life_cycle-kdf - The KDF algorithm life-cycle
All key derivation functions (KDFs) and pseudo random functions (PRFs) go through a number of stages in their life-cycle:
This state represents the KDF/PRF before it has been allocated. It is the starting state for any life-cycle transitions.
This state represents the KDF/PRF after it has been allocated.
This state represents the KDF/PRF when it is set up and capable of generating output.
This state is entered when the KDF/PRF is freed. It is the terminal state for all life-cycle transitions.
The usual life-cycle of a KDF/PRF is illustrated:
This section defines all of the legal state transitions. This is the canonical list.
| Function Call | Current State | |||
|---|---|---|---|---|
| start | newed | deriving | freed | |
| EVP_KDF_CTX_new | newed | |||
| EVP_KDF_derive | deriving | deriving | ||
| EVP_KDF_CTX_free | freed | freed | freed | |
| EVP_KDF_CTX_reset | newed | newed | ||
| EVP_KDF_CTX_get_params | newed | deriving | ||
| EVP_KDF_CTX_set_params | newed | deriving | ||
| EVP_KDF_CTX_gettable_params | newed | deriving | ||
| EVP_KDF_CTX_settable_params | newed | deriving | ||
At some point the EVP layer will begin enforcing the transitions described herein.
The provider KDF interface was introduced in OpenSSL 3.0.
Copyright 2021 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the Apache License 2.0 (the "License"). You may not use this file except in compliance with the License. You can obtain a copy in the file LICENSE in the source distribution or at https://www.openssl.org/source/license.html.