Common mistakes: HTTP practical demonstration DCV method

To validate your domain using the HTTP Practical Demonstration DCV method, DigiCert provides you with a URL and a token value. The URL does two things:

  • It contains the FQDN (fully qualified domain name) of the domain you want us to validate.
  • It tells us where to look so that we can find the verificationtoken.txt you add the generated random value to.

Below are some of the more common issues we run into when troubleshooting the reason HTTP Practical Demonstration checks fail. The HTTP Practical Demonstration DCV process was designed to keep an unauthorized individual from using a domain they do control to validate and get a certificate for a domain they don’t control, such as one of yours.

Don’t Modify the URL Provided

If you modify the URL in any way (change to the FQDN, capitalize a lowercase letter, forget to add a period, etc.), we won’t find the verificationtoken.txt file with our generated random value in it.

For example, if we provide you with this URL: [http://yourdomain.com]/.well-known/pki-validation/verificationtoken.txt, don’t add www to it ([http://www.yourdomain.com]/.well-known/pki-validation/verificationtoken.txt) or capitalize a letter that wasn’t capitalized in the original URL ([http://yourdomain.com]/.well-known/PKI-validation/verificationtoken.txt).

Don’t Place the verificationtoken.txt on a Different Domain or Subdomain

To complete domain control validation for yourdomain.com, place the verificationtoken.txt file on the exact domain you want validated; the one we generate the URL for. We won’t look at a different domain or subdomain to find our random token. We only look at the domain you want validated (such as the domain on your certificate order).

For example, if you need yourdomain.com validated so that you can request TLS/SSL certificates for it, we generate a URL for this domain – [http://yourdomain.com]/.well-known/pki-validation/verificationtoken.txt. Don’t place the verificationtoken.txt file on sub.yourdomain.com or modify the URL and place it on yourotherdomain.com – it won’t work. We can’t find the verificationtoken.txt file on these domains – only on yourdomain.com.

yourdomain.com and www.yourdomain.com

If you want us to validate www.yourdomain.com and yourdomain.com, place the verificationtoken.txt file on yourdomain.com. This validates both yourdomain.com and www.yourdomain.com. We won’t look at www.yourdomain.com to find the verificationtoken.txt file.

Free Base Domain SAN

If you received a free base domain SAN on your SSL certificate, make sure to place the verificationtoken.txt file on the base domain. We need to validate the domain on the SSL certificate order.

Don’t Include Any Additional Content in the verificationtoken.txt File

When you create the verificationtoken.txt file, copy the DigiCert provided token value and paste it in the file. Don't add the word "token" or any other text.

Because we only read the first 2kb of the verificationtoken.txt file, additional text blocks us from validating your control over the domain.

Don’t Place the verificationtoken.txt File on a Page with Multiple Redirects

When using the HTTP Practical Demonstration method for domain validation, the verificationtoken.txt file may be placed on a page that contains up to one redirect. With a single redirect, we are still able to locate the verificationtoken.txt file and verify your control over the domain.

For example, you need a certificate for http://example.com, but the page redirects to https://www.example.com. That’s okay. You can place the verificationtoken.txt file on the http://example.com page. We will still be able to follow the single redirect to validate your control over http://example.com.

However, if you place the verificationtoken.txt file on a page with multiple redirects, we won’t be able to locate the file. Multiple redirects block us from locating the verificationtoken.txt file and validating your control over the domain.

For example, you need a certificate for http://multiple-redirect.com, but the page redirects to https://www.multiple-redirect.com and then redirects again to https://www.single-redirect.com. In this case, you must still place the verificationtoken.txt file on the http://multiple-redirect.com page. However, you will need to disable the second redirect (https://www.single-redirect.com) long enough for us to locate the verificationtoken.txt and validate your control over http://multiple-redirect.com.