Nokia Lifeblog Posting Protocol Update

Nokia seem to have updated their Atom upload protocol in recent versions of their phones.

I’ve just got hold of a Nokia N93 and tried posting to this blog using Lifeblog and the new Web Upload functionality in the Gallery with use the Atom protocol.

These postings were failing with a bad password error. I know my username and password are correct and they worked using my old phone.

As I had written my own blogging software, and it’s Atom upload functionality I was able to debug the messages being sent from the phone to the server.

It turns out that newer versions of Nokia Lifeblog encrypt their passwords differently to older versions.

They use a method called WSSE. See my previous article on how to use WSSE with Perl for more details on how this works, plus example code.

Very quickly, the password isn’t sent, but a digest of the password and the values to generate the digest yourself are. These are then encoded using base64 for transmission over the internet.

Older versions (pre Lifeblog 2.0) expect a value called the nonce to be used as sent while the password digest is generated. Newer versions (Lifeblog 2.0+) expect the nonce to be decoded from base64 before the digest is generated.

Once I had worked out what was going on, it was simple to modify my code to check against both possible versions of the password digest. This means I can now post using old and new versions of Lifeblog, or the web upload functionality.

Here’s a very quick bit of example Perl code. Assume $my_digest is the digest with the original nonce left in place and $my_alternative_digest is the digest with the nonce decoded first. $digest is the digest sent my incoming Atom request.

## example perl code to check digests)
if (($digest eq $my_digest) || ($digest eq $my_alternative_digest)) {
## one of the digests has validated, so continue here
} else {
## neither digests has validated, so return invalid password responses here.

I don’t think this change has been communicated very well amongst the development community. It has probably come about due to changes in the Atom spec, but (admittedly only quickly) checking the documentation I’ve not found it.

I will be updating my WSSE validation example accordingly, and a new version of that allows posting from Lifeblog 2.0 to Movable Type shortly.