- Make constants static: Shrinks code and data size.
- Avoid overflow in limit calculation.
- Use uint8_t instead of u_char to match types
While here:
- Remove unnecessary casts
- s/u_int8_t/uint8_t/g
designated initializers.
I have not built every extant kernel so I have probably broken at
least one build; however I've also found and fixed some wrong
cdevsw/bdevsw entries so even if so I think we come out ahead.
are existing references.
Note that manual unloading is not prevented.
OK christos@
XXX Also note that there is still a small window where the ref-count can
XXX be decremented, and then the process/thread preempted. If auto-unload
XXX happens before that thread can return from the module's code, bad
XXX things (tm) could happen.
consttime_memequal is the same as the old consttime_bcmp.
explicit_memset is to memset as explicit_bzero was to bcmp.
Passes amd64 release and i386/ALL, but I'm sure I missed some spots,
so please let me know.
abd userland, as proposed on tech-security, with explicit_bzero using
a volatile function pointer as suggested by Alan Barrett.
Both do what the name says. For userland, both are prefixed by "__"
to keep them out of the user namespace.
Change some memset/memcmp uses to the new functions where it makes
sense -- these are just some examples, more to come.
arc4random() hacks in rump with stubs that call the host arc4random() to
get numbers that are hopefully actually random (arc4random() keyed with
stack junk is not). This should fix some of the currently failing anita
tests -- we should no longer generate duplicate "random" MAC addresses in
the test environment.
<20111022023242.BA26F14A158@mail.netbsd.org>. This change includes
the following:
An initial cleanup and minor reorganization of the entropy pool
code in sys/dev/rnd.c and sys/dev/rndpool.c. Several bugs are
fixed. Some effort is made to accumulate entropy more quickly at
boot time.
A generic interface, "rndsink", is added, for stream generators to
request that they be re-keyed with good quality entropy from the pool
as soon as it is available.
The arc4random()/arc4randbytes() implementation in libkern is
adjusted to use the rndsink interface for rekeying, which helps
address the problem of low-quality keys at boot time.
An implementation of the FIPS 140-2 statistical tests for random
number generator quality is provided (libkern/rngtest.c). This
is based on Greg Rose's implementation from Qualcomm.
A new random stream generator, nist_ctr_drbg, is provided. It is
based on an implementation of the NIST SP800-90 CTR_DRBG by
Henric Jungheim. This generator users AES in a modified counter
mode to generate a backtracking-resistant random stream.
An abstraction layer, "cprng", is provided for in-kernel consumers
of randomness. The arc4random/arc4randbytes API is deprecated for
in-kernel use. It is replaced by "cprng_strong". The current
cprng_fast implementation wraps the existing arc4random
implementation. The current cprng_strong implementation wraps the
new CTR_DRBG implementation. Both interfaces are rekeyed from
the entropy pool automatically at intervals justifiable from best
current cryptographic practice.
In some quick tests, cprng_fast() is about the same speed as
the old arc4randbytes(), and cprng_strong() is about 20% faster
than rnd_extract_data(). Performance is expected to improve.
The AES code in src/crypto/rijndael is no longer an optional
kernel component, as it is required by cprng_strong, which is
not an optional kernel component.
The entropy pool output is subjected to the rngtest tests at
startup time; if it fails, the system will reboot. There is
approximately a 3/10000 chance of a false positive from these
tests. Entropy pool _input_ from hardware random numbers is
subjected to the rngtest tests at attach time, as well as the
FIPS continuous-output test, to detect bad or stuck hardware
RNGs; if any are detected, they are detached, but the system
continues to run.
A problem with rndctl(8) is fixed -- datastructures with
pointers in arrays are no longer passed to userspace (this
was not a security problem, but rather a major issue for
compat32). A new kernel will require a new rndctl.
The sysctl kern.arandom() and kern.urandom() nodes are hooked
up to the new generators, but the /dev/*random pseudodevices
are not, yet.
Manual pages for the new kernel interfaces are forthcoming.
and can not disappear -- no need to hold crypto_mtx to check the
driver list
(the whole check is questionable)
-crp->crp_cv (the condition variable) is used by userland cryptodev
exclusively -- move its initialization there, no need to waste
cycles of in-kernel callers
-add a comment which members of "struct cryptop" are used
by opencrypto(9) and which by crypto(4)
(this should be split, no need to waste memory for in-kernel callers)
This is still somewhat experimental. Tested between 2 similar boxes
so far. There is much potential for performance improvement. For now,
I've changed the gmac code to accept any data alignment, as the "char *"
pointer suggests. As the code is practically used, 32-bit alignment
can be assumed, at the cost of data copies. I don't know whether
bytewise access or copies are worse performance-wise. For efficient
implementations using SSE2 instructions on x86, even stricter
alignment requirements might arise.
For this to fit, an API change in cryptosoft was adopted from OpenBSD
(addition of a "Setkey" method to hashes) which was done for GCM/GMAC
support there, so it might be useful in the future anyway.
tested against KAME IPSEC
AFAICT, FAST_IPSEC now supports as much as KAME.
implementation thing) from the abstract xform descriptor to
the cryptosoft implementation part -- for sanity, and now clients
of opencrypto don't depend on headers of cipher implementations anymore
instead of arc4random(). AES-CTR is sensitive against IV recurrence
(with the same key / nonce), and a random number doesn't give that
guarantee.
This needs a little API change in cryptosoft -- I've suggested it to
Open/FreeBSD, might change it depending on feedback.
Thanks to Steven Bellovin for hints.
anywhere afaics
(The confusion comes probably from use of arc4random() at various places,
but this lives in libkern and doesn't share code with the former.)
-g/c non-implementation of arc4 encryption in swcrypto(4)
-remove special casing of ARC4 in crypto(4) -- the point is that it
doesn't use an IV, and this fact is made explicit by the new "ivsize"
property of xforms
christos