phpcryptographyencryption-symmetricsymmetric-key

Generating a symmetric key in php

Im trying to generate a symmetric key, which i can use to both encrypt and decrypt a message with the same key, in php.

I've made my way through the php documentation below but can only find public/private key generations: http://www.php.net/manual/en/function.openssl-pkey-new.php

Any ideas on how i can use these key generating functions for making a symmetric key?

Thanks, Joe

Solution

  • A symetric key is basically a random set of bytes. If you want to use the openssl extension use openssl_random_pseudo_bytes():

    $symetric_key = openssl_random_pseudo_bytes($length);