[HTTPCORE-743] Add support for IDNA 2008 (RFC 5891)

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 5.0
• Fix Version/s: 5.3-alpha1
• Labels: stuck volunteers-wanted
• Environment: Android SDK 30

Language

kotlin

• Assignee: Unassigned
• Reporter: Julien Bernard
• Created: 12/Nov/21 21:15
• Updated: 26/Apr/23 07:24
• Resolved: 26/Apr/23 07:24

Description

The tests have been conducted with Kotlin on Android SDK 30 with Apache HttpClient Android extensions which ships with HttpClient version 5.0.1 but any HttpClient component on any platform may be impacted.

Before making an HTTP query the client should convert the URL domain to A-label as described in RFC 5891.

Here is an example with the trustworthy ICU4J library:
 

int flags = IDNA.CHECK_BIDI
       | IDNA.CHECK_CONTEXTJ
       | IDNA.CHECK_CONTEXTO
       |  IDNA.NONTRANSITIONAL_TO_ASCII
       | IDNA.USE_STD3_RULES;
IDNA idna = IDNA.getUTS46Instance(flags);
IDNA.Info info = new IDNA.Info();
String domainAscii = idna.nameToASCII(domain, new StringBuilder(), info);
// check error with info.hasErrors()