Cryptic

OpenSSL makes use of standard input and standard output, and it supports a wide range of parameters, such as commandline switches, environment variables, named pipes, file descriptors, and files. You can take advantage of these features to quickly write Bash (Bourne-Again Shell) scripts that automate tasks, such as testing SSL/ TLS (Secure Socket Layer/Transport Layer Security) connections, bulk conversions between different formats of cryptographic keys and certificates, batch signing/ encrypting of files, auditing password protected files, and implementing or testing a PKI (Public Key Infrastructure).

The OpenSSL toolkit provides many modules that each perform a specific task. Each module is not a separate executable, but is, instead, selected with the first parameter of the openssl executable. On the other hand, each module has a separate manual page. For example, a module named x509 manages X.509 digital certificates and a module named pkcs12 manages PKCS12 packages.