c2dm 401 error when sending messages after receiving id and auth token

Question

I have seen many similiar questions but no good answer despite some of them being accepted. I have registered for C2DM. I received confirmation email. Then I wrote some simple app to register for C2DM. I get the id (tried on emulator and on real device). Then I got the auth token (with curl) for my email that I used for C2DM registration (the same email that I use in app for acquiring the id).
When I try to do the push (also with curl), I get 401 error (like the auth token is wrong).

I read many tutorials and I am running out of ideas.

Answer 1

Let me try it (with curl only):

At first we are applying for the auth token:

curl.exe -v -k https://www.google.com/accounts/ClientLogin -d [email protected] -d Passwd=secret -d accountType=GOOGLE -d source=your.registered.domain -d service=ac2dm

In the result your are receiving the auth token:

< HTTP/1.1 200 OK
SID=XXX
LSID=XXX
Auth=XXX
* Connection #0 to host www.google.com left intact
* Closing connection #0
* SSLv3, TLS alert, Client hello (1):

Please note that the Auth response is in the result with an uppercase first letter: "Auth=XXX"!

Now we are using the result for the next request but with lowercase first letter:
curl.exe -v -k --header "Authorization: GoogleLogin auth=XXX" https://android.apis.google.com/c2dm/send -d "registration_id=XXX" -d "data=helloooo" -d collapse_key=Z

And this works! But you are getting a 401 error, if you are using the auth like in the first response (upper case A in "Auth"):

curl.exe" -v -k --header "Authorization: GoogleLogin Auth=XXX" https://android.apis.google.com/c2dm/send -d "registration_id=XXX" -d "data=helloooo" -d collapse_key=Z

So the "auth" of request 2 is case sensitive. I think this is a pitfall 50% of the users are stepping into. Hope that helps.