HsOpenSSL is a (part of) OpenSSL binding for Haskell. It can generate RSA keys, read and write PEM files, generate message digests, sign and verify messages, encrypt and decrypt messages. But since OpenSSL is a very large library, it is uneasy to cover everything in it.

Features that aren't (yet) supported:

TLS/SSL network connection

ssl(3) functionalities are totally uncovered. They should be covered someday.

Low-level API to symmetric ciphers

Only high-level APIs (EVP and BIO) are available. But I believe no one will be lost without functions like DES_set_odd_parity.

Low-level API to asymmetric ciphers

Only a high-level API (EVP) is available. But I believe no one will complain about the absence of functions like RSA_public_encrypt.

Key generation of DSA and Diffie-Hellman algorithms

Only RSA keys can currently be generated.

X.509 v3 extension handling

It should be supported in the future.

HMAC message authentication

Low-level API to message digest functions

Just use EVP or BIO instead of something like MD5_Update.

pseudo-random number generator

rand(3) functionalities are uncovered, but OpenSSL works very well by default.

API to PKCS#12 functionality

It should be covered someday.

BIO

BIO isn't needed because we are Haskell hackers. Though HsOpenSSL itself uses BIO internally.

ENGINE cryptographic module

The default implementations work very well, don't they?

So if you find out some features you want aren't supported, you must write your own patch. Happy hacking.

Computation of withOpenSSL action initializes the OpenSSL library and computes action. Every applications that use OpenSSL must wrap any other operations related to OpenSSL or they might crash.

 module Main where
 import OpenSSL

 main :: IO ()
 main = withOpenSSL $
        do ...