1=pod 2 3=head1 NAME 4 5OSSL_DISPATCH - OpenSSL Core type to define a dispatchable function table 6 7=head1 SYNOPSIS 8 9 #include <openssl/core.h> 10 11 typedef struct ossl_dispatch_st OSSL_DISPATCH; 12 struct ossl_dispatch_st { 13 int function_id; 14 void (*function)(void); 15 }; 16 17=head1 DESCRIPTION 18 19This type is a tuple of function identity and function pointer. 20Arrays of this type are passed between the OpenSSL libraries and the 21providers to describe what functionality one side provides to the other. 22 23Arrays of this type must be terminated with a tuple having function identity 24zero and function pointer NULL. 25 26=head2 B<OSSL_DISPATCH> fields 27 28=over 4 29 30=item I<function_id> 31 32OpenSSL defined function identity of the implemented function. 33 34=item I<function> 35 36Pointer to the implemented function itself. Despite the generic definition 37of this field, the implemented function it points to must have a function 38signature that corresponds to the I<function_id> 39 40=back 41 42Available function identities and corresponding function signatures are 43defined in L<openssl-core_dispatch.h(7)>. 44Furthermore, the chosen function identities and associated function 45signature must be chosen specifically for the operation that it's intended 46for, as determined by the intended L<OSSL_ALGORITHM(3)> array. 47 48Any function identity not recognised by the recipient of this type 49will be ignored. 50This ensures that providers built with one OpenSSL version in mind 51will work together with any other OpenSSL version that supports this 52mechanism. 53 54=begin comment RETURN VALUES doesn't make sense for a manual that only 55describes a type, but document checkers still want that section, and 56to have more than just the section title. 57 58=head1 RETURN VALUES 59 60txt 61 62=end comment 63 64=head1 SEE ALSO 65 66L<crypto(7)>, L<openssl-core_dispatch.h(7)>, L<OSSL_ALGORITHM(3)> 67 68=head1 HISTORY 69 70B<OSSL_DISPATCH> was added in OpenSSL 3.0. 71 72=head1 COPYRIGHT 73 74Copyright 2022 The OpenSSL Project Authors. All Rights Reserved. 75 76Licensed under the Apache License 2.0 (the "License"). You may not use 77this file except in compliance with the License. You can obtain a copy 78in the file LICENSE in the source distribution or at 79L<https://www.openssl.org/source/license.html>. 80 81=cut 82