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 | newed | deriving | ||
| EVP_KDF_CTX_free | newed | deriving | ||
| EVP_KDF_CTX_reset | freed | freed | freed | |
| 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.
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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.