PIPEX_MPPE_NOLDKEY
pool_init(&mppe_key_pool, PIPEX_MPPE_KEYLEN * PIPEX_MPPE_NOLDKEY, 0,
<= 0x1000 - PIPEX_MPPE_NOLDKEY) {
#define PIPEX_MPPE_OLDKEYMASK (PIPEX_MPPE_NOLDKEY - 1)