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API
From OpenSSLWiki
Placeholder for an overview of the OpenSSL API
Some languages comes with openssl wrapper to provide openssl acces within native. Whole Openssl library API is in 'C' ie you need to compile with C headers and link with libraries.
C API
Perl API
Net::SSLeay
http://alioth.debian.org/projects/net-ssleay
Python API
M2Crypto
http://chandlerproject.org/Projects/MeTooCrypto
PyOpenssl
https://launchpad.net/pyopenssl
PHP API
openssl access is natively provided by php by explicitly compiling php with openssl. http://php.net/manual/en/book.openssl.php