(PHP 7 >= 7.3.0, PHP 8)
openssl_pkey_derive — Computes shared secret for public value of remote and local DH or ECDH key
$public_key, #[\SensitiveParameter] OpenSSLAsymmetricKey|OpenSSLCertificate|array|string $private_key, int $key_length = 0): string|false
openssl_pkey_derive() takes a set of a public_key
and private_key and derives a shared secret, for either DH or EC keys.
public_key
public_key is the public key for the derivation.
See Public/Private Key parameters for a list of valid values.
private_key
private_key is the private key for the derivation.
See Public/Private Key parameters for a list of valid values.
key_lengthIf not zero, will set the desired length of the derived secret.
The derived secret on success or false on failure.
Example #1 openssl_pkey_derive() example
<?php
// Load in private key
$priv = openssl_pkey_get_private("-----BEGIN PRIVATE KEY-----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-----END PRIVATE KEY-----
");
// Load in public key
$pub = openssl_pkey_get_public("-----BEGIN PUBLIC KEY-----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-----END PUBLIC KEY-----
");
// Outputs the hex version of the derived key
echo bin2hex(openssl_pkey_derive($pub,$priv));