Idempotent XML processing

[Michael Ekstrand]

On Aug 19, 2005, at 1:20 PM, Robert Kern wrote:
> Read up on XML canonicalization (abrreviated as c14n). lxml implements
> this, also xml.dom.ext.c14n in PyXML. You'll need to canonicalize on
> both ends before hashing.
>
> To paraphrase an Old Master, if you are running a cryptographic hash
> over a non-canonical XML string representation, then you are living in 
> a
> state of sin.

Canonicalization seems to be the needed thing. Looking at the protocol 
specification again, it mentions canonicalization; I had glossed over 
that previously because I was unware of any defined meaning it had. But 
the c14n module should provide the needed results (now that I've 
finally dug up documentation for it).

-Michael