CURLOPT_SSH_HOST_PUBLIC_KEY_MD5(3)                    Library Functions Manual

NAME
       CURLOPT_SSH_HOST_PUBLIC_KEY_MD5 - MD5 checksum of SSH server public key

SYNOPSIS
       #include <curl/curl.h>

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_SSH_HOST_PUBLIC_KEY_MD5,
                                 char *md5);

DESCRIPTION
       Pass a char pointer pointing to a string containing 32 hexadecimal
       digits. The string should be the 128 bit MD5 checksum of the remote
       host's public key, and libcurl aborts the connection to the host unless
       the MD5 checksum match.

       MD5 is a weak algorithm. We strongly recommend using
       CURLOPT_SSH_HOST_PUBLIC_KEY_SHA256(3) instead.

       The application does not have to keep the string around after setting
       this option.

       Using this option multiple times makes the last set string override the
       previous ones. Set it to NULL to disable its use again.

DEFAULT
       NULL

PROTOCOLS
       This functionality affects scp and sftp

EXAMPLE
       int main(void)
       {
         CURL *curl = curl_easy_init();
         if(curl) {
           CURLcode res;
           curl_easy_setopt(curl, CURLOPT_URL, "sftp://example.com/file");
           curl_easy_setopt(curl, CURLOPT_SSH_HOST_PUBLIC_KEY_MD5,
                            "afe17cd62a0f3b61f1ab9cb22ba269a7");
           res = curl_easy_perform(curl);
           curl_easy_cleanup(curl);
         }
       }

AVAILABILITY
       Added in curl 7.17.1

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
       CURLOPT_SSH_AUTH_TYPES(3), CURLOPT_SSH_HOST_PUBLIC_KEY_SHA256(3),
       CURLOPT_SSH_KNOWNHOSTS(3), CURLOPT_SSH_PUBLIC_KEYFILE(3)

libcurl                           2025-06-04
                                            CURLOPT_SSH_HOST_PUBLIC_KEY_MD5(3)