Ubuntu Manpage: CURLOPT_PROXY_SSL_OPTIONS - HTTPS proxy SSL behavior options

Provided by: libcurl4-doc_8.5.0-2ubuntu10.6_all

NAME

       CURLOPT_PROXY_SSL_OPTIONS - HTTPS proxy SSL behavior options

SYNOPSIS

       #include <curl/curl.h>

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_PROXY_SSL_OPTIONS,
                                 long bitmask);

DESCRIPTION

Pass a long with a bitmask to tell libcurl about specific SSL behaviors. Available bits:

CURLSSLOPT_ALLOW_BEAST
Tells libcurl to not attempt to use any workarounds for a security flaw in the SSL3 and TLS1.0
protocols. If this option is not used or this bit is set to 0, the SSL layer libcurl uses may use
a work-around for this flaw although it might cause interoperability problems with some (older)
SSL implementations. WARNING: avoiding this work-around lessens the security, and by setting this
option to 1 you ask for exactly that. This option is only supported for Secure Transport and
OpenSSL.

CURLSSLOPT_NO_REVOKE
Tells libcurl to disable certificate revocation checks for those SSL backends where such behavior
is present. This option is only supported for Schannel (the native Windows SSL library), with an
exception in the case of Windows' Untrusted Publishers block list which it seems cannot be
bypassed. (Added in 7.44.0)

CURLSSLOPT_NO_PARTIALCHAIN
Tells libcurl to not accept "partial" certificate chains, which it otherwise does by default. This
option is only supported for OpenSSL and fails the certificate verification if the chain ends with
an intermediate certificate and not with a root cert. (Added in 7.68.0)

CURLSSLOPT_REVOKE_BEST_EFFORT
Tells libcurl to ignore certificate revocation checks in case of missing or offline distribution
points for those SSL backends where such behavior is present. This option is only supported for
Schannel (the native Windows SSL library). If combined with CURLSSLOPT_NO_REVOKE, the latter takes
precedence. (Added in 7.70.0)

CURLSSLOPT_NATIVE_CA
Tell libcurl to use the operating system's native CA store for certificate verification. If you
set this option and also set a CA certificate file or directory then during verification those
certificates are searched in addition to the native CA store.

Works with wolfSSL on Windows, Linux (Debian, Ubuntu, Gentoo, Fedora, RHEL), macOS, Android and
iOS (added in 8.3.0), with GnuTLS (added in 8.5.0) or on Windows when built to use OpenSSL (Added
in 7.71.0).

CURLSSLOPT_AUTO_CLIENT_CERT
Tell libcurl to automatically locate and use a client certificate for authentication, when
requested by the server. This option is only supported for Schannel (the native Windows SSL
library). Prior to 7.77.0 this was the default behavior in libcurl with Schannel. Since the server
can request any certificate that supports client authentication in the OS certificate store it
could be a privacy violation and unexpected. (Added in 7.77.0)

DEFAULT

PROTOCOLS

       All TLS-based protocols

EXAMPLE

       int main(void)
       {
         CURL *curl = curl_easy_init();
         if(curl) {
           CURLcode res;
           curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
           curl_easy_setopt(curl, CURLOPT_PROXY, "https://proxy");
           /* weaken TLS only for use with silly proxies */
           curl_easy_setopt(curl, CURLOPT_PROXY_SSL_OPTIONS, CURLSSLOPT_ALLOW_BEAST |
                            CURLSSLOPT_NO_REVOKE);
           res = curl_easy_perform(curl);
           curl_easy_cleanup(curl);
         }
       }

AVAILABILITY

       Added in 7.52.0

RETURN VALUE

       Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.