Re: The "prohibited" encodings...

From: Asmus Freytag (asmusf@ix.netcom.com)
Date: Tue Dec 29 2009 - 17:06:25 CST

  • Next message: Phillips, Addison: "RE: The "prohibited" encodings..."

    On 12/29/2009 2:03 PM, Phillips, Addison wrote:
    > No, that's not it.
    >
    > UTF-7, BOCU, and SCSU are banned either because they auto-detect as something other than themselves or because an otherwise "innocuous" byte sequence detects as being one of them, thus serving as the basis for an XSS attack. UTF-32 is banned apparently because naïve implementations might detect it as UTF-16.
    >
    > None of these encodings encode the same (full) sequence of code points in more than one way,
    Hmmm. Not what I remember about SCSU. The encoder has wide latitude in
    picking compression techniques in SCSU, if I remember from my sample
    implementation. The result would be that two strings that were identical
    in UTF-16 can become two different byte strings if encoded with two
    different encoders for SCSU.

    A./
    > unless you mean that some of them encode identical subsequences of a larger document using different byte values? But that's not the same thing.
    >
    > Addison
    >
    > Addison Phillips
    > Globalization Architect -- Lab126
    >
    > Internationalization is not a feature.
    > It is an architecture.
    >
    >
    >
    >> -----Original Message-----
    >> From: unicode-bounce@unicode.org [mailto:unicode-bounce@unicode.org]
    >> On Behalf Of Andrew Lipscomb
    >> Sent: Tuesday, December 29, 2009 1:01 PM
    >> To: unicode@unicode.org
    >> Subject: The "prohibited" encodings...
    >>
    >> I think I just realized what they have in common--each one has the
    >> ability to represent binary-identical strings in *more than one*
    >> way.
    >>
    >>
    >
    >
    >
    >
    >



    This archive was generated by hypermail 2.1.5 : Tue Dec 29 2009 - 17:09:14 CST