CURLOPT_SSH_HOST_PUBLIC_KEY_MD5(3) Library Functions Manual CURLOPT_SSH_HOST_PUBLIC_KEY_MD5(3)

CURLOPT_SSH_HOST_PUBLIC_KEY_MD5 - MD5 checksum of SSH server public key

#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_SSH_HOST_PUBLIC_KEY_MD5,
                          char *md5);

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.

NULL

This functionality affects scp and sftp

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);
  }
}

Added in curl 7.17.1

Returns CURLE_OK if the option is supported, CURLE_UNKNOWN_OPTION if not, or CURLE_OUT_OF_MEMORY if there was insufficient heap space.

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

2024-09-18 libcurl