Have the same problem and cannot understand the reason.
openSSL version OpenSSL 1.0.2j-fips 26 Sep 2016
php5 version PHP 5.6.1 (cli)
cURL in PHP calls uses OpenSSL/1.0.2j and TLS 1.2
The PayPal test delivers:
curl -i https://tlstest.paypal.com
HTTP/1.1 200 OK
Content-Type: text/html
Content-Length: 20
Date: Thu, 26 Jan 2017 10:40:51 GMT
Connection: keep-alive
PayPal_Connection_OK
So what is going wrong? From my point of view, everthing should work fine!
BR
Michael
