---
name: "life_cycle-cipher"
section: "7ssl"
platform: "linux"
package: "openssl"
version: "3.6.5-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/life_cycle-cipher"
---

# life\_cycle-cipher(7ssl)

The cipher algorithm life-cycle

## 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:\
                                  \+---------------------------+\
                                  \|                           \|\
                                  \|           start           \|\
                                  \|                           \|\
                                  \+---------------------------+   + - - - - - - - - - - - - - +\
                                        \|                         '  any of the initialised   '\
                                        \| EVP\_CIPHER\_CTX\_new      ' updated or finaled states '\
                                        v                         '                           '\
                                  \+---------------------------+   + - - - - - - - - - - - - - +\
                                  \|                           \|      \|\
                                  \|           newed           \|      \| EVP\_CIPHER\_CTX\_reset\
                                  \|                           \| \<----+\
                                  \+---------------------------+\
                                     \|   \|                 \|\
                           \+---------+   \|                 +---------+\
           EVP\_DecryptInit \|             \| EVP\_CipherInit            \| EVP\_EncryptInit\
                           v             v                           v\
  \+---------------------------+   +---------------------------+   +---------------------------+\
  \|                           \|   \|                           \|   \|                           \|\
  \|        initialised        \|   \|        initialised        \|   \|        initialised        \|\
  \|       for decryption      \|   \|                           \|   \|       for encryption      \|\
  \+---------------------------+   +---------------------------+   +---------------------------+\
    \|                                   \|                                                   \|\
    \| EVP\_DecryptUpdate                 \| EVP\_CipherUpdate                EVP\_EncryptUpdate \|\
    \|                                   v                                                   \|\
    \|                             +---------------------------+                             \|\
    \|                             \|                           \|--------------------+        \|\
    \|                             \|          updated          \|   EVP\_CipherUpdate \|        \|\
    \|                             \|                           \| \<------------------+        \|\
    v                             +---------------------------+                             v\
  \+---------------------------+                         \|         +---------------------------+\
  \|                           \|---------------------+   \|         \|                           \|\
  \|          updated          \|   EVP\_DecryptUpdate \|   \|         \|          updated          \|------+\
  \|       for decryption      \| \<-------------------+   \|         \|       for encryption      \|      \|\
  \+---------------------------+                         \|         +---------------------------+      \|\
                           \|            EVP\_CipherFinal \|            \|           ^                   \|\
                           \+-------+                    \|   +--------+           \|                   \|\
                  EVP\_DecryptFinal \|                    \|   \| EVP\_EncryptFinal   +-------------------+\
                                   v                    v   v                      EVP\_EncryptUpdate\
                                  \+---------------------------+\
                                  \|                           \|-----------------------------+\
                                  \|          finaled          \|                             \|\
                                  \|                           \| \<---------------------------+\
                                  \+---------------------------+   EVP\_CIPHER\_CTX\_get\_params\
                                        \|                             (AEAD encryption)\
                                        \| EVP\_CIPHER\_CTX\_free\
                                        v\
                                  \+---------------------------+\
                                  \|                           \|\
                                  \|           freed           \|\
                                  \|                           \|\
                                  \+---------------------------+

### Formal State Transitions

This section defines all of the legal state transitions. This is the canonical list.\
  Function Call                ---------------------------------------------- Current State -----------------------------------------------\
                               start   newed    initialised   updated     finaled   initialised   updated    initialised   updated    freed\
                                                                                     decryption  decryption   encryption  encryption\
  EVP\_CIPHER\_CTX\_new           newed\
  EVP\_CipherInit                    initialised initialised initialised initialised initialised initialised  initialised initialised\
  EVP\_DecryptInit                   initialised initialised initialised initialised initialised initialised  initialised initialised\
                                     decryption  decryption  decryption  decryption  decryption  decryption  decryption  decryption\
  EVP\_EncryptInit                   initialised initialised initialised initialised initialised initialised  initialised initialised\
                                     encryption  encryption  encryption  encryption  encryption  encryption  encryption  encryption\
  EVP\_CipherUpdate                                updated     updated\
  EVP\_DecryptUpdate                                                                   updated     updated\
                                                                                     decryption  decryption\
  EVP\_EncryptUpdate                                                                                            updated     updated\
                                                                                                              encryption  encryption\
  EVP\_CipherFinal                                             finaled\
  EVP\_DecryptFinal                                                                                finaled\
  EVP\_EncryptFinal                                                                                                         finaled\
  EVP\_CIPHER\_CTX\_free          freed   freed       freed       freed       freed       freed       freed        freed       freed\
  EVP\_CIPHER\_CTX\_reset                 newed       newed       newed       newed       newed       newed        newed       newed\
  EVP\_CIPHER\_CTX\_get\_params            newed    initialised   updated               initialised   updated    initialised   updated\
                                                                                     decryption  decryption   encryption  encryption\
  EVP\_CIPHER\_CTX\_set\_params            newed    initialised   updated               initialised   updated    initialised   updated\
                                                                                     decryption  decryption   encryption  encryption\
  EVP\_CIPHER\_CTX\_gettable\_params       newed    initialised   updated               initialised   updated    initialised   updated\
                                                                                     decryption  decryption   encryption  encryption\
  EVP\_CIPHER\_CTX\_settable\_params       newed    initialised   updated               initialised   updated    initialised   updated\
                                                                                     decryption  decryption   encryption  encryption

## 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\>.