http-01 Challenge

With the http-01 challenge, you prove to the CA that you are able to control the web site content of the domain to be authorized, by making a file with a signed content available at a given path.

Http01Challenge provides two strings:

Http01Challenge challenge = auth.findChallenge(Http01Challenge.TYPE);

String token = challenge.getToken();
String content = challenge.getAuthorization();

token is the name of the file that will be requested by the CA server. It must contain the content string, without any leading or trailing white spaces or line breaks. The Content-Type header must be either text/plain or absent.

The expected path is (assuming that ${domain} is your domain and ${token} is the token):


The challenge is completed when the CA was able to download that file and found content in it.

Note that the request is sent to port 80 only. There is no way to choose a different port, for security reasons. This is a limitation of the ACME protocol, not of acme4j.