Constant Description
    ENGINE_METHOD_RSA Limit engine usage to RSA
    ENGINE_METHOD_DSA Limit engine usage to DSA
    ENGINE_METHOD_DH Limit engine usage to DH
    ENGINE_METHOD_RAND Limit engine usage to RAND
    ENGINE_METHOD_EC Limit engine usage to EC
    ENGINE_METHOD_CIPHERS Limit engine usage to CIPHERS
    ENGINE_METHOD_DIGESTS Limit engine usage to DIGESTS
    ENGINE_METHOD_PKEY_METHS Limit engine usage to PKEY_METHDS
    ENGINE_METHOD_PKEY_ASN1_METHS Limit engine usage to PKEY_ASN1_METHS
    ENGINE_METHOD_ALL
    ENGINE_METHOD_NONE