A library to decrypt pdf files

Hi,

        Does Adobe have any library just to work with pdf encryption. I don't need a full pdf library. All I need to do is to decrypt pdfs (given its password/s). Can you suggest the best way to do this? Any libraries? If not, where would I get such libraries (AES, RC4 is what manaul says). Any help appreciated. (Ideally, an Adobe library for this would be nice.)

Thanks