz wrote:
>>> 1) What happens to the existing SSL connections on certification expiry?
>>> Does the openssl disconnects the existing connection?
> No, once authenticated, TLS connections continue indefinitely,
> until either party chooses to disconnect.  The expiration of the
> certificate does not invalidate the integrity of the original key
> exchange, and presents no obvious increased risk of active attack.
>> Generally speaking:
>> openssl has nothing to do with a SSL/TLS connection.  It created the
>> certificate, it is not the application using the certificate.
> This is wrong.  Many applications delegate certificate verification
> to the OpenSSL library.  OpenSSL does not limit connection lifetime
> based on certificate expiration.

Argh, you are right.  The libraries are indeed used.  I was thinking the 
whole program.  My error.  Thinking too narrowly.

>> That is commonly a server app (HTTPS, IMAPS, VPN server, etc.) and a client
>> (Web browser, Mail client, VPN client).  Most of these pay no attention to
>> the expiry date.
> This is wrong.

They pay no attention to the expiry date to force the session to end at 
that time by adjusting the session lifetime to be no later than the 
expiry date.  Though there are probably apps out there with this behavior.

They do indeed ensure that the certificate is within its dates.  A 
nuance that I did not make clear.

More information about the openssl-users mailing list