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Re: [Json] secdir review of draft-ietf-jsonbis-rfc7159bis-03

2017-03-11 00:13:10
On 2017-03-11 03:08, John Cowan wrote:

On Thu, Mar 9, 2017 at 12:53 AM, Benjamin Kaduk <kaduk(_at_)mit(_dot_)edu
<mailto:kaduk(_at_)mit(_dot_)edu>> wrote:

    If that's what's supposed to happen, it should probably be more
    clear, yes.  (But aren't there texts that have valid interpretations
    in multiple encodings?)


Not if the content is well-formed JSON and the only possible encodings
are UTF-8, UTF-16, and UTF-32.  It suffices to examine the first four
bytes of the input.  If there are no NUL bytes in the first four bytes,
it is UTF-8; if there are two NUL bytes, it is UTF-16; if there are
three NUL bytes, it is UTF-32.  This works because the grammar requires
the first character to be in the ASCII repertoire, and the NUL
*character* (U+0000) is not allowed at all.

Good explanation. Maybe the spec should include it.

Best regards, Julian