org.apache.sshd.common.config.keys

Class KeyRandomArt

java.lang.Object

org.apache.sshd.common.config.keys.KeyRandomArt

All Implemented Interfaces:

AlgorithmNameProvider, KeySizeIndicator

public class KeyRandomArt
extends java.lang.Object
implements AlgorithmNameProvider, KeySizeIndicator

Draw an ASCII-Art representing the fingerprint so human brain can profit from its built-in pattern recognition ability. This technique is called "random art" and can be found in some scientific publications like this original paper: "Hash Visualization: a New Technique to improve Real-World Security", Perrig A. and Song D., 1999, International Workshop on Cryptographic Techniques and E-Commerce (CrypTEC '99)

See Also:

Original article, C implementation

Field Summary

Fields

Modifier and Type	Field and Description
private java.lang.String	algorithm
static java.lang.String	AUGMENTATION_STRING
private char[][]	field
static int	FLDBASE
static int	FLDSIZE_X
static int	FLDSIZE_Y
private int	keySize

Constructor Summary

Constructors

Constructor and Description
KeyRandomArt(java.security.PublicKey key)
KeyRandomArt(java.security.PublicKey key, Digest d)
KeyRandomArt(java.security.PublicKey key, Factory<? extends Digest> f)
KeyRandomArt(java.lang.String algorithm, int keySize, byte[] digest)

Method Summary

Modifier and Type	Method and Description
<A extends java.lang.Appendable> A	append(A sb) Outputs the generated random art
static <A extends java.lang.Appendable> A	combine(A sb, char separator, java.util.Collection<? extends KeyRandomArt> arts) Combines the arts in a user-friendly way so they are aligned with each other
static java.lang.String	combine(char separator, java.util.Collection<? extends KeyRandomArt> arts) Combines the arts in a user-friendly way so they are aligned with each other
static <A extends java.lang.Appendable> A	combine(SessionContext session, A sb, char separator, KeyIdentityProvider provider) Appends the combined random art entries for the provided keys
static java.lang.String	combine(SessionContext session, char separator, KeyIdentityProvider provider) Creates the combined representation of the random art entries for the provided keys
static java.util.Collection<KeyRandomArt>	generate(SessionContext session, KeyIdentityProvider provider) Extracts and generates random art entries for all key in the provider
java.lang.String	getAlgorithm()
int	getKeySize()
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

FLDBASE

public static final int FLDBASE

See Also:

Constant Field Values

FLDSIZE_Y

public static final int FLDSIZE_Y

See Also:

Constant Field Values

FLDSIZE_X

public static final int FLDSIZE_X

See Also:

Constant Field Values

AUGMENTATION_STRING

public static final java.lang.String AUGMENTATION_STRING

See Also:

Constant Field Values

algorithm

private final java.lang.String algorithm

keySize

private final int keySize

field

private final char[][] field

Constructor Detail

KeyRandomArt

public KeyRandomArt(java.security.PublicKey key)
             throws java.lang.Exception

Throws:

java.lang.Exception

KeyRandomArt

public KeyRandomArt(java.security.PublicKey key,
                    Factory<? extends Digest> f)
             throws java.lang.Exception

Throws:

java.lang.Exception

KeyRandomArt

public KeyRandomArt(java.security.PublicKey key,
                    Digest d)
             throws java.lang.Exception

Throws:

java.lang.Exception

KeyRandomArt

public KeyRandomArt(java.lang.String algorithm,
                    int keySize,
                    byte[] digest)

Parameters:

algorithm - The key algorithm

keySize - The key size in bits

digest - The key digest

Method Detail

getAlgorithm

public java.lang.String getAlgorithm()

Specified by:

getAlgorithm in interface AlgorithmNameProvider

Returns:

The algorithm that was used to generate the key - e.g., "RSA", "DSA", "EC".

getKeySize

public int getKeySize()

Specified by:

getKeySize in interface KeySizeIndicator

Returns:

The number of bits used in the key

append

public <A extends java.lang.Appendable> A append(A sb)
                                          throws java.io.IOException

Outputs the generated random art

Type Parameters:

A - The Appendable output writer

Parameters:

sb - The writer

Returns:

The updated writer instance

Throws:

java.io.IOException - If failed to write the combined result

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

combine

public static java.lang.String combine(char separator,
                                       java.util.Collection<? extends KeyRandomArt> arts)

Combines the arts in a user-friendly way so they are aligned with each other

Parameters:

separator - The separator to use between the arts - if empty char ('\0') then no separation is done

arts - The KeyRandomArts to combine - ignored if null/empty

Returns:

The combined result

combine

public static java.lang.String combine(SessionContext session,
                                       char separator,
                                       KeyIdentityProvider provider)
                                throws java.lang.Exception

Creates the combined representation of the random art entries for the provided keys

Parameters:

session - The SessionContext for invoking this load command - may be null if not invoked within a session context (e.g., offline tool or session unknown).

separator - The separator to use between the arts - if empty char ('\0') then no separation is done

provider - The KeyIdentityProvider - ignored if null or has no keys to provide

Returns:

The combined representation

Throws:

java.lang.Exception - If failed to extract or combine the entries

See Also:

combine(SessionContext, Appendable, char, KeyIdentityProvider)

combine

public static <A extends java.lang.Appendable> A combine(SessionContext session,
                                                         A sb,
                                                         char separator,
                                                         KeyIdentityProvider provider)
                                                  throws java.lang.Exception

Appends the combined random art entries for the provided keys

Type Parameters:

A - The Appendable output writer

Parameters:

session - The SessionContext for invoking this load command - may be null if not invoked within a session context (e.g., offline tool or session unknown).

sb - The writer

separator - The separator to use between the arts - if empty char ('\0') then no separation is done

provider - The KeyIdentityProvider - ignored if null or has no keys to provide

Returns:

The updated writer instance

Throws:

java.lang.Exception - If failed to extract or write the entries

See Also:

generate(SessionContext, KeyIdentityProvider), combine(Appendable, char, Collection)

generate

public static java.util.Collection<KeyRandomArt> generate(SessionContext session,
                                                          KeyIdentityProvider provider)
                                                   throws java.lang.Exception

Extracts and generates random art entries for all key in the provider

Parameters:

session - The SessionContext for invoking this load command - may be null if not invoked within a session context (e.g., offline tool or session unknown).

provider - The KeyIdentityProvider - ignored if null or has no keys to provide

Returns:

The extracted KeyRandomArts

Throws:

java.lang.Exception - If failed to extract the entries

See Also:

KeyIdentityProvider.loadKeys(SessionContext)

combine

public static <A extends java.lang.Appendable> A combine(A sb,
                                                         char separator,
                                                         java.util.Collection<? extends KeyRandomArt> arts)
                                                  throws java.io.IOException

Combines the arts in a user-friendly way so they are aligned with each other

Type Parameters:

A - The Appendable output writer

Parameters:

sb - The writer

separator - The separator to use between the arts - if empty char ('\0') then no separation is done

arts - The KeyRandomArts to combine - ignored if null/empty

Returns:

The updated writer instance

Throws:

java.io.IOException - If failed to write the combined result