Commit Graph

12 Commits

Author SHA1 Message Date
Jaswinder Singh Rajput
2f32bfd834 crypto: ansi_cprng - Move FIPS functions under CONFIG_CRYPTO_FIPS
fips_cprng_get_random and fips_cprng_reset is used only by
CONFIG_CRYPTO_FIPS. This also fixes compilation warnings:

 crypto/ansi_cprng.c:360: warning: ‘fips_cprng_get_random’ defined but not used
 crypto/ansi_cprng.c:393: warning: ‘fips_cprng_reset’ defined but not used

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-11-23 20:25:50 +08:00
Roel Kluin
2024e7d680 crypto: ansi_cprng - Fix test in get_prng_bytes
size_t nbytes cannot be less than 0 and the test was redundant.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-10-27 18:51:33 +08:00
Neil Horman
667b6294bf crypto: ansi_cprng - Add FIPS wrapper
Patch to add fips(ansi_cprng) alg, which is ansi_cprng plus a continuous test

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-10-19 11:57:02 +09:00
Steffen Klassert
a367b17f34 crypto: ansi_cprng - Fix module initialization
Return the value we got from crypto_register_alg() instead of
returning 0 in any case.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-08-29 17:36:25 +10:00
Sebastian Andrzej Siewior
fd09d7facb crypto: ansi_prng - alloc cipher just in init
As reported by Eric Sesterhenn the re-allocation of the cipher in reset leads
to:
|BUG: sleeping function called from invalid context at kernel/rwsem.c:21
|in_atomic(): 1, irqs_disabled(): 0, pid: 4926, name: modprobe
|INFO: lockdep is turned off.
|Pid: 4926, comm: modprobe Tainted: G   M 2.6.31-rc1-22297-g5298976 #24
|Call Trace:
| [<c011dd93>] __might_sleep+0xf9/0x101
| [<c0777aa0>] down_read+0x16/0x68
| [<c048bf04>] crypto_alg_lookup+0x16/0x34
| [<c048bf52>] crypto_larval_lookup+0x30/0xf9
| [<c048c038>] crypto_alg_mod_lookup+0x1d/0x62
| [<c048c13e>] crypto_alloc_base+0x1e/0x64
| [<c04bf991>] reset_prng_context+0xab/0x13f
| [<c04e5cfc>] ? __spin_lock_init+0x27/0x51
| [<c04bfce1>] cprng_init+0x2a/0x42
| [<c048bb4c>] __crypto_alloc_tfm+0xfa/0x128
| [<c048c153>] crypto_alloc_base+0x33/0x64
| [<c04933c9>] alg_test_cprng+0x30/0x1f4
| [<c0493329>] alg_test+0x12f/0x19f
| [<c0177f1f>] ? __alloc_pages_nodemask+0x14d/0x481
| [<d09219e2>] do_test+0xf9d/0x163f [tcrypt]
| [<d0920de6>] do_test+0x3a1/0x163f [tcrypt]
| [<d0926035>] tcrypt_mod_init+0x35/0x7c [tcrypt]
| [<c010113c>] _stext+0x54/0x12c
| [<d0926000>] ? tcrypt_mod_init+0x0/0x7c [tcrypt]
| [<c01398a3>] ? up_read+0x16/0x2b
| [<c0139fc4>] ? __blocking_notifier_call_chain+0x40/0x4c
| [<c014ee8d>] sys_init_module+0xa9/0x1bf
| [<c010292b>] sysenter_do_call+0x12/0x32

because a spin lock is held and crypto_alloc_base() may sleep.
There is no reason to re-allocate the cipher, the state is resetted in
->setkey(). This patches makes the cipher allocation a one time thing and
moves it to init.

Reported-by: Eric Sesterhenn <eric.sesterhenn@lsexperts.de>
Signed-off-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-07-03 12:10:47 +08:00
Sebastian Andrzej Siewior
ed94070058 crypto: ansi_prng - Use just a BH lock
The current code uses a mix of sping_lock() & spin_lock_irqsave(). This can
lead to deadlock with the correct timming & cprng_get_random() + cprng_reset()
sequence.
I've converted them to bottom half locks since all three user grab just a BH
lock so this runs probably in softirq :)

Signed-off-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-07-03 12:09:41 +08:00
Neil Horman
c5b1e545a5 crypto: ansi_cprng - Panic on CPRNG test failure when in FIPS mode
FIPS 140-2 specifies that all access to various cryptographic modules be
prevented in the event that any of the provided self tests fail on the various
implemented algorithms.  We already panic when any of the test in testmgr.c
fail when we are operating in fips mode.  The continuous test in the cprng here
was missed when that was implmented.  This code simply checks for the
fips_enabled flag if the test fails, and warns us via syslog or panics the box
accordingly.

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-02-18 16:48:07 +08:00
Neil Horman
d7992f42c6 crypto: ansi_cprng - Force reset on allocation
Pseudo RNGs provide predictable outputs based on input parateters {key, V, DT},
the idea behind them is that only the user should know what the inputs are.
While its nice to have default known values for testing purposes, it seems
dangerous to allow the use of those default values without some sort of safety
measure in place, lest an attacker easily guess the output of the cprng.  This
patch forces the NEED_RESET flag on when allocating a cprng context, so that any
user is forced to reseed it before use.  The defaults can still be used for
testing, but this will prevent their inadvertent use, and be more secure.
   
Signed-off-by: Neil Horman <nhorman@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-02-18 16:48:06 +08:00
Jarod Wilson
09fbf7c0f2 crypto: ansi_cprng - fix inverted DT increment routine
The ANSI X9.31 PRNG docs aren't particularly clear on how to increment DT,
but empirical testing shows we're incrementing from the wrong end. A 10,000
iteration Monte Carlo RNG test currently winds up not getting the expected
result.

From http://csrc.nist.gov/groups/STM/cavp/documents/rng/RNGVS.pdf :

# CAVS 4.3
# ANSI931 MCT
[X9.31]
[AES 128-Key]

COUNT = 0
Key = 9f5b51200bf334b5d82be8c37255c848
DT = 6376bbe52902ba3b67c925fa701f11ac
V = 572c8e76872647977e74fbddc49501d1
R = 48e9bd0d06ee18fbe45790d5c3fc9b73

Currently, we get 0dd08496c4f7178bfa70a2161a79459a after 10000 loops.

Inverting the DT increment routine results in us obtaining the expected result
of 48e9bd0d06ee18fbe45790d5c3fc9b73. Verified on both x86_64 and ppc64.

Signed-off-by: Jarod Wilson <jarod@redhat.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-12-25 11:01:49 +11:00
Jarod Wilson
aa1a85dbd1 crypto: ansi_cprng - Avoid incorrect extra call to _get_more_prng_bytes
While working with some FIPS RNGVS test vectors yesterday, I discovered a
little bug in the way the ansi_cprng code works right now.

For example, the following test vector (complete with expected result)
from http://csrc.nist.gov/groups/STM/cavp/documents/rng/RNGVS.pdf ...

Key = f3b1666d13607242ed061cabb8d46202
DT = e6b3be782a23fa62d71d4afbb0e922fc
V = f0000000000000000000000000000000
R = 88dda456302423e5f69da57e7b95c73a

...when run through ansi_cprng, yields an incorrect R value
of e2afe0d794120103d6e86a2b503bdfaa.

If I load up ansi_cprng w/dbg=1 though, it was fairly obvious what was
going wrong:

----8<----
getting 16 random bytes for context ffff810033fb2b10
Calling _get_more_prng_bytes for context ffff810033fb2b10
Input DT: 00000000: e6 b3 be 78 2a 23 fa 62 d7 1d 4a fb b0 e9 22 fc 
Input I: 00000000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
Input V: 00000000: f0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
tmp stage 0: 00000000: e6 b3 be 78 2a 23 fa 62 d7 1d 4a fb b0 e9 22 fc 
tmp stage 1: 00000000: f4 8e cb 25 94 3e 8c 31 d6 14 cd 8a 23 f1 3f 84 
tmp stage 2: 00000000: 8c 53 6f 73 a4 1a af d4 20 89 68 f4 58 64 f8 be 
Returning new block for context ffff810033fb2b10
Output DT: 00000000: e7 b3 be 78 2a 23 fa 62 d7 1d 4a fb b0 e9 22 fc 
Output I: 00000000: 04 8e cb 25 94 3e 8c 31 d6 14 cd 8a 23 f1 3f 84 
Output V: 00000000: 48 89 3b 71 bc e4 00 b6 5e 21 ba 37 8a 0a d5 70 
New Random Data: 00000000: 88 dd a4 56 30 24 23 e5 f6 9d a5 7e 7b 95 c7 3a 
Calling _get_more_prng_bytes for context ffff810033fb2b10
Input DT: 00000000: e7 b3 be 78 2a 23 fa 62 d7 1d 4a fb b0 e9 22 fc 
Input I: 00000000: 04 8e cb 25 94 3e 8c 31 d6 14 cd 8a 23 f1 3f 84 
Input V: 00000000: 48 89 3b 71 bc e4 00 b6 5e 21 ba 37 8a 0a d5 70 
tmp stage 0: 00000000: e7 b3 be 78 2a 23 fa 62 d7 1d 4a fb b0 e9 22 fc 
tmp stage 1: 00000000: 80 6b 3a 8c 23 ae 8f 53 be 71 4c 16 fc 13 b2 ea 
tmp stage 2: 00000000: 2a 4d e1 2a 0b 58 8e e6 36 b8 9c 0a 26 22 b8 30 
Returning new block for context ffff810033fb2b10
Output DT: 00000000: e8 b3 be 78 2a 23 fa 62 d7 1d 4a fb b0 e9 22 fc 
Output I: 00000000: c8 e2 01 fd 9f 4a 8f e5 e0 50 f6 21 76 19 67 9a 
Output V: 00000000: ba 98 e3 75 c0 1b 81 8d 03 d6 f8 e2 0c c6 54 4b 
New Random Data: 00000000: e2 af e0 d7 94 12 01 03 d6 e8 6a 2b 50 3b df aa 
returning 16 from get_prng_bytes in context ffff810033fb2b10
----8<----

The expected result is there, in the first "New Random Data", but we're
incorrectly making a second call to _get_more_prng_bytes, due to some checks
that are slightly off, which resulted in our original bytes never being
returned anywhere.

One approach to fixing this would be to alter some byte_count checks in
get_prng_bytes, but it would mean the last DEFAULT_BLK_SZ bytes would be
copied a byte at a time, rather than in a single memcpy, so a slightly more
involved, equally functional, and ultimately more efficient way of fixing this
was suggested to me by Neil, which I'm submitting here. All of the RNGVS ANSI
X9.31 AES128 VST test vectors I've passed through ansi_cprng are now returning
the expected results with this change.

Signed-off-by: Jarod Wilson <jarod@redhat.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-12-25 11:01:47 +11:00
Neil Horman
2566578a6f crypto: ansi_cprng - Allow resetting of DT value
This is a patch that was sent to me by Jarod Wilson, marking off my
outstanding todo to allow the ansi cprng to set/reset the DT counter value in a
cprng instance.  Currently crytpo_rng_reset accepts a seed byte array which is
interpreted by the ansi_cprng as a {V key} tuple.  This patch extends that tuple
to now be {V key DT}, with DT an optional value during reset.  This patch also
fixes  a bug we noticed in which the offset of the key area of the seed is
started at DEFAULT_PRNG_KSZ rather than DEFAULT_BLK_SZ as it should be.

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-12-25 11:01:21 +11:00
Neil Horman
17f0f4a47d crypto: rng - RNG interface and implementation
This patch adds a random number generator interface as well as a
cryptographic pseudo-random number generator based on AES.  It is
meant to be used in cases where a deterministic CPRNG is required.

One of the first applications will be as an input in the IPsec IV
generation process.

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-08-29 15:50:04 +10:00