RSA

$pub = <<<SOMEDATA777
-----BEGIN PUBLIC KEY-----
MFwwDQYJKoZIhvcNAQEBBQADSwAwSAJBAKbjQrkMe05zwvPrF/FvhiHLuagSffCz
DT4bEy3bkGghzj4pJTVdFbddoUfNZAKYi645z45EL4tR/fB5L1dyhX0CAwEAAQ==
-----END PUBLIC KEY-----
SOMEDATA777;
$data = "PHP is my secret love.";
$pk  = openssl_get_publickey($pub);
openssl_public_encrypt($data, $encrypted, $pk);
echo chunk_split(base64_encode($encrypted));		

$key = <<<SOMEDATA777
-----BEGIN RSA PRIVATE KEY-----
MIIBOgIBAAJBAKbjQrkMe05zwvPrF/FvhiHLuagSffCzDT4bEy3bkGghzj4pJTVd
FbddoUfNZAKYi645z45EL4tR/fB5L1dyhX0CAwEAAQJAALkjZOHk9uYRhjUSmX0+
O49CcrQBz7U27Xn4j05QReM90ccEz+1ocLA5PGfuedMBLlMhW4ICMniyVkhDKryf
kQIhAN4HtRWd/FQymimaXOpm69sNeosHRIpI7NIhxZsRuEeDAiEAwGvIQwUmvAX3
0UA3yvR7G5lBW2ODhGA8x8UlpzPjbv8CIDo6JThFFV5zYtCURdfHJAVvdHqvbj8h
vtGgv7TaIczHAiBbzhDKCRcl9iL6bw0vg92ImWIZXC1PZysYlPMWByenuQIhANOi
AbLseUsXuD0tmlckGF5TWlnv5fm7JvEzR4kQ2kVd
-----END RSA PRIVATE KEY-----
SOMEDATA777;
$data = "kwW667PWOg62YlNDIg0vfafmgTGVtirmrHq+B/IDgtF7auS97jbceqQfs5SBdPp/6g3+Ng54Xnpy fIJe5MXSHQ==";
$pk  = openssl_get_privatekey($key);
openssl_private_decrypt(base64_decode($data), $out, $pk);
echo $out;

header('Content-Type: text/html; charset=utf-8');

$com = "openssl genrsa -out private.pem 512";		
$res = exec( $com, $output);

$com = "openssl rsa -in private.pem -out public.pem -outform PEM -pubout";		
$res = exec( $com, $output);