.\" generated by cd2nroff 0.1 from CURLOPT_SOCKS5_AUTH.md .TH CURLOPT_SOCKS5_AUTH 3 "2026-09-02" libcurl .SH NAME CURLOPT_SOCKS5_AUTH \- methods for SOCKS5 proxy authentication .SH SYNOPSIS .nf #include CURLcode curl_easy_setopt(CURL *handle, CURLOPT_SOCKS5_AUTH, long bitmask); .fi .SH DESCRIPTION Pass a long as parameter, which is set to a bitmask, to tell libcurl which authentication method(s) are allowed for SOCKS5 proxy authentication. The only supported flags are \fICURLAUTH_BASIC\fP, which allows username/password authentication, \fICURLAUTH_GSSAPI\fP, which allows GSS\-API authentication, and \fICURLAUTH_NONE\fP, which allows no authentication. Set the actual username and password with the \fICURLOPT_PROXYUSERPWD(3)\fP option. The specific socks authentication method is an \fIaccess property\fP, it does not change the security context. This means that this option changes how the connection and access to the proxy happens when a connection is setup, but it does not affect which proxy connections libcurl can reuse. libcurl may reuse a connection that was set up with a different socks authentication method. Proxy connection reuse still depends on other properties matching, such as the protocol, proxy hostname, port number, credentials and other settings that affect the connection. .SH DEFAULT CURLAUTH_BASIC | CURLAUTH_GSSAPI .SH PROTOCOLS This functionality affects all supported protocols .SH EXAMPLE .nf int main(void) { CURL *curl = curl_easy_init(); if(curl) { CURLcode result; curl_easy_setopt(curl, CURLOPT_URL, "https://example.com"); /* request to use a SOCKS5 proxy */ curl_easy_setopt(curl, CURLOPT_PROXY, "socks5://user:pass@myproxy.com"); /* enable username/password authentication only */ curl_easy_setopt(curl, CURLOPT_SOCKS5_AUTH, CURLAUTH_BASIC); /* Perform the request */ result = curl_easy_perform(curl); curl_easy_cleanup(curl); } } .fi .SH HISTORY \fBCURLAUTH_\fP* macros became \fIlong\fP types in 7.26.0, prior to this version a \fIlong\fP cast was necessary when passed to \fIcurl_easy_setopt(3)\fP. .SH AVAILABILITY Added in curl 7.55.0 .SH RETURN VALUE \fIcurl_easy_setopt(3)\fP returns a CURLcode indicating success or error. CURLE_OK (0) means everything was OK, non\-zero means an error occurred, see \fIlibcurl\-errors(3)\fP. .SH SEE ALSO .BR CURLOPT_PROXY (3), .BR CURLOPT_PROXYTYPE (3)