Crypto Engine¶
Overview¶
The crypto engine (CE) API is a crypto queue manager.
Requirement¶
You must put, at the start of your transform context your_tfm_ctx, the structure crypto_engine:
struct your_tfm_ctx {
struct crypto_engine engine;
...
};
The crypto engine only manages asynchronous requests in the form of
crypto_async_request. It cannot know the underlying request type and thus only
has access to the transform structure. It is not possible to access the context
using container_of. In addition, the engine knows nothing about your
structure "struct your_tfm_ctx
". The engine assumes (requires) the placement
of the known member struct crypto_engine
at the beginning.
Order of operations¶
You are required to obtain a struct crypto_engine via crypto_engine_alloc_init()
.
Start it via crypto_engine_start()
. When finished with your work, shut down the
engine using crypto_engine_stop()
and destroy the engine with
crypto_engine_exit()
.
Before transferring any request, you have to fill the context enginectx by providing functions for the following:
prepare_crypt_hardware
: Called once before any prepare functions are called.unprepare_crypt_hardware
: Called once after all unprepare functions have been called.prepare_cipher_request
/prepare_hash_request
: Called before each corresponding request is performed. If some processing or other preparatory work is required, do it here.unprepare_cipher_request
/unprepare_hash_request
: Called after each request is handled. Clean up / undo what was done in the prepare function.cipher_one_request
/hash_one_request
: Handle the current request by performing the operation.
Note that these functions access the crypto_async_request structure associated with the received request. You are able to retrieve the original request by using:
container_of(areq, struct yourrequesttype_request, base);
When your driver receives a crypto_request, you must to transfer it to the crypto engine via one of:
- crypto_transfer_ablkcipher_request_to_engine()
- crypto_transfer_aead_request_to_engine()
- crypto_transfer_akcipher_request_to_engine()
- crypto_transfer_hash_request_to_engine()
- crypto_transfer_skcipher_request_to_engine()
At the end of the request process, a call to one of the following functions is needed:
- crypto_finalize_ablkcipher_request()
- crypto_finalize_aead_request()
- crypto_finalize_akcipher_request()
- crypto_finalize_hash_request()
- crypto_finalize_skcipher_request()