I expect from RFC 8555 that an ACME server issues a full chain certificate as a reply body in the PEM format. The media type is 'application/pem-certificate-chain'. I can only guess from RFC 1421, sec. 4.3.1 that the byte encoding of the certificate necessarily uses <CR><LF> line breaks. I get US-ASCII from encguess <file>.pem. Paging PEM files with less does NOT show ^M at the end of each or any line.
Are PEM files, e.g. the private key pair files and certificate files needed by Web servers, necessarily in US-ASCII? Are PEM files typically/conventionally stored in the line break encoding of the native operating system? Should PEM files always or normally be transmitted with the <CR><LF> line break encoding? Douglas Morris
