[PATCH v2 02/15] crypto: morus - fix handling chunked inputs

From: Eric Biggers
Date: Fri Feb 01 2019 - 02:53:34 EST


From: Eric Biggers <ebiggers@xxxxxxxxxx>

The generic MORUS implementations all fail the improved AEAD tests
because they produce the wrong result with some data layouts. The issue
is that they assume that if the skcipher_walk API gives 'nbytes' not
aligned to the walksize (a.k.a. walk.stride), then it is the end of the
data. In fact, this can happen before the end. Fix them.

Fixes: 396be41f16fd ("crypto: morus - Add generic MORUS AEAD implementations")
Cc: <stable@xxxxxxxxxxxxxxx> # v4.18+
Cc: Ondrej Mosnacek <omosnace@xxxxxxxxxx>
Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
---
crypto/morus1280.c | 13 +++++++------
crypto/morus640.c | 13 +++++++------
2 files changed, 14 insertions(+), 12 deletions(-)

diff --git a/crypto/morus1280.c b/crypto/morus1280.c
index 78ba09db7328c..0747732d5b78a 100644
--- a/crypto/morus1280.c
+++ b/crypto/morus1280.c
@@ -362,18 +362,19 @@ static void crypto_morus1280_process_crypt(struct morus1280_state *state,
const struct morus1280_ops *ops)
{
struct skcipher_walk walk;
- u8 *dst;
- const u8 *src;

ops->skcipher_walk_init(&walk, req, false);

while (walk.nbytes) {
- src = walk.src.virt.addr;
- dst = walk.dst.virt.addr;
+ unsigned int nbytes = walk.nbytes;

- ops->crypt_chunk(state, dst, src, walk.nbytes);
+ if (nbytes < walk.total)
+ nbytes = round_down(nbytes, walk.stride);

- skcipher_walk_done(&walk, 0);
+ ops->crypt_chunk(state, walk.dst.virt.addr, walk.src.virt.addr,
+ nbytes);
+
+ skcipher_walk_done(&walk, walk.nbytes - nbytes);
}
}

diff --git a/crypto/morus640.c b/crypto/morus640.c
index 5cf530139b271..1617a1eb8be13 100644
--- a/crypto/morus640.c
+++ b/crypto/morus640.c
@@ -361,18 +361,19 @@ static void crypto_morus640_process_crypt(struct morus640_state *state,
const struct morus640_ops *ops)
{
struct skcipher_walk walk;
- u8 *dst;
- const u8 *src;

ops->skcipher_walk_init(&walk, req, false);

while (walk.nbytes) {
- src = walk.src.virt.addr;
- dst = walk.dst.virt.addr;
+ unsigned int nbytes = walk.nbytes;

- ops->crypt_chunk(state, dst, src, walk.nbytes);
+ if (nbytes < walk.total)
+ nbytes = round_down(nbytes, walk.stride);

- skcipher_walk_done(&walk, 0);
+ ops->crypt_chunk(state, walk.dst.virt.addr, walk.src.virt.addr,
+ nbytes);
+
+ skcipher_walk_done(&walk, walk.nbytes - nbytes);
}
}

--
2.20.1