Files
chatmail-core/src/dc_strencode.rs
2019-09-15 16:36:31 +02:00

466 lines
15 KiB
Rust

use std::borrow::Cow;
use std::ffi::CString;
use std::ptr;
use charset::Charset;
use mmime::mailmime_decode::*;
use mmime::mmapstring::*;
use mmime::other::*;
use percent_encoding::{percent_decode, utf8_percent_encode, AsciiSet, CONTROLS};
use crate::dc_tools::*;
use crate::x::*;
/**
* Encode non-ascii-strings as `=?UTF-8?Q?Bj=c3=b6rn_Petersen?=`.
* Belongs to RFC 2047: https://tools.ietf.org/html/rfc2047
*
* We do not fold at position 72; this would result in empty words as `=?utf-8?Q??=` which are correct,
* but cannot be displayed by some mail programs (eg. Android Stock Mail).
* however, this is not needed, as long as _one_ word is not longer than 72 characters.
* _if_ it is, the display may get weird. This affects the subject only.
* the best solution wor all this would be if libetpan encodes the line as only libetpan knowns when a header line is full.
*
* @param to_encode Null-terminated UTF-8-string to encode.
* @return Returns the encoded string which must be free()'d when no longed needed.
* On errors, NULL is returned.
*/
pub unsafe fn dc_encode_header_words(to_encode: *const libc::c_char) -> *mut libc::c_char {
let mut ok_to_continue = true;
let mut ret_str: *mut libc::c_char = ptr::null_mut();
let mut cur: *const libc::c_char = to_encode;
let mmapstr: *mut MMAPString = mmap_string_new(b"\x00" as *const u8 as *const libc::c_char);
if to_encode.is_null() || mmapstr.is_null() {
ok_to_continue = false;
}
loop {
if !ok_to_continue {
if !mmapstr.is_null() {
mmap_string_free(mmapstr);
}
break;
} else {
if *cur as libc::c_int != '\u{0}' as i32 {
let begin: *const libc::c_char;
let mut end: *const libc::c_char;
let mut do_quote: bool;
let mut quote_words: libc::c_int;
begin = cur;
end = begin;
quote_words = 0i32;
do_quote = true;
while *cur as libc::c_int != '\u{0}' as i32 {
get_word(cur, &mut cur, &mut do_quote);
if !do_quote {
break;
}
quote_words = 1i32;
end = cur;
if *cur as libc::c_int != '\u{0}' as i32 {
cur = cur.offset(1isize)
}
}
if 0 != quote_words {
if !quote_word(
b"utf-8\x00" as *const u8 as *const libc::c_char,
mmapstr,
begin,
end.wrapping_offset_from(begin) as libc::size_t,
) {
ok_to_continue = false;
continue;
}
if *end as libc::c_int == ' ' as i32 || *end as libc::c_int == '\t' as i32 {
if mmap_string_append_c(mmapstr, *end).is_null() {
ok_to_continue = false;
continue;
}
end = end.offset(1isize)
}
if *end as libc::c_int != '\u{0}' as i32 {
if mmap_string_append_len(
mmapstr,
end,
cur.wrapping_offset_from(end) as libc::size_t,
)
.is_null()
{
ok_to_continue = false;
continue;
}
}
} else if mmap_string_append_len(
mmapstr,
begin,
cur.wrapping_offset_from(begin) as libc::size_t,
)
.is_null()
{
ok_to_continue = false;
continue;
}
if !(*cur as libc::c_int == ' ' as i32 || *cur as libc::c_int == '\t' as i32) {
continue;
}
if mmap_string_append_c(mmapstr, *cur).is_null() {
ok_to_continue = false;
continue;
}
cur = cur.offset(1isize);
} else {
ret_str = strdup((*mmapstr).str_0);
ok_to_continue = false;
}
}
}
ret_str
}
unsafe fn quote_word(
display_charset: *const libc::c_char,
mmapstr: *mut MMAPString,
word: *const libc::c_char,
size: libc::size_t,
) -> bool {
let mut cur: *const libc::c_char;
let mut i = 0;
let mut hex: [libc::c_char; 4] = [0; 4];
// let mut col: libc::c_int = 0i32;
if mmap_string_append(mmapstr, b"=?\x00" as *const u8 as *const libc::c_char).is_null() {
return false;
}
if mmap_string_append(mmapstr, display_charset).is_null() {
return false;
}
if mmap_string_append(mmapstr, b"?Q?\x00" as *const u8 as *const libc::c_char).is_null() {
return false;
}
// col = (*mmapstr).len as libc::c_int;
cur = word;
while i < size {
let mut do_quote_char = false;
match *cur as u8 as char {
',' | ':' | '!' | '"' | '#' | '$' | '@' | '[' | '\\' | ']' | '^' | '`' | '{' | '|'
| '}' | '~' | '=' | '?' | '_' => do_quote_char = true,
_ => {
if *cur as u8 >= 128 {
do_quote_char = true;
}
}
}
if do_quote_char {
print_hex(hex.as_mut_ptr(), cur);
if mmap_string_append(mmapstr, hex.as_mut_ptr()).is_null() {
return false;
}
// col += 3i32
} else {
if *cur as libc::c_int == ' ' as i32 {
if mmap_string_append_c(mmapstr, '_' as i32 as libc::c_char).is_null() {
return false;
}
} else if mmap_string_append_c(mmapstr, *cur).is_null() {
return false;
}
// col += 3i32
}
cur = cur.offset(1isize);
i = i.wrapping_add(1)
}
if mmap_string_append(mmapstr, b"?=\x00" as *const u8 as *const libc::c_char).is_null() {
return false;
}
true
}
unsafe fn get_word(
begin: *const libc::c_char,
pend: *mut *const libc::c_char,
pto_be_quoted: *mut bool,
) {
let mut cur: *const libc::c_char = begin;
while *cur as libc::c_int != ' ' as i32
&& *cur as libc::c_int != '\t' as i32
&& *cur as libc::c_int != '\u{0}' as i32
{
cur = cur.offset(1isize)
}
*pto_be_quoted = to_be_quoted(begin, cur.wrapping_offset_from(begin) as libc::size_t);
*pend = cur;
}
/* ******************************************************************************
* Encode/decode header words, RFC 2047
******************************************************************************/
/* see comment below */
unsafe fn to_be_quoted(word: *const libc::c_char, size: libc::size_t) -> bool {
let mut cur: *const libc::c_char = word;
let mut i = 0;
while i < size {
match *cur as libc::c_int {
44 | 58 | 33 | 34 | 35 | 36 | 64 | 91 | 92 | 93 | 94 | 96 | 123 | 124 | 125 | 126
| 61 | 63 | 95 => return true,
_ => {
if *cur as libc::c_uchar as libc::c_int >= 128i32 {
return true;
}
}
}
cur = cur.offset(1isize);
i = i.wrapping_add(1)
}
false
}
pub unsafe fn dc_decode_header_words(in_0: *const libc::c_char) -> *mut libc::c_char {
if in_0.is_null() {
return ptr::null_mut();
}
let mut out: *mut libc::c_char = ptr::null_mut();
let mut cur_token = 0;
let r: libc::c_int = mailmime_encoded_phrase_parse(
b"iso-8859-1\x00" as *const u8 as *const libc::c_char,
in_0,
strlen(in_0),
&mut cur_token,
b"utf-8\x00" as *const u8 as *const libc::c_char,
&mut out,
);
if r != MAILIMF_NO_ERROR as libc::c_int || out.is_null() {
out = dc_strdup(in_0)
}
out
}
pub fn dc_decode_header_words_safe(input: &str) -> String {
static FROM_ENCODING: &[u8] = b"iso-8859-1\x00";
static TO_ENCODING: &[u8] = b"utf-8\x00";
let mut out = ptr::null_mut();
let mut cur_token = 0;
let input_c = CString::yolo(input);
unsafe {
let r = mailmime_encoded_phrase_parse(
FROM_ENCODING.as_ptr().cast(),
input_c.as_ptr(),
input.len(),
&mut cur_token,
TO_ENCODING.as_ptr().cast(),
&mut out,
);
if r as u32 != MAILIMF_NO_ERROR || out.is_null() {
input.to_string()
} else {
let res = to_string(out);
free(out.cast());
res
}
}
}
pub fn dc_needs_ext_header(to_check: impl AsRef<str>) -> bool {
let to_check = to_check.as_ref();
if to_check.is_empty() {
return false;
}
to_check.chars().any(|c| {
!(c.is_ascii_alphanumeric()
|| c == '-'
|| c == '_'
|| c == '_'
|| c == '.'
|| c == '~'
|| c == '%')
})
}
const EXT_ASCII_ST: &AsciiSet = &CONTROLS
.add(b' ')
.add(b'-')
.add(b'_')
.add(b'.')
.add(b'~')
.add(b'%');
/// Encode an UTF-8 string to the extended header format.
pub fn dc_encode_ext_header(to_encode: impl AsRef<str>) -> String {
let encoded = utf8_percent_encode(to_encode.as_ref(), &EXT_ASCII_ST);
format!("utf-8''{}", encoded)
}
/// Decode an extended-header-format strings to UTF-8.
pub fn dc_decode_ext_header(to_decode: &[u8]) -> Cow<str> {
if let Some(index) = bytes!(b'\'').find(to_decode) {
let (charset, rest) = to_decode.split_at(index);
if !charset.is_empty() {
// skip language
if let Some(index2) = bytes!(b'\'').find(&rest[1..]) {
let decoded = percent_decode(&rest[index2 + 2..]);
if charset != b"utf-8" && charset != b"UTF-8" {
if let Some(encoding) = Charset::for_label(charset) {
let bytes = decoded.collect::<Vec<u8>>();
let (res, _, _) = encoding.decode(&bytes);
return Cow::Owned(res.into_owned());
} else {
return decoded.decode_utf8_lossy();
}
} else {
return decoded.decode_utf8_lossy();
}
}
}
}
String::from_utf8_lossy(to_decode)
}
unsafe fn print_hex(target: *mut libc::c_char, cur: *const libc::c_char) {
assert!(!target.is_null());
assert!(!cur.is_null());
let bytes = std::slice::from_raw_parts(cur as *const _, strlen(cur));
let raw = CString::yolo(format!("={}", &hex::encode_upper(bytes)[..2]));
libc::memcpy(target as *mut _, raw.as_ptr() as *const _, 4);
}
#[cfg(test)]
mod tests {
use super::*;
use std::ffi::CStr;
#[test]
fn test_dc_decode_header_words() {
unsafe {
let mut buf1: *mut libc::c_char = dc_decode_header_words(
b"=?utf-8?B?dGVzdMOkw7bDvC50eHQ=?=\x00" as *const u8 as *const libc::c_char,
);
assert_eq!(
strcmp(
buf1,
b"test\xc3\xa4\xc3\xb6\xc3\xbc.txt\x00" as *const u8 as *const libc::c_char
),
0
);
free(buf1 as *mut libc::c_void);
buf1 =
dc_decode_header_words(b"just ascii test\x00" as *const u8 as *const libc::c_char);
assert_eq!(CStr::from_ptr(buf1).to_str().unwrap(), "just ascii test");
free(buf1 as *mut libc::c_void);
buf1 = dc_encode_header_words(b"abcdef\x00" as *const u8 as *const libc::c_char);
assert_eq!(CStr::from_ptr(buf1).to_str().unwrap(), "abcdef");
free(buf1 as *mut libc::c_void);
buf1 = dc_encode_header_words(
b"test\xc3\xa4\xc3\xb6\xc3\xbc.txt\x00" as *const u8 as *const libc::c_char,
);
assert_eq!(
strncmp(buf1, b"=?utf-8\x00" as *const u8 as *const libc::c_char, 7),
0
);
let buf2: *mut libc::c_char = dc_decode_header_words(buf1);
assert_eq!(
strcmp(
buf2,
b"test\xc3\xa4\xc3\xb6\xc3\xbc.txt\x00" as *const u8 as *const libc::c_char
),
0
);
free(buf1 as *mut libc::c_void);
free(buf2 as *mut libc::c_void);
buf1 = dc_decode_header_words(
b"=?ISO-8859-1?Q?attachment=3B=0D=0A_filename=3D?= =?ISO-8859-1?Q?=22test=E4=F6=FC=2Etxt=22=3B=0D=0A_size=3D39?=\x00" as *const u8 as *const libc::c_char
);
assert_eq!(
strcmp(
buf1,
b"attachment;\r\n filename=\"test\xc3\xa4\xc3\xb6\xc3\xbc.txt\";\r\n size=39\x00" as *const u8 as *const libc::c_char,
),
0
);
free(buf1 as *mut libc::c_void);
}
}
#[test]
fn test_dc_encode_ext_header() {
let buf1 = dc_encode_ext_header("Björn Petersen");
assert_eq!(&buf1, "utf-8\'\'Bj%C3%B6rn%20Petersen");
let buf2 = dc_decode_ext_header(buf1.as_bytes());
assert_eq!(&buf2, "Björn Petersen",);
let buf1 = dc_decode_ext_header(b"iso-8859-1\'en\'%A3%20rates");
assert_eq!(buf1, "£ rates",);
let buf1 = dc_decode_ext_header(b"wrong\'format");
assert_eq!(buf1, "wrong\'format",);
let buf1 = dc_decode_ext_header(b"\'\'");
assert_eq!(buf1, "\'\'");
let buf1 = dc_decode_ext_header(b"x\'\'");
assert_eq!(buf1, "");
let buf1 = dc_decode_ext_header(b"\'");
assert_eq!(buf1, "\'");
let buf1 = dc_decode_ext_header(b"");
assert_eq!(buf1, "");
// regressions
assert_eq!(
dc_decode_ext_header(dc_encode_ext_header("%0A").as_bytes()),
"%0A"
);
}
#[test]
fn test_dc_needs_ext_header() {
assert_eq!(dc_needs_ext_header("Björn"), true);
assert_eq!(dc_needs_ext_header("Bjoern"), false);
assert_eq!(dc_needs_ext_header(""), false);
assert_eq!(dc_needs_ext_header(" "), true);
assert_eq!(dc_needs_ext_header("a b"), true);
}
#[test]
fn test_print_hex() {
let mut hex: [libc::c_char; 4] = [0; 4];
let cur = b"helloworld" as *const u8 as *const libc::c_char;
unsafe { print_hex(hex.as_mut_ptr(), cur) };
assert_eq!(to_string(hex.as_ptr() as *const _), "=68");
let cur = b":" as *const u8 as *const libc::c_char;
unsafe { print_hex(hex.as_mut_ptr(), cur) };
assert_eq!(to_string(hex.as_ptr() as *const _), "=3A");
}
use proptest::prelude::*;
proptest! {
#[test]
fn test_ext_header_roundtrip(buf: String) {
let encoded = dc_encode_ext_header(&buf);
let decoded = dc_decode_ext_header(encoded.as_bytes());
assert_eq!(buf, decoded);
}
#[test]
fn test_ext_header_decode_anything(buf: Vec<u8>) {
// make sure this never panics
let _decoded = dc_decode_ext_header(&buf);
}
}
}