[PATCH 5.9 087/757] crypto: caam/qi2 - add support for more XTS key lengths

Greg Kroah-Hartman
2020-10-27T15:43:28Z

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

commit 596efd57cfa1e1bee575e2a2df44fd8ec5e4a42d 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: 226853ac3ebe ("crypto: caam/qi2 - add skcipher algorithms")
Cc: <stable@vger.kernel.org> # v4.20+
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_qi2.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)

--- a/drivers/crypto/caam/caamalg_qi2.c
+++ b/drivers/crypto/caam/caamalg_qi2.c
@@ -19,6 +19,7 @@
#include <linux/fsl/mc.h>
#include <soc/fsl/dpaa2-io.h>
#include <soc/fsl/dpaa2-fd.h>
+#include <crypto/xts.h>
#include <asm/unaligned.h>

#define CAAM_CRA_PRIORITY 2000
@@ -81,6 +82,7 @@ struct caam_ctx {
struct alginfo adata;
struct alginfo cdata;
unsigned int authsize;
+ bool xts_key_fallback;
struct crypto_skcipher *fallback;
};

@@ -1060,11 +1062,15 @@ static int xts_skcipher_setkey(struct cr
u32 *desc;
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(dev, "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;
@@ -1474,7 +1480,8 @@ static int skcipher_encrypt(struct skcip
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)) {
skcipher_request_set_tfm(&caam_req->fallback_req, ctx->fallback);
skcipher_request_set_callback(&caam_req->fallback_req,
req->base.flags,
@@ -1522,7 +1529,8 @@ static int skcipher_decrypt(struct skcip
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)) {
skcipher_request_set_tfm(&caam_req->fallback_req, ctx->fallback);
skcipher_request_set_callback(&caam_req->fallback_req,
req->base.flags,