1LIFE_CYCLE-MAC(7ossl) OpenSSL LIFE_CYCLE-MAC(7ossl)
2
6 life_cycle-mac - The MAC algorithm life-cycle
7
9 All message authentication codes (MACs) go through a number of stages
10 in their life-cycle:
11 start
13 This state represents the MAC before it has been allocated. It is
14 the starting state for any life-cycle transitions.
15 newed
17 This state represents the MAC after it has been allocated.
18 initialised
20 This state represents the MAC when it is set up and capable of
21 processing input.
22 updated
24 This state represents the MAC when it is set up and capable of
25 processing additional input or generating output.
26 finaled
28 This state represents the MAC when it has generated output.
29 freed
31 This state is entered when the MAC is freed. It is the terminal
32 state for all life-cycle transitions.
33 State Transition Diagram
35 The usual life-cycle of a MAC is illustrated:
36 +-------------------+
37 | start |
38 +-------------------+
39 |
40 | EVP_MAC_CTX_new
41 v
42 +-------------------+
43 | newed |
44 +-------------------+
45 |
46 | EVP_MAC_init
47 v
48 +-------------------+
49 +> | initialised | <+
50 | +-------------------+ |
51 | | |
52 | | EVP_MAC_update | EVP_MAC_init
53 | v |
54 EVP_MAC_init | +-------------------+ |
55 | | updated | -+
56 | +-------------------+
57 | | |
58 | | EVP_MAC_final | EVP_MAC_finalXOF
59 | v v
60 | +-------------------+
61 +- | finaled |
62 +-------------------+
63 |
64 | EVP_MAC_CTX_free
65 v
66 +-------------------+
67 | freed |
68 +-------------------+
69 Formal State Transitions
71 This section defines all of the legal state transitions. This is the
72 canonical list.
73 Function Call --------------------- Current State
74 ----------------------
75 start newed initialised updated
76 finaled freed
77 EVP_MAC_CTX_new newed
78 EVP_MAC_init initialised initialised
79 initialised initialised
80 EVP_MAC_update updated updated
81 EVP_MAC_final finaled
82 EVP_MAC_finalXOF finaled
83 EVP_MAC_CTX_free freed freed freed freed
84 freed
85 EVP_MAC_CTX_get_params newed initialised updated
86 EVP_MAC_CTX_set_params newed initialised updated
87 EVP_MAC_CTX_gettable_params newed initialised updated
88 EVP_MAC_CTX_settable_params newed initialised updated
89
91 At some point the EVP layer will begin enforcing the transitions
92 described herein.
93
95 provider-mac(7), EVP_MAC(3).
96
98 The provider MAC interface was introduced in OpenSSL 3.0.
99
101 Copyright 2021 The OpenSSL Project Authors. All Rights Reserved.
102 Licensed under the Apache License 2.0 (the "License"). You may not use
104 this file except in compliance with the License. You can obtain a copy
105 in the file LICENSE in the source distribution or at
106 <https://www.openssl.org/source/license.html>.
1073.0.5 2022-11-01 LIFE_CYCLE-MAC(7ossl)