Package 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 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)

Author:

Apache MINA SSHD Project

See Also:

• Original article
• C implementation

Field Summary

Fields

Modifier and Type	Field	Description
static final String	AUGMENTATION_STRING
static final int	FLDBASE
static final int	FLDSIZE_X
static final int	FLDSIZE_Y

Constructor Summary

Constructors

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

Method Summary

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

Methods inherited from class java.lang.Object

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

Field Details

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 String AUGMENTATION_STRING

See Also:

• Constant Field Values

Constructor Details

KeyRandomArt

public KeyRandomArt(PublicKey key)
             throws Exception

Throws:

Exception

KeyRandomArt

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

Throws:

Exception

KeyRandomArt

public KeyRandomArt(PublicKey key,
 Digest d)
             throws Exception

Throws:

Exception

KeyRandomArt

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

Parameters:

algorithm - The key algorithm

keySize - The key size in bits

digest - The key digest

Method Details

getAlgorithm

public 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 Appendable> A append(A sb)
                                throws IOException

Outputs the generated random art

Type Parameters:

A - The Appendable output writer

Parameters:

sb - The writer

Returns:

The updated writer instance

Throws:

IOException - If failed to write the combined result

toString

public String toString()

Overrides:

toString in class Object

combine

public static String combine(char separator,
 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 String combine(SessionContext session,
 char separator,
 KeyIdentityProvider provider)
                      throws 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:

Exception - If failed to extract or combine the entries

See Also:

• combine(SessionContext, Appendable, char, KeyIdentityProvider)

combine

public static <A extends Appendable> A combine(SessionContext session,
 A sb,
 char separator,
 KeyIdentityProvider provider)
                                        throws 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:

Exception - If failed to extract or write the entries

See Also:

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

generate

public static Collection<KeyRandomArt> generate(SessionContext session,
 KeyIdentityProvider provider)
                                         throws 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:

Exception - If failed to extract the entries

See Also:

• KeyIdentityProvider.loadKeys(SessionContext)

combine

public static <A extends Appendable> A combine(A sb,
 char separator,
 Collection<? extends KeyRandomArt> arts)
                                        throws 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:

IOException - If failed to write the combined result