Is it possible that after cbc encryption, null character appears in the resulting multibyte data. If yes, what precaution should I take to avoid it.
Is it possible that after cbc encryption, null character appears in the resulting multibyte data.
Absolutely. It would not be a pseudo-random function if values like 0's were missing.
If yes, what precaution should I take to avoid it.
Treat everything as a byte array with embedded NULLs. Never treat it like a char*.
If you want to treat it like a char*, then you will need to encode it first. Try hexadecimal, Base32 or Base64.
来源：https://stackoverflow.com/questions/22969876/null-character-in-encrypted-data