diff options
| author | Daniele Alessandrelli | 2021-02-03 15:42:10 +0000 |
|---|---|---|
| committer | Herbert Xu | 2021-02-10 17:55:59 +1100 |
| commit | 0db5bc85c5d871188b6f66ee26bc712a309a4a3d (patch) | |
| tree | 66a1a3c0561a72d86e6a4b96d5e86b5210e9fa63 | |
| parent | cfb28fde083761bfb839bc53059068bab5634b6a (diff) | |
crypto: keembay-ocs-aes - Fix 'q' assignment during CCM B0 generation
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>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
| -rw-r--r-- | drivers/crypto/keembay/ocs-aes.c | 6 |
1 files changed, 3 insertions, 3 deletions
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]; /* |