PIPEX_MPPE_KEYLEN
pool_init(&mppe_key_pool, PIPEX_MPPE_KEYLEN * PIPEX_MPPE_NOLDKEY, 0,
mppe->session_key, PIPEX_MPPE_KEYLEN);
u_char master_key[PIPEX_MPPE_KEYLEN]; /* mppe master key */
u_char master_key[PIPEX_MPPE_KEYLEN]; /* [m] master key of MPPE */
u_char session_key[PIPEX_MPPE_KEYLEN]; /* [m] session key of MPPE */
u_char (*old_session_keys)[PIPEX_MPPE_KEYLEN];