There is the part where the usage of X.509 certificates for DNS names on the Internet, as opposed to in the context of the (nonexistent) X.500 directory, is a g

There is the part where the usage of X.509 certificates for DNS names on the Internet, as opposed to in the context of the (nonexistent) X.500 directory, is a gigantic hack[1]. This means the definition of “when it was built” is rather hazy. Also, the 1994 Netscape implementation literally accepted a CN=foo.com certificate when connecting to bar.org, so the state of SSL when it was built is not exactly a stellar reference. Still, the name constraints extension, which restricts all certificates (transitively) issued from a given CA to a given DNS subtree, has been in the “Internet profile” of X.509 (PKIX) since the December 1996 draft[2]. The problem from this technical point of view is that very few implementations supported it until a couple of years ago[3]. [1] https://medium.com/@sleevi_/x-520-whats-in-a-name-da6ea8954b4f https://medium.com/@sleevi_/x-520-whats-in-a-name-da6ea8954b... [2] https://datatracker.ietf.org/doc/html/draft-ietf-pkix-ipki-part1-03#section-4.2.1.11 https://datatracker.ietf.org/doc/html/draft-ietf-pkix-ipki-p... [3] https://bettertls.com/ https://bettertls.com/