diff options
Diffstat (limited to 'Documentation/crypto')
| -rw-r--r-- | Documentation/crypto/crypto_engine.rst | 48 | ||||
| -rw-r--r-- | Documentation/crypto/devel-algos.rst | 8 |
2 files changed, 56 insertions, 0 deletions
diff --git a/Documentation/crypto/crypto_engine.rst b/Documentation/crypto/crypto_engine.rst new file mode 100644 index 000000000000..8272ac92a14f --- /dev/null +++ b/Documentation/crypto/crypto_engine.rst @@ -0,0 +1,48 @@ +============= +CRYPTO ENGINE +============= + +Overview +-------- +The crypto engine API (CE), is a crypto queue manager. + +Requirement +----------- +You have to put at start of your tfm_ctx the struct crypto_engine_ctx +struct your_tfm_ctx { + struct crypto_engine_ctx enginectx; + ... +}; +Why: Since CE manage only crypto_async_request, it cannot know the underlying +request_type and so have access only on the TFM. +So using container_of for accessing __ctx is impossible. +Furthermore, the crypto engine cannot know the "struct your_tfm_ctx", +so it must assume that crypto_engine_ctx is at start of it. + +Order of operations +------------------- +You have to obtain a struct crypto_engine via crypto_engine_alloc_init(). +And start it via crypto_engine_start(). + +Before transferring any request, you have to fill the enginectx. +- prepare_request: (taking a function pointer) If you need to do some processing before doing the request +- unprepare_request: (taking a function pointer) Undoing what's done in prepare_request +- do_one_request: (taking a function pointer) Do encryption for current request + +Note: that those three functions get the crypto_async_request associated with the received request. +So your need to get the original request via container_of(areq, struct yourrequesttype_request, base); + +When your driver receive a crypto_request, you have to transfer it to +the cryptoengine 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 function is needed: +- crypto_finalize_ablkcipher_request +- crypto_finalize_aead_request +- crypto_finalize_akcipher_request +- crypto_finalize_hash_request +- crypto_finalize_skcipher_request diff --git a/Documentation/crypto/devel-algos.rst b/Documentation/crypto/devel-algos.rst index 66f50d32dcec..c45c6f400dbd 100644 --- a/Documentation/crypto/devel-algos.rst +++ b/Documentation/crypto/devel-algos.rst @@ -236,6 +236,14 @@ when used from another part of the kernel. | '---------------> HASH2 +Note that it is perfectly legal to "abandon" a request object: +- call .init() and then (as many times) .update() +- _not_ call any of .final(), .finup() or .export() at any point in future + +In other words implementations should mind the resource allocation and clean-up. +No resources related to request objects should remain allocated after a call +to .init() or .update(), since there might be no chance to free them. + Specifics Of Asynchronous HASH Transformation ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |