Probably the US, or France or Germany or Russia gave someone the technology. Certainly not the taliban or the aQ.
The difrrence, my fair fork-tongued friend, is that which was given did not have the application of a "dirty bomb" as its end point
More like electricity or power applications.
The essence of your post is that the aQ use is somehow "legitamised" because they used available tech.
The capacity to fund and make such a bomb was certainly NOT from the aforementioned countries but much more likely from the likes of SH, Gaddaffyduck, Iran etc etc