I have a PHP 5.x script which requires OpenSSL 0.9.8k or higher.
In regard to OpenSSL, I found the following two relevant constants:
OPENSSL_VERSION_TEXT (with value 'OpenSSL 1.0.0c 2 Dec 2010')
OPENSSL_VERSION_NUMBER (with value '268435519')
Unfortunately, I have no clue how to do the mentioned check on these values.
The source for version 0.9.8k has a constant
OPENSSL_VERSION_NUMBERof0x009080bf