(PHP 4 >= 4.0.4, PHP 5, PHP 7) Free key resource

(PHP 4 >= 4.0.6, PHP 5, PHP 7) Return openSSL error message

(PHP 5 >= 5.5.0, PHP 7) Checks if the given hash matches the given options

(PHP 4 >= 4.2.0, PHP 5, PHP 7) Gets an exportable representation of a key into a string

(PHP 4 >= 4.0.4, PHP 5, PHP 7) Verify signature

(PHP 4 >= 4.0.6, PHP 5, PHP 7) Encrypt an S/MIME message

(PHP 5 >= 5.3.0, PHP 7) Copy hashing context

(PHP 5 >= 5.1.2, PHP 7, PECL hash >= 1.1) Pump data into an active hashing context from an open stream

(PHP 4 >= 4.0.4, PHP 5, PHP 7) Generate signature

(PHP 4 >= 4.0.4, PHP 5, PHP 7) Generates a key