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/*
* SPDX-FileCopyrightText: 2020 Stalwart Labs LLC <hello@stalw.art>
*
* SPDX-License-Identifier: Apache-2.0 OR MIT
*/
use crate::{decoders::charsets::map::charset_decoder, parsers::MessageStream};
use super::DecodeWordFnc;
enum Rfc2047State {
Init,
Charset,
Encoding,
Data,
}
impl MessageStream<'_> {
pub fn decode_rfc2047(&mut self) -> Option<String> {
let mut state = Rfc2047State::Init;
let mut charset_start = 0;
let mut charset_end = 0;
let mut decode_fnc: Option<DecodeWordFnc<'_>> = None;
while let Some(ch) = self.next() {
match state {
Rfc2047State::Init => {
if ch != &b'?' {
return None;
}
state = Rfc2047State::Charset;
charset_start = self.offset();
charset_end = self.offset();
}
Rfc2047State::Charset => match ch {
b'?' => {
if charset_end == charset_start {
charset_end = self.offset() - 1;
}
if (charset_end - charset_start) < 2 {
return None;
}
state = Rfc2047State::Encoding;
}
b'*' => {
if charset_end == charset_start {
charset_end = self.offset() - 1;
}
}
b'\n' => {
return None;
}
_ => (),
},
Rfc2047State::Encoding => {
match ch {
b'q' | b'Q' => {
decode_fnc = Some(MessageStream::decode_quoted_printable_word)
}
b'b' | b'B' => decode_fnc = Some(MessageStream::decode_base64_word),
_ => {
return None;
}
}
state = Rfc2047State::Data;
}
Rfc2047State::Data => {
if ch != &b'?' {
return None;
} else {
break;
}
}
}
}
if let Some(bytes) = decode_fnc.and_then(|fnc| fnc(self)) {
if let Some(decoder) = charset_decoder(self.bytes(charset_start..charset_end)) {
decoder(&bytes).into()
} else {
String::from_utf8(bytes)
.unwrap_or_else(|e| String::from_utf8_lossy(e.as_bytes()).into_owned())
.into()
}
} else {
None
}
}
}
#[cfg(test)]
mod tests {
use crate::parsers::MessageStream;
#[test]
fn decode_rfc2047() {
for (input, expected_result, _) in [
(
"?iso-8859-1?q?this=20is=20some=20text?=",
"this is some text",
true,
),
(
"?iso-8859-1?q?this is some text?=",
"this is some text",
true,
),
("?US-ASCII?Q?Keith_Moore?=", "Keith Moore", false),
(
"?iso_8859-1:1987?Q?Keld_J=F8rn_Simonsen?=",
"Keld Jørn Simonsen",
true,
),
(
"?ISO-8859-1?B?SWYgeW91IGNhbiByZWFkIHRoaXMgeW8=?=",
"If you can read this yo",
true,
),
(
"?ISO-8859-2?B?dSB1bmRlcnN0YW5kIHRoZSBleGFtcGxlLg==?=",
"u understand the example.",
true,
),
("?ISO-8859-1?Q?Olle_J=E4rnefors?=", "Olle Järnefors", true),
(
"?ISO-8859-1?Q?Patrik_F=E4ltstr=F6m?=",
"Patrik Fältström",
true,
),
("?ISO-8859-1*?Q?a?=", "a", true),
("?ISO-8859-1**?Q?a_b?=", "a b", true),
(
"?utf-8?b?VGjDrXMgw61zIHbDoWzDrWQgw5pURjg=?=",
"Thís ís válíd ÚTF8",
false,
),
(
"?utf-8*unknown?q?Th=C3=ADs_=C3=ADs_v=C3=A1l=C3=ADd_=C3=9ATF8?=",
"Thís ís válíd ÚTF8",
false,
),
(
"?Iso-8859-6?Q?=E5=D1=CD=C8=C7 =C8=C7=E4=D9=C7=E4=E5?=",
"مرحبا بالعالم",
true,
),
(
"?Iso-8859-6*arabic?b?5dHNyMcgyMfk2cfk5Q==?=",
"مرحبا بالعالم",
true,
),
#[cfg(feature = "full_encoding")]
(
"?shift_jis?B?g26DjYFbgUWDj4Fbg4uDaA==?=",
"ハロー・ワールド",
true,
),
#[cfg(feature = "full_encoding")]
(
"?iso-2022-jp?q?=1B$B%O%m!<!&%o!<%k%I=1B(B?=",
"ハロー・ワールド",
true,
),
] {
match MessageStream::new(input.as_bytes()).decode_rfc2047() {
Some(result) => {
//println!("Decoded '{}'", string);
assert_eq!(result, expected_result);
}
_ => panic!("Failed to decode '{}'", input),
}
}
}
}