1LIFE_CYCLE-KDF(7ossl)               OpenSSL              LIFE_CYCLE-KDF(7ossl)
2
3
4

NAME

6       life_cycle-kdf - The KDF algorithm life-cycle
7

DESCRIPTION

9       All key derivation functions (KDFs) and pseudo random functions (PRFs)
10       go through a number of stages in their life-cycle:
11
12       start
13           This state represents the KDF/PRF before it has been allocated.  It
14           is the starting state for any life-cycle transitions.
15
16       newed
17           This state represents the KDF/PRF after it has been allocated.
18
19       deriving
20           This state represents the KDF/PRF when it is set up and capable of
21           generating output.
22
23       freed
24           This state is entered when the KDF/PRF is freed.  It is the
25           terminal state for all life-cycle transitions.
26
27   State Transition Diagram
28       The usual life-cycle of a KDF/PRF is illustrated:
29                            +-------------------+
30                            |       start       |
31                            +-------------------+
32                              |
33                              | EVP_KDF_CTX_new
34                              v
35                            +-------------------+
36                            |       newed       | <+
37                            +-------------------+  |
38                              |                    |
39                              | EVP_KDF_derive     |
40                              v                    | EVP_KDF_CTX_reset
41           EVP_KDF_derive   +-------------------+  |
42         + - - - - - - - -  |                   |  |
43         '                  |     deriving      |  |
44         + - - - - - - - -> |                   | -+
45                            +-------------------+
46                              |
47                              | EVP_KDF_CTX_free
48                              v
49                            +-------------------+
50                            |       freed       |
51                            +-------------------+
52
53   Formal State Transitions
54       This section defines all of the legal state transitions.  This is the
55       canonical list.
56        Function Call                   ------------- Current State
57       -------------
58                                        start       newed       deriving
59       freed
60        EVP_KDF_CTX_new                 newed
61        EVP_KDF_derive                             deriving     deriving
62        EVP_KDF_CTX_free                freed       freed        freed
63        EVP_KDF_CTX_reset                           newed        newed
64        EVP_KDF_CTX_get_params                      newed       deriving
65        EVP_KDF_CTX_set_params                      newed       deriving
66        EVP_KDF_CTX_gettable_params                 newed       deriving
67        EVP_KDF_CTX_settable_params                 newed       deriving
68

NOTES

70       At some point the EVP layer will begin enforcing the transitions
71       described herein.
72

SEE ALSO

74       provider-kdf(7), EVP_KDF(3).
75

HISTORY

77       The provider KDF interface was introduced in OpenSSL 3.0.
78

80       Copyright 2021 The OpenSSL Project Authors. All Rights Reserved.
81
82       Licensed under the Apache License 2.0 (the "License").  You may not use
83       this file except in compliance with the License.  You can obtain a copy
84       in the file LICENSE in the source distribution or at
85       <https://www.openssl.org/source/license.html>.
86
87
88
893.0.5                             2022-07-05             LIFE_CYCLE-KDF(7ossl)
Impressum