curl/docs/libcurl/opts/CURLOPT_SSH_HOSTKEYDATA.md

---

c: Copyright (C) Daniel Stenberg, daniel@haxx.se, et al. SPDX-License-Identifier: curl Title: CURLOPT_SSH_HOSTKEYDATA Section: 3 Source: libcurl See-also:

• CURLOPT_SSH_HOSTKEYFUNCTION (3) Protocol:
• SFTP
• SCP Added-in: 7.84.0 ---

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(3).

DEFAULT

NULL

%PROTOCOLS%

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%

RETURN VALUE

Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.