On 29 Dec 2016, at 20:56, Patrick Domack <[email protected]> wrote
> Quoting Michael Grimm <[email protected]>:


>> #) Would it be possible to get *two* distinct LE certificates, one for the 
>> IMAP and one for the webserver ..
>> #) .. and simultaneously *keep* my selfsigned certificate for the the 
>> mailserver ..
>> #) .. and forget about the issues mentioned above?
>> 
>> #) Or should I strictly separate my mailserver from the rest by means of 
>> distinct domains, instead?
> 
> You can get multiple certificates, I have several myself in a single domain, 
> and so this same thing.

Thanks for your feedback. Then I will gor for that.

> I am using an LE certificate for my DANE TLSA records, and I do have the 
> auto-rotation script update the TLSA entry. While this is as simple as it 
> sounds, dnssec makes it more complicated.

> 
> You have to remember your dns ttl and and dnssec rrsig ttl and rrsig 
> expiration for the given entry. I have switched to using dns slave servers 
> and in my implementation that means dnssec rrsig values are signed valid for 
> a week, so I don't push out the new certificate from LE, till two weeks after 
> I added the TLSA dns record, to be safe.

See my answers to Viktor. I am very hesitant when it comes to human 
intervention. Thus, I will avoid it.

> The only issue I have had with selfsigned certs is that some mailservers will 
> not send you email if you use one, since the sender has turned on certificate 
> verification, and it will not fail back to non-encrypted to send email. This 
> is mainly a misconfig on their part, but it matters if you want email from 
> them. This has been very minimal impact, but I have seen it a few times.

I haven't run into that issue, yet, luckily. If that will happen to my users, I 
will have to take the burden and apply LE certificates for port 25 as well. But 
until that time, I will avoid human intervention into a process where two 
autorotation tools go for "incompatible" tasks :-) Or is there one single tool 
dealing with DNSSEC, TLSA rotation, and LE upgrades on the market?

Thank you for your valuable input and with kind regards,
Michael


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