libcrypto.X509V3_EXT_print.argtypes=(c_void_p,POINTER(_x509_ext),c_long,c_int)
libcrypto.X509_get_ext.restype=c_void_p
libcrypto.X509_get_ext.argtypes=(c_void_p,c_int)
libcrypto.X509V3_EXT_print.argtypes=(c_void_p,POINTER(_x509_ext),c_long,c_int)
libcrypto.X509_get_ext.restype=c_void_p
libcrypto.X509_get_ext.argtypes=(c_void_p,c_int)