OpenSSL 0.9.8zg used by PHP does not support TLSv1.2 or TLSv1.1 As part of the installation a PHP 5.4 cartridge from openshift.com on my Mac with OS X 10.10.5 in the Terminal I noticed a message about it loading OpenSSL 0.9.8 for compatibilty with PHP.

Later, trying to install getcomposer.org it is giving me a warning:


  Some settings on your machine may cause stability issues with Composer.
  If you encounter issues, try to change the following:
  
  The OpenSSL library (0.9.8zc) used by PHP does not support TLSv1.2 or TLSv1.1.  If possible you should upgrade OpenSSL to version 1.0.1 or above.


openssl version command in terminal reported OpenSSL 0.9.8zg 14 July 2015

Should I update to OpenSSL version 1.0.1?
OpenSSL 0.9.8zc or 0.9.8zg does not support TLSv1.1/1.2 which can cause vulnerabilities while downloading using HTTPS links.

You should update OpenSSL to latest version from official site.