Re: Implementation of SASLprep for SCRAM-SHA-256

On 04/07/2017 05:30 AM, Michael Paquier wrote:
> On Fri, Apr 7, 2017 at 2:47 AM, Heikki Linnakangas <hlinnaka(at)iki(dot)fi> wrote:
>> On 04/06/2017 08:42 PM, Heikki Linnakangas wrote:
>>>> There is for example this portion in the new tables:
>>>> +static const Codepoint prohibited_output_chars[] =
>>>> +{
>>>> + 0xD800, 0xF8FF, /* C.3, C.5 */
>>>>
>>>> ----- Start Table C.5 -----
>>>> D800-DFFF; [SURROGATE CODES]
>>>> ----- End Table C.5 -----
>>>> This indicates a range of values. Wouldn't it be better to split this
>>>> table in two, one for the range of codepoints and another one with the
>>>> single entries?
>>>
>>> I considered that, but there are relatively few singular codepoints in
>>> the tables, so it wouldn't save much space. In this patch, singular
>>> codepoints are represented by a range like "0x3000, 0x3000".
>
> I am really wondering if this should not reflect the real range
> reported by the RFC. I understand that you have grouped things to save
> a couple of bytes, but that would protect from any updates of the
> codepoints within those ranges (unlikely to happen I agree).

It just means that there will be some more work required to apply the
changes to the current lists. I constructed the lists manually to begin
with, copy-pasting the lists from the RFC, and moving and merging
entries by hand. I wouldn't mind doing that by hand again, if the lists
change. But as you said, it seems unlikely that they would change any
time soon.

> You may want to add a .gitignore in src/common/unicode for norm_test
> and norm_test_table.h.

Added, and pushed, with some more comment fixes.

Many thanks, Michael!

- Heikki