Re: [PATCH] crypto: hash.h: Prevent use of req->digest in ahash update

[Kamil Konieczny]

On 06.03.2018 19:04, Tom Lendacky wrote:
> On 3/6/2018 5:45 AM, Kamil Konieczny wrote:
>> Prevent improper use of req->digest field in ahash update, init, export and
> 
> Shouldn't that be req->result (here and below)?

Yes, it should, I will send version 2 soon,
thank you.

Best regards,
Kamil Konieczny

>> import functions in drivers code. A driver should use ahash request context
>> if it needs to save internal state.
>>
>> Signed-off-by: Kamil Konieczny 
>> ---
>>  include/crypto/hash.h | 11 +++
>>  1 file changed, 7 insertions(+), 4 deletions(-)
>>
>> diff --git a/include/crypto/hash.h b/include/crypto/hash.h
>> index 2d1849dffb80..e97c2e662d6a 100644
>> --- a/include/crypto/hash.h
>> +++ b/include/crypto/hash.h
>> @@ -74,7 +74,8 @@ struct ahash_request {
>>   * @init: **[mandatory]** Initialize the transformation context. Intended 
>> only to initialize the
>>   *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.
>> + *transformation. No data processing happens at this point. Driver code
>> + *implementation must not use req->digest.
>>   * @update: **[mandatory]** 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
>> @@ -83,7 +84,8 @@ struct ahash_request {
>>   * transformation. This function shall not modify the transformation
>>   * 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.
>> + * [SHASH] or asynchronously [AHASH] at this point. Driver must not use
>> + * req->digest.
>>   * @final: **[mandatory]** 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
>> @@ -120,11 +122,12 @@ struct ahash_request {
>>   *  you want to save partial result of the transformation after
>>   *  processing certain amount of data and reload this partial result
>>   *  multiple times later on for multiple re-use. No data processing
>> - *  happens at this point.
>> + *  happens at this point. Driver must not use req->digest.
>>   * @import: Import partial state of the transformation. This function loads 
>> the
>>   *  entire state of the ongoing transformation from a provided block of
>>   *  data so the transformation can continue from this point onward. No
>> - *  data processing happens at this point.
>> + *  data processing happens at this point. Driver must not use
>> + *  req->digest.
>>   * @halg: see struct hash_alg_common
>>   */
>>  struct ahash_alg {
>>
> 
> 
> 

Re: [PATCH] crypto: hash.h: Prevent use of req->digest in ahash update

[Tom Lendacky]

On 3/6/2018 5:45 AM, Kamil Konieczny wrote:
> Prevent improper use of req->digest field in ahash update, init, export and

Shouldn't that be req->result (here and below)?

Thanks,
Tom

> import functions in drivers code. A driver should use ahash request context
> if it needs to save internal state.
> 
> Signed-off-by: Kamil Konieczny 
> ---
>  include/crypto/hash.h | 11 +++
>  1 file changed, 7 insertions(+), 4 deletions(-)
> 
> diff --git a/include/crypto/hash.h b/include/crypto/hash.h
> index 2d1849dffb80..e97c2e662d6a 100644
> --- a/include/crypto/hash.h
> +++ b/include/crypto/hash.h
> @@ -74,7 +74,8 @@ struct ahash_request {
>   * @init: **[mandatory]** Initialize the transformation context. Intended 
> only to initialize the
>   * 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.
> + * transformation. No data processing happens at this point. Driver code
> + * implementation must not use req->digest.
>   * @update: **[mandatory]** 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
> @@ -83,7 +84,8 @@ struct ahash_request {
>   *  transformation. This function shall not modify the transformation
>   *  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.
> + *  [SHASH] or asynchronously [AHASH] at this point. Driver must not use
> + *  req->digest.
>   * @final: **[mandatory]** 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
> @@ -120,11 +122,12 @@ struct ahash_request {
>   *   you want to save partial result of the transformation after
>   *   processing certain amount of data and reload this partial result
>   *   multiple times later on for multiple re-use. No data processing
> - *   happens at this point.
> + *   happens at this point. Driver must not use req->digest.
>   * @import: Import partial state of the transformation. This function loads 
> the
>   *   entire state of the ongoing transformation from a provided block of
>   *   data so the transformation can continue from this point onward. No
> - *   data processing happens at this point.
> + *   data processing happens at this point. Driver must not use
> + *   req->digest.
>   * @halg: see struct hash_alg_common
>   */
>  struct ahash_alg {
>