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=head1 NAME

SSL_CTX_set_min_proto_version, SSL_CTX_set_max_proto_version,

SSL_CTX_get_min_proto_version, SSL_CTX_get_max_proto_version,

SSL_set_min_proto_version, SSL_set_max_proto_version,

SSL_get_min_proto_version, SSL_get_max_proto_version - Get and set minimum

and maximum supported protocol version

=head1 SYNOPSIS

 #include <openssl/ssl.h>

 int SSL_CTX_set_min_proto_version(SSL_CTX *ctx, int version);

 int SSL_CTX_set_max_proto_version(SSL_CTX *ctx, int version);

 int SSL_CTX_get_min_proto_version(SSL_CTX *ctx);

 int SSL_CTX_get_max_proto_version(SSL_CTX *ctx);

 int SSL_set_min_proto_version(SSL *ssl, int version);

 int SSL_set_max_proto_version(SSL *ssl, int version);

 int SSL_get_min_proto_version(SSL *ssl);

 int SSL_get_max_proto_version(SSL *ssl);

=head1 DESCRIPTION

The functions get or set the minimum and maximum supported protocol versions

for the B<ctx> or B<ssl>.

This works in combination with the options set via

L<SSL_CTX_set_options(3)> that also make it possible to disable

specific protocol versions.

Use these functions instead of disabling specific protocol versions.

Setting the minimum or maximum version to 0, will enable protocol

versions down to the lowest version, or up to the highest version

supported by the library, respectively.

Getters return 0 in case B<ctx> or B<ssl> have been configured to

automatically use the lowest or highest version supported by the library.

Currently supported versions are B<SSL3_VERSION>, B<TLS1_VERSION>,

B<TLS1_1_VERSION>, B<TLS1_2_VERSION>, B<TLS1_3_VERSION> for TLS and

B<DTLS1_VERSION>, B<DTLS1_2_VERSION> for DTLS.

=head1 RETURN VALUES

These setter functions return 1 on success and 0 on failure. The getter

functions return the configured version or 0 for auto-configuration of

lowest or highest protocol, respectively.

=head1 NOTES

All these functions are implemented using macros.

=head1 SEE ALSO

L<SSL_CTX_set_options(3)>, L<SSL_CONF_cmd(3)>

=head1 HISTORY

The setter functions were added in OpenSSL 1.1.0. The getter functions

were added in OpenSSL 1.1.1.

=head1 COPYRIGHT

Copyright 2016-2019 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the OpenSSL license (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>.

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