i've made a couple more changes to get my application userIDs from being used as the foreign key, instead of the email addresses. in class.proxyauthenticator.php i forced the UniqueID to be used instead of the user email address.

         $UserEmail = ArrayValue('Email', $Response);
         $UserName = ArrayValue('Name', $Response);

         #make sure the uniqueID is read out from the response
         $UserID  = ArrayValue('UniqueID', $Response);

         $UserName = trim(preg_replace('/[^a-z0-9-]+/i','',$UserName));
         $TransientKey = ArrayValue('TransientKey', $Response, NULL);

         #the below will use the email address to associate foreignkeys
         #$AuthResponse = $this->ProcessAuthorizedRequest($Provider['AuthenticationKey'], $UserEmail, $UserName, $TransientKey);

         #the below will use the user unique ID to associate foreignkeys
         $AuthResponse = $this->ProcessAuthorizedRequest($Provider['AuthenticationKey'], $UserID, $UserName, $TransientKey);

however, i found an unimplemented function that was throwing errors and short circuiting the authentication process silently. i just commented it out. this doesn't feel right, but i don't fully understand the Nonces and whatnot to implement the function myself.

further down in the same file, just uncomment the following:

if ($Token && !is_null($ForeignNonce)) {
            $TokenKey = $Token['Token'];

            #SetNonce is not implemented in this file (or i can't find where it is inherited from?)
            #$this->SetNonce($TokenKey, $ForeignNonce);
         }

in summary, the previous code changes will get the original service's userIDs to be used as the foreign keys, i've now got a working proxyconnect with a service running on a different subdomain as my forum.

in total, i've had to make a number of changes overall:

1. added back support of json encoding of user info from original service (code change in plugin, add entry in config)
2. modified ProcessAuthorizeRequest to use uniqueID as a foreign key for user association rather than the email address which can change (code change in plugin)
3. uncommented out unimplemented function (code change in plugin)
4. had to modify ProxyRequest in vanilla as it was not handling proxying to a different host than that of the form (code change in vanilla, in library/core/general.functions.php, see here: http://vanillaforums.org/discussion/12214/proxyrequest-internal-question-in-functions.general.php/#Item_1)

@tim, you are correct, the original code change i suggested in the first post (Requestion->DefaultController) was not needed. it was not a cookie domain mismatch, but just not me clearing out my cookies each time as i was trying to get the proxy to use my foreignkeys that i needed).

all the other changes however are working and necessary for application uniqueIDs to be used as foreignKeys

2.0

i git pulled whatever was on git hub as of last night.

my bad.

i was assuming the function didn't exist. didn't bother looking into inherited functions.

there is likely an error that is popping up in there, that breaks out of the try statement from earlier on, so when i comment it out, i get my authentication working. i can further drill in to see where it errors out.

thanks @tim.

that wasn't my problem in the end.

what was happening was that TransientKey was being interpreted as some empty NON-Null value, which was triggering the if() block to then run SetNonce. that block should only be run if ForeignNonce is NOT null (which will only happen if TransientKey is NOT null)

i modified the following where the Response from the proxyRequest is parsed out into an array:

if ($Result) {
            $ReturnArray = array(
               'Email'        => ArrayValue('Email', $Result),
               'Name'         => ArrayValue('Name', $Result),
               'UniqueID'     => ArrayValue('UniqueID', $Result),
               'TransientKey' => ArrayValue('TransientKey', $Result)
            );
            return $ReturnArray;
         }

to:

if ($Result) {
            $ReturnArray = array(
               'Email'        => ArrayValue('Email', $Result),
               'Name'         => ArrayValue('Name', $Result),
               'UniqueID'     => ArrayValue('UniqueID', $Result),
               'TransientKey' => ArrayValue('TransientKey', $Result, NULL)
            );
            return $ReturnArray;
         }

now my TransientKey (which is not present in my json encoded user array) evaluates to NULL and that port of the code is never triggered.