Key authorization file error, even though the match

[2jonathan]

I am trying to get a certificate for my website using certbot on my PC.
I am running the command:
cerbot certonly --manual
I go through all the steps, but when I have to verify that I am actually owning the server I get a strange error:
"
IMPORTANT NOTES:

• The following errors were reported by the server:

  Domain: not important
  Type: unauthorized
  Detail: The key authorization file from the server did not match
  this challenge
  [_d7nZ1MkdBFFX0mcMoPYhuMsYn3GMe3LXdPvglYeH3Q.XrYU8qK1Ye4vMRcbqpaf6oZYdfgmtkXyN2DF6PzBwfk]
  !=
  [_d7nZ1MkdBFFX0mcMoPYhuMsYn3GMe3LXdPvglYeH3Q.XrYU8qK1Ye4vMRcbqpaf6oZYdfgmtkXyN2DF6PzBwfk]
  "

To me these strings look exactly the same. I therefore do not understand why it is not working.
Thank you for your help

[JuergenAuer]

Hi @2jonathan

please answer the following questions. That’s the standard template of #help

---

Please fill out the fields below so we can help you better. Note: you must provide your domain name to get help. Domain names for issued certificates are all made public in Certificate Transparency logs (e.g. https://crt.sh/?q=example.com), so withholding your domain name here does not increase secrecy, but only makes it harder for us to provide help.

My domain is:

I ran this command:

It produced this output:

My web server is (include version):

The operating system my web server runs on is (include version):

My hosting provider, if applicable, is:

I can login to a root shell on my machine (yes or no, or I don’t know):

I’m using a control panel to manage my site (no, or provide the name and version of the control panel):

The version of my client is (e.g. output of certbot --version or certbot-auto --version if you’re using Certbot):

---

Your domain is the most important information.

[_az]

@2jonathan

The key authorization file from the server did not match
this challenge

This is probably because you have smuggled a Unicode Byte Order Mark into the first bytes of the file.

If you view the hex:

cat _d7nZ1MkdBFFX0mcMoPYhuMsYn3GMe3LXdPvglYeH3Q | xxd

you would probably see something like:

0000000: efbb bf5f 6437 6e5a 314d 6b64 4246 4658  ..._d7nZ1MkdBFFX

The error message from Let's Encrypt does not include the BOM, because it has no visible representation.

This was probably caused by you using a certain text editor to create the file.

[2jonathan]

Thank you a lot, I have now used a different editor (nano) and it worked perfectly!

[cpu]

@_az

This is probably because you have smuggled a Unicode Byte Order Mark into the first bytes of the file.

Nice catch @_az That's a subtle one.