site_archiver@lists.apple.com Delivered-To: darwin-dev@lists.apple.com Importance: Normal User-agent: SquirrelMail/1.4.2 Clark Cox said:

On Mon, 28 Mar 2005 14:09:11 -0500, Michael B Allen <mba2000@ioplex.com> wrote:

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On Mon, 28 Mar 2005 08:39:25 -0500 Clark Cox <clarkcox3@gmail.com> wrote:

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Actually, you will *never* see UTF-8 with more than 4 octets per codepoint. Period. That is the way that UTF-8 is defined. If you see a 5 or 6 octet character, then you are not reading UTF-8 data.

This is incorrect. Please read the first sentence in section 2 of RFC 2279

RFC 2279 has been obsoleted by RFC 3629 for years now: http://www.ietf.org/rfc/rfc3629.txt

First, this is dated 16 months ago. Pardon me for googling "utf-8 rfc" but don't be a twit - it's not "years".

From said RFC: [snip] 3. UTF-8 definition

UTF-8 is defined by the Unicode Standard [UNICODE]. Descriptions and formulae can also be found in Annex D of ISO/IEC 10646-1 [ISO.10646]

In UTF-8, characters from the U+0000..U+10FFFF range (the UTF-16 accessible range) are encoded using sequences of 1 to 4 octets.

This just says that range takes 4 octects. Well yeah. Duh. As I stated previously is the only practical range of values one would ever see but technically UTF-8 can encode 6 bytes. RFC 3269 mentions this in the Security Considerations section: Another security issue occurs when encoding to UTF-8: the ISO/IEC 10646 description of UTF-8 allows encoding character numbers up to U+7FFFFFFF, yielding sequences of up to 6 bytes. There is therefore a risk of buffer overflow if the range of character numbers is not explicitly limited to U+10FFFF or if buffer sizing doesn't take into account the possibility of 5- and 6-byte sequences. Man, it really doesn't pay to be pedantic these days. EOT _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.appl... This email sent to site_archiver@lists.apple.com