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

From: Corentin Labbe
Date: Wed Apr 13 2022 - 15:13:47 EST


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@xxxxxxxxxxxx>
---
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(-)

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,
--
2.35.1