libressl-SSL_get_version3
Get the protocol information of a connection
Usage
SSL Library (libssl, -lssl) libcrypto
#include <openssl/ssl.h>
const char *
SSL_get_version(const SSL *ssl);
int
SSL_is_dtls(const SSL *ssl);
int
SSL_version(const SSL *ssl);
Overview
SSL_get_version() returns the name of the protocol used for the connection ssl.
SSL_is_dtls() returns 1 if the connection is using DTLS, 0 if not.
SSL_version() returns an integer constant representing that protocol.
These functions only return reliable results after the initial handshake has been completed.
Return values
The following strings or integers can be returned by SSL_get_version() and SSL_version():
- "TLSv1" or TLS1_VERSION
-
The connection uses the TLSv1.0 protocol.
- "TLSv1.1" or TLS1_1_VERSION
-
The connection uses the TLSv1.1 protocol.
- "TLSv1.2" or TLS1_2_VERSION
-
The connection uses the TLSv1.2 protocol.
- "TLSv1.3" or TLS1_3_VERSION
-
The connection uses the TLSv1.3 protocol.
- "DTLSv1" or DTLS1_VERSION
-
The connection uses the Datagram Transport Layer Security 1.0 protocol.
- "DTLSv1.2" or DTLS1_2_VERSION
-
The connection uses the Datagram Transport Layer Security 1.2 protocol.
- "unknown"
-
This indicates an unknown protocol version; it cannot currently happen with LibreSSL.
SSL_is_dtls() returns 1 if the connection uses DTLS, 0 if not.