Find out location of OpenSSL and GnuPG using PHP?

Is there a cross-platform compliant way of finding out the path to the main executables of OpenSSL开发者_高级运维 and GnuPG? Obviously this would be null if the software was not installed or detected.

You can explode $_ENV['PATH'] by PATH_SEPARATOR and look for either openssl or openssl.exe (on Windows) in each of the paths (analogous for GunPG).