org.apache.sshd.common.signature

Class SignatureDSA

java.lang.Object

org.apache.sshd.common.signature.AbstractSignature

org.apache.sshd.common.signature.SignatureDSA

All Implemented Interfaces:

AlgorithmNameProvider, Signature

public class SignatureDSA
extends AbstractSignature

DSA Signature

Author:

Apache MINA SSHD Project

See Also:

RFC4253 section 6.6

Field Summary

Fields

Modifier and Type	Field and Description
static String	DEFAULT_ALGORITHM
static int	DSA_SIGNATURE_LENGTH
static int	MAX_SIGNATURE_VALUE_LENGTH

Constructor Summary

Constructors

Modifier	Constructor and Description
	SignatureDSA()
protected	SignatureDSA(String algorithm)

Method Summary

Modifier and Type	Method and Description
static void	putBigInteger(BigInteger value, byte[] result, int offset)
byte[]	sign(SessionContext session) Compute the signature
boolean	verify(SessionContext session, byte[] sig) Verify against the given signature

Methods inherited from class org.apache.sshd.common.signature.AbstractSignature

doInitSignature, doVerify, extractEncodedSignature, extractEncodedSignature, getAlgorithm, getSignature, initSigner, initVerifier, toString, update

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.sshd.common.signature.Signature

getSshAlgorithmName, update

Field Detail

DEFAULT_ALGORITHM

public static final String DEFAULT_ALGORITHM

See Also:

Constant Field Values

DSA_SIGNATURE_LENGTH

public static final int DSA_SIGNATURE_LENGTH

See Also:

Constant Field Values

MAX_SIGNATURE_VALUE_LENGTH

public static final int MAX_SIGNATURE_VALUE_LENGTH

See Also:

Constant Field Values

Constructor Detail

SignatureDSA

public SignatureDSA()

SignatureDSA

protected SignatureDSA(String algorithm)

Method Detail

sign

public byte[] sign(SessionContext session)
            throws Exception

Description copied from interface: Signature

Compute the signature

Specified by:

sign in interface Signature

Overrides:

sign in class AbstractSignature

Parameters:

session - The SessionContext for calling this method - may be null if not called within a session context

Returns:

The signature value

Throws:

Exception - If failed to calculate the signature

putBigInteger

public static void putBigInteger(BigInteger value,
                                 byte[] result,
                                 int offset)

verify

public boolean verify(SessionContext session,
                      byte[] sig)
               throws Exception

Description copied from interface: Signature

Verify against the given signature

Parameters:

session - The SessionContext for calling this method - may be null if not called within a session context

sig - The signed data

Returns:

true if signature is valid

Throws:

Exception - If failed to extract signed data for validation