CURLOPT_SSH_HOSTKEYFUNCTION − callback to check host key
#include <curl/curl.h>
int
keycallback(void *clientp,
int keytype,
const char *key,
size_t keylen);
CURLcode
curl_easy_setopt(CURL *handle, CURLOPT_SSH_HOSTKEYFUNCTION,
keycallback);
Pass a pointer to your callback function, which should match the prototype shown above. It overrides CURLOPT_SSH_KNOWNHOSTS(3).
This callback gets called when the verification of the SSH host key is needed.
key is keylen bytes long and is the key to check. keytype says what type it is, from the CURLKHTYPE_* series in the curl_khtype enum.
clientp is a custom pointer set with CURLOPT_SSH_HOSTKEYDATA(3).
The callback
MUST return one of the following return codes to tell
libcurl how to act:
CURLKHMATCH_OK
The host key is accepted, the connection should continue.
CURLKHMATCH_MISMATCH
the host key is rejected, the connection is canceled.
NULL
SCP and SFTP
struct mine {
void *custom;
};
int
hostkeycb(void *clientp, /* passed with
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)
{
struct mine callback_data;
CURL *curl = curl_easy_init();
if(curl) {
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);
}
}
Added in 7.84.0 , work only with libssh2 backend.
Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.
CURLOPT_SSH_HOSTKEYDATA(3), CURLOPT_SSH_KNOWNHOSTS(3)