[5/6] crypto: img-hash - Add support for export and import

Commit Message

Will Thomas July 11, 2016, 9:33 a.m. UTC

From: James Hartley <[e-mail]>

Currently the img-hash accelerator does not probe
successfully due to a change in the checks made during
registration with the crypto framework. This is due to
import and export functions not being defined. Correct
this.

Signed-off-by: James Hartley <[e-mail]>
Reviewed-by: Will Thomas <[e-mail]>
---
 drivers/crypto/img-hash.c | 38 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)

Comments

Herbert Xu July 12, 2016, 7:49 a.m. UTC | #1

Will Thomas <[e-mail]> wrote:
>
> @@ -714,9 +740,12 @@ static struct ahash_alg img_algs[] = {
>                .update = img_hash_update,
>                .final = img_hash_final,
>                .finup = img_hash_finup,
> +               .export = img_hash_export,
> +               .import = img_hash_import,
>                .digest = img_hash_digest,
>                .halg = {
>                        .digestsize = MD5_DIGEST_SIZE,
> +                       .statesize = sizeof(struct md5_state),

This is wrong.  The fallback state size is not guaranteed to be
the same as the generic MD5.  I suppose the easiest fix is to
explicitly request for md5-generic/sha1-generic/etc. when you
allocate the fallback.

Thanks,

Will Thomas July 13, 2016, 2:01 p.m. UTC | #2

Hi Herbert,

I don't see any other drivers explicitly requesting a fallback
driver by name. Anyways, should this be done using  "sha1-generic"
in the crypto_alloc_ahash call when setting up the fallback tfm?

Thanks,
Will

On 12/07/16 08:49, Herbert Xu wrote:
> Will Thomas <[e-mail]> wrote:
>>
>> @@ -714,9 +740,12 @@ static struct ahash_alg img_algs[] = {
>>                .update = img_hash_update,
>>                .final = img_hash_final,
>>                .finup = img_hash_finup,
>> +               .export = img_hash_export,
>> +               .import = img_hash_import,
>>                .digest = img_hash_digest,
>>                .halg = {
>>                        .digestsize = MD5_DIGEST_SIZE,
>> +                       .statesize = sizeof(struct md5_state),
> 
> This is wrong.  The fallback state size is not guaranteed to be
> the same as the generic MD5.  I suppose the easiest fix is to
> explicitly request for md5-generic/sha1-generic/etc. when you
> allocate the fallback.
> 
> Thanks,
> 
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Herbert Xu July 18, 2016, 6:13 a.m. UTC | #3

On Wed, Jul 13, 2016 at 03:01:38PM +0100, Will Thomas wrote:
> 
> I don't see any other drivers explicitly requesting a fallback
> driver by name. Anyways, should this be done using  "sha1-generic"

The problem is that you're relying on the fallback to implement
import/export.  So if the fallback changes, then your algorithm
parameters will change which is not allowed.

> in the crypto_alloc_ahash call when setting up the fallback tfm?

Yes that should be sufficient.

Cheers,

Patch

diff --git a/drivers/crypto/img-hash.c b/drivers/crypto/img-hash.c
index ed4408a..c2fdc35 100644
--- a/drivers/crypto/img-hash.c
+++ b/drivers/crypto/img-hash.c
@@ -590,6 +590,32 @@  static int img_hash_finup(struct ahash_request *req)
 	return crypto_ahash_finup(&rctx->fallback_req);
 }
 
+static int img_hash_import(struct ahash_request *req, const void *in)
+{
+	struct img_hash_request_ctx *rctx = ahash_request_ctx(req);
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+	struct img_hash_ctx *ctx = crypto_ahash_ctx(tfm);
+
+	ahash_request_set_tfm(&rctx->fallback_req, ctx->fallback);
+	rctx->fallback_req.base.flags = req->base.flags
+		& CRYPTO_TFM_REQ_MAY_SLEEP;
+
+	return crypto_ahash_import(&rctx->fallback_req, in);
+}
+
+static int img_hash_export(struct ahash_request *req, void *out)
+{
+	struct img_hash_request_ctx *rctx = ahash_request_ctx(req);
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+	struct img_hash_ctx *ctx = crypto_ahash_ctx(tfm);
+
+	ahash_request_set_tfm(&rctx->fallback_req, ctx->fallback);
+	rctx->fallback_req.base.flags = req->base.flags
+		& CRYPTO_TFM_REQ_MAY_SLEEP;
+
+	return crypto_ahash_export(&rctx->fallback_req, out);
+}
+
 static int img_hash_digest(struct ahash_request *req)
 {
 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
@@ -714,9 +740,12 @@  static struct ahash_alg img_algs[] = {
 		.update = img_hash_update,
 		.final = img_hash_final,
 		.finup = img_hash_finup,
+		.export = img_hash_export,
+		.import = img_hash_import,
 		.digest = img_hash_digest,
 		.halg = {
 			.digestsize = MD5_DIGEST_SIZE,
+			.statesize = sizeof(struct md5_state),
 			.base = {
 				.cra_name = "md5",
 				.cra_driver_name = "img-md5",
@@ -737,9 +766,12 @@  static struct ahash_alg img_algs[] = {
 		.update = img_hash_update,
 		.final = img_hash_final,
 		.finup = img_hash_finup,
+		.export = img_hash_export,
+		.import = img_hash_import,
 		.digest = img_hash_digest,
 		.halg = {
 			.digestsize = SHA1_DIGEST_SIZE,
+			.statesize = sizeof(struct sha1_state),
 			.base = {
 				.cra_name = "sha1",
 				.cra_driver_name = "img-sha1",
@@ -760,9 +792,12 @@  static struct ahash_alg img_algs[] = {
 		.update = img_hash_update,
 		.final = img_hash_final,
 		.finup = img_hash_finup,
+		.export = img_hash_export,
+		.import = img_hash_import,
 		.digest = img_hash_digest,
 		.halg = {
 			.digestsize = SHA224_DIGEST_SIZE,
+			.statesize = sizeof(struct sha256_state),
 			.base = {
 				.cra_name = "sha224",
 				.cra_driver_name = "img-sha224",
@@ -783,9 +818,12 @@  static struct ahash_alg img_algs[] = {
 		.update = img_hash_update,
 		.final = img_hash_final,
 		.finup = img_hash_finup,
+		.export = img_hash_export,
+		.import = img_hash_import,
 		.digest = img_hash_digest,
 		.halg = {
 			.digestsize = SHA256_DIGEST_SIZE,
+			.statesize = sizeof(struct sha256_state),
 			.base = {
 				.cra_name = "sha256",
 				.cra_driver_name = "img-sha256",