2017-08-17 10:27:12

by Kamil Konieczny

[permalink] [raw]
Subject: [PATCH] crypto: doc - clarify return values for async hash methods

>From af1b10e1e6aaf67f8dc45ed78de89b0469794a98 Mon Sep 17 00:00:00 2001
From: Kamil Konieczny <[email protected]>
Date: Thu, 17 Aug 2017 12:11:36 +0200
Subject: [PATCH] crypto: doc - clarify return values for async hash methods

* fix documentation of return values for crypto_ahash_init(),
crypto_ahash_finup(), crypto_ahash_final(),
crypto_ahash_digest() and crypto_ahash_update()

Also while at it:

* add notes for device driver developers in struct ahash_alg
description

* fix description of @final method in struct ahash_alg

* fix typo in crypto_ahash_finup() description

Signed-off-by: Kamil Konieczny <[email protected]>
---
include/crypto/hash.h | 28 ++++++++++++++++------------
1 file changed, 16 insertions(+), 12 deletions(-)

diff --git a/include/crypto/hash.h b/include/crypto/hash.h
index b5727bcd2336..0ed31fd80242 100644
--- a/include/crypto/hash.h
+++ b/include/crypto/hash.h
@@ -75,6 +75,7 @@ struct ahash_request {
* state of the HASH transformation at the beginning. This shall fill in
* the internal structures used during the entire duration of the whole
* transformation. No data processing happens at this point.
+ * Note: mandatory.
* @update: Push a chunk of data into the driver for transformation. This
* function actually pushes blocks of data from upper layers into the
* driver, which then passes those to the hardware as seen fit. This
@@ -84,16 +85,20 @@ struct ahash_request {
* context, as this function may be called in parallel with the same
* transformation object. Data processing can happen synchronously
* [SHASH] or asynchronously [AHASH] at this point.
+ * Note: mandatory.
* @final: Retrieve result from the driver. This function finalizes the
* transformation and retrieves the resulting hash from the driver and
* pushes it back to upper layers. No data processing happens at this
- * point.
+ * point unless hardware requires it to finish the transformation
+ * (then the data buffered by the device driver is processed).
+ * Note: mandatory.
* @finup: Combination of @update and @final. This function is effectively a
* combination of @update and @final calls issued in sequence. As some
* hardware cannot do @update and @final separately, this callback was
* added to allow such hardware to be used at least by IPsec. Data
* processing can happen synchronously [SHASH] or asynchronously [AHASH]
* at this point.
+ * Note: optional.
* @digest: Combination of @init and @update and @final. This function
* effectively behaves as the entire chain of operations, @init,
* @update and @final issued in sequence. Just like @finup, this was
@@ -416,11 +421,10 @@ static inline bool crypto_ahash_has_setkey(struct crypto_ahash *tfm)
* needed to perform the cipher operation
*
* This function is a "short-hand" for the function calls of
- * crypto_ahash_update and crypto_shash_final. The parameters have the same
+ * crypto_ahash_update and crypto_ahash_final. The parameters have the same
* meaning as discussed for those separate functions.
*
- * Return: 0 if the message digest creation was successful; < 0 if an error
- * occurred
+ * Return: see crypto_ahash_final()
*/
int crypto_ahash_finup(struct ahash_request *req);

@@ -433,8 +437,11 @@ int crypto_ahash_finup(struct ahash_request *req);
* based on all data added to the cipher handle. The message digest is placed
* into the output buffer registered with the ahash_request handle.
*
- * Return: 0 if the message digest creation was successful; < 0 if an error
- * occurred
+ * Return:
+ * 0 if the message digest was successfully calculated;
+ * -EINPROGRESS if data is feeded into hardware (DMA) or queued for later;
+ * -EBUSY if queue is full and request should be resubmitted later;
+ * other < 0 if an error occurred
*/
int crypto_ahash_final(struct ahash_request *req);

@@ -447,8 +454,7 @@ int crypto_ahash_final(struct ahash_request *req);
* crypto_ahash_update and crypto_ahash_final. The parameters have the same
* meaning as discussed for those separate three functions.
*
- * Return: 0 if the message digest creation was successful; < 0 if an error
- * occurred
+ * Return: see crypto_ahash_final()
*/
int crypto_ahash_digest(struct ahash_request *req);

@@ -493,8 +499,7 @@ static inline int crypto_ahash_import(struct ahash_request *req, const void *in)
* handle. Any potentially existing state created by previous operations is
* discarded.
*
- * Return: 0 if the message digest initialization was successful; < 0 if an
- * error occurred
+ * Return: see crypto_ahash_final()
*/
static inline int crypto_ahash_init(struct ahash_request *req)
{
@@ -510,8 +515,7 @@ static inline int crypto_ahash_init(struct ahash_request *req)
* is pointed to by the scatter/gather list registered in the &ahash_request
* handle
*
- * Return: 0 if the message digest update was successful; < 0 if an error
- * occurred
+ * Return: see crypto_ahash_final()
*/
static inline int crypto_ahash_update(struct ahash_request *req)
{
--
2.7.4


2017-09-22 10:13:07

by Herbert Xu

[permalink] [raw]
Subject: Re: [PATCH] crypto: doc - clarify return values for async hash methods

On Thu, Aug 17, 2017 at 12:27:12PM +0200, Kamil Konieczny wrote:
> >From af1b10e1e6aaf67f8dc45ed78de89b0469794a98 Mon Sep 17 00:00:00 2001
> From: Kamil Konieczny <[email protected]>
> Date: Thu, 17 Aug 2017 12:11:36 +0200
> Subject: [PATCH] crypto: doc - clarify return values for async hash methods
>
> * fix documentation of return values for crypto_ahash_init(),
> crypto_ahash_finup(), crypto_ahash_final(),
> crypto_ahash_digest() and crypto_ahash_update()
>
> Also while at it:
>
> * add notes for device driver developers in struct ahash_alg
> description
>
> * fix description of @final method in struct ahash_alg
>
> * fix typo in crypto_ahash_finup() description
>
> Signed-off-by: Kamil Konieczny <[email protected]>

Patch applied. Thanks.
--
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt