Signing and validating using the same credential

[Pascal Mainini]

Hi Brent

many thanks for your fast reply and for confirming my approach!

Issue solved: in fact, your hint with pretty-printing noticed me of an
issue with the generating code - thus the content was effectively
altered *after* signature. That's a consequence of writing the
generating code weeks before the validating one - I didn't remember
having that change in there - it only served me for testing puroses. ;-)

However, it's also a bit the error message of the validator which got me
slightly on the wrong track:

>> "Signature did not validate against the credential's key"

I assumed that there must be an issue with the key - and not with the
signature ;-)

Anyway, thanks and have a good time!

Pascal