CURLOPT_SSH_HOSTKEYDATA explained

Name

CURLOPT_SSH_HOSTKEYDATA - pointer to pass to the SSH host key callback

Synopsis

#include <curl/curl.h>
 
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_SSH_HOSTKEYDATA, void *pointer);

Description

Pass a void * as parameter. This pointer is passed along untouched to the callback set with CURLOPT_SSH_HOSTKEYFUNCTION.

Default

NULL

Protocols

This functionality affects scp and sftp

Example

struct mine {
  void *custom;
};
 
static int hostkeycb(void *clientp,   /* CURLOPT_SSH_HOSTKEYDATA */
                     int keytype,     /* CURLKHTYPE */
                     const char *key, /* host key to check */
                     size_t keylen)   /* length of the key */
{
  /* 'clientp' points to the callback_data struct */
  /* investigate the situation and return the correct value */
  return CURLKHMATCH_OK;
}
 
int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    struct mine callback_data;
    curl_easy_setopt(curl, CURLOPT_URL, "sftp://example.com/thisfile.txt");
    curl_easy_setopt(curl, CURLOPT_SSH_HOSTKEYFUNCTION, hostkeycb);
    curl_easy_setopt(curl, CURLOPT_SSH_HOSTKEYDATA, &callback_data);
 
    curl_easy_perform(curl);
  }
}

Notes

Works only with the libssh2 backend.

Availability

Added in curl 7.84.0

Return value

curl_easy_setopt returns a CURLcode indicating success or error.

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