openssl/doc/man3/SSL_get_value_uint.pod

=pod

=head1 NAME

SSL_get_value_uint, SSL_set_value_uint, SSL_get_generic_value_uint,
SSL_set_generic_value_uint, SSL_get_feature_request_uint,
SSL_set_feature_request_uint, SSL_get_feature_peer_request_uint,
SSL_get_feature_negotiated_uint, SSL_get_quic_stream_bidi_local_avail,
SSL_get_quic_stream_bidi_remote_avail, SSL_get_quic_stream_uni_local_avail,
SSL_get_quic_stream_uni_remote_avail, SSL_VALUE_CLASS_GENERIC,
SSL_VALUE_CLASS_FEATURE_REQUEST, SSL_VALUE_CLASS_FEATURE_PEER_REQUEST,
SSL_VALUE_CLASS_FEATURE_NEGOTIATED, SSL_VALUE_QUIC_STREAM_BIDI_LOCAL_AVAIL,
SSL_VALUE_QUIC_STREAM_BIDI_REMOTE_AVAIL, SSL_VALUE_QUIC_STREAM_UNI_LOCAL_AVAIL,
SSL_VALUE_QUIC_STREAM_UNI_REMOTE_AVAIL, SSL_VALUE_QUIC_IDLE_TIMEOUT - manage
negotiable features and configuration values for a SSL object

=head1 SYNOPSIS

 #include <openssl/ssl.h>

 int SSL_get_value_uint(SSL *ssl, uint32_t class_, uint32_t id,
                        uint64_t *value);
 int SSL_set_value_uint(SSL *ssl, uint32_t class_, uint32_t id,
                        uint64_t value);

 #define SSL_VALUE_CLASS_GENERIC
 #define SSL_VALUE_CLASS_FEATURE_REQUEST
 #define SSL_VALUE_CLASS_FEATURE_PEER_REQUEST
 #define SSL_VALUE_CLASS_FEATURE_NEGOTIATED

 #define SSL_VALUE_QUIC_STREAM_BIDI_LOCAL_AVAIL
 #define SSL_VALUE_QUIC_STREAM_BIDI_REMOTE_AVAIL
 #define SSL_VALUE_QUIC_STREAM_UNI_LOCAL_AVAIL
 #define SSL_VALUE_QUIC_STREAM_UNI_REMOTE_AVAIL
 #define SSL_VALUE_QUIC_IDLE_TIMEOUT

The following convenience macros can also be used:

 int SSL_get_generic_value_uint(SSL *ssl, uint32_t id, uint64_t *value);
 int SSL_set_generic_value_uint(SSL *ssl, uint32_t id, uint64_t value);

 int SSL_get_feature_request_uint(SSL *ssl, uint32_t id, uint64_t *value);
 int SSL_set_feature_request_uint(SSL *ssl, uint32_t id, uint64_t value);

 int SSL_get_feature_peer_request_uint(SSL *ssl, uint32_t id, uint64_t *value);
 int SSL_get_feature_negotiated_uint(SSL *ssl, uint32_t id, uint64_t *value);

 int SSL_get_quic_stream_bidi_local_avail(SSL *ssl, uint64_t *value);
 int SSL_get_quic_stream_bidi_remote_avail(SSL *ssl, uint64_t *value);
 int SSL_get_quic_stream_uni_local_avail(SSL *ssl, uint64_t *value);
 int SSL_get_quic_stream_uni_remote_avail(SSL *ssl, uint64_t *value);

=head1 DESCRIPTION

SSL_get_value_uint() and SSL_set_value_uint() provide access to configurable
parameters for a given SSL object. Amongst other things, they are used to
provide control over the feature negotiation process during establishment of a
connection, and access to statistics about that connection.

SSL_get_value_uint() and SSL_set_value_uint() get and set configurable values
within a given value class. The value classes are enumerated by
B<SSL_VALUE_CLASS> and are as follows:

=over 4

=item B<SSL_VALUE_CLASS_GENERIC>

Values in this class do not participate in the feature negotiation process. They
may represent connection parameters which do not participate in explicit
negotiation or provide connection statistics. Values in this class might be
read-write or read-only.

You can access values in this class using the convenience macros
SSL_get_generic_value_uint() and SSL_set_generic_value_uint() for brevity.

=item B<SSL_VALUE_CLASS_FEATURE_REQUEST>

Values in this class are read-write, and represent what the local party is
requesting during feature negotiation. Such a request will not necessarily be
honoured; see B<SSL_VALUE_CLASS_FEATURE_NEGOTIATED>.

A value in this class may become read-only in certain circumstances; for
example, after a connection has been established, for a value which cannot be
renegotiated after connection establishment. Setting a value in this class after
connection establishment represents a request for online renegotiation of the
specified feature.

You can access values in this class using the convenience macros
SSL_get_feature_request_uint() and SSL_set_feature_request_uint() for brevity.

=item B<SSL_VALUE_CLASS_FEATURE_PEER_REQUEST>

Values in this value class are read-only, and represent what was requested by a
peer during feature negotiation. Such a request has not necessarily been
honoured; see B<SSL_VALUE_CLASS_FEATURE_NEGOTIATED>.

You can access values in this class using the convenience macro
SSL_get_feature_peer_request_uint() for brevity.

=item B<SSL_VALUE_CLASS_FEATURE_NEGOTIATED>

Values in this value class are read-only, and represent the value which was
actually negotiated based on both local and peer input during feature
negotiation. This is the effective value in actual use.

Attempting to read a value in this class will generally fail if the feature
negotiation process has not yet completed and the value is therefore currently
unknown, unless the nature of the feature in question causes a provisional value
to be used prior to completion of feature negotiation, in which case that value
may be returned. If an online (post-handshake) renegotiation of a feature is
in progress, retrieving the negotiated value will continue to retrieve the
previous negotiated value until that process is completed. See the documentation
of specific values for full details of its behaviour.

You can access values in this class using the convenience macro
SSL_get_feature_negotiated_uint() for brevity.

=back

=head1 CONFIGURABLE VALUES FOR QUIC CONNECTIONS

The following configurable values are supported for QUIC connection SSL objects:

=over 4

=item B<SSL_VALUE_QUIC_IDLE_TIMEOUT>

Negotiated feature value. This configures the desired QUIC idle timeout in
milliseconds, where 0 represents a lack of an idle timeout. This feature can
only be configured prior to connection establishment and cannot be subsequently
changed.

This release of OpenSSL uses a default value of 30 seconds. This default value
may change between releases of OpenSSL.

=item B<SSL_VALUE_QUIC_STREAM_BIDI_LOCAL_AVAIL>

Generic read-only statistical value. The number of bidirectional,
locally-initiated streams available to be created (but not yet created). For
example, a value of 100 would mean that L<SSL_new_stream(3)> could be called 100
times to create 100 bidirectional streams before L<SSL_new_stream(3)> would
block or fail due to backpressure.

Can be queried using the convenience macro
SSL_get_quic_stream_bidi_local_avail().

=item B<SSL_VALUE_QUIC_STREAM_UNI_LOCAL_AVAIL>

As above, but provides the number of unidirectional, locally-initiated streams
available to be created (but not yet created).

Can be queried using the convenience macro
SSL_get_quic_stream_uni_local_avail().

=item B<SSL_VALUE_QUIC_STREAM_BIDI_REMOTE_AVAIL>

As above, but provides the number of bidirectional, remotely-initiated streams
available to be created (but not yet created) by the peer. This represents the
number of streams the local endpoint has authorised the peer to create in terms
of QUIC stream creation flow control.

Can be queried using the convenience macro
SSL_get_quic_stream_bidi_remote_avail().

=item B<SSL_VALUE_QUIC_STREAM_UNI_REMOTE_AVAIL>

As above, but provides the number of unidirectional, remotely-initiated streams
available to be created (but not yet created).

Can be queried using the convenience macro
SSL_get_quic_stream_uni_remote_avail().

=back

No configurable values are currently defined for QUIC stream SSL objects or for
other kinds of SSL object.

=head1 RETURN VALUES

Returns 1 on success or 0 on failure. This function can fail for a number of
reasons:

=over 4

=item

An argument is invalid (e.g. NULL pointer or invalid class).

=item

The given value is not supported by the SSL object on which it was called.

=item

The given operation (get or set) is not supported by the specified
configurable value.

=item

You are trying to modify the given value and the value is not modifiable at this
time.

=back

=head1 SEE ALSO

L<SSL_ctrl(3)>, L<SSL_get_accept_stream_queue_len(3)>,
L<SSL_get_stream_read_state(3)>, L<SSL_get_stream_write_state(3)>,
L<SSL_get_stream_read_error_code(3)>, L<SSL_get_stream_write_error_code(3)>,
L<SSL_set_default_stream_mode(3)>, L<SSL_set_incoming_stream_policy(3)>

=head1 HISTORY

These functions were added in OpenSSL 3.3.

=head1 COPYRIGHT

Copyright 2002-2024 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