com.jcraft.jsch

Interface HostKeyRepository

public interface HostKeyRepository

A repository for known host keys. This will be used when connecting remote servers to check that their public keys are the same as we think they should be.

The library contains an implementation based on the OpenSSH known Hosts file format - this will be the default implementation if no other is given explicitely.

An application might want to implement this class to provide an alternative repository of valid server keys to use.

See Also:

JSch.setHostKeyRepository(com.jcraft.jsch.HostKeyRepository)

Field Summary

Fields

Modifier and Type	Field and Description
static int	CHANGED Constant for the result of check(java.lang.String, byte[]): The host has another key.
static int	NOT_INCLUDED Constant for the result of check(java.lang.String, byte[]): The host does not exist yet in the list.
static int	OK Constant for the result of check(java.lang.String, byte[]): The host has the given key.

Method Summary

Modifier and Type	Method and Description
void	add(HostKey hostkey, UserInfo ui) Adds a hostname-key-pair to the repository.
int	check(String host, byte[] key) Checks whether some host has a given key.
HostKey[]	getHostKey() returns all host keys in this repository.
HostKey[]	getHostKey(String host, String type) returns all host keys of a certain host.
String	getKnownHostsRepositoryID() returns an identifier for this repository.
void	remove(String host, String type) Removes a host key if there exists mached key with host, type.
void	remove(String host, String type, byte[] key) removes a specific key of a host from the repository.

Field Detail

OK

static final int OK

Constant for the result of check(java.lang.String, byte[]): The host has the given key.

See Also:

Constant Field Values

NOT_INCLUDED

static final int NOT_INCLUDED

Constant for the result of check(java.lang.String, byte[]): The host does not exist yet in the list.

See Also:

Constant Field Values

CHANGED

static final int CHANGED

Constant for the result of check(java.lang.String, byte[]): The host has another key. (This could be indicating a man-in-the-middle attack.)

See Also:

Constant Field Values

Method Detail

check

int check(String host,
          byte[] key)

Checks whether some host has a given key.

Parameters:

host - the host name to check

key - the public key the remote host uses.

Returns:

one of the constants OK (this host is known to use this key), NOT_INCLUDED (the host is unknown) or CHANGED (the host is known to use another key).

add

void add(HostKey hostkey,
         UserInfo ui)

Adds a hostname-key-pair to the repository.

Parameters:

hostkey - the key to add

ui - an UserInfo object which may be used to ask the user whether to create the file (and directory), or other similar questions, if necessary.

remove

void remove(String host,
            String type)

Removes a host key if there exists mached key with host, type.

See Also:

remove(String host, String type, byte[] key)

remove

void remove(String host,
            String type,
            byte[] key)

removes a specific key of a host from the repository.

Parameters:

host - the host name whose key is to remove.

type - the type of key to remove. If null, all keys of this host will be removed (without looking at key).

key - the key to be removed. If null, all keys of the given type and host will be removed.

Throws:

NullPointerException - if host == null.

getKnownHostsRepositoryID

String getKnownHostsRepositoryID()

returns an identifier for this repository. This could be the file name of the file being accessed, for example.

This will be used for messages to the user speaking about the repository.

getHostKey

HostKey[] getHostKey()

returns all host keys in this repository. This method does the same as getHostKey(null,null). This method should have been named getHostKeys().

getHostKey

HostKey[] getHostKey(String host,
                     String type)

returns all host keys of a certain host. This method should have been named getHostKeys(...).

Parameters:

host - a hostname used in searching host keys. If null is given, every host key will be listed.

type - a key type used in searching host keys, and it should be "ssh-dss" or "ssh-rsa". If null is given, a key type type will not be ignored.