--- name: "life_cycle-pkey" 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-pkey" --- # life\_cycle-pkey(7ssl) The PKEY algorithm life-cycle ## NAME life\_cycle-pkey - The PKEY algorithm life-cycle ## DESCRIPTION All public keys (PKEYs) go through a number of stages in their life-cycle: - start This state represents the PKEY before it has been allocated. It is the starting state for any life-cycle transitions. - newed This state represents the PKEY after it has been allocated. - decapsulate This state represents the PKEY when it is ready to perform a private key decapsulation operation. - decrypt This state represents the PKEY when it is ready to decrypt some ciphertext. - derive This state represents the PKEY when it is ready to derive a shared secret. - digest sign This state represents the PKEY when it is ready to perform a private key signature operation. - encapsulate This state represents the PKEY when it is ready to perform a public key encapsulation operation. - encrypt This state represents the PKEY when it is ready to encrypt some plaintext. - key generation This state represents the PKEY when it is ready to generate a new public/private key. - parameter generation This state represents the PKEY when it is ready to generate key parameters. - verify This state represents the PKEY when it is ready to verify a public key signature. - verify recover This state represents the PKEY when it is ready to recover a public key signature data. - freed This state is entered when the PKEY is freed. It is the terminal state for all life-cycle transitions. ### State Transition Diagram The usual life-cycle of a PKEY object is illustrated:\ \+-------------+\ \| \|\ \| start \|\ \| \|\ EVP\_PKEY\_derive +-------------+\ \+-------------+ EVP\_PKEY\_derive\_set\_peer \| +-------------+\ \| \|----------------------------+ \| +----------------------------\| \|\ \| derive \| \| \| \| EVP\_PKEY\_verify \| verify \|\ \| \|\<---------------------------+ \| +---------------------------\>\| \|\ \+-------------+ \| +-------------+\ ^ \| ^\ \| EVP\_PKEY\_derive\_init \| EVP\_PKEY\_verify\_init \|\ \+---------------------------------------+ \| +---------------------------------------+\ \| \| \|\ \+-------------+ \| \| \| +-------------+\ \| \|----------------------------+ \| \| \| +----------------------------\| \|\ \| digest sign \| EVP\_PKEY\_sign \| \| \| \| \| EVP\_PKEY\_verify\_recover \| verify \|\ \| \|\<---------------------------+ \| \| \| +---------------------------\>\| recover \|\ \+-------------+ \| \| \| +-------------+\ ^ \| \| \| ^\ \| EVP\_PKEY\_sign\_init \| \| \| EVP\_PKEY\_verify\_recover\_init \|\ \+---------------------------------+ \| \| \| +---------------------------------+\ \| \| \| \| \|\ \+-------------+ \| \| \| \| \| +-------------+\ \| \|----------------------------+ \| \| \| \| \| +----------------------------\| \|\ \| decapsulate \| EVP\_PKEY\_decapsulate \| \| \| \| \| \| \| EVP\_PKEY\_decrypt \| decrypt \|\ \| \|\<---------------------------+ \| \| v \| \| +---------------------------\>\| \|\ \+-------------+ \| +-------------+ \| +-------------+\ ^ +---\| \|---+ ^\ \| EVP\_PKEY\_decapsulate\_init \| \| EVP\_PKEY\_decrypt\_init \|\ \+-------------------------------------\| newed \|-------------------------------------+\ \| \|\ \+---\| \|---+\ \+-------------+ \| +-------------+ \| +-------------+\ \| \|----------------------------+ \| \| \| \| +----------------------------\| \|\ \| encapsulate \| EVP\_PKEY\_encapsulate \| \| \| \| \| \| EVP\_PKEY\_encrypt \| encrypt \|\ \| \|\<---------------------------+ \| \| \| \| +---------------------------\>\| \|\ \+-------------+ \| \| \| \| +-------------+\ ^ \| \| \| \| ^\ \| EVP\_PKEY\_encapsulate\_init \| \| \| \| EVP\_PKEY\_encrypt\_init \|\ \+---------------------------------+ \| \| +---------------------------------+\ \| \|\ \+---------------------------------------+ +---------------------------------------+\ \| EVP\_PKEY\_paramgen\_init EVP\_PKEY\_keygen\_init \|\ v v\ \+-------------+ +-------------+\ \| \|----------------------------+ +----------------------------\| \|\ \| parameter \| \| \| \| key \|\ \| generation \|\<---------------------------+ +---------------------------\>\| generation \|\ \+-------------+ EVP\_PKEY\_paramgen EVP\_PKEY\_keygen +-------------+\ EVP\_PKEY\_gen EVP\_PKEY\_gen \+ - - - - - + +-----------+\ ' ' EVP\_PKEY\_CTX\_free \| \|\ ' any state '-------------------\>\| freed \|\ ' ' \| \|\ \+ - - - - - + +-----------+ ### Formal State Transitions This section defines all of the legal state transitions. This is the canonical list.\ Function Call ---------------------------------------------------------------------- Current State ----------------------------------------------------------------------\ start newed digest verify verify encrypt decrypt derive encapsulate decapsulate parameter key freed\ sign recover generation generation\ EVP\_PKEY\_CTX\_new newed\ EVP\_PKEY\_CTX\_new\_id newed\ EVP\_PKEY\_CTX\_new\_from\_name newed\ EVP\_PKEY\_CTX\_new\_from\_pkey newed\ EVP\_PKEY\_sign\_init digest digest digest digest digest digest digest digest digest digest digest\ sign sign sign sign sign sign sign sign sign sign sign\ EVP\_PKEY\_sign digest\ sign\ EVP\_PKEY\_verify\_init verify verify verify verify verify verify verify verify verify verify verify\ EVP\_PKEY\_verify verify\ EVP\_PKEY\_verify\_recover\_init verify verify verify verify verify verify verify verify verify verify verify\ recover recover recover recover recover recover recover recover recover recover recover\ EVP\_PKEY\_verify\_recover verify\ recover\ EVP\_PKEY\_encrypt\_init encrypt encrypt encrypt encrypt encrypt encrypt encrypt encrypt encrypt encrypt encrypt\ EVP\_PKEY\_encrypt encrypt\ EVP\_PKEY\_decrypt\_init decrypt decrypt decrypt decrypt decrypt decrypt decrypt decrypt decrypt decrypt decrypt\ EVP\_PKEY\_decrypt decrypt\ EVP\_PKEY\_derive\_init derive derive derive derive derive derive derive derive derive derive derive\ EVP\_PKEY\_derive\_set\_peer derive\ EVP\_PKEY\_derive derive\ EVP\_PKEY\_encapsulate\_init encapsulate encapsulate encapsulate encapsulate encapsulate encapsulate encapsulate encapsulate encapsulate encapsulate encapsulate\ EVP\_PKEY\_encapsulate encapsulate\ EVP\_PKEY\_decapsulate\_init decapsulate decapsulate decapsulate decapsulate decapsulate decapsulate decapsulate decapsulate decapsulate decapsulate decapsulate\ EVP\_PKEY\_decapsulate decapsulate\ EVP\_PKEY\_paramgen\_init parameter parameter parameter parameter parameter parameter parameter parameter parameter parameter parameter\ generation generation generation generation generation generation generation generation generation generation generation\ EVP\_PKEY\_paramgen parameter\ generation\ EVP\_PKEY\_keygen\_init key key key key key key key key key key key\ generation generation generation generation generation generation generation generation generation generation generation\ EVP\_PKEY\_keygen key\ generation\ EVP\_PKEY\_gen parameter key\ generation generation\ EVP\_PKEY\_CTX\_get\_params newed digest verify verify encrypt decrypt derive encapsulate decapsulate parameter key\ sign recover generation generation\ EVP\_PKEY\_CTX\_set\_params newed digest verify verify encrypt decrypt derive encapsulate decapsulate parameter key\ sign recover generation generation\ EVP\_PKEY\_CTX\_gettable\_params newed digest verify verify encrypt decrypt derive encapsulate decapsulate parameter key\ sign recover generation generation\ EVP\_PKEY\_CTX\_settable\_params newed digest verify verify encrypt decrypt derive encapsulate decapsulate parameter key\ sign recover generation generation\ EVP\_PKEY\_CTX\_free freed freed freed freed freed freed freed freed freed freed freed freed ## NOTES At some point the EVP layer will begin enforcing the transitions described herein. ## SEE ALSO **EVP\_PKEY\_new**(3), **EVP\_PKEY\_decapsulate**(3), **EVP\_PKEY\_decrypt**(3), **EVP\_PKEY\_encapsulate**(3), **EVP\_PKEY\_encrypt**(3), **EVP\_PKEY\_derive**(3), **EVP\_PKEY\_keygen**(3), **EVP\_PKEY\_sign**(3), **EVP\_PKEY\_verify**(3), **EVP\_PKEY\_verify\_recover**(3) ## HISTORY The provider PKEY interface was introduced in OpenSSL 3.0. ## COPYRIGHT Copyright 2021-2022 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 \.