com.sshtools.publickey

Class KnownHostsKeyVerification

java.lang.Object

com.sshtools.publickey.KnownHostsKeyVerification

All Implemented Interfaces:

HostKeyUpdater, HostKeyVerification

Direct Known Subclasses:

KnownHostsFile

public class KnownHostsKeyVerification
extends Object
implements HostKeyVerification, HostKeyUpdater

An abstract HostKeyVerification class implementation providing validation against the known_hosts format.

Author:

Lee David Painter

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	KnownHostsKeyVerification.BlankEntry
class	KnownHostsKeyVerification.CertAuthorityEntry
class	KnownHostsKeyVerification.CommentEntry
class	KnownHostsKeyVerification.HostFileEntry
class	KnownHostsKeyVerification.InvalidEntry
class	KnownHostsKeyVerification.KeyEntry
class	KnownHostsKeyVerification.RevokedEntry
class	KnownHostsKeyVerification.Ssh2KeyEntry

Constructor Summary

Constructors

Constructor and Description
KnownHostsKeyVerification()
KnownHostsKeyVerification(InputStream in)
KnownHostsKeyVerification(String knownhosts)

Method Summary

Modifier and Type	Method and Description
void	addEntry(SshPublicKey key, String comment, String... names)
void	addListener(HostKeyVerificationListener listener)
void	allowHost(String host, SshPublicKey key, boolean always)
void	clear()
Set<String>	getAlgorithmsForHost(String host)
Set<KnownHostsKeyVerification.KeyEntry>	getKeyEntries()
boolean	isHostFileWriteable()
boolean	isKnownHost(String host, SshPublicKey key)
void	load(InputStream in)
protected void	onHostKeyAdded(Set<String> names, SshPublicKey key)
protected void	onHostKeyMismatch(String host, List<SshPublicKey> allowedHostKey, SshPublicKey actualHostKey) Called by the verifyHost method when the host key supplied by the host does not match the current key recording in the known hosts file.
protected void	onHostKeyRemoved(Set<String> names, SshPublicKey key)
protected void	onHostKeyUpdated(Set<String> names, SshPublicKey key)
protected void	onInvalidHostEntry(String entry)
protected void	onRevokedKey(String host, SshPublicKey key) Called by the verifyHost method when the host key supplied is listed as a revoked key.
protected void	onUnknownHost(String host, SshPublicKey key) Called by the verifyHost method when the host key supplied is not recorded in the known_hosts file.
void	removeEntries(SshPublicKey key)
void	removeEntries(String... hosts)
void	removeEntries(String host) Removes an allowed host.
void	removeEntries(String host, SshPublicKey key)
void	removeEntry(KnownHostsKeyVerification.KeyEntry... keys)
protected Set<String>	resolveNames(String host)
void	setComment(KnownHostsKeyVerification.KeyEntry entry, String comment)
void	setHashHosts(boolean hashHosts)
void	setUseCanonicalHostnames(boolean value)
void	setUseReverseDNS(boolean value)
String	toString() Outputs the allowed hosts in the known_hosts file format.
void	updateHostKey(String host, SshPublicKey key)
boolean	useCanonicalHostname()
boolean	useHashHosts()
boolean	useReverseDNS()
boolean	verifyHost(String host, SshPublicKey pk) Verifies a host key against the list of known_hosts.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

KnownHostsKeyVerification

public KnownHostsKeyVerification(InputStream in)
                          throws SshException,
                                 IOException

Throws:

SshException

IOException

KnownHostsKeyVerification

public KnownHostsKeyVerification(String knownhosts)
                          throws SshException,
                                 IOException

Throws:

SshException

IOException

KnownHostsKeyVerification

public KnownHostsKeyVerification()

Method Detail

addListener

public void addListener(HostKeyVerificationListener listener)

clear

public void clear()

load

public void load(InputStream in)
          throws SshException,
                 IOException

Throws:

SshException

IOException

onHostKeyAdded

protected void onHostKeyAdded(Set<String> names,
                              SshPublicKey key)

setComment

public void setComment(KnownHostsKeyVerification.KeyEntry entry,
                       String comment)

setHashHosts

public void setHashHosts(boolean hashHosts)

onInvalidHostEntry

protected void onInvalidHostEntry(String entry)
                           throws SshException

Throws:

SshException

onHostKeyMismatch

protected void onHostKeyMismatch(String host,
                                 List<SshPublicKey> allowedHostKey,
                                 SshPublicKey actualHostKey)
                          throws SshException

Called by the verifyHost method when the host key supplied by the host does not match the current key recording in the known hosts file.

Parameters:

host - the name of the host

allowedHostKey - the current key recorded in the known_hosts file.

actualHostKey - the actual key supplied by the user

Throws:

SshException - if an error occurs

Since:

0.2.0

onUnknownHost

protected void onUnknownHost(String host,
                             SshPublicKey key)
                      throws SshException

Called by the verifyHost method when the host key supplied is not recorded in the known_hosts file.

Parameters:

host - the name of the host

key - the public key supplied by the host

Throws:

SshException - if an error occurs

Since:

0.2.0

onRevokedKey

protected void onRevokedKey(String host,
                            SshPublicKey key)

Called by the verifyHost method when the host key supplied is listed as a revoked key. This is informational, any changes made to the current entries will still result in a failed host verification.

Parameters:

host -

key -

Throws:

SshException

removeEntries

public void removeEntries(String host)
                   throws SshException

Removes an allowed host.

Parameters:

host - the host to remove

Throws:

SshException

Since:

0.2.0

removeEntries

public void removeEntries(String host,
                          SshPublicKey key)
                   throws SshException

Throws:

SshException

removeEntries

public void removeEntries(String... hosts)
                   throws SshException

Throws:

SshException

removeEntries

public void removeEntries(SshPublicKey key)

removeEntry

public void removeEntry(KnownHostsKeyVerification.KeyEntry... keys)

onHostKeyRemoved

protected void onHostKeyRemoved(Set<String> names,
                                SshPublicKey key)

isHostFileWriteable

public boolean isHostFileWriteable()

allowHost

public void allowHost(String host,
                      SshPublicKey key,
                      boolean always)
               throws SshException

Throws:

SshException

addEntry

public void addEntry(SshPublicKey key,
                     String comment,
                     String... names)
              throws SshException

Throws:

SshException

verifyHost

public boolean verifyHost(String host,
                          SshPublicKey pk)
                   throws SshException

Verifies a host key against the list of known_hosts.

If the host unknown or the key does not match the currently allowed host key the abstract onUnknownHost or onHostKeyMismatch methods are called so that the caller may identify and allow the host.

Specified by:

verifyHost in interface HostKeyVerification

Parameters:

host - the name of the host

pk - the host key supplied

Returns:

true if the host is accepted, otherwise false

Throws:

SshException - if an error occurs

Since:

0.2.0

getAlgorithmsForHost

public Set<String> getAlgorithmsForHost(String host)
                                 throws SshException

Throws:

SshException

resolveNames

protected Set<String> resolveNames(String host)

useCanonicalHostname

public boolean useCanonicalHostname()

useReverseDNS

public boolean useReverseDNS()

useHashHosts

public boolean useHashHosts()

toString

public String toString()

Outputs the allowed hosts in the known_hosts file format.

The format consists of any number of lines each representing one key for a single host.

titan,192.168.1.12 ssh-dss AAAAB3NzaC1kc3MAAACBAP1/U4Ed..... titan,192.168.1.12 ssh-rsa AAAAB3NzaC1kc3MAAACBAP1/U4Ed..... einstein,192.168.1.40 ssh-dss AAAAB3NzaC1kc3MAAACBAP1/U4Ed.....

Overrides:

toString in class Object

Returns:

String

Since:

0.2.0

setUseCanonicalHostnames

public void setUseCanonicalHostnames(boolean value)

setUseReverseDNS

public void setUseReverseDNS(boolean value)

getKeyEntries

public Set<KnownHostsKeyVerification.KeyEntry> getKeyEntries()

isKnownHost

public boolean isKnownHost(String host,
                           SshPublicKey key)
                    throws SshException

Specified by:

isKnownHost in interface HostKeyUpdater

Throws:

SshException

updateHostKey

public void updateHostKey(String host,
                          SshPublicKey key)
                   throws SshException

Specified by:

updateHostKey in interface HostKeyUpdater

Throws:

SshException

onHostKeyUpdated

protected void onHostKeyUpdated(Set<String> names,
                                SshPublicKey key)