Solution: Client with the currently selected authenticator does not support any combination of challenges that will satisfy the CA

Thanks!!! This was life saver

Thanks, its works !!! <3

Same error when I try to run:
certbot --apache certonly

Client with the currently selected authenticator does not support any combination of challenges that will satisfy the CA.

Yes. That tries to use TLS-SNI-01 validation, which is disabled, and then not configure Apache to install the certificate.

If you want to do the opposite, "certbot --authenticator webroot --installer apache" will work.

What do you need to do?

1 Like

Around when will the TLS-SNI-01 challenge be re-enabled?

Hi @davidshoda,

Seems a couple of days:

Over the next 48 hours we will be building a list of vulnerable providers and their associated IP addresses. Our tentative plan, once the list is completed, is to re-enable the TLS-SNI-01 challenge type with vulnerable providers blocked from using it.

For more info check this pinned post 2018.01.09 Issue with TLS-SNI-01 and Shared Hosting Infrastructure


1 Like

same error here with:
certbot-auto renew --standalone --quiet --no-self-upgrade --renew-hook '/path/to/'

(Edit: I misread you originally, and rewrote this post.)

"certbot-auto renew" tries to reuse the same settings, including the validation method, that were used when the certificate was originally created.

Do you need to renew your certificate immediately? If the certificate is expiring 29 days from now, it would be easiest to ignore the failure for a few days until the dust settles.

If you need to renew it now, with different options, run the command to issue a new certificate. For example:

certbot-auto --standalone --preferred-challenges http -d -d

Edit: To clarify, if you run that, future renewals (starting 60 days from now) will use the new options too.

@mnordhoff: my fault, I misunderstood that --standalone implies the TLS-SNI-01 challenge

Well, it uses TLS-SNI-01 by default, but also supports HTTP-01.

is there something I did wrong here?

(this is the first cert on this server btw)

sudo certbot --authenticator standalone --installer apache -d -d -d -d --pre-hook "systemctl stop apache2" --post-hook "systemctl start apache2"

Saving debug log to /var/log/letsencrypt/letsencrypt.log
Plugins selected: Authenticator standalone, Installer apache
Running pre-hook command: systemctl stop apache2
Obtaining a new certificate
Performing the following challenges:
http-01 challenge for
http-01 challenge for
http-01 challenge for
http-01 challenge for
Waiting for verification…
Cleaning up challenges
Running post-hook command: systemctl start apache2
Failed authorization procedure. (http-01): urn:acme:error:connection :: The server could not connect to the client to verify the domain :: DNS problem: NXDOMAIN looking up A for

I checked each one is going to the apache start page… so DNS is working as expected.

Hope I did not hijack the thread. Let me know and I will move this to a new topic.

Thank you

I noticed the liy instead of ily … corrected and it ran as expected. Sorry for the confusion

I assume you meant “family” not “famliy”


again… sorry for the confusion

Very timely. That was exactly my problem. I’ll wait.

I appreciate there is a straightforward work around, and I also understand the security vulnerability as well as the importance of maintaining your ability to issue certificates.

However we’ve already deployed certbot with auto renewal across dozens of environments and hundreds of sites – do you recommend we switch everything over now or is there going to be an anticipated fix to restore original functionality?

Thank you for all your work?

A post was split to a new topic: Question about Certbot Apache autoconfiguration

It would be good if TLS-SNI were to be re-enabled at least on staging…

6 posts were split to a new topic: TLS-SNI disabled and only port 443 available

2 posts were split to a new topic: Problem with Certbot standalone plugin