| =pod |
| |
| =head1 NAME |
| |
| SSL_client_version, SSL_get_version, SSL_is_dtls, SSL_version - get the |
| protocol information of a connection |
| |
| =head1 SYNOPSIS |
| |
| #include <openssl/ssl.h> |
| |
| int SSL_client_version(const SSL *s); |
| |
| const char *SSL_get_version(const SSL *ssl); |
| |
| int SSL_is_dtls(const SSL *ssl); |
| |
| int SSL_version(const SSL *s); |
| |
| =head1 DESCRIPTION |
| |
| SSL_client_version() returns the numeric protocol version advertised by the |
| client in the legacy_version field of the ClientHello when initiating the |
| connection. Note that, for TLS, this value will never indicate a version greater |
| than TLSv1.2 even if TLSv1.3 is subsequently negotiated. SSL_get_version() |
| returns the name of the protocol used for the connection. SSL_version() returns |
| the numeric protocol version used for the connection. They should only be called |
| after the initial handshake has been completed. Prior to that the results |
| returned from these functions may be unreliable. |
| |
| SSL_is_dtls() returns one if the connection is using DTLS, zero if not. |
| |
| =head1 RETURN VALUES |
| |
| |
| SSL_get_version() returns one of the following strings: |
| |
| =over 4 |
| |
| =item SSLv3 |
| |
| The connection uses the SSLv3 protocol. |
| |
| =item TLSv1 |
| |
| The connection uses the TLSv1.0 protocol. |
| |
| =item TLSv1.1 |
| |
| The connection uses the TLSv1.1 protocol. |
| |
| =item TLSv1.2 |
| |
| The connection uses the TLSv1.2 protocol. |
| |
| =item TLSv1.3 |
| |
| The connection uses the TLSv1.3 protocol. |
| |
| =item unknown |
| |
| This indicates an unknown protocol version. |
| |
| =back |
| |
| SSL_version() and SSL_client_version() return an integer which could include any |
| of the following: |
| |
| =over 4 |
| |
| =item SSL3_VERSION |
| |
| The connection uses the SSLv3 protocol. |
| |
| =item TLS1_VERSION |
| |
| The connection uses the TLSv1.0 protocol. |
| |
| =item TLS1_1_VERSION |
| |
| The connection uses the TLSv1.1 protocol. |
| |
| =item TLS1_2_VERSION |
| |
| The connection uses the TLSv1.2 protocol. |
| |
| =item TLS1_3_VERSION |
| |
| The connection uses the TLSv1.3 protocol (never returned for |
| SSL_client_version()). |
| |
| =back |
| |
| =head1 SEE ALSO |
| |
| L<ssl(7)> |
| |
| =head1 HISTORY |
| |
| The SSL_is_dtls() function was added in OpenSSL 1.1.0. |
| |
| =head1 COPYRIGHT |
| |
| Copyright 2001-2018 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 |
