diff mbox series

[2/2] crypto: marvell: cesa: Add fallback for handling empty length case

Message ID 20220413191155.1429137-2-clabbe@baylibre.com (mailing list archive)
State Changes Requested
Delegated to: Herbert Xu
Headers show
Series [1/2] crypto: marvell: cesa: ECB does not IV | expand

Commit Message

Corentin Labbe April 13, 2022, 7:11 p.m. UTC 
The driver does not handle case where cryptlen is zero and fail crypto selftests.
So let's add a fallback for this case.

Fixes: f63601fd616ab ("crypto: marvell/cesa - add a new driver for Marvell's CESA")
Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
---
 drivers/crypto/marvell/Kconfig       |  4 ++
 drivers/crypto/marvell/cesa/cesa.h   | 12 +++--
 drivers/crypto/marvell/cesa/cipher.c | 69 ++++++++++++++++++++++++----
 3 files changed, 72 insertions(+), 13 deletions(-)

Comments

Herbert Xu April 21, 2022, 9:50 a.m. UTC | #1 
On Wed, Apr 13, 2022 at 07:11:55PM +0000, Corentin Labbe wrote:
> The driver does not handle case where cryptlen is zero and fail crypto selftests.
> So let's add a fallback for this case.

Wouldn't it be easier to just handle this in the software? After
all, a zero encryption/decryption is just a no-op, right?

Thanks,
diff mbox series

Patch

diff --git a/drivers/crypto/marvell/Kconfig b/drivers/crypto/marvell/Kconfig
index a48591af12d0..6d8a625e2208 100644
--- a/drivers/crypto/marvell/Kconfig
+++ b/drivers/crypto/marvell/Kconfig
@@ -13,6 +13,10 @@  config CRYPTO_DEV_MARVELL_CESA
 	select CRYPTO_SKCIPHER
 	select CRYPTO_HASH
 	select SRAM
+	select CRYPTO_ECB
+	select CRYPTO_CBC
+	select CRYPTO_DES
+	select CRYPTO_AES
 	select CRYPTO_DEV_MARVELL
 	help
 	  This driver allows you to utilize the Cryptographic Engines and
diff --git a/drivers/crypto/marvell/cesa/cesa.h b/drivers/crypto/marvell/cesa/cesa.h
index d215a6bed6bc..93736eed19f1 100644
--- a/drivers/crypto/marvell/cesa/cesa.h
+++ b/drivers/crypto/marvell/cesa/cesa.h
@@ -487,12 +487,14 @@  struct mv_cesa_req_ops {
 
 /**
  * struct mv_cesa_ctx - CESA operation context
- * @ops:	crypto operations
+ * @ops:		crypto operations
+ * @fallback_tfm:	pointer to the fallback TFM
  *
  * Base context structure inherited by operation specific ones.
  */
 struct mv_cesa_ctx {
 	const struct mv_cesa_req_ops *ops;
+	struct crypto_skcipher *fallback_tfm;
 };
 
 /**
@@ -563,15 +565,17 @@  struct mv_cesa_skcipher_std_req {
 
 /**
  * struct mv_cesa_skcipher_req - cipher request
- * @req:	type specific request information
- * @src_nents:	number of entries in the src sg list
- * @dst_nents:	number of entries in the dest sg list
+ * @req:		type specific request information
+ * @src_nents:		number of entries in the src sg list
+ * @dst_nents:		number of entries in the dest sg list
+ * @fallback_req:	request struct for invoking the fallback skcipher TFM
  */
 struct mv_cesa_skcipher_req {
 	struct mv_cesa_req base;
 	struct mv_cesa_skcipher_std_req std;
 	int src_nents;
 	int dst_nents;
+	struct skcipher_request fallback_req;   // keep at the end
 };
 
 /**
diff --git a/drivers/crypto/marvell/cesa/cipher.c b/drivers/crypto/marvell/cesa/cipher.c
index c6f2fa753b7c..6da44651635f 100644
--- a/drivers/crypto/marvell/cesa/cipher.c
+++ b/drivers/crypto/marvell/cesa/cipher.c
@@ -37,6 +37,26 @@  struct mv_cesa_skcipher_dma_iter {
 	struct mv_cesa_sg_dma_iter dst;
 };
 
+static int cesa_skcipher_fallback(struct skcipher_request *areq,
+				  struct mv_cesa_op_ctx *tmpl)
+{
+	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
+	struct mv_cesa_ctx *op = crypto_skcipher_ctx(tfm);
+	struct mv_cesa_skcipher_req *rctx = skcipher_request_ctx(areq);
+	int err;
+
+	skcipher_request_set_tfm(&rctx->fallback_req, op->fallback_tfm);
+	skcipher_request_set_callback(&rctx->fallback_req, areq->base.flags,
+				      areq->base.complete, areq->base.data);
+	skcipher_request_set_crypt(&rctx->fallback_req, areq->src, areq->dst,
+				   areq->cryptlen, areq->iv);
+	if (mv_cesa_get_op_cfg(tmpl) & CESA_SA_DESC_CFG_DIR_DEC)
+		err = crypto_skcipher_decrypt(&rctx->fallback_req);
+	else
+		err = crypto_skcipher_encrypt(&rctx->fallback_req);
+	return err;
+}
+
 static inline void
 mv_cesa_skcipher_req_iter_init(struct mv_cesa_skcipher_dma_iter *iter,
 			       struct skcipher_request *req)
@@ -240,15 +260,25 @@  static const struct mv_cesa_req_ops mv_cesa_skcipher_req_ops = {
 
 static void mv_cesa_skcipher_cra_exit(struct crypto_tfm *tfm)
 {
-	void *ctx = crypto_tfm_ctx(tfm);
+	struct mv_cesa_ctx *ctx = crypto_tfm_ctx(tfm);
 
 	memzero_explicit(ctx, tfm->__crt_alg->cra_ctxsize);
+	crypto_free_skcipher(ctx->fallback_tfm);
 }
 
 static int mv_cesa_skcipher_cra_init(struct crypto_tfm *tfm)
 {
 	struct mv_cesa_ctx *ctx = crypto_tfm_ctx(tfm);
+	struct crypto_skcipher *sktfm = __crypto_skcipher_cast(tfm);
+	const char *name = crypto_tfm_alg_name(tfm);
+
+	ctx->fallback_tfm = crypto_alloc_skcipher(name, 0, CRYPTO_ALG_NEED_FALLBACK);
+	if (IS_ERR(ctx->fallback_tfm)) {
+		return PTR_ERR(ctx->fallback_tfm);
+	}
 
+	sktfm->reqsize = sizeof(struct mv_cesa_ctx) +
+		crypto_skcipher_reqsize(ctx->fallback_tfm);
 	ctx->ops = &mv_cesa_skcipher_req_ops;
 
 	crypto_skcipher_set_reqsize(__crypto_skcipher_cast(tfm),
@@ -276,7 +306,10 @@  static int mv_cesa_aes_setkey(struct crypto_skcipher *cipher, const u8 *key,
 	for (i = 0; i < remaining; i++)
 		ctx->aes.key_dec[4 + i] = ctx->aes.key_enc[offset + i];
 
-	return 0;
+	crypto_skcipher_clear_flags(ctx->base.fallback_tfm, CRYPTO_TFM_REQ_MASK);
+	crypto_skcipher_set_flags(ctx->base.fallback_tfm, cipher->base.crt_flags & CRYPTO_TFM_REQ_MASK);
+
+	return crypto_skcipher_setkey(ctx->base.fallback_tfm, key, len);
 }
 
 static int mv_cesa_des_setkey(struct crypto_skcipher *cipher, const u8 *key,
@@ -291,7 +324,10 @@  static int mv_cesa_des_setkey(struct crypto_skcipher *cipher, const u8 *key,
 
 	memcpy(ctx->key, key, DES_KEY_SIZE);
 
-	return 0;
+	crypto_skcipher_clear_flags(ctx->base.fallback_tfm, CRYPTO_TFM_REQ_MASK);
+	crypto_skcipher_set_flags(ctx->base.fallback_tfm, cipher->base.crt_flags & CRYPTO_TFM_REQ_MASK);
+
+	return crypto_skcipher_setkey(ctx->base.fallback_tfm, key, len);
 }
 
 static int mv_cesa_des3_ede_setkey(struct crypto_skcipher *cipher,
@@ -306,7 +342,10 @@  static int mv_cesa_des3_ede_setkey(struct crypto_skcipher *cipher,
 
 	memcpy(ctx->key, key, DES3_EDE_KEY_SIZE);
 
-	return 0;
+	crypto_skcipher_clear_flags(ctx->base.fallback_tfm, CRYPTO_TFM_REQ_MASK);
+	crypto_skcipher_set_flags(ctx->base.fallback_tfm, cipher->base.crt_flags & CRYPTO_TFM_REQ_MASK);
+
+	return crypto_skcipher_setkey(ctx->base.fallback_tfm, key, len);
 }
 
 static int mv_cesa_skcipher_dma_req_init(struct skcipher_request *req,
@@ -458,6 +497,13 @@  static int mv_cesa_skcipher_queue_req(struct skcipher_request *req,
 	int ret;
 	struct mv_cesa_skcipher_req *creq = skcipher_request_ctx(req);
 	struct mv_cesa_engine *engine;
+	bool need_fallback = false;
+
+	if (!req->cryptlen)
+		need_fallback = true;
+
+	if (need_fallback)
+		return cesa_skcipher_fallback(req, tmpl);
 
 	ret = mv_cesa_skcipher_req_init(req, tmpl);
 	if (ret)
@@ -520,7 +566,8 @@  struct skcipher_alg mv_cesa_ecb_des_alg = {
 		.cra_driver_name = "mv-ecb-des",
 		.cra_priority = 300,
 		.cra_flags = CRYPTO_ALG_KERN_DRIVER_ONLY | CRYPTO_ALG_ASYNC |
-			     CRYPTO_ALG_ALLOCATES_MEMORY,
+			     CRYPTO_ALG_ALLOCATES_MEMORY |
+			     CRYPTO_ALG_NEED_FALLBACK,
 		.cra_blocksize = DES_BLOCK_SIZE,
 		.cra_ctxsize = sizeof(struct mv_cesa_des_ctx),
 		.cra_alignmask = 0,
@@ -571,7 +618,8 @@  struct skcipher_alg mv_cesa_cbc_des_alg = {
 		.cra_driver_name = "mv-cbc-des",
 		.cra_priority = 300,
 		.cra_flags = CRYPTO_ALG_KERN_DRIVER_ONLY | CRYPTO_ALG_ASYNC |
-			     CRYPTO_ALG_ALLOCATES_MEMORY,
+			     CRYPTO_ALG_ALLOCATES_MEMORY |
+			     CRYPTO_ALG_NEED_FALLBACK,
 		.cra_blocksize = DES_BLOCK_SIZE,
 		.cra_ctxsize = sizeof(struct mv_cesa_des_ctx),
 		.cra_alignmask = 0,
@@ -629,7 +677,8 @@  struct skcipher_alg mv_cesa_ecb_des3_ede_alg = {
 		.cra_driver_name = "mv-ecb-des3-ede",
 		.cra_priority = 300,
 		.cra_flags = CRYPTO_ALG_KERN_DRIVER_ONLY | CRYPTO_ALG_ASYNC |
-			     CRYPTO_ALG_ALLOCATES_MEMORY,
+			     CRYPTO_ALG_ALLOCATES_MEMORY |
+			     CRYPTO_ALG_NEED_FALLBACK,
 		.cra_blocksize = DES3_EDE_BLOCK_SIZE,
 		.cra_ctxsize = sizeof(struct mv_cesa_des3_ctx),
 		.cra_alignmask = 0,
@@ -683,7 +732,8 @@  struct skcipher_alg mv_cesa_cbc_des3_ede_alg = {
 		.cra_driver_name = "mv-cbc-des3-ede",
 		.cra_priority = 300,
 		.cra_flags = CRYPTO_ALG_KERN_DRIVER_ONLY | CRYPTO_ALG_ASYNC |
-			     CRYPTO_ALG_ALLOCATES_MEMORY,
+			     CRYPTO_ALG_ALLOCATES_MEMORY |
+			     CRYPTO_ALG_NEED_FALLBACK,
 		.cra_blocksize = DES3_EDE_BLOCK_SIZE,
 		.cra_ctxsize = sizeof(struct mv_cesa_des3_ctx),
 		.cra_alignmask = 0,
@@ -756,7 +806,8 @@  struct skcipher_alg mv_cesa_ecb_aes_alg = {
 		.cra_driver_name = "mv-ecb-aes",
 		.cra_priority = 300,
 		.cra_flags = CRYPTO_ALG_KERN_DRIVER_ONLY | CRYPTO_ALG_ASYNC |
-			     CRYPTO_ALG_ALLOCATES_MEMORY,
+			     CRYPTO_ALG_ALLOCATES_MEMORY |
+			     CRYPTO_ALG_NEED_FALLBACK,
 		.cra_blocksize = AES_BLOCK_SIZE,
 		.cra_ctxsize = sizeof(struct mv_cesa_aes_ctx),
 		.cra_alignmask = 0,