We work on a google cloud print integration and need to connect to google talk via oauth2.
While testing the smack library I could not login to talk.google.com with the auth error response of incorrect-encoding.
On investigating the issue I found it seems to be related to a double base64 encoding of the authentication text. (I’m no expert in smack so I might be wrong) Here is what I think is going on:
SASLXOauth2Mechanism.getAuthenticationText():
encodes the authentication text to a base64 encoded byte array with
Base64.encode(toBytes(’\u0000’ + authenticationId + ‘\u0000’ + password));
This would be Base64.encode(byte[] ) for the first time.
SASLMechanism.authenticate():
Calls the SASLXOauth2Mechanism.getAuthenticationText() to get the authentication text as a byte array.
It then converts the byte array to a string with Base64.encodeToString(byte[])
Base64.encodeToString(byte[]):
Before calling the String constructor it calls Base64.encode(byte[] ) on the byte array input argument.
This would be Base64.encode(byte[] ) for the second time.
So as far as I can see the authentication text is double base64 encoded and hence the incorrect-encoding issue. (google can’t find the ‘\u0000’ separators)
When I replaced the original SASLXOauth2Mechanism.getAuthenticationText() with the simple line
return toBytes(’\u0000’ + authenticationId + ‘\u0000’ + password);
The login returned with a success message.
Yes the fix worked for me.
On a side note I used 4.1.7 and the switch to 4.2.0 had a little hick up.
Before I could test the fix I got a “java.security.KeyStoreException: Uninitialized keystore” exception.
So I needed to set XMPPTCPConnectionConfiguration.builder().setKeystoreType(null) to get it working.
As a user I would have expected it to just run with the default value for this advanced setting.
Nonetheless… Thank you very much for the fast response and fix.
Thank you very much for the fast response and fix.