PHP ios push nofitcation error: stream_socket_client(): SSL operation failed with code 1

Question

I've read all the other posts on this issue but still no avail.

Im aware this issue can come up with bad certificates, however I verified both my certificate and my key were valid before combining them into a single .pem file which I put on the server.

I have absolutely no idea how to troubleshoot this next so any and all advice is greatly appreciated. Here is my server code

$ctx = stream_context_create();
        stream_context_set_option($ctx, 'ssl', 'local_cert', 'ck.pem');
        stream_context_set_option($ctx, 'ssl', 'passphrase', $passphrase);

        // Open a connection to the APNS server
        $fp = stream_socket_client('ssl://gateway.sandbox.push.apple.com:2195', $err, $errstr, 60, STREAM_CLIENT_CONNECT|STREAM_CLIENT_PERSISTENT, $ctx);

P.S. the ck.pem file is in the same directory with read permissions set.

Here is the full error message:

Warning: stream_socket_client(): SSL operation failed with code 1. OpenSSL Error messages: error:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify failed in /var/www/site/pages/Callback.php on line 3515 Warning: stream_socket_client(): Failed to enable crypto in /var/www/site/pages/Callback.php on line 3515 Warning: stream_socket_client(): unable to connect to ssl://gateway.sandbox.push.apple.com:2195 (Unknown error) in /var/www/site/pages/Callback.php on line 3515 Failed to connect BECUSE OF ERROR: 0
UPDATE
It does seem to be a certificate validation issue after all but Im not sure why, when I check the ssl against APNS I get this error:
depth=1 /C=US/O=Entrust, Inc./OU=www.entrust.net/rpa is incorporated by reference/OU=(c) 2009 Entrust, Inc./CN=Entrust Certification Authority - L1C
verify error:num=20:unable to get local issuer certificate
verify return:0
---
Certificate chain
 0 s:/C=US/ST=California/L=Cupertino/O=Apple Inc./OU=iTMS Engineering/CN=gateway.sandbox.push.apple.com
   i:/C=US/O=Entrust, Inc./OU=www.entrust.net/rpa is incorporated by reference/OU=(c) 2009 Entrust, Inc./CN=Entrust Certification Authority - L1C
 1 s:/C=US/O=Entrust, Inc./OU=www.entrust.net/rpa is incorporated by reference/OU=(c) 2009 Entrust, Inc./CN=Entrust Certification Authority - L1C
   i:/O=Entrust.net/OU=www.entrust.net/CPS_2048 incorp. by ref. (limits liab.)/OU=(c) 1999 Entrust.net Limited/CN=Entrust.net Certification Authority (2048)
---
No client certificate CA names sent

Answer 1

Download entrust_2048_ca.cer

Add full path to entrust_2048_ca.cer

/var/www/site/pages/entrust_2048_ca.cer