Php/docs/openssl.key-types
From Get docs
Key types
OPENSSL_KEYTYPE_RSA
(int)OPENSSL_KEYTYPE_DSA
(int)OPENSSL_KEYTYPE_DH
(int)OPENSSL_KEYTYPE_EC
(int)- This constant is only available when PHP is compiled with OpenSSL 0.9.8+. Added in PHP 5.2.0.