CURLOPT_SOCKS5_AUTH(3) Library Functions Manual CURLOPT_SOCKS5_AUTH(3)

CURLOPT_SOCKS5_AUTH - methods for SOCKS5 proxy authentication

#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_SOCKS5_AUTH, long bitmask);

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 CURLAUTH_BASIC, which allows username/password authentication, CURLAUTH_GSSAPI, which allows GSS-API authentication, and CURLAUTH_NONE, which allows no authentication. Set the actual username and password with the CURLOPT_PROXYUSERPWD(3) option.

CURLAUTH_BASIC|CURLAUTH_GSSAPI

This functionality affects all supported protocols

int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    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, (long)CURLAUTH_BASIC);
    /* Perform the request */
    curl_easy_perform(curl);
  }
}

Added in curl 7.55.0

curl_easy_setopt(3) returns a CURLcode indicating success or error.

CURLE_OK (0) means everything was OK, non-zero means an error occurred, see libcurl-errors(3).

CURLOPT_PROXY(3), CURLOPT_PROXYTYPE(3)

2025-02-13 libcurl