Questionable Test

[sco0ter]

Original report by Anonymous.

---

Are you sure the testUnicodeDomain test is valid?

https://bitbucket.org/sco0ter/precis/src/40503f4cf4fca40c5844c1a75b9f81a42495c637/src/test/java/rocks/xmpp/precis/IDNProfileTest.java#lines-23:27

When I test the domain name in IDNA 2008 in an Erlang implementation, I get an error:

Eshell V10.3.1  (abort with ^G)
1> idna:encode("x{10D}echy.example").
** exception exit: {bad_label,{alabel,"The label \"x{10D}echy\"  is not a valid A-label: ulabel error={bad_label,\n                                                              {context,\n                                                               \"Codepoint 123 not allowed ('DISALLOWED') at posion 1 in \\\"x{10d}echy\\\"\"}}"}}
     in function  idna:alabel/1 (/Users/varnerac/xmpp_light/_build/default/lib/idna/src/idna.erl, line 277)
     in call from idna:encode_1/2 (/Users/varnerac/xmpp_light/_build/default/lib/idna/src/idna.erl, line 145)

[sco0ter]

Original comment by Christian Schudt (Bitbucket: sco0ter, GitHub: sco0ter).

---

I’ve found the example here:

https://tools.ietf.org/html/rfc5122#section-2.7.3

So I assume it is valid, because the document also says it’s valid 😉

As far as I know an A-label is a label which starts with “xn--” and is the ASCII form of a unicode label.

I assume you first have to convert the input string to an ASCII label, i.e. convert “čechy.example” to “xn--echy-fua.example” (see Puny Code).