NAME

life_cycle-cipher - The cipher algorithm life-cycle

DESCRIPTION

All symmetric ciphers (CIPHERs) go through a number of stages in their life-cycle:

start

This state represents the CIPHER before it has been allocated. It is the starting state for any life-cycle transitions.

newed

This state represents the CIPHER after it has been allocated.

initialised

These states represent the CIPHER when it is set up and capable of processing input. There are three possible initialised states:

initialised using EVP_CipherInit

initialised for decryption using EVP_DecryptInit

initialised for encryption using EVP_EncryptInit

updated

These states represent the CIPHER when it is set up and capable of processing additional input or generating output. The three possible states directly correspond to those for initialised above. The three different streams should not be mixed.

finaled

This state represents the CIPHER when it has generated output.

freed

This state is entered when the CIPHER is freed. It is the terminal state for all life-cycle transitions.

State Transition Diagram

The usual life-cycle of a CIPHER is illustrated:

Formal State Transitions

This section defines all of the legal state transitions. This is the canonical list.

NOTES

At some point the EVP layer will begin enforcing the transitions described herein.

SEE ALSO

provider-cipher(7), EVP_EncryptInit(3)

COPYRIGHT

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.