The government agency I work with sends me files encrypted with epm. I have the passwords. Is there a way to decrypt these files using Linux?
I had never heard of EPM before. After ten minutes scrobbling around the internet, I'm fairly confident you're talking about a disk/volume encryption format from Check Point Software:
On the specifications tab it doesn't include Linux as a supported operating system and because this is a proprietary media encryption format, I feel it's unlikely that there are any open source tools to decrypt the volume.
That leaves you with a few options, none ideal: