| Message ID | 20210203154210.246667-1-daniele.alessandrelli@linux.intel.com |
|---|---|
| State | New |
| Headers | show |
| Series | crypto: keembay-ocs-aes - Fix 'q' assignment during CCM B0 generation | expand |
On Wed, Feb 03, 2021 at 03:42:10PM +0000, Daniele Alessandrelli wrote: > From: Daniele Alessandrelli <daniele.alessandrelli@intel.com> > > In ocs_aes_ccm_write_b0(), 'q' (the octet length of the binary > representation of the octet length of the payload) is set to 'iv[0]', > while it should be set to 'iv[0] & 0x7' (i.e., only the last 3 > bits of iv[0] should be used), as documented in NIST Special Publication > 800-38C: > https://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication800-38c.pdf > > In practice, this is not an issue, since 'iv[0]' is checked to be in the > range [1-7] by ocs_aes_validate_inputs(), but let's fix the assignment > anyway, in order to make the code more robust. > > Signed-off-by: Daniele Alessandrelli <daniele.alessandrelli@intel.com> > --- > drivers/crypto/keembay/ocs-aes.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) Patch applied. Thanks. -- Email: Herbert Xu <herbert@gondor.apana.org.au> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
diff --git a/drivers/crypto/keembay/ocs-aes.c b/drivers/crypto/keembay/ocs-aes.c index b85c89477afa..be9f32fc8f42 100644 --- a/drivers/crypto/keembay/ocs-aes.c +++ b/drivers/crypto/keembay/ocs-aes.c @@ -1080,15 +1080,15 @@ static int ocs_aes_ccm_write_b0(const struct ocs_aes_dev *aes_dev, /* * q is the octet length of Q. * q can only be an element of {2, 3, 4, 5, 6, 7, 8} and is encoded as - * q - 1 == iv[0] + * q - 1 == iv[0] & 0x7; */ b0[0] |= iv[0] & 0x7; /* * Copy the Nonce N from IV to B0; N is located in iv[1]..iv[15 - q] * and must be copied to b0[1]..b0[15-q]. - * q == iv[0] + 1 + * q == (iv[0] & 0x7) + 1 */ - q = iv[0] + 1; + q = (iv[0] & 0x7) + 1; for (i = 1; i <= 15 - q; i++) b0[i] = iv[i]; /*