The HsOpenSSL package
HsOpenSSL is an OpenSSL binding for Haskell. It can generate RSA and DSA keys, read and write PEM files, generate message digests, sign and verify messages, encrypt and decrypt messages. It has also some capabilities of creating SSL clients and servers.
Please note that this project has started at the time when there were no pure-Haskell implementations of TLS. Now there is tls package (http://hackage.haskell.org/package/tls), which looks pretty saner than HsOpenSSL especially for initialisation and error handlings. So PHO (the initial author of HsOpenSSL) wants to encourage you to use and improve the tls package instead as long as possible. The only problem is that the tls package has not received as much review as OpenSSL from cryptography specialists yet, thus we can't assume it's secure enough.
Enable fast moving of bignums between OpenSSL and GMP (GHC Only).
Use -f <flag> to enable a flag, or -f -<flag> to disable that flag. More info
For package maintainers and hackage trustees