Can UTF-8 contain zero byte?

Question

Can UTF-8 string contain zerobytes? I\'m going to send it over ascii plaintext protocol, should I encode it with something like base64?

Answer 1

A UTF-8 encoded string can have most values from 0x00 to 0xff in a given byte position for of backing memory (although a few specific combinations are not allowed, see http://en.wikipedia.org/wiki/UTF-8 and the octet values C0, C1, F5 to FF never appear).

If you are transporting across a channel such as an ASCII stream that does not support binary data, you will have to appropriately encode. Base64 is broadly supported and will certainly solve that problem, though it is not entirely efficient since it uses a 64 character space to encode data, whereas ASCII allows for a 128 character space.

There is a sourceforge project that provides base 91 encoding, which is more space efficient while avoiding non-printable characters http://base91.sourceforge.net/