OpenSSL is a descendant of SSLeay, the SSL library by Eric A. Young, actively maintained by Ralf Engelschall. The package includes libssl.so: My implementation of SSLv2, SSLv3 and the required code to support both SSLv2 and SSLv3 in the one server. libcrypto.so: General encryption and X509 stuff needed by SSL but not actually logically part of it. It includes routines for the following: Ciphers libdes - My libdes DES encryption. RC4, RC2, Blowfish, IDEA encryption Digests MD5 and MD2 message digest algorithms, fast implementations, SHA (SHA-0) and SHA-1 message digest algorithms, MDC2 message digest. A DES based hash that is polular on smart cards. Public Key RSA encryption/decryption/generation. DSA encryption/decryption/generation. Diffie-Hellman key-exchange/key generation. There is no limit on the number of bits. X509v3 certificates X509 encoding/decoding into/from binary ASN1 and a PEM. Program to generate RSA and DSA certificate requests and certificates.