RC5_FLAGS
IMPLEMENT_cipher(rc5, RC5, ecb, ECB, RC5_FLAGS, 128, 64, 0, block)
IMPLEMENT_cipher(rc5, RC5, cbc, CBC, RC5_FLAGS, 128, 64, 64, block)
IMPLEMENT_cipher(rc5, RC5, ofb64, OFB, RC5_FLAGS, 128, 8, 64, stream)
IMPLEMENT_cipher(rc5, RC5, cfb64, CFB, RC5_FLAGS, 128, 8, 64, stream)