CURLOPT_SSH_KNOWNHOSTS(3) curl_easy_setopt options CURLOPT_SSH_KNOWNHOSTS(3)NAME
CURLOPT_SSH_KNOWNHOSTS - file name holding the SSH known hosts
SYNOPSIS
#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_SSH_KNOWNHOSTS, char *fname);
DESCRIPTION
Pass a pointer to a zero terminated string holding the file name of the known_host file to use. The known_hosts file should use the
OpenSSH file format as supported by libssh2. If this file is specified, libcurl will only accept connections with hosts that are known and
present in that file, with a matching public key. Use CURLOPT_SSH_KEYFUNCTION(3) to alter the default behavior on host and key (mis)match-
ing.
The application does not have to keep the string around after setting this option.
DEFAULT
NULL
PROTOCOLS
SFTP and SCP
EXAMPLE
TODO
AVAILABILITY
Added in 7.19.6
RETURN VALUE
Returns CURLE_OK if the option is supported, CURLE_UNKNOWN_OPTION if not, or CURLE_OUT_OF_MEMORY if there was insufficient heap space.
SEE ALSO CURLOPT_SSH_AUTH_TYPES(3), CURLOPT_SSH_HOST_PUBLIC_KEY_MD5(3),
libcurl 7.54.0 December 21, 2016 CURLOPT_SSH_KNOWNHOSTS(3)
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CURLOPT_SSH_KEYFUNCTION(3) curl_easy_setopt options CURLOPT_SSH_KEYFUNCTION(3)NAME
CURLOPT_SSH_KEYFUNCTION - callback for known host matching logic
SYNOPSIS
#include <curl/curl.h>
enum curl_khstat {
CURLKHSTAT_FINE_ADD_TO_FILE,
CURLKHSTAT_FINE,
CURLKHSTAT_REJECT, /* reject the connection, return an error */
CURLKHSTAT_DEFER, /* do not accept it, but we can't answer right
now so this causes a CURLE_DEFER error but
otherwise the connection will be left intact
etc */
};
enum curl_khmatch {
CURLKHMATCH_OK, /* match */
CURLKHMATCH_MISMATCH, /* host found, key mismatch! */
CURLKHMATCH_MISSING, /* no matching host/key found */
};
struct curl_khkey {
const char *key; /* points to a zero-terminated string encoded with
base64 if len is zero, otherwise to the "raw"
data */
size_t len;
enum curl_khtype keytype;
};
int ssh_keycallback(CURL *easy,
const struct curl_khkey *knownkey,
const struct curl_khkey *foundkey,
enum curl_khmatch,
void *clientp);
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_SSH_KEYFUNCTION,
ssh_keycallback);
DESCRIPTION
Pass a pointer to your callback function, which should match the prototype shown above.
It gets called when the known_host matching has been done, to allow the application to act and decide for libcurl how to proceed. The call-
back will only be called if CURLOPT_SSH_KNOWNHOSTS(3) is also set.
This callback function gets passed the CURL handle, the key from the known_hosts file knownkey, the key from the remote site foundkey, info
from libcurl on the matching status and a custom pointer (set with CURLOPT_SSH_KEYDATA(3)). It MUST return one of the following return
codes to tell libcurl how to act:
CURLKHSTAT_FINE_ADD_TO_FILE
The host+key is accepted and libcurl will append it to the known_hosts file before continuing with the connection. This will also
add the host+key combo to the known_host pool kept in memory if it wasn't already present there. The adding of data to the file is
done by completely replacing the file with a new copy, so the permissions of the file must allow this.
CURLKHSTAT_FINE
The host+key is accepted libcurl will continue with the connection. This will also add the host+key combo to the known_host pool
kept in memory if it wasn't already present there.
CURLKHSTAT_REJECT
The host+key is rejected. libcurl will deny the connection to continue and it will be closed.
CURLKHSTAT_DEFER
The host+key is rejected, but the SSH connection is asked to be kept alive. This feature could be used when the app wants to some-
how return back and act on the host+key situation and then retry without needing the overhead of setting it up from scratch again.
DEFAULT
NULL
PROTOCOLS
SFTP and SCP
EXAMPLE
TODO
AVAILABILITY
Added in 7.19.6
RETURN VALUE
Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.
SEE ALSO CURLOPT_SSH_KEYDATA(3), CURLOPT_SSH_KNOWNHOSTS(3),
libcurl 7.54.0 February 03, 2016 CURLOPT_SSH_KEYFUNCTION(3)