releases/4.14.17/crypto-inside-secure-fix-hash-when-length-is-a-multiple-of-a-block.patch

   1 From 809778e02cd45d0625439fee67688f655627bb3c Mon Sep 17 00:00:00 2001
   2 From: =?UTF-8?q?Antoine=20T=C3=A9nart?= <antoine.tenart@free-electrons.com>
   3 Date: Tue, 26 Dec 2017 17:21:17 +0100
   4 Subject: crypto: inside-secure - fix hash when length is a multiple of a block
   5
   6 From: Antoine Tenart <antoine.tenart@free-electrons.com>
   7
   8 commit 809778e02cd45d0625439fee67688f655627bb3c upstream.
   9
  10 This patch fixes the hash support in the SafeXcel driver when the update
  11 size is a multiple of a block size, and when a final call is made just
  12 after with a size of 0. In such cases the driver should cache the last
  13 block from the update to avoid handling 0 length data on the final call
  14 (that's a hardware limitation).
  15
  16 Fixes: 1b44c5a60c13 ("crypto: inside-secure - add SafeXcel EIP197 crypto engine driver")
  17 Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
  18 Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
  19 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  20
  21 ---
  22  drivers/crypto/inside-secure/safexcel_hash.c |   34 +++++++++++++++++++--------
  23  1 file changed, 24 insertions(+), 10 deletions(-)
  24
  25 --- a/drivers/crypto/inside-secure/safexcel_hash.c
  26 +++ b/drivers/crypto/inside-secure/safexcel_hash.c
  27 @@ -185,17 +185,31 @@ static int safexcel_ahash_send(struct cr
  28         else
  29                 cache_len = queued - areq->nbytes;
  30
  31 -       /*
  32 -        * If this is not the last request and the queued data does not fit
  33 -        * into full blocks, cache it for the next send() call.
  34 -        */
  35 -       extra = queued & (crypto_ahash_blocksize(ahash) - 1);
  36 -       if (!req->last_req && extra) {
  37 -               sg_pcopy_to_buffer(areq->src, sg_nents(areq->src),
  38 -                                  req->cache_next, extra, areq->nbytes - extra);
  39 +       if (!req->last_req) {
  40 +               /* If this is not the last request and the queued data does not
  41 +                * fit into full blocks, cache it for the next send() call.
  42 +                */
  43 +               extra = queued & (crypto_ahash_blocksize(ahash) - 1);
  44 +               if (!extra)
  45 +                       /* If this is not the last request and the queued data
  46 +                        * is a multiple of a block, cache the last one for now.
  47 +                        */
  48 +                       extra = queued - crypto_ahash_blocksize(ahash);
  49
  50 -               queued -= extra;
  51 -               len -= extra;
  52 +               if (extra) {
  53 +                       sg_pcopy_to_buffer(areq->src, sg_nents(areq->src),
  54 +                                          req->cache_next, extra,
  55 +                                          areq->nbytes - extra);
  56 +
  57 +                       queued -= extra;
  58 +                       len -= extra;
  59 +
  60 +                       if (!queued) {
  61 +                               *commands = 0;
  62 +                               *results = 0;
  63 +                               return 0;
  64 +                       }
  65 +               }
  66         }
  67
  68         spin_lock_bh(&priv->ring[ring].egress_lock);