mirror of
https://github.com/CloverHackyColor/CloverBootloader.git
synced 2024-12-02 13:03:28 +01:00
132 lines
4.1 KiB
Plaintext
132 lines
4.1 KiB
Plaintext
=pod
|
|
|
|
=head1 NAME
|
|
|
|
SSL_CTX_set_async_callback,
|
|
SSL_CTX_set_async_callback_arg,
|
|
SSL_set_async_callback,
|
|
SSL_set_async_callback_arg,
|
|
SSL_get_async_status,
|
|
SSL_async_callback_fn
|
|
- manage asynchronous operations
|
|
|
|
=head1 SYNOPSIS
|
|
|
|
=for openssl multiple includes
|
|
|
|
#include <openssl/ssl.h>
|
|
|
|
typedef int (*SSL_async_callback_fn)(SSL *s, void *arg);
|
|
int SSL_CTX_set_async_callback(SSL_CTX *ctx, SSL_async_callback_fn callback);
|
|
int SSL_CTX_set_async_callback_arg(SSL_CTX *ctx, void *arg);
|
|
int SSL_set_async_callback(SSL *s, SSL_async_callback_fn callback);
|
|
int SSL_set_async_callback_arg(SSL *s, void *arg);
|
|
int SSL_get_async_status(SSL *s, int *status);
|
|
|
|
=head1 DESCRIPTION
|
|
|
|
SSL_CTX_set_async_callback() sets an asynchronous callback function. All B<SSL>
|
|
objects generated based on this B<SSL_CTX> will get this callback. If an engine
|
|
supports the callback mechanism, it will be automatically called if
|
|
B<SSL_MODE_ASYNC> has been set and an asynchronous capable engine completes a
|
|
cryptography operation to notify the application to resume the paused work flow.
|
|
|
|
SSL_CTX_set_async_callback_arg() sets the callback argument.
|
|
|
|
SSL_set_async_callback() allows an application to set a callback in an
|
|
asynchronous B<SSL> object, so that when an engine completes a cryptography
|
|
operation, the callback will be called to notify the application to resume the
|
|
paused work flow.
|
|
|
|
SSL_set_async_callback_arg() sets an argument for the B<SSL> object when the
|
|
above callback is called.
|
|
|
|
SSL_get_async_status() returns the engine status. This function facilitates the
|
|
communication from the engine to the application. During an SSL session,
|
|
cryptographic operations are dispatched to an engine. The engine status is very
|
|
useful for an application to know if the operation has been successfully
|
|
dispatched. If the engine does not support this additional callback method,
|
|
B<ASYNC_STATUS_UNSUPPORTED> will be returned. See ASYNC_WAIT_CTX_set_status()
|
|
for a description of all of the status values.
|
|
|
|
An example of the above functions would be the following:
|
|
|
|
=over 4
|
|
|
|
=item 1.
|
|
|
|
Application sets the async callback and callback data on an SSL connection
|
|
by calling SSL_set_async_callback().
|
|
|
|
=item 2.
|
|
|
|
Application sets B<SSL_MODE_ASYNC> and makes an asynchronous SSL call
|
|
|
|
=item 3.
|
|
|
|
OpenSSL submits the asynchronous request to the engine. If a retry occurs at
|
|
this point then the status within the B<ASYNC_WAIT_CTX> would be set and the
|
|
async callback function would be called (goto Step 7).
|
|
|
|
=item 4.
|
|
|
|
The OpenSSL engine pauses the current job and returns, so that the
|
|
application can continue processing other connections.
|
|
|
|
=item 5.
|
|
|
|
At a future point in time (probably via a polling mechanism or via an
|
|
interrupt) the engine will become aware that the asynchronous request has
|
|
finished processing.
|
|
|
|
=item 6.
|
|
|
|
The engine will call the application's callback passing the callback data as
|
|
a parameter.
|
|
|
|
=item 7.
|
|
|
|
The callback function should then run. Note: it is a requirement that the
|
|
callback function is small and nonblocking as it will be run in the context of
|
|
a polling mechanism or an interrupt.
|
|
|
|
=item 8.
|
|
|
|
It is the application's responsibility via the callback function to schedule
|
|
recalling the OpenSSL asynchronous function and to continue processing.
|
|
|
|
=item 9.
|
|
|
|
The callback function has the option to check the status returned via
|
|
SSL_get_async_status() to determine whether a retry happened instead of the
|
|
request being submitted, allowing different processing if required.
|
|
|
|
=back
|
|
|
|
=head1 RETURN VALUES
|
|
|
|
SSL_CTX_set_async_callback(), SSL_set_async_callback(),
|
|
SSL_CTX_set_async_callback_arg(), SSL_CTX_set_async_callback_arg() and
|
|
SSL_get_async_status() return 1 on success or 0 on error.
|
|
|
|
=head1 SEE ALSO
|
|
|
|
L<ssl(7)>
|
|
|
|
=head1 HISTORY
|
|
|
|
SSL_CTX_set_async_callback(), SSL_CTX_set_async_callback_arg(),
|
|
SSL_set_async_callback(), SSL_set_async_callback_arg() and
|
|
SSL_get_async_status() were first added to OpenSSL 3.0.
|
|
|
|
=head1 COPYRIGHT
|
|
|
|
Copyright 2019-2021 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
|