DigitalPersona 4 and Firefox 3.5

HP recently made DigitalPersona 4 (4.0) fingerprint management software available for download on it’s support website. This version of DigitalPersona resolves two important issues with the software:

  • DigitalPersona 4 is compatible with Windows Internet Explorer 8
  • DigitalPersona 4 works great on Windows 7 (Release Candidate)

Grab the 32-bit version here and the 64-bit version here.

DigitalPersona 4 is also compatible with Firefox 3.0.x, but they weren’t prepared for Firefox 3.5, which has been in a long beta & RC phase and was released today. And now Firefox 3.5 reports that DigitalPersona 4 is incompatible with it.

Now, I use the fingerprint login capability provided by DigitalPersona extensively and didn’t want to miss out either on this feature or on using Firefox 3.5. I had been using Firefox 3.5 pre-release versions with extension compatibility checker disabled, but didn’t feel like doing that with the release version.

So I set out to see if I could get DigitalPersona 4 to work with Firefox 3.5 and I didn’t disappoint myself ;).

Here’s what you should do to get it to work:

  • Close all open Firefox windows.
  • Open an elevated Command Prompt and navigate to the DigitalPersona Firefox extension folder (type command in Command Prompt):
cd %programfiles%\DigitalPersona\Bin\FirefoxExt\

  • Open install.rdf in WordPad (type command in Command Prompt):
write install.rdf

  • Change <em:maxVersion>3.1.*</em:maxVersion> to <em:maxVersion>3.5.*</em:maxVersion>
  • Make a note of the <em:id> value —  it was {ec8030f7-c20a-464f-9b0e-13a3a9e97384} on my computer.
  • Save and exit WordPad


Update: Turns out there is an easy way to package this modified DigitalPersona Firefox extension and reinstall it in Firefox 3.5. Follow instructions in the highlighted post here and skip the steps listed below.

  • Navigate to your Firefox profiles folder (type command in Command Prompt):
cd %appdata%\Mozilla\Firefox\Profiles\

  • If you have multiple Firefox profiles set up, you will find a number of sub folders here. But for most users, there should be just a single folder in the following format: <random_characters>.default. Navigate to that folder (type command in Command Prompt):
cd *.default

  • Open extensions.rdf in WordPad (type command in Command Prompt):
write extensions.rdf

  • Search for DigitalPersona Extension. Four lines below that, you should find something like this <NS1:targetApplication RDF:resource=”rdf:#$GyBtJ”/>. Note the RDF:resource value.
  • Scroll back up to the top of the file, place your mouse pointer on the first line and search for rdf:#$GyBtJ (i.e., the RDF:resource value you noted down in the previous step).
  • Ensure that the NS1:id in the next line matches with <em:id> noted from install.rdf above.
  • Change NS1:maxVersion=”3.1.*” to NS1:maxVersion=”3.5.*”
  • Save and exit WordPad

DigitalPersona_Extensions_rdf_RDF-resource DigitalPersona_Extensions_rdf_version

  • Restart Windows and resume browsing in Firefox 3.5, now with DigitalPersona 4 fingerprint login enabled!