/**
* Convert JWK to PEM.
*
* @return PEM PUBLIC KEY
*/
public function toPEM()
{
$n = $this->modulusParameter()->number()->base10();
$e = $this->exponentParameter()->number()->base10();
$pk = new RSAPublicKey($n, $e);
$pki = new PublicKeyInfo(new RSAEncryptionAlgorithmIdentifier(), $pk->toDER());
return $pki->toPEM();
}
/**
* Initialize public key from PEM.
*
* @param PEM $pem
* @throws \UnexpectedValueException
* @return self
*/
public static function fromPEM(PEM $pem)
{
switch ($pem->type()) {
case PEM::TYPE_RSA_PUBLIC_KEY:
return RSAPublicKey::fromDER($pem->data());
case PEM::TYPE_PUBLIC_KEY:
return PublicKeyInfo::fromPEM($pem)->publicKey();
}
throw new \UnexpectedValueException("PEM type " . $pem->type() . " is not a valid public key.");
}
/**
* Get public key.
*
* @throws \RuntimeException
* @return PublicKey
*/
public function publicKey()
{
$algo = $this->algorithmIdentifier();
switch ($algo->oid()) {
// RSA
case AlgorithmIdentifier::OID_RSA_ENCRYPTION:
return RSAPublicKey::fromDER($this->_publicKeyData);
// elliptic curve
// elliptic curve
case AlgorithmIdentifier::OID_EC_PUBLIC_KEY:
if (!$algo instanceof ECPublicKeyAlgorithmIdentifier) {
throw new \UnexpectedValueException("Not an EC algorithm.");
}
// ECPoint is directly mapped into public key data
return new ECPublicKey($this->_publicKeyData, $algo->namedCurve());
}
throw new \RuntimeException("Public key " . $algo->oid() . " not supported.");
}