Requirements
In order to use the OpenSSL functions you need to install the » OpenSSL package. PHP between versions 4.0.5 and 4.3.1 will work with OpenSSL >= 0.9.5. Other versions (PHP <=4.0.4 and >= 4.3.2) require OpenSSL >= 0.9.6.
Warning
You are strongly encouraged to use the most recent OpenSSL version, otherwise your web server could be vulnerable to attack.
Коментарии
for windows it might be better to just get the setup at http://gnuwin32.sourceforge.net/packages/openssl.htm
instead of the sources and try to compile 'em yourself ^_~