(PHP 5 >= 5.6.0, PHP 7) Retrieve the available certificate locations

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

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

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

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

(PHP 4 >= 4.2.0, PHP 5, PHP 7) Frees a private key

(PHP 5.6, PHP 7) Calculates the fingerprint, or digest, of a given X.509 certificate

(PHP 4 >= 4.2.0, PHP 5, PHP 7) Get a private key

(PHP 4 >= 4.2.0, PHP 5, PHP 7) Exports a certificate as a string

(PHP 5 >= 5.6.0, PHP 7) Generate a new signed public key and challenge