预定义常量
PHP Manual

Key types

OPENSSL_KEYTYPE_RSA (integer)
OPENSSL_KEYTYPE_DSA (integer)
OPENSSL_KEYTYPE_DH (integer)
OPENSSL_KEYTYPE_EC (integer)
This constant is only available when PHP is compiled with OpenSSL 0.9.8+.

Note:

This constant was added in 5.2.0.

OPENSSL_KEYTYPE_EC


预定义常量
PHP Manual