crypto: caam/jr - add fallback for XTS with more than 8B IV

A hardware limitation exists for CAAM until Era 9 which restricts
the accelerator to IVs with only 8 bytes. When CAAM has a lower era
a fallback is necessary to process 16 bytes IV.

Fixes: c6415a6016bf ("crypto: caam - add support for acipher xts(aes)")
Cc: <stable@vger.kernel.org> # v4.4+
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/Kconfig b/drivers/crypto/caam/Kconfig
index bc35aa0..dfeaad8 100644 (file)
--- a/drivers/crypto/caam/Kconfig
+++ b/drivers/crypto/caam/Kconfig
@@ -101,6 +101,7 @@ config CRYPTO_DEV_FSL_CAAM_CRYPTO_API
        select CRYPTO_AUTHENC
        select CRYPTO_SKCIPHER
        select CRYPTO_LIB_DES
+       select CRYPTO_XTS
        help
          Selecting this will offload crypto for users of the
          scatterlist crypto API (such as the linux native IPSec

diff --git a/drivers/crypto/caam/caamalg.c b/drivers/crypto/caam/caamalg.c
index 91feda5..adb2c05 100644 (file)
--- a/drivers/crypto/caam/caamalg.c
+++ b/drivers/crypto/caam/caamalg.c
@@ -57,6 +57,7 @@
 #include "key_gen.h"
 #include "caamalg_desc.h"
 #include <crypto/engine.h>
+#include <asm/unaligned.h>
 
 /*
  * crypto alg
@@ -114,10 +115,12 @@ struct caam_ctx {
        struct alginfo adata;
        struct alginfo cdata;
        unsigned int authsize;
+       struct crypto_skcipher *fallback;
 };
 
 struct caam_skcipher_req_ctx {
        struct skcipher_edesc *edesc;
+       struct skcipher_request fallback_req;
 };
 
 struct caam_aead_req_ctx {
@@ -830,12 +833,17 @@ static int xts_skcipher_setkey(struct crypto_skcipher *skcipher, const u8 *key,
        struct caam_ctx *ctx = crypto_skcipher_ctx(skcipher);
        struct device *jrdev = ctx->jrdev;
        u32 *desc;
+       int err;
 
        if (keylen != 2 * AES_MIN_KEY_SIZE  && keylen != 2 * AES_MAX_KEY_SIZE) {
                dev_dbg(jrdev, "key size mismatch\n");
                return -EINVAL;
        }
 
+       err = crypto_skcipher_setkey(ctx->fallback, key, keylen);
+       if (err)
+               return err;
+
        ctx->cdata.keylen = keylen;
        ctx->cdata.key_virt = key;
        ctx->cdata.key_inline = true;
@@ -1755,6 +1763,14 @@ static int skcipher_do_one_req(struct crypto_engine *engine, void *areq)
        return ret;
 }
 
+static inline bool xts_skcipher_ivsize(struct skcipher_request *req)
+{
+       struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
+       unsigned int ivsize = crypto_skcipher_ivsize(skcipher);
+
+       return !!get_unaligned((u64 *)(req->iv + (ivsize / 2)));
+}
+
 static inline int skcipher_crypt(struct skcipher_request *req, bool encrypt)
 {
        struct skcipher_edesc *edesc;
@@ -1768,6 +1784,21 @@ static inline int skcipher_crypt(struct skcipher_request *req, bool encrypt)
        if (!req->cryptlen)
                return 0;
 
+       if (ctx->fallback && xts_skcipher_ivsize(req)) {
+               struct caam_skcipher_req_ctx *rctx = skcipher_request_ctx(req);
+
+               skcipher_request_set_tfm(&rctx->fallback_req, ctx->fallback);
+               skcipher_request_set_callback(&rctx->fallback_req,
+                                             req->base.flags,
+                                             req->base.complete,
+                                             req->base.data);
+               skcipher_request_set_crypt(&rctx->fallback_req, req->src,
+                                          req->dst, req->cryptlen, req->iv);
+
+               return encrypt ? crypto_skcipher_encrypt(&rctx->fallback_req) :
+                                crypto_skcipher_decrypt(&rctx->fallback_req);
+       }
+
        /* allocate extended descriptor */
        edesc = skcipher_edesc_alloc(req, DESC_JOB_IO_LEN * CAAM_CMD_SZ);
        if (IS_ERR(edesc))
@@ -1905,6 +1936,7 @@ static struct caam_skcipher_alg driver_algs[] = {
                        .base = {
                                .cra_name = "xts(aes)",
                                .cra_driver_name = "xts-aes-caam",
+                               .cra_flags = CRYPTO_ALG_NEED_FALLBACK,
                                .cra_blocksize = AES_BLOCK_SIZE,
                        },
                        .setkey = xts_skcipher_setkey,
@@ -3344,13 +3376,35 @@ static int caam_cra_init(struct crypto_skcipher *tfm)
        struct caam_skcipher_alg *caam_alg =
                container_of(alg, typeof(*caam_alg), skcipher);
        struct caam_ctx *ctx = crypto_skcipher_ctx(tfm);
-
-       crypto_skcipher_set_reqsize(tfm, sizeof(struct caam_skcipher_req_ctx));
+       u32 alg_aai = caam_alg->caam.class1_alg_type & OP_ALG_AAI_MASK;
+       int ret = 0;
 
        ctx->enginectx.op.do_one_request = skcipher_do_one_req;
 
-       return caam_init_common(crypto_skcipher_ctx(tfm), &caam_alg->caam,
-                               false);
+       if (alg_aai == OP_ALG_AAI_XTS) {
+               const char *tfm_name = crypto_tfm_alg_name(&tfm->base);
+               struct crypto_skcipher *fallback;
+
+               fallback = crypto_alloc_skcipher(tfm_name, 0,
+                                                CRYPTO_ALG_NEED_FALLBACK);
+               if (IS_ERR(fallback)) {
+                       dev_err(ctx->jrdev, "Failed to allocate %s fallback: %ld\n",
+                               tfm_name, PTR_ERR(fallback));
+                       return PTR_ERR(fallback);
+               }
+
+               ctx->fallback = fallback;
+               crypto_skcipher_set_reqsize(tfm, sizeof(struct caam_skcipher_req_ctx) +
+                                           crypto_skcipher_reqsize(fallback));
+       } else {
+               crypto_skcipher_set_reqsize(tfm, sizeof(struct caam_skcipher_req_ctx));
+       }
+
+       ret = caam_init_common(ctx, &caam_alg->caam, false);
+       if (ret && ctx->fallback)
+               crypto_free_skcipher(ctx->fallback);
+
+       return ret;
 }
 
 static int caam_aead_init(struct crypto_aead *tfm)
@@ -3378,7 +3432,11 @@ static void caam_exit_common(struct caam_ctx *ctx)
 
 static void caam_cra_exit(struct crypto_skcipher *tfm)
 {
-       caam_exit_common(crypto_skcipher_ctx(tfm));
+       struct caam_ctx *ctx = crypto_skcipher_ctx(tfm);
+
+       if (ctx->fallback)
+               crypto_free_skcipher(ctx->fallback);
+       caam_exit_common(ctx);
 }
 
 static void caam_aead_exit(struct crypto_aead *tfm)
@@ -3412,8 +3470,8 @@ static void caam_skcipher_alg_init(struct caam_skcipher_alg *t_alg)
        alg->base.cra_module = THIS_MODULE;
        alg->base.cra_priority = CAAM_CRA_PRIORITY;
        alg->base.cra_ctxsize = sizeof(struct caam_ctx);
-       alg->base.cra_flags = CRYPTO_ALG_ASYNC | CRYPTO_ALG_ALLOCATES_MEMORY |
-                             CRYPTO_ALG_KERN_DRIVER_ONLY;
+       alg->base.cra_flags |= (CRYPTO_ALG_ASYNC | CRYPTO_ALG_ALLOCATES_MEMORY |
+                             CRYPTO_ALG_KERN_DRIVER_ONLY);
 
        alg->init = caam_cra_init;
        alg->exit = caam_cra_exit;