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diff --git a/doc/man7/life_cycle-digest.pod b/doc/man7/life_cycle-digest.pod new file mode 100644 index 000000000000..709fd0d04ce7 --- /dev/null +++ b/doc/man7/life_cycle-digest.pod @@ -0,0 +1,221 @@ +=pod + +=head1 NAME + +life_cycle-digest - The digest algorithm life-cycle + +=head1 DESCRIPTION + +All message digests (MDs) go through a number of stages in their life-cycle: + +=over 4 + +=item start + +This state represents the MD before it has been allocated. It is the +starting state for any life-cycle transitions. + +=item newed + +This state represents the MD after it has been allocated. + +=item initialised + +This state represents the MD when it is set up and capable of processing +input. + +=item updated + +This state represents the MD when it is set up and capable of processing +additional input or generating output. + +=item finaled + +This state represents the MD when it has generated output. + +=item freed + +This state is entered when the MD is freed. It is the terminal state +for all life-cycle transitions. + +=back + +=head2 State Transition Diagram + +The usual life-cycle of a MD is illustrated: + +=begin man + + +-------------------+ + | start | + +-------------------+ + | + | EVP_MD_CTX_new + v + +-------------------+ EVP_MD_CTX_reset + | newed | <------------------------------+ + +-------------------+ | + | | + | EVP_DigestInit | + v | + +-------------------+ | + +--> | initialised | <+ EVP_DigestInit | + | +-------------------+ | | + | | | EVP_DigestUpdate | + | | EVP_DigestUpdate | +------------------+ | + | v | v | | + | +------------------------------------------------+ | + EVP_DigestInit | | updated | --+ + | +------------------------------------------------+ | + | | | | + | | EVP_DigestFinal | EVP_DigestFinalXOF | + | v v | + | +------------------------------------------------+ | + +--- | finaled | --+ + +------------------------------------------------+ + | + | EVP_MD_CTX_free + v + +-------------------+ + | freed | + +-------------------+ + +=end man + +=for html <img src="img/digest.png"> + +=head2 Formal State Transitions + +This section defines all of the legal state transitions. +This is the canonical list. + +=begin man + + Function Call --------------------- Current State ---------------------- + start newed initialised updated finaled freed + EVP_MD_CTX_new newed + EVP_DigestInit initialised initialised initialised initialised + EVP_DigestUpdate updated updated + EVP_DigestFinal finaled + EVP_DigestFinalXOF finaled + EVP_MD_CTX_free freed freed freed freed freed + EVP_MD_CTX_reset newed newed newed newed + EVP_MD_CTX_get_params newed initialised updated + EVP_MD_CTX_set_params newed initialised updated + EVP_MD_CTX_gettable_params newed initialised updated + EVP_MD_CTX_settable_params newed initialised updated + +=end man + +=begin html + +<table style="border:1px solid; border-collapse:collapse"> +<tr><th style="border:1px solid" align="left">Function Call</th> + <th style="border:1px solid" colspan="6">Current State</th></tr> +<tr><th style="border:1px solid"></th> + <th style="border:1px solid" align="center">start</th> + <th style="border:1px solid" align="center">newed</th> + <th style="border:1px solid" align="center">initialised</th> + <th style="border:1px solid" align="center">updated</th> + <th style="border:1px solid" align="center">finaled</th> + <th style="border:1px solid" align="center">freed</th></tr> +<tr><th style="border:1px solid" align="left">EVP_MD_CTX_new</th> + <td style="border:1px solid" align="center">newed</td> + <td style="border:1px solid" align="center"></td> + <td style="border:1px solid" align="center"></td> + <td style="border:1px solid" align="center"></td> + <td style="border:1px solid" align="center"></td> + <td style="border:1px solid" align="center"></td></tr> +<tr><th style="border:1px solid" align="left">EVP_DigestInit</th> + <td style="border:1px solid" align="center"></td> + <td style="border:1px solid" align="center">initialised</td> + <td style="border:1px solid" align="center">initialised</td> + <td style="border:1px solid" align="center">initialised</td> + <td style="border:1px solid" align="center">initialised</td> + <td style="border:1px solid" align="center"></td></tr> +<tr><th style="border:1px solid" align="left">EVP_DigestUpdate</th> + <td style="border:1px solid" align="center"></td> + <td style="border:1px solid" align="center"></td> + <td style="border:1px solid" align="center">updated</td> + <td style="border:1px solid" align="center">updated</td> + <td style="border:1px solid" align="center"></td> + <td style="border:1px solid" align="center"></td></tr> +<tr><th style="border:1px solid" align="left">EVP_DigestFinal</th> + <td style="border:1px solid" align="center"></td> + <td style="border:1px solid" align="center"></td> + <td style="border:1px solid" align="center"></td> + <td style="border:1px solid" align="center">finaled</td> + <td style="border:1px solid" align="center"></td> + <td style="border:1px solid" align="center"></td></tr> +<tr><th style="border:1px solid" align="left">EVP_DigestFinalXOF</th> + <td style="border:1px solid" align="center"></td> + <td style="border:1px solid" align="center"></td> + <td style="border:1px solid" align="center"></td> + <td style="border:1px solid" align="center">finaled</td> + <td style="border:1px solid" align="center"></td> + <td style="border:1px solid" align="center"></td></tr> +<tr><th style="border:1px solid" align="left">EVP_MD_CTX_free</th> + <td style="border:1px solid" align="center">freed</td> + <td style="border:1px solid" align="center">freed</td> + <td style="border:1px solid" align="center">freed</td> + <td style="border:1px solid" align="center">freed</td> + <td style="border:1px solid" align="center">freed</td> + <td style="border:1px solid" align="center"></td></tr> +<tr><th style="border:1px solid" align="left">EVP_MD_CTX_reset</th> + <td style="border:1px solid" align="center"></td> + <td style="border:1px solid" align="center">newed</td> + <td style="border:1px solid" align="center">newed</td> + <td style="border:1px solid" align="center">newed</td> + <td style="border:1px solid" align="center">newed</td> + <td style="border:1px solid" align="center"></td></tr> +<tr><th style="border:1px solid" align="left">EVP_MD_CTX_get_params</th> + <td style="border:1px solid" align="center"></td> + <td style="border:1px solid" align="center">newed</td> + <td style="border:1px solid" align="center">initialised</td> + <td style="border:1px solid" align="center">updated</td> + <td style="border:1px solid" align="center"></td> + <td style="border:1px solid" align="center"></td></tr> +<tr><th style="border:1px solid" align="left">EVP_MD_CTX_set_params</th> + <td style="border:1px solid" align="center"></td> + <td style="border:1px solid" align="center">newed</td> + <td style="border:1px solid" align="center">initialised</td> + <td style="border:1px solid" align="center">updated</td> + <td style="border:1px solid" align="center"></td> + <td style="border:1px solid" align="center"></td></tr> +<tr><th style="border:1px solid" align="left">EVP_MD_CTX_gettable_params</th> + <td style="border:1px solid" align="center"></td> + <td style="border:1px solid" align="center">newed</td> + <td style="border:1px solid" align="center">initialised</td> + <td style="border:1px solid" align="center">updated</td> + <td style="border:1px solid" align="center"></td> + <td style="border:1px solid" align="center"></td></tr> +<tr><th style="border:1px solid" align="left">EVP_MD_CTX_settable_params</th> + <td style="border:1px solid" align="center"></td> + <td style="border:1px solid" align="center">newed</td> + <td style="border:1px solid" align="center">initialised</td> + <td style="border:1px solid" align="center">updated</td> + <td style="border:1px solid" align="center"></td> + <td style="border:1px solid" align="center"></td></tr> +</table> + +=end html + +=head1 NOTES + +At some point the EVP layer will begin enforcing the transitions described +herein. + +=head1 SEE ALSO + +L<provider-digest(7)>, L<EVP_DigestInit(3)> + +=head1 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 +L<https://www.openssl.org/source/license.html>. + +=cut |