[PATCH 5.9 083/757] crypto: caam/qi - add support for more XTS key lengths

Greg Kroah-Hartman
2020-10-27T15:32:05Z

From: Andrei Botila <andrei.botila@nxp.com>

commit 62b9a6690926ee199445b23fd46e6349d9057146 upstream.

CAAM accelerator only supports XTS-AES-128 and XTS-AES-256 since
it adheres strictly to the standard. All the other key lengths
are accepted and processed through a fallback as long as they pass
the xts_verify_key() checks.

Fixes: b189817cf789 ("crypto: caam/qi - add ablkcipher and authenc algorithms")
Cc: <stable@vger.kernel.org> # v4.12+
Signed-off-by: Andrei Botila <andrei.botila@nxp.com>
Reviewed-by: Horia Geantă <horia.geanta@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/crypto/caam/caamalg_qi.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)

--- a/drivers/crypto/caam/caamalg_qi.c
+++ b/drivers/crypto/caam/caamalg_qi.c
@@ -18,6 +18,7 @@
#include "qi.h"
#include "jr.h"
#include "caamalg_desc.h"
+#include <crypto/xts.h>
#include <asm/unaligned.h>

/*
@@ -68,6 +69,7 @@ struct caam_ctx {
struct device *qidev;
spinlock_t lock; /* Protects multiple init of driver context */
struct caam_drv_ctx *drv_ctx[NUM_OP];
+ bool xts_key_fallback;
struct crypto_skcipher *fallback;
};

@@ -734,11 +736,15 @@ static int xts_skcipher_setkey(struct cr
int ret = 0;
int err;

- if (keylen != 2 * AES_MIN_KEY_SIZE && keylen != 2 * AES_MAX_KEY_SIZE) {
+ err = xts_verify_key(skcipher, key, keylen);
+ if (err) {
dev_dbg(jrdev, "key size mismatch\n");
- return -EINVAL;
+ return err;
}

+ if (keylen != 2 * AES_KEYSIZE_128 && keylen != 2 * AES_KEYSIZE_256)
+ ctx->xts_key_fallback = true;
+
err = crypto_skcipher_setkey(ctx->fallback, key, keylen);
if (err)
return err;
@@ -1407,7 +1413,8 @@ static inline int skcipher_crypt(struct
if (!req->cryptlen && !ctx->fallback)
return 0;

- if (ctx->fallback && xts_skcipher_ivsize(req)) {
+ if (ctx->fallback && (xts_skcipher_ivsize(req) ||
+ ctx->xts_key_fallback)) {
struct caam_skcipher_req_ctx *rctx = skcipher_request_ctx(req);

skcipher_request_set_tfm(&rctx->fallback_req, ctx->fallback);