crypto: caam/qi - add support for more XTS key lengths

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>

diff --git a/drivers/crypto/caam/caamalg_qi.c b/drivers/crypto/caam/caamalg_qi.c
index ee80137..30aceaf 100644 (file)
--- 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 crypto_skcipher *skcipher, const u8 *key,
        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;
@@ -1402,7 +1408,8 @@ static inline int skcipher_crypt(struct skcipher_request *req, bool encrypt)
        if (!req->cryptlen)
                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);