fix issue 2299: Unicode code points higher than 0x10000 decoding fails.

- Use CESU8 decoder instead of UTF-8 in StringBlock.
- DEX uses Modified UTF-8 which is close to CESU-8 (https://source.android.com/devices/tech/dalvik/dex-format#mutf-8)
This commit is contained in:
Comnir 2020-12-10 12:33:06 +02:00
parent 201b5976bb
commit f1321c8437

View File

@ -298,10 +298,22 @@ public class StringBlock {
@VisibleForTesting
String decodeString(int offset, int length) {
final ByteBuffer wrappedBuffer = ByteBuffer.wrap(m_strings, offset, length);
try {
return (m_isUTF8 ? UTF8_DECODER : UTF16LE_DECODER).decode(
ByteBuffer.wrap(m_strings, offset, length)).toString();
return (m_isUTF8 ? UTF8_DECODER : UTF16LE_DECODER).decode(wrappedBuffer).toString();
} catch (CharacterCodingException ex) {
LOGGER.warning("Failed to decode a string at offset " + offset + " of length " + length);
if (!m_isUTF8) {
return null;
}
}
try {
// in some places, Android uses 3-byte UTF-8 sequences instead of 4-bytes.
// If decoding failed, we try to use CESU-8 decoder, which is closer to what Android actually uses.
return CESU8_DECODER.decode(wrappedBuffer).toString();
} catch (CharacterCodingException e) {
LOGGER.warning("Failed to decode a string with CESU-8 decoder.");
return null;
}
}
@ -362,6 +374,7 @@ public class StringBlock {
private final CharsetDecoder UTF16LE_DECODER = Charset.forName("UTF-16LE").newDecoder();
private final CharsetDecoder UTF8_DECODER = Charset.forName("UTF-8").newDecoder();
private final CharsetDecoder CESU8_DECODER = Charset.forName("CESU8").newDecoder();
private static final Logger LOGGER = Logger.getLogger(StringBlock.class.getName());
// ResChunk_header = header.type (0x0001) + header.headerSize (0x001C)