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crypto: caam - properly set IV after {en,de}crypt

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Certain cipher modes like CTS expect the IV (req->info) of
ablkcipher_request (or equivalently req->iv of skcipher_request) to
contain the last ciphertext block when the {en,de}crypt operation is done.
This is currently not the case for the CAAM driver which in turn breaks
e.g. cts(cbc(aes)) when the CAAM driver is enabled.

This patch fixes the CAAM driver to properly set the IV after the
{en,de}crypt operation of ablkcipher finishes.

This issue was revealed by the changes in the SW CTS mode in commit
0605c41cc5 ("crypto: cts - Convert to skcipher")

Cc: <stable@vger.kernel.org> # 4.8+
Signed-off-by: David Gstir <david@sigma-star.at>
Reviewed-by: Horia Geantă <horia.geanta@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
David Gstir 2017-06-28 15:27:10 +02:00 committed by Herbert Xu
parent 1606043f21
commit 854b06f768
1 changed files with 18 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
drivers/crypto/caam/caamalg.c
View File

@ -882,10 +882,10 @@ static void ablkcipher_encrypt_done(struct device *jrdev, u32 *desc, u32 err,
{
struct ablkcipher_request *req = context;
struct ablkcipher_edesc *edesc;
#ifdef DEBUG
struct crypto_ablkcipher *ablkcipher = crypto_ablkcipher_reqtfm(req);
int ivsize = crypto_ablkcipher_ivsize(ablkcipher);
#ifdef DEBUG
dev_err(jrdev, "%s %d: err 0x%x\n", __func__, __LINE__, err);
#endif
@ -904,6 +904,14 @@ static void ablkcipher_encrypt_done(struct device *jrdev, u32 *desc, u32 err,
#endif
ablkcipher_unmap(jrdev, edesc, req);
/*
* The crypto API expects us to set the IV (req->info) to the last
* ciphertext block. This is used e.g. by the CTS mode.
*/
scatterwalk_map_and_copy(req->info, req->dst, req->nbytes - ivsize,
ivsize, 0);
kfree(edesc);
ablkcipher_request_complete(req, err);
@ -914,10 +922,10 @@ static void ablkcipher_decrypt_done(struct device *jrdev, u32 *desc, u32 err,
{
struct ablkcipher_request *req = context;
struct ablkcipher_edesc *edesc;
#ifdef DEBUG
struct crypto_ablkcipher *ablkcipher = crypto_ablkcipher_reqtfm(req);
int ivsize = crypto_ablkcipher_ivsize(ablkcipher);
#ifdef DEBUG
dev_err(jrdev, "%s %d: err 0x%x\n", __func__, __LINE__, err);
#endif
@ -935,6 +943,14 @@ static void ablkcipher_decrypt_done(struct device *jrdev, u32 *desc, u32 err,
#endif
ablkcipher_unmap(jrdev, edesc, req);
/*
* The crypto API expects us to set the IV (req->info) to the last
* ciphertext block.
*/
scatterwalk_map_and_copy(req->info, req->src, req->nbytes - ivsize,
ivsize, 0);
kfree(edesc);
ablkcipher_request_complete(req, err);