mirror of
https://github.com/LadybirdBrowser/ladybird.git
synced 2024-08-17 01:10:28 +03:00
LibIMAP: Handle invalid escape sequences in Quoted-Printable parser
When an invalid escape sequence is encountered, we now output the characters unaltered instead of crashing.
This commit is contained in:
parent
debb4edcc8
commit
80238f29d2
Notes:
sideshowbarker
2024-07-17 10:54:57 +09:00
Author: https://github.com/tcl3 Commit: https://github.com/SerenityOS/serenity/commit/80238f29d2 Pull-request: https://github.com/SerenityOS/serenity/pull/21343 Reviewed-by: https://github.com/awesomekling
@ -46,4 +46,17 @@ TEST_CASE(test_decode)
|
||||
|
||||
auto illegal_character_decode = MUST(IMAP::decode_quoted_printable(illegal_character_builder.to_deprecated_string()));
|
||||
EXPECT(illegal_character_decode.is_empty());
|
||||
|
||||
// If an escape sequence is invalid the characters are output unaltered. Illegal characters are ignored as usual.
|
||||
decode_equal("="sv, "="sv);
|
||||
decode_equal("=Z"sv, "=Z"sv);
|
||||
decode_equal("=\x7F"sv, "="sv);
|
||||
decode_equal("=\x7F\x7F"sv, "="sv);
|
||||
decode_equal("=A\x7F"sv, "=A"sv);
|
||||
decode_equal("=A"sv, "=A"sv);
|
||||
decode_equal("=AZ"sv, "=AZ"sv);
|
||||
decode_equal("=\r"sv, "=\r"sv);
|
||||
decode_equal("=\r\r"sv, "=\r\r"sv);
|
||||
decode_equal("=\n\r"sv, "=\n\r"sv);
|
||||
decode_equal("=\rA"sv, "=\rA"sv);
|
||||
}
|
||||
|
@ -22,6 +22,18 @@ ErrorOr<ByteBuffer> decode_quoted_printable(StringView input)
|
||||
GenericLexer lexer(input);
|
||||
StringBuilder output;
|
||||
|
||||
// For any invalid escape sequence. RFC 2045 says a reasonable solution is just to append '=' followed by the unaltered escape characters.
|
||||
auto append_invalid_escape_sequence = [&](Optional<char> first = {}, Optional<char> second = {}) -> ErrorOr<void> {
|
||||
TRY(output.try_append('='));
|
||||
if (first.has_value() && !is_illegal_character(first.value()))
|
||||
TRY(output.try_append(first.value()));
|
||||
|
||||
if (second.has_value() && !is_illegal_character(second.value()))
|
||||
TRY(output.try_append(second.value()));
|
||||
|
||||
return {};
|
||||
};
|
||||
|
||||
// NOTE: The RFC says that encoded lines must not be longer than 76 characters.
|
||||
// However, the RFC says implementations can ignore this and parse as is,
|
||||
// which is the approach we're taking.
|
||||
@ -34,7 +46,8 @@ ErrorOr<ByteBuffer> decode_quoted_printable(StringView input)
|
||||
|
||||
if (potential_character == '=') {
|
||||
if (lexer.is_eof()) {
|
||||
TODO();
|
||||
TRY(append_invalid_escape_sequence());
|
||||
continue;
|
||||
}
|
||||
|
||||
char first_escape_character = lexer.consume();
|
||||
@ -43,7 +56,8 @@ ErrorOr<ByteBuffer> decode_quoted_printable(StringView input)
|
||||
// Thus we can use is_ascii_hex_digit.
|
||||
if (is_ascii_hex_digit(first_escape_character)) {
|
||||
if (lexer.is_eof()) {
|
||||
TODO();
|
||||
TRY(append_invalid_escape_sequence(first_escape_character));
|
||||
continue;
|
||||
}
|
||||
|
||||
char second_escape_character = lexer.consume();
|
||||
@ -52,11 +66,13 @@ ErrorOr<ByteBuffer> decode_quoted_printable(StringView input)
|
||||
u8 actual_character = (parse_ascii_hex_digit(first_escape_character) << 4) | parse_ascii_hex_digit(second_escape_character);
|
||||
TRY(output.try_append(actual_character));
|
||||
} else {
|
||||
TODO();
|
||||
TRY(append_invalid_escape_sequence(first_escape_character, second_escape_character));
|
||||
continue;
|
||||
}
|
||||
} else if (first_escape_character == '\r') {
|
||||
if (lexer.is_eof()) {
|
||||
TODO();
|
||||
TRY(append_invalid_escape_sequence(first_escape_character));
|
||||
continue;
|
||||
}
|
||||
|
||||
char second_escape_character = lexer.consume();
|
||||
@ -64,16 +80,12 @@ ErrorOr<ByteBuffer> decode_quoted_printable(StringView input)
|
||||
if (second_escape_character == '\n') {
|
||||
// This is a soft line break. Don't append anything to the output.
|
||||
} else {
|
||||
TODO();
|
||||
TRY(append_invalid_escape_sequence(first_escape_character, second_escape_character));
|
||||
continue;
|
||||
}
|
||||
} else {
|
||||
if (is_illegal_character(first_escape_character)) {
|
||||
TODO();
|
||||
}
|
||||
|
||||
// Invalid escape sequence. RFC 2045 says a reasonable solution is just to append '=' followed by the character.
|
||||
TRY(output.try_append('='));
|
||||
TRY(output.try_append(first_escape_character));
|
||||
TRY(append_invalid_escape_sequence(first_escape_character));
|
||||
continue;
|
||||
}
|
||||
} else {
|
||||
TRY(output.try_append(potential_character));
|
||||
|
Loading…
Reference in New Issue
Block a user