Method CheckIntraStringDataItem

Bcore/src/main/cpp/dex/dex_file_verifier.cc:1332–1416

}

bool DexFileVerifier::CheckIntraStringDataItem() {
  DECODE_UNSIGNED_CHECKED_FROM(ptr_, size);
  const uint8_t* file_end = begin_ + size_;

  for (uint32_t i = 0; i < size; i++) {
    CHECK_LT(i, size);  // b/15014252 Prevents hitting the impossible case below
    if (UNLIKELY(ptr_ >= file_end)) {
      ErrorStringPrintf("String data would go beyond end-of-file");
      return false;
    }

    uint8_t byte = *(ptr_++);

    // Switch on the high 4 bits.
    switch (byte >> 4) {
      case 0x00:
        // Special case of bit pattern 0xxx.
        if (UNLIKELY(byte == 0)) {
          CHECK_LT(i, size);  // b/15014252 Actually hit this impossible case with clang
          ErrorStringPrintf("String data shorter than indicated utf16_size %x", size);
          return false;
        }
        break;
      case 0x01:
      case 0x02:
      case 0x03:
      case 0x04:
      case 0x05:
      case 0x06:
      case 0x07:
        // No extra checks necessary for bit pattern 0xxx.
        break;
      case 0x08:
      case 0x09:
      case 0x0a:
      case 0x0b:
      case 0x0f:
        // Illegal bit patterns 10xx or 1111.
        // Note: 1111 is valid for normal UTF-8, but not here.
        ErrorStringPrintf("Illegal start byte %x in string data", byte);
        return false;
      case 0x0c:
      case 0x0d: {
        // Bit pattern 110x has an additional byte.
        uint8_t byte2 = *(ptr_++);
        if (UNLIKELY((byte2 & 0xc0) != 0x80)) {
          ErrorStringPrintf("Illegal continuation byte %x in string data", byte2);
          return false;
        }
        uint16_t value = ((byte & 0x1f) << 6) | (byte2 & 0x3f);
        if (UNLIKELY((value != 0) && (value < 0x80))) {
          ErrorStringPrintf("Illegal representation for value %x in string data", value);
          return false;
        }
        break;
      }
      case 0x0e: {
        // Bit pattern 1110 has 2 additional bytes.