This package contains the openssl binary and related tools. . It is part of the OpenSSL implementation of SSL. . You need it to perform certain cryptographic actions like: - Creation of RSA, DH and DSA key parameters; - Creation of X.509 certificates, CSRs and CRLs; - Calculation of message digests; - Encryption and decryption with ciphers; - SSL/TLS client and server tests; - Handling of S/MIME signed or encrypted mail.