com.mindbright.ssh2

Class SSH2Signature

java.lang.Object

com.mindbright.ssh2.SSH2Signature

All Implemented Interfaces:

SSH2PKISigner

Direct Known Subclasses:

SSH2SimpleSignature

public abstract class SSH2Signature
extends java.lang.Object
implements SSH2PKISigner

Abstract base class for classes implementing the ssh2 signature algorithms.

Field Summary

Fields

Modifier and Type	Field and Description
protected java.lang.String	algorithm
protected byte[]	pubKeyBlob
protected java.security.PublicKey	publicKey
protected java.security.Signature	signature

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	SSH2Signature() Constructor.

Method Summary

Methods

Modifier and Type	Method and Description
void	clearSensitiveData() Try to remove any sensitive data from memory.
protected abstract java.security.PublicKey	decodePublicKey(byte[] pubKeyBlob) Decode a public key blob.
protected abstract byte[]	decodeSignature(byte[] sigBlob) Decode the given signature blob from the ssh standard form to the internal form.
protected abstract byte[]	encodePublicKey(java.security.PublicKey publicKey) Encode the given public key into a public key blob.
protected abstract byte[]	encodeSignature(byte[] sigRaw) Encode the given, internal form, signature into the ssh standard form.
java.lang.String	getAlgorithmName() Get the algorithm this instance handles.
static SSH2Signature	getEncodingInstance(java.lang.String algorithm) Get a SSH2Signature instance suitable for encoding with the given algorithm.
static SSH2Signature	getInstance(java.lang.String algorithm) Get a SSH2Signature instance suitable for encoding with the given algorithm.
java.security.PublicKey	getPublicKey() Get the public key associated with this SSH2Signature object.
byte[]	getPublicKeyBlob() Get the public key associated with this SSH2Signature object.
protected abstract java.lang.String	getSignatureAlgorithm() Get the signature algorithm.
void	initSign(java.security.PrivateKey privateKey) Prepare for signing with the given private key.
void	initVerify(byte[] pubKeyBlob) Prepare to verify a signature with the given public key.
void	initVerify(java.security.PublicKey publicKey) Prepare to verify a signature with the given public key.
void	setIncompatibility(SSH2Transport transport) Set eventual incompatibility modes depending on the remote end.
void	setPublicKey(java.security.PublicKey publicKey) Associate a public key with this object.
byte[]	sign(byte[] data) Sign the given data.
boolean	verify(byte[] sigBlob, byte[] data) Verify that the given signature matches the given data and the public key.

Methods inherited from class java.lang.Object

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

Field Detail

algorithm

protected java.lang.String algorithm

signature

protected java.security.Signature signature

publicKey

protected java.security.PublicKey publicKey

pubKeyBlob

protected byte[] pubKeyBlob

Constructor Detail

SSH2Signature

protected SSH2Signature()

Constructor.

Method Detail

getInstance

public static SSH2Signature getInstance(java.lang.String algorithm)
                                 throws SSH2Exception

Get a SSH2Signature instance suitable for encoding with the given algorithm.

Parameters:

algorithm - The algorithm. Currently the valid values are "ssh-dss" and "ssh-rsa".

Returns:

An instance of the apropriate signature class.

Throws:

SSH2Exception

getEncodingInstance

public static SSH2Signature getEncodingInstance(java.lang.String algorithm)
                                         throws SSH2Exception

Get a SSH2Signature instance suitable for encoding with the given algorithm.

Parameters:

algorithm - The algorithm. Currently the valid values are "ssh-dss" and "ssh-rsa".

Returns:

An instance of the apropriate signature class.

Throws:

SSH2Exception

getAlgorithmName

public final java.lang.String getAlgorithmName()

Get the algorithm this instance handles.

Specified by:

getAlgorithmName in interface SSH2PKISigner

Returns:

The algorithm name.

getPublicKeyBlob

public final byte[] getPublicKeyBlob()
                              throws SSH2SignatureException

Get the public key associated with this SSH2Signature object.

Specified by:

getPublicKeyBlob in interface SSH2PKISigner

Returns:

A public key blob.

Throws:

SSH2SignatureException

getPublicKey

public final java.security.PublicKey getPublicKey()
                                           throws SSH2SignatureException

Get the public key associated with this SSH2Signature object.

Returns:

A public key object.

Throws:

SSH2SignatureException

setPublicKey

public final void setPublicKey(java.security.PublicKey publicKey)

Associate a public key with this object.

Parameters:

publicKey - The key to associate.

setIncompatibility

public void setIncompatibility(SSH2Transport transport)

Description copied from interface: SSH2PKISigner

Set eventual incompatibility modes depending on the remote end. Some older ssh implementations use slightly incompatible algorithms when signing data.

Specified by:

setIncompatibility in interface SSH2PKISigner

Parameters:

transport - An SSH2Transport object which identifies the other end.

initSign

public final void initSign(java.security.PrivateKey privateKey)
                    throws SSH2Exception

Prepare for signing with the given private key.

Parameters:

privateKey - Key to use for signing.

Throws:

SSH2Exception

initVerify

public final void initVerify(java.security.PublicKey publicKey)
                      throws SSH2Exception

Prepare to verify a signature with the given public key.

Parameters:

publicKey - Key to use when verifying.

Throws:

SSH2Exception

initVerify

public final void initVerify(byte[] pubKeyBlob)
                      throws SSH2Exception

Prepare to verify a signature with the given public key.

Parameters:

pubKeyBlob - key to use when verifying, encoded as a public key blob.

Throws:

SSH2Exception

sign

public byte[] sign(byte[] data)
            throws SSH2SignatureException

Sign the given data. The object must have been initialized for signing first.

Specified by:

sign in interface SSH2PKISigner

Parameters:

data - Data to sign.

Returns:

A signature blob encoded in the ssh format.

Throws:

SSH2SignatureException

verify

public boolean verify(byte[] sigBlob,
             byte[] data)
               throws SSH2SignatureException

Verify that the given signature matches the given data and the public key. The public key is given in the initialization call.

Parameters:

sigBlob - Signature blob encoded in the ssh format.

data - Signed data.

Returns:

True if the signature matches.

Throws:

SSH2SignatureException

getSignatureAlgorithm

protected abstract java.lang.String getSignatureAlgorithm()

Get the signature algorithm.

Returns:

The algorithm name.

encodePublicKey

protected abstract byte[] encodePublicKey(java.security.PublicKey publicKey)
                                   throws SSH2Exception

Encode the given public key into a public key blob.

Parameters:

publicKey - The public key to encode. Must be an instance of DSAPublicKey.

Returns:

A byte array containing the key suitably encoded.

Throws:

SSH2Exception

decodePublicKey

protected abstract java.security.PublicKey decodePublicKey(byte[] pubKeyBlob)
                                                    throws SSH2Exception

Decode a public key blob.

Parameters:

pubKeyBlob - A byte array containing a public key blob.

Returns:

A Publickey instance.

Throws:

SSH2Exception

encodeSignature

protected abstract byte[] encodeSignature(byte[] sigRaw)

Encode the given, internal form, signature into the ssh standard form.

Parameters:

sigRaw - The raw signature.

Returns:

A byte array containing the signature suitably encoded.

decodeSignature

protected abstract byte[] decodeSignature(byte[] sigBlob)
                                   throws SSH2SignatureException

Decode the given signature blob from the ssh standard form to the internal form.

Parameters:

sigBlob - The encoded signature.

Returns:

A raw signature blob.

Throws:

SSH2SignatureException

clearSensitiveData

public void clearSensitiveData()

Description copied from interface: SSH2PKISigner

Try to remove any sensitive data from memory.

Specified by:

clearSensitiveData in interface SSH2PKISigner