Well, I haven't seen your code so it is not easy to figure out an estimate. Your code might be velvet to my eyes or a trainwreck that sends me into cardiac arrest just by looking at it
I take it you are using botan for this, so let me have a look at it. If I solve your problem within an hour I'll charge for an hour, within two I'll charge for two hours. If it takes any longer then that is on me. If I don't find a solution it won't cost you anything. Just give me the repository details I can pull the source from and I will get right on it.