Add client certificate in socket connection

I am stuck with this problem since last few days but could not get any solution.

I am using net php-epp client and here is my code...

$context = stream_context_create(
    array(
        'ssl'=>array(
            'local_cert'=> dirname(__FILE__).'/cert.pem',
            'passphrase' => dirname(__FILE__).'/key.pem',
        )
    )
);

$greeting = $client->connect($host, $port, $timeout, $ssl, $context);
echo $greeting;

I am getting following error...

Warning: stream_socket_client(): Unable to set private key file

And before you ask key.pem starts with -----BEGIN RSA PRIVATE KEY----- and cert.pem starts with -----BEGIN CERTIFICATE-----

However i can connect using...

openssl s_client -connect epp.dom.net:700 -key key.pem -cert cert.pem -CApath /etc/ssl/certs/

This command shows connected, so does that mean my certificates are fine?

Please someone help me to fix this. Please

Thank You.

According to the PHP documentation, the private key must be specified in the local_pk stream context option. The passphrase option (which you are currently using) is necessary when the private key file itself was encrypted with a passphrase:

local_pk string

Path to local private key file on filesystem in case of separate files for certificate (local_cert) and private key.

passphrase string

Passphrase with which your local_cert file was encoded.

This means your stream context should be initialized like this:

$context = stream_context_create(array(
    'ssl' => array(
        'local_cert' => dirname(__FILE__) . '/cert.pem',
        'local_pk' => dirname(__FILE__) . '/key.pem',
    )
));

Alternatively, you can also concatenate certificate and private key into one file and use the local_cert option only (plus a passphrase option if -- and only if -- your private key is encrypted with a passphrase).