[OpenID] Interoperability problem with OpenID POST response between myopenid and Google

[André Cruz]

Hello.

I've detected a problem regarding openid responses that are sent via  
POST (when they exceed the 2047 byte limit on URLs).

For example, create a myopenid account and a persona with a very large  
full name and nickname so as to force openid responses (those that  
request these attributes) to go via POST.

myopenid -> blogger FAIL
myopenid -> plaxo FAIL
myopenid -> sourceforge FAIL

Claimid is even worse. It does not convert the response to a POST and  
so the URL is cropped.

I then build a custom OP based on janrain python lib (I think myopenid  
is based on this) and a custom SP based on openid4java. Although they  
talked to one another correctly using POST responses my OP still  
failed against blogger, plaxo and sourceforge and my SP didn't accept  
myopenid POST responses throwing an invalid signature...

Who's got the correct implementation? :)

Best regards,
André Cruz