CURLOPT_SOCKS5_AUTH(3)

💅 CURLOPT_SOCKS5_AUTH — like, the whole manual page, bestie

Okay so this is CURLOPT_SOCKS5_AUTH(3) from the libcurl Library Functions Manual and it's literally all about which auth methods your SOCKS5 proxy is allowed to use 🧦✨

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✨ NAME ✨

CURLOPT_SOCKS5_AUTH — methods for SOCKS5 proxy authentication 🫶

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🌸 SYNOPSIS 🌸

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_SOCKS5_AUTH, long bitmask);

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🦋 DESCRIPTION 🦋

So you pass a long as the parameter, right? And it gets set to a bitmask, and that bitmask tells libcurl which authentication method(s) are allowed for SOCKS5 proxy authentication. That's it, that's the whole vibe 💅

The only supported flags are:

• CURLAUTH_BASIC — allows username/password authentication 🔑
• CURLAUTH_GSSAPI — allows GSS-API authentication 🎫
• CURLAUTH_NONE — allows no authentication, like, at all 🙈

And if you actually want to set the real username and password? That's a whole different option, bestie — use CURLOPT_PROXYUSERPWD(3) for that ✨

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🎀 DEFAULT 🎀

CURLAUTH_BASIC | CURLAUTH_GSSAPI

That's the starting point, no cap 👑

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🌈 PROTOCOLS 🌈

This functionality affects all supported protocols — every single one, she's versatile like that 💖

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⭐ EXAMPLE ⭐

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, CURLAUTH_BASIC);

    /* Perform the request */
    curl_easy_perform(curl);
  }
}

Look at her go 😭 so clean, so iconic 💅

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🧚 HISTORY 🧚

The CURLAUTH_* macros became long types in 7.26.0. Before that version? You had to do a long cast when passing them to curl_easy_setopt(3). Dark times, fr fr 💀

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🍓 AVAILABILITY 🍓

Added in curl 7.55.0 ✨ (she's not ancient, but she's been around 💜)

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🔥 RETURN VALUE 🔥

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

• CURLE_OK (0) — means everything was OK, we ate, no notes 🎀
• non-zero — means an error occurred 😭 go check libcurl-errors(3) for what went wrong

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💜 SEE ALSO 💜

• CURLOPT_PROXY(3)
• CURLOPT_PROXYTYPE(3)

Go read those too, iykyk 🦋

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libcurl · 2026-10-12 · CURLOPT_SOCKS5_AUTH(3) — and that's the whole page, bestie, you're welcome, mwah 💋✨