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// Copyright 2013-2014 The rust-url developers.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// option. This file may not be copied, modified, or distributed
// except according to those terms.
//! Deprecated API for [*Unicode IDNA Compatibility Processing*
#![allow(deprecated)]
use alloc::borrow::Cow;
use alloc::string::String;
use crate::uts46::*;
use crate::Errors;
/// Performs preprocessing equivalent to UTS 46 transitional processing
/// if `transitional` is `true`. If `transitional` is `false`, merely
/// lets the input pass through as-is (for call site convenience).
///
/// The output of this function is to be passed to [`Uts46::process`].
fn map_transitional(domain: &str, transitional: bool) -> Cow<'_, str> {
if !transitional {
return Cow::Borrowed(domain);
}
let mut chars = domain.chars();
loop {
let prev = chars.clone();
if let Some(c) = chars.next() {
match c {
'ß' | 'ẞ' | 'ς' | '\u{200C}' | '\u{200D}' => {
let mut s = String::with_capacity(domain.len());
let tail = prev.as_str();
let head = &domain[..domain.len() - tail.len()];
s.push_str(head);
for c in tail.chars() {
match c {
'ß' | 'ẞ' => {
s.push_str("ss");
}
'ς' => {
s.push('σ');
}
'\u{200C}' | '\u{200D}' => {}
_ => {
s.push(c);
}
}
}
return Cow::Owned(s);
}
_ => {}
}
} else {
break;
}
}
Cow::Borrowed(domain)
}
/// Deprecated. Use the crate-top-level functions or [`Uts46`].
#[derive(Default)]
#[deprecated]
pub struct Idna {
config: Config,
}
impl Idna {
pub fn new(config: Config) -> Self {
Self { config }
}
#[allow(clippy::wrong_self_convention)] // Retain old weirdness in deprecated API
pub fn to_ascii(&mut self, domain: &str, out: &mut String) -> Result<(), Errors> {
let mapped = map_transitional(domain, self.config.transitional_processing);
match Uts46::new().process(
mapped.as_bytes(),
self.config.deny_list(),
self.config.hyphens(),
ErrorPolicy::FailFast, // Old code did not appear to expect the output to be useful in the error case.
|_, _, _| false,
out,
None,
) {
Ok(ProcessingSuccess::Passthrough) => {
if self.config.verify_dns_length && !verify_dns_length(&mapped, true) {
return Err(crate::Errors::default());
}
out.push_str(&mapped);
Ok(())
}
Ok(ProcessingSuccess::WroteToSink) => {
if self.config.verify_dns_length && !verify_dns_length(out, true) {
return Err(crate::Errors::default());
}
Ok(())
}
Err(ProcessingError::ValidityError) => Err(crate::Errors::default()),
Err(ProcessingError::SinkError) => unreachable!(),
}
}
#[allow(clippy::wrong_self_convention)] // Retain old weirdness in deprecated API
pub fn to_unicode(&mut self, domain: &str, out: &mut String) -> Result<(), Errors> {
let mapped = map_transitional(domain, self.config.transitional_processing);
match Uts46::new().process(
mapped.as_bytes(),
self.config.deny_list(),
self.config.hyphens(),
ErrorPolicy::MarkErrors,
|_, _, _| true,
out,
None,
) {
Ok(ProcessingSuccess::Passthrough) => {
out.push_str(&mapped);
Ok(())
}
Ok(ProcessingSuccess::WroteToSink) => Ok(()),
Err(ProcessingError::ValidityError) => Err(crate::Errors::default()),
Err(ProcessingError::SinkError) => unreachable!(),
}
}
}
/// Deprecated configuration API.
#[derive(Clone, Copy)]
#[must_use]
#[deprecated]
pub struct Config {
use_std3_ascii_rules: bool,
transitional_processing: bool,
verify_dns_length: bool,
check_hyphens: bool,
}
/// The defaults are that of _beStrict=false_ in the [WHATWG URL Standard](https://url.spec.whatwg.org/#idna)
impl Default for Config {
fn default() -> Self {
Config {
use_std3_ascii_rules: false,
transitional_processing: false,
check_hyphens: false,
// Only use for to_ascii, not to_unicode
verify_dns_length: false,
}
}
}
impl Config {
/// Whether to enforce STD3 or WHATWG URL Standard ASCII deny list.
///
/// `true` for STD3, `false` for no deny list.
///
/// Note that `true` rejects pseudo-hosts used by various TXT record-based protocols.
#[inline]
pub fn use_std3_ascii_rules(mut self, value: bool) -> Self {
self.use_std3_ascii_rules = value;
self
}
/// Whether to enable (deprecated) transitional processing.
///
/// Note that Firefox, Safari, and Chrome do not use transitional
/// processing.
#[inline]
pub fn transitional_processing(mut self, value: bool) -> Self {
self.transitional_processing = value;
self
}
/// Whether the _VerifyDNSLength_ operation should be performed
/// by `to_ascii`.
///
/// For compatibility with previous behavior, even when set to `true`,
/// the trailing root label dot is allowed contrary to the spec.
#[inline]
pub fn verify_dns_length(mut self, value: bool) -> Self {
self.verify_dns_length = value;
self
}
/// Whether to enforce STD3 rules for hyphen placement.
///
/// `true` to deny hyphens in the first and last positions.
/// `false` to not enforce hyphen placement.
///
/// Note that for backward compatibility this is not the same as
/// UTS 46 _CheckHyphens_, which also disallows hyphens in the
/// third and fourth positions.
///
/// Note that `true` rejects real-world names, including some GitHub user pages.
#[inline]
pub fn check_hyphens(mut self, value: bool) -> Self {
self.check_hyphens = value;
self
}
/// Obsolete method retained to ease migration. The argument must be `false`.
///
/// Panics
///
/// If the argument is `true`.
#[inline]
#[allow(unused_mut)]
pub fn use_idna_2008_rules(mut self, value: bool) -> Self {
assert!(!value, "IDNA 2008 rules are no longer supported");
self
}
/// Compute the deny list
fn deny_list(&self) -> AsciiDenyList {
if self.use_std3_ascii_rules {
AsciiDenyList::STD3
} else {
AsciiDenyList::EMPTY
}
}
/// Compute the hyphen mode
fn hyphens(&self) -> Hyphens {
if self.check_hyphens {
Hyphens::CheckFirstLast
} else {
Hyphens::Allow
}
}
pub fn to_ascii(self, domain: &str) -> Result<String, Errors> {
let mut result = String::with_capacity(domain.len());
let mut codec = Idna::new(self);
codec.to_ascii(domain, &mut result).map(|()| result)
}
pub fn to_unicode(self, domain: &str) -> (String, Result<(), Errors>) {
let mut codec = Idna::new(self);
let mut out = String::with_capacity(domain.len());
let result = codec.to_unicode(domain, &mut out);
(out, result)
}
}