Request for comments: Sorting fields in signature generation

Marius Scurtescu marius at sxip.com
Tue Sep 26 23:49:57 UTC 2006


On 26-Sep-06, at 4:13 PM, Josh Hoyt wrote:

> On 9/26/06, Barry Ferg <barry at sxip.com> wrote:
>> The signature generation algorithm specifies that the fields to be
>> signed be ordered in byte order form.  It seems to be implied that
>> the ordering is based on using the field names as sorting keys
>
> I think the real topic of this discussion is whether or not multiple
> parameters with the same name should be allowed by the specification.
>
> I *strongly* prefer tightening the specification by *disallowing*
> duplicate parameter names. PHP is one environment in which the
> implementation will be problematic, but other common environments
> (e.g. Rails) do not easily support this idiom. There is *no deployed
> code* that depends on duplicated parameter names, and I'd like to keep
> it that way. Keep it simple if possible.

Yes, it  is quite unfortunate that PHP makes it hard to access  
multiple values.  It is not impossible or terrible hard though. A  
helper function in the PHP libraries can provide the needed  
functionality. You can use either HTTP_RAW_POST_DATA or reading from  
php://input, this gives you the url encoded list of parameters.  
Parsing this is trivial.

I would guess that there is a work around for Ruby on Rails as well.

The core protocol can disallow duplicate parameter names, but I think  
it should allow extensions to do that. Not sure about pass through  
parameters.

>
> I agree that the language in the specification should be clarified so
> that the sort order is fully explicit. I would resolve this issue by
> stating that the pairs must be sorted by key.

Also, the spec should make it clear that duplicate parameter names  
cannot occur.




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