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

(PHP 4 >= 4.2.0, PHP 5, PHP 7) Checks if a private key corresponds to a certificate

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

(PHP 4 >= 4.0.2, PHP 5, PHP 7) Gets an array of all supported modes

(PHP 4 >= 4.2.0, PHP 5, PHP 7) Exports a CSR to a file

(PHP 4 >= 4.2.0, PHP 5, PHP 7) Generates a CSR

(PHP 5 >= 5.6.0, PHP 7) Exports a valid PEM formatted public key signed public key and challenge

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

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

(PHP 5 >= 5.1.2, PHP 7, PECL hash >= 1.1) Generate a keyed hash value using the HMAC method and the contents