doc/man7/life_cycle-mac.pod

   1 =pod
   2
   3 =head1 NAME
   4
   5 life_cycle-mac - The MAC algorithm life-cycle
   6
   7 =head1 DESCRIPTION
   8
   9 All message authentication codes (MACs)
  10 go through a number of stages in their life-cycle:
  11
  12 =over 4
  13
  14 =item start
  15
  16 This state represents the MAC before it has been allocated.  It is the
  17 starting state for any life-cycle transitions.
  18
  19 =item newed
  20
  21 This state represents the MAC after it has been allocated.
  22
  23 =item initialised
  24
  25 This state represents the MAC when it is set up and capable of processing
  26 input.
  27
  28 =item updated
  29
  30 This state represents the MAC when it is set up and capable of processing
  31 additional input or generating output.
  32
  33 =item finaled
  34
  35 This state represents the MAC when it has generated output.
  36
  37 =item freed
  38
  39 This state is entered when the MAC is freed.  It is the terminal state
  40 for all life-cycle transitions.
  41
  42 =back
  43
  44 =head2 State Transition Diagram
  45
  46 The usual life-cycle of a MAC is illustrated:
  47
  48 =begin man
  49
  50                  +-------------------+
  51                  |       start       |
  52                  +-------------------+
  53                    |
  54                    | EVP_MAC_CTX_new
  55                    v
  56                  +-------------------+
  57                  |       newed       |
  58                  +-------------------+
  59                    |
  60                    | EVP_MAC_init
  61                    v
  62                  +-------------------+
  63               +> |    initialised    | <+
  64               |  +-------------------+  |
  65               |    |                    |
  66               |    | EVP_MAC_update     | EVP_MAC_init
  67               |    v                    |
  68  EVP_MAC_init |  +-------------------+  |
  69               |  |      updated      | -+
  70               |  +-------------------+
  71               |    |               |
  72               |    | EVP_MAC_final | EVP_MAC_finalXOF
  73               |    v               v
  74               |  +-------------------+
  75               +- |      finaled      |
  76                  +-------------------+
  77                    |
  78                    | EVP_MAC_CTX_free
  79                    v
  80                  +-------------------+
  81                  |       freed       |
  82                  +-------------------+
  83
  84 =end man
  85
  86 =for html <img src="img/mac.png">
  87
  88 =head2 Formal State Transitions
  89
  90 This section defines all of the legal state transitions.
  91 This is the canonical list.
  92
  93 =begin man
  94
  95  Function Call                   --------------------- Current State ----------------------
  96                                  start   newed    initialised   updated     finaled   freed
  97  EVP_MAC_CTX_new                 newed
  98  EVP_MAC_init                         initialised initialised initialised initialised
  99  EVP_MAC_update                                     updated     updated
 100  EVP_MAC_final                                                  finaled
 101  EVP_MAC_finalXOF                                               finaled
 102  EVP_MAC_CTX_free                freed   freed       freed       freed       freed
 103  EVP_MAC_CTX_get_params                  newed    initialised   updated
 104  EVP_MAC_CTX_set_params                  newed    initialised   updated
 105  EVP_MAC_CTX_gettable_params             newed    initialised   updated
 106  EVP_MAC_CTX_settable_params             newed    initialised   updated
 107
 108 =end man
 109
 110 =begin html
 111
 112 <table style="border:1px solid; border-collapse:collapse">
 113 <tr><th style="border:1px solid" align="left">Function Call</th>
 114     <th style="border:1px solid" colspan="6">Current State</th></tr>
 115 <tr><th style="border:1px solid"></th>
 116     <th style="border:1px solid" align="center">start</th>
 117     <th style="border:1px solid" align="center">newed</th>
 118     <th style="border:1px solid" align="center">initialised</th>
 119     <th style="border:1px solid" align="center">updated</th>
 120     <th style="border:1px solid" align="center">finaled</th>
 121     <th style="border:1px solid" align="center">freed</th></tr>
 122 <tr><th style="border:1px solid" align="left">EVP_MAC_CTX_new</th>
 123     <td style="border:1px solid" align="center">newed</td>
 124     <td style="border:1px solid" align="center"></td>
 125     <td style="border:1px solid" align="center"></td>
 126     <td style="border:1px solid" align="center"></td>
 127     <td style="border:1px solid" align="center"></td>
 128     <td style="border:1px solid" align="center"></td></tr>
 129 <tr><th style="border:1px solid" align="left">EVP_MAC_init</th>
 130     <td style="border:1px solid" align="center"></td>
 131     <td style="border:1px solid" align="center">initialised</td>
 132     <td style="border:1px solid" align="center">initialised</td>
 133     <td style="border:1px solid" align="center">initialised</td>
 134     <td style="border:1px solid" align="center">initialised</td>
 135     <td style="border:1px solid" align="center"></td></tr>
 136 <tr><th style="border:1px solid" align="left">EVP_MAC_update</th>
 137     <td style="border:1px solid" align="center"></td>
 138     <td style="border:1px solid" align="center"></td>
 139     <td style="border:1px solid" align="center">updated</td>
 140     <td style="border:1px solid" align="center">updated</td>
 141     <td style="border:1px solid" align="center"></td>
 142     <td style="border:1px solid" align="center"></td></tr>
 143 <tr><th style="border:1px solid" align="left">EVP_MAC_final</th>
 144     <td style="border:1px solid" align="center"></td>
 145     <td style="border:1px solid" align="center"></td>
 146     <td style="border:1px solid" align="center"></td>
 147     <td style="border:1px solid" align="center">finaled</td>
 148     <td style="border:1px solid" align="center"></td>
 149     <td style="border:1px solid" align="center"></td></tr>
 150 <tr><th style="border:1px solid" align="left">EVP_MAC_finalXOF</th>
 151     <td style="border:1px solid" align="center"></td>
 152     <td style="border:1px solid" align="center"></td>
 153     <td style="border:1px solid" align="center"></td>
 154     <td style="border:1px solid" align="center">finaled</td>
 155     <td style="border:1px solid" align="center"></td>
 156     <td style="border:1px solid" align="center"></td></tr>
 157 <tr><th style="border:1px solid" align="left">EVP_MAC_CTX_free</th>
 158     <td style="border:1px solid" align="center">freed</td>
 159     <td style="border:1px solid" align="center">freed</td>
 160     <td style="border:1px solid" align="center">freed</td>
 161     <td style="border:1px solid" align="center">freed</td>
 162     <td style="border:1px solid" align="center">freed</td>
 163     <td style="border:1px solid" align="center"></td></tr>
 164 <tr><th style="border:1px solid" align="left">EVP_MAC_CTX_get_params</th>
 165     <td style="border:1px solid" align="center"></td>
 166     <td style="border:1px solid" align="center">newed</td>
 167     <td style="border:1px solid" align="center">initialised</td>
 168     <td style="border:1px solid" align="center">updated</td>
 169     <td style="border:1px solid" align="center"></td>
 170     <td style="border:1px solid" align="center"></td></tr>
 171 <tr><th style="border:1px solid" align="left">EVP_MAC_CTX_set_params</th>
 172     <td style="border:1px solid" align="center"></td>
 173     <td style="border:1px solid" align="center">newed</td>
 174     <td style="border:1px solid" align="center">initialised</td>
 175     <td style="border:1px solid" align="center">updated</td>
 176     <td style="border:1px solid" align="center"></td>
 177     <td style="border:1px solid" align="center"></td></tr>
 178 <tr><th style="border:1px solid" align="left">EVP_MAC_CTX_gettable_params</th>
 179     <td style="border:1px solid" align="center"></td>
 180     <td style="border:1px solid" align="center">newed</td>
 181     <td style="border:1px solid" align="center">initialised</td>
 182     <td style="border:1px solid" align="center">updated</td>
 183     <td style="border:1px solid" align="center"></td>
 184     <td style="border:1px solid" align="center"></td></tr>
 185 <tr><th style="border:1px solid" align="left">EVP_MAC_CTX_settable_params</th>
 186     <td style="border:1px solid" align="center"></td>
 187     <td style="border:1px solid" align="center">newed</td>
 188     <td style="border:1px solid" align="center">initialised</td>
 189     <td style="border:1px solid" align="center">updated</td>
 190     <td style="border:1px solid" align="center"></td>
 191     <td style="border:1px solid" align="center"></td></tr>
 192 </table>
 193
 194 =end html
 195
 196 =head1 NOTES
 197
 198 At some point the EVP layer will begin enforcing the transitions described
 199 herein.
 200
 201 =head1 SEE ALSO
 202
 203 L<provider-mac(7)>, L<EVP_MAC(3)>.
 204
 205 =head1 HISTORY
 206
 207 The provider MAC interface was introduced in OpenSSL 3.0.
 208
 209 =head1 COPYRIGHT
 210
 211 Copyright 2021 The OpenSSL Project Authors. All Rights Reserved.
 212
 213 Licensed under the Apache License 2.0 (the "License").  You may not use
 214 this file except in compliance with the License.  You can obtain a copy
 215 in the file LICENSE in the source distribution or at
 216 L<https://www.openssl.org/source/license.html>.
 217
 218 =cut