adjust to new aes_xts routines.
allow optional offset in the 4th argument where the encrypted
sectors start instead of hardcoding the 64K header area for
cryptsetup.
avoid allocating temporary buffer for cryptio() reads, we can
just decrypt in place there.
use sdmalloc() to allocate the temporary buffer for cryptio()
writes so that devsd wont need to allocate and copy in case
it didnt like our alignment.
do not duplicate the error reporting code, just use io()
that is what it is for.
allow 2*256 bit keys in addition to 2*128 bit keys.
the previous implementation was not portable at all, assuming
little endian in gf_mulx() and that one can cast unaligned
pointers to ulong in xor128(). also the error code is likely
to be ignored, so better abort() when the length is not a
multiple of the AES block size.
we also pass in full AESstate structures now instead of
the expanded key longs, so that we do not need to hardcode
the number of rounds. this allows each indiviaul keys to
be bigger than 128 bit.
the QLp structure used to occupy 24 bytes on amd64.
with some rearranging the fields we can get it to 16 bytes,
saving 8K in the data section for the 1024 preallocated
structs in the ql arena.
the rest of the changes are of cosmetic nature:
- getqlp() zeros the next pointer, so there is no need to set
it when queueing the entry.
- always explicitely compare pointers to nil.
- delete unused code from ape's qlock.c
the initial issue was that wunlock() would wakeup readers while
holding the spinlock causing deadlock in libthread programs where
rendezvous() would do a thread switch within the same process
which then can acquire the RWLock again.
the first fix tried to prevent holding the spinlock, waking up
one reader at a time with releasing an re-acquiering the spinlock.
this violates the invariant that readers can only wakup writers
in runlock() when multiple readers where queued at the time of
wunlock(). at the first wakeup, q->head != nil so runlock() would
find a reader queued on runlock() when it expected a writer.
this (hopefully last) fix unlinks *all* the reader QLp's atomically
and in order while holding the spinlock and then traverses the
dequeued chain of QLp structures again to call rendezvous() so
the invariant described above holds.
when the alarm hits while the process is currently in syslog(), holding
the sl lock, then calling syslog again will deadlock:
/proc/1729193/text:386 plan 9 executable
/sys/lib/acid/port
/sys/lib/acid/386
acid: lstk()
sleep()+0x7 /sys/src/libc/9syscall/sleep.s:5
lock(lk=0x394d8)+0xb7 /sys/src/libc/port/lock.c:25
i=0x3e8
syslog(logname=0x41c64,cons=0x0,fmt=0x41c6a)+0x2d /sys/src/libc/9sys/syslog.c:60
err=0x79732f27
d=0x0
ctim=0x0
buf=0x0
p=0x0
arg=0x0
n=0x0
catchalarm(msg=0xdfffc854)+0x7a /sys/src/cmd/upas/smtp/smtpd.c:71
notifier+0x30 /sys/src/libc/port/atnotify.c:15
this implements the mitigation suggested in section "6.5 Countermeasures" of
"Key Reinstallation Attacks: Forcing Nonce Resuse in WPA2" [1].
[1] https://papers.mathyvanhoef.com/ccs2017.pdf
copying files from the uefi shell works, reading plan9.ini works,
loading the kernel by calling Read to read in the DATA section of
the kernel *FAILS*. my guess is that uefi filesystem driver or
nvme driver tries to allocate a temporary buffer and hasnt got
the space. limiting the read size fixes it.
the cachetab just keeps track of recent messages that have not
been called cachefree() on. under some conditions, the fixed
table could overflow (all messages having refs > 0). with a
linked list, overflow becomes non fatal and the algorithm is
simpler to implement.
there isnt much of a point in keep maintaining separate
kernel configurations for terminal and cpu kernels as
the role can be switched with service=cpu boot parameter.
to make stuff cosistent, we will just have one "pc" kernel
and one "pc64" kernel configuration now.
