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.TH CURLINFO_TLS_SESSION 3 "12 Sep 2015" "libcurl 7.44.0" "curl_easy_getinfo options"
.SH NAME
CURLINFO_TLS_SESSION \- get TLS session info
.SH SYNOPSIS
.nf
#include <curl/curl.h>

CURLcode curl_easy_getinfo(CURL *handle, CURLINFO_TLS_SESSION,
                           struct curl_tlssessioninfo **session);
.SH DESCRIPTION
Pass a pointer to a 'struct curl_tlssessioninfo *'.  The pointer will be
initialized to refer to a 'struct curl_tlssessioninfo *' that will contain an
enum indicating the SSL library used for the handshake and the respective
internal TLS session structure of this underlying SSL library.

This may then be used to extract certificate information in a format
convenient for further processing, such as manual validation. NOTE: this
option may not be available for all SSL backends; unsupported SSL backends
will always return NULL in the \fIinternals\fP pointer to indicate that they
are not supported.

.nf
struct curl_tlssessioninfo {
  curl_sslbackend backend;
  void *internals;
};
.fi

The \fIbackend\fP struct member is one of the defines in the CURLSSLBACKEND_*
series: CURLSSLBACKEND_NONE (when built without TLS support),
CURLSSLBACKEND_OPENSSL, CURLSSLBACKEND_GNUTLS, CURLSSLBACKEND_NSS,
CURLSSLBACKEND_GSKIT, CURLSSLBACKEND_POLARSSL, CURLSSLBACKEND_CYASSL,
CURLSSLBACKEND_SCHANNEL, CURLSSLBACKEND_DARWINSSL or
CURLSSLBACKEND_AXTLS. (Note that the OpenSSL forks are all reported as just
OpenSSL here.)

The \fIinternals\fP struct member will point to a TLS library specific pointer
with the following underlying types:
.RS
.IP OpenSSL
SSL_CTX *
.IP GnuTLS
gnutls_session_t
.IP NSS
PRFileDesc *
.IP gskit
gsk_handle
.RE
.SH PROTOCOLS
All TLS-based
.SH EXAMPLE
TODO
.SH AVAILABILITY
Added in 7.34.0
.SH RETURN VALUE
Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.
.SH "SEE ALSO"
.BR curl_easy_getinfo "(3), " curl_easy_setopt "(3), "