diff mbox series

crypto: starfive - Align rsa input data to 32-bit

Message ID 20240529002553.1372257-1-jiajie.ho@starfivetech.com
State New
Headers show
Series crypto: starfive - Align rsa input data to 32-bit | expand

Commit Message

Jia Jie Ho May 29, 2024, 12:25 a.m. UTC
Hardware expects RSA input plain/ciphertext to be 32-bit aligned.
Allocate aligned buffer and shift data accordingly.

Signed-off-by: Jia Jie Ho <jiajie.ho@starfivetech.com>
---
 drivers/crypto/starfive/jh7110-cryp.h |  3 +--
 drivers/crypto/starfive/jh7110-rsa.c  | 17 ++++++++++-------
 2 files changed, 11 insertions(+), 9 deletions(-)

Comments

Jia Jie Ho June 10, 2024, 10:50 a.m. UTC | #1
> On Wed, May 29, 2024 at 08:25:53AM +0800, Jia Jie Ho wrote:
> > Hardware expects RSA input plain/ciphertext to be 32-bit aligned.
> > Allocate aligned buffer and shift data accordingly.
> >
> > Signed-off-by: Jia Jie Ho <jiajie.ho@starfivetech.com>
> > ---
> >  drivers/crypto/starfive/jh7110-cryp.h |  3 +--
> > drivers/crypto/starfive/jh7110-rsa.c  | 17 ++++++++++-------
> >  2 files changed, 11 insertions(+), 9 deletions(-)
> >
> > diff --git a/drivers/crypto/starfive/jh7110-cryp.h
> > b/drivers/crypto/starfive/jh7110-cryp.h
> > index 494a74f52706..eeb4e2b9655f 100644
> > --- a/drivers/crypto/starfive/jh7110-cryp.h
> > +++ b/drivers/crypto/starfive/jh7110-cryp.h
> > @@ -217,12 +217,11 @@ struct starfive_cryp_request_ctx {
> >  	struct scatterlist			*out_sg;
> >  	struct ahash_request			ahash_fbk_req;
> >  	size_t					total;
> > -	size_t					nents;
> >  	unsigned int				blksize;
> >  	unsigned int				digsize;
> >  	unsigned long				in_sg_len;
> >  	unsigned char				*adata;
> > -	u8 rsa_data[] __aligned(sizeof(u32));
> > +	u8					*rsa_data;
> 
> You didn't explain why this is moving from a pre-allocated buffer to one that's
> allocated on the run.  It would appear that there is no reason why you can't
> build the extra space used for shifting into reqsize.
> 

I'll update this in the next version.
Thanks for reviewing this.

Best regards,
Jia Jie
Jia Jie Ho June 12, 2024, 2:58 a.m. UTC | #2
> On Wed, May 29, 2024 at 08:25:53AM +0800, Jia Jie Ho wrote:
> > Hardware expects RSA input plain/ciphertext to be 32-bit aligned.
> > Allocate aligned buffer and shift data accordingly.
> >
> > Signed-off-by: Jia Jie Ho <jiajie.ho@starfivetech.com>
> > ---
> >  drivers/crypto/starfive/jh7110-cryp.h |  3 +--
> > drivers/crypto/starfive/jh7110-rsa.c  | 17 ++++++++++-------
> >  2 files changed, 11 insertions(+), 9 deletions(-)
> >
> > diff --git a/drivers/crypto/starfive/jh7110-cryp.h
> > b/drivers/crypto/starfive/jh7110-cryp.h
> > index 494a74f52706..eeb4e2b9655f 100644
> > --- a/drivers/crypto/starfive/jh7110-cryp.h
> > +++ b/drivers/crypto/starfive/jh7110-cryp.h
> > @@ -217,12 +217,11 @@ struct starfive_cryp_request_ctx {
> >  	struct scatterlist			*out_sg;
> >  	struct ahash_request			ahash_fbk_req;
> >  	size_t					total;
> > -	size_t					nents;
> >  	unsigned int				blksize;
> >  	unsigned int				digsize;
> >  	unsigned long				in_sg_len;
> >  	unsigned char				*adata;
> > -	u8 rsa_data[] __aligned(sizeof(u32));
> > +	u8					*rsa_data;
> 
> You didn't explain why this is moving from a pre-allocated buffer to one that's
> allocated on the run.  It would appear that there is no reason why you can't
> build the extra space used for shifting into reqsize.
> 
Hi Herbert,

Can I fix the buffer length of the pre-allocated buffer to 256 bytes instead of
the current variable length buffer? 

-        u8 rsa_data[] __aligned(sizeof(u32));
+       u8 rsa_data[STARFIVE_RSA_MAX_KEYSZ];

That's the maximum length supported by the hardware and 
most applications now use rsa2048 and above.

Thanks,
Jia Jie
Herbert Xu June 12, 2024, 7:46 a.m. UTC | #3
On Wed, Jun 12, 2024 at 02:58:18AM +0000, JiaJie Ho wrote:
>
> Can I fix the buffer length of the pre-allocated buffer to 256 bytes instead of
> the current variable length buffer? 
> 
> -        u8 rsa_data[] __aligned(sizeof(u32));
> +       u8 rsa_data[STARFIVE_RSA_MAX_KEYSZ];
> 
> That's the maximum length supported by the hardware and 
> most applications now use rsa2048 and above.

I think that's fine.

Thanks,
diff mbox series

Patch

diff --git a/drivers/crypto/starfive/jh7110-cryp.h b/drivers/crypto/starfive/jh7110-cryp.h
index 494a74f52706..eeb4e2b9655f 100644
--- a/drivers/crypto/starfive/jh7110-cryp.h
+++ b/drivers/crypto/starfive/jh7110-cryp.h
@@ -217,12 +217,11 @@  struct starfive_cryp_request_ctx {
 	struct scatterlist			*out_sg;
 	struct ahash_request			ahash_fbk_req;
 	size_t					total;
-	size_t					nents;
 	unsigned int				blksize;
 	unsigned int				digsize;
 	unsigned long				in_sg_len;
 	unsigned char				*adata;
-	u8 rsa_data[] __aligned(sizeof(u32));
+	u8					*rsa_data;
 };
 
 struct starfive_cryp_dev *starfive_cryp_find_dev(struct starfive_cryp_ctx *ctx);
diff --git a/drivers/crypto/starfive/jh7110-rsa.c b/drivers/crypto/starfive/jh7110-rsa.c
index 33093ba4b13a..8e4ea607102a 100644
--- a/drivers/crypto/starfive/jh7110-rsa.c
+++ b/drivers/crypto/starfive/jh7110-rsa.c
@@ -74,14 +74,13 @@  static int starfive_rsa_montgomery_form(struct starfive_cryp_ctx *ctx,
 {
 	struct starfive_cryp_dev *cryp = ctx->cryp;
 	struct starfive_cryp_request_ctx *rctx = ctx->rctx;
-	int count = rctx->total / sizeof(u32) - 1;
+	int count = (ALIGN(rctx->total, sizeof(u32)) >> 2) - 1;
 	int loop;
 	u32 temp;
 	u8 opsize;
 
 	opsize = (bit_len - 1) >> 5;
 	rctx->csr.pka.v = 0;
-
 	writel(rctx->csr.pka.v, cryp->base + STARFIVE_PKA_CACR_OFFSET);
 
 	for (loop = 0; loop <= opsize; loop++)
@@ -117,7 +116,6 @@  static int starfive_rsa_montgomery_form(struct starfive_cryp_ctx *ctx,
 		rctx->csr.pka.cmd = CRYPTO_CMD_AERN;
 		rctx->csr.pka.start = 1;
 		rctx->csr.pka.ie = 1;
-
 		writel(rctx->csr.pka.v, cryp->base + STARFIVE_PKA_CACR_OFFSET);
 
 		if (starfive_pka_wait_done(ctx))
@@ -251,12 +249,17 @@  static int starfive_rsa_enc_core(struct starfive_cryp_ctx *ctx, int enc)
 	struct starfive_cryp_dev *cryp = ctx->cryp;
 	struct starfive_cryp_request_ctx *rctx = ctx->rctx;
 	struct starfive_rsa_key *key = &ctx->rsa_key;
-	int ret = 0;
+	int ret = 0, shift = 0;
 
 	writel(STARFIVE_RSA_RESET, cryp->base + STARFIVE_PKA_CACR_OFFSET);
 
-	rctx->total = sg_copy_to_buffer(rctx->in_sg, rctx->nents,
-					rctx->rsa_data, rctx->total);
+	rctx->rsa_data = kzalloc(key->key_sz, GFP_KERNEL);
+
+	if (!IS_ALIGNED(rctx->total, sizeof(u32)))
+		shift = sizeof(u32) - (rctx->total & 0x3);
+
+	rctx->total = sg_copy_to_buffer(rctx->in_sg, sg_nents(rctx->in_sg),
+					rctx->rsa_data + shift, rctx->total);
 
 	if (enc) {
 		key->bitlen = key->e_bitlen;
@@ -275,6 +278,7 @@  static int starfive_rsa_enc_core(struct starfive_cryp_ctx *ctx, int enc)
 		       rctx->rsa_data, key->key_sz, 0, 0);
 
 err_rsa_crypt:
+	kfree(rctx->rsa_data);
 	writel(STARFIVE_RSA_RESET, cryp->base + STARFIVE_PKA_CACR_OFFSET);
 	return ret;
 }
@@ -305,7 +309,6 @@  static int starfive_rsa_enc(struct akcipher_request *req)
 	rctx->in_sg = req->src;
 	rctx->out_sg = req->dst;
 	rctx->total = req->src_len;
-	rctx->nents = sg_nents(rctx->in_sg);
 	ctx->rctx = rctx;
 
 	return starfive_rsa_enc_core(ctx, 1);