GNU R toolkit for encryption, signatures and certificates based on OpenSSL

 Bindings to OpenSSL libssl and libcrypto, plus custom SSH pubkey
 parsers. Supports RSA, DSA and NIST curves P-256, P-384 and P-521.
 Cryptographic signatures can either be created and verified manually or
 via x509 certificates. AES block cipher is used in CBC mode for
 symmetric encryption; RSA for asymmetric (public key) encryption. High-
 level envelope functions combine RSA and AES for encrypting arbitrary
 sized data. Other utilities include key generators, hash functions (md5,
 sha1, sha256, etc), base64 encoder, a secure random number generator,
 and 'bignum' math methods for manually performing crypto calculations on
 large multibyte integers.