Allow optional use of Node Buffers.

[techhead]

The hash(Sync) and compare(Sync) methods will now accept data as a string or Buffer.

Also removed a few extraneous string copy operations.

[recrsn]

We would need Buffer support in async as well, async is the most widely used mode.

Thanks for your contribution

[techhead]

We would need Buffer support in async as well, async is the most widely used mode.

Thanks for your contribution

Yes, both modes are included, hash/hashSync, compare/compareSync. That's what the parenthesis were supposed to indicate. Sorry that wasn't more clear.

[flintinatux]

Are there any other concerns about this PR? Would be great to have support for Buffers.

I landed here looking for a solution to bcrypt-ing passwords longer that 72 bytes. One way to do so is to get the sha512 digest of the password, and then pass the digest to bcrypt. However, converting that digest to a String causes it either to go over 72 bytes or to run the risk of getting null characters. If I can leave it as a Buffer before passing to bcrypt that would be optimal.