+libcrypto.sk_set.argtypes=(c_void_p,c_int,c_void_p)
+libcrypto.sk_set.restype=c_void_p
+libcrypto.sk_value.argtypes=(c_void_p,c_int)
+libcrypto.sk_value.restype=c_void_p
+libcrypto.X509_dup.restype=c_void_p
+libcrypto.sk_new_null.restype=c_void_p
+libcrypto.X509_dup.argtypes=(c_void_p,)