curl/docs/libcurl/opts/CURLOPT_PROXY_SSLVERSION.3

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proxy: Support HTTPS proxy and SOCKS+HTTP(s) * HTTPS proxies: An HTTPS proxy receives all transactions over an SSL/TLS connection. Once a secure connection with the proxy is established, the user agent uses the proxy as usual, including sending CONNECT requests to instruct the proxy to establish a [usually secure] TCP tunnel with an origin server. HTTPS proxies protect nearly all aspects of user-proxy communications as opposed to HTTP proxies that receive all requests (including CONNECT requests) in vulnerable clear text. With HTTPS proxies, it is possible to have two concurrent _nested_ SSL/TLS sessions: the "outer" one between the user agent and the proxy and the "inner" one between the user agent and the origin server (through the proxy). This change adds supports for such nested sessions as well. A secure connection with a proxy requires its own set of the usual SSL options (their actual descriptions differ and need polishing, see TODO): --proxy-cacert FILE CA certificate to verify peer against --proxy-capath DIR CA directory to verify peer against --proxy-cert CERT[:PASSWD] Client certificate file and password --proxy-cert-type TYPE Certificate file type (DER/PEM/ENG) --proxy-ciphers LIST SSL ciphers to use --proxy-crlfile FILE Get a CRL list in PEM format from the file --proxy-insecure Allow connections to proxies with bad certs --proxy-key KEY Private key file name --proxy-key-type TYPE Private key file type (DER/PEM/ENG) --proxy-pass PASS Pass phrase for the private key --proxy-ssl-allow-beast Allow security flaw to improve interop --proxy-sslv2 Use SSLv2 --proxy-sslv3 Use SSLv3 --proxy-tlsv1 Use TLSv1 --proxy-tlsuser USER TLS username --proxy-tlspassword STRING TLS password --proxy-tlsauthtype STRING TLS authentication type (default SRP) All --proxy-foo options are independent from their --foo counterparts, except --proxy-crlfile which defaults to --crlfile and --proxy-capath which defaults to --capath. Curl now also supports %{proxy_ssl_verify_result} --write-out variable, similar to the existing %{ssl_verify_result} variable. Supported backends: OpenSSL, GnuTLS, and NSS. * A SOCKS proxy + HTTP/HTTPS proxy combination: If both --socks* and --proxy options are given, Curl first connects to the SOCKS proxy and then connects (through SOCKS) to the HTTP or HTTPS proxy. TODO: Update documentation for the new APIs and --proxy-* options. Look for "Added in 7.XXX" marks.
2016-11-16 12:49:15 -05:00
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.TH CURLOPT_PROXY_SSLVERSION 3 "16 Nov 2016" "libcurl 7.51.1" "curl_easy_setopt options"
.SH NAME
CURLOPT_PROXY_SSLVERSION \- set proxy preferred TLS/SSL version
.SH SYNOPSIS
#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_PROXY_SSLVERSION, long version);
.SH DESCRIPTION
TODO: Make this text specific to HTTPS proxy. (Added in 7.XXX)
Pass a long as parameter to control which version of SSL/TLS to attempt to
use.
Use one of the available defines for this purpose. The available options are:
.RS
.IP CURL_SSLVERSION_DEFAULT
The default action. This will attempt to figure out the remote SSL protocol
version.
.IP CURL_SSLVERSION_TLSv1
TLSv1.x
.IP CURL_SSLVERSION_SSLv2
SSLv2
.IP CURL_SSLVERSION_SSLv3
SSLv3
.IP CURL_SSLVERSION_TLSv1_0
TLSv1.0 (Added in 7.34.0)
.IP CURL_SSLVERSION_TLSv1_1
TLSv1.1 (Added in 7.34.0)
.IP CURL_SSLVERSION_TLSv1_2
TLSv1.2 (Added in 7.34.0)
.IP CURL_SSLVERSION_TLSv1_3
TLSv1.3 (Added in 7.51.1)
.RE
.SH DEFAULT
CURL_SSLVERSION_DEFAULT
.SH PROTOCOLS
All TLS based protocols: HTTPS, FTPS, IMAPS, POP3S, SMTPS etc.
.SH EXAMPLE
.nf
CURL *curl = curl_easy_init();
if(curl) {
curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
/* ask libcurl to use TLS version 1.0 or later */
curl_easy_setopt(curl, CURLOPT_PROXY_SSLVERSION, CURL_SSLVERSION_TLSv1);
/* Perform the request */
curl_easy_perform(curl);
}
.fi
.SH AVAILABILITY
SSLv2 is disabled by default since 7.18.1. Other SSL versions availability may
vary depending on which backend libcurl has been built to use.
SSLv3 is disabled by default since 7.39.0.
.SH RETURN VALUE
Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.
.SH "SEE ALSO"
.BR CURLOPT_USE_SSL "(3), " CURLOPT_HTTP_VERSION "(3), "
.BR CURLOPT_IPRESOLVE "(3) "