CURLOPT_SS...KEY_SHA256(3)

📦
version 8.18.0 · 23 versions
, in fedora 44

💖 CURLOPT_SSH_HOST_PUBLIC_KEY_SHA256(3) 💖

okay bestie, this cutie comes straight out of the Library Functions Manual, and it's here to check the SHA256 hash of an SSH server's public key. no cap. ✨

🌸 NAME 🌸

CURLOPT_SSH_HOST_PUBLIC_KEY_SHA256 — SHA256 hash of SSH server public key.

✨ SYNOPSIS ✨

       #include <curl/curl.h>

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_SSH_HOST_PUBLIC_KEY_SHA256,
                                 char *sha256);

💅 DESCRIPTION 💅

You pass a char pointer pointing to a string containing a Base64-encoded SHA256 hash of the remote host's public key. The transfer fails if the given hash does not match the hash the remote host provides. 🫶

The application does not have to keep the string around after setting this option. So you can let it go after setting it — she's done her job. 💅

Using this option multiple times makes the last set string override the previous ones. Set it to NULL to disable its use again. Last one wins, periodt. 👑

🍓 DEFAULT 🍓

NULL

🦋 PROTOCOLS 🦋

This functionality affects scp and sftp. 🧚

🔥 EXAMPLE 🔥

       int main(void)
       {
         CURL *curl = curl_easy_init();
         if(curl) {
           CURLcode result;
           curl_easy_setopt(curl, CURLOPT_URL, "sftp://example.com/file");
           curl_easy_setopt(curl, CURLOPT_SSH_HOST_PUBLIC_KEY_SHA256,
                            "NDVkMTQxMGQ1ODdmMjQ3MjczYjAyOTY5MmRkMjVmNDQ=");
           result = curl_easy_perform(curl);
           curl_easy_cleanup(curl);
         }
       }

💀 NOTES 💀

Requires the libssh2 backend. so like, no libssh2, no vibe check. 😭

👑 AVAILABILITY 👑

Added in curl 7.80.0. ⭐

🌈 RETURN VALUE 🌈

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). 💖

🫶 SEE ALSO 🫶

mwah 💋 this page is from source/version libcurl, dated 2026-10-12, and its footer title is CURLOPT_SS...KEY_SHA256(3). bye bestie, go check those hashes 💜

📦 where this page comes from