iaik.ixsil.algorithms

Class SignatureAlgorithmImplRSA

java.lang.Object

iaik.ixsil.algorithms.Algorithm

iaik.ixsil.algorithms.SignatureAlgorithm

iaik.ixsil.algorithms.SignatureAlgorithmImplRSA

public class SignatureAlgorithmImplRSA
extends SignatureAlgorithm

Provides an signature algorithm implementation of the RSA signature algorithm, as it has been specified in XML Signature, Signature Algorithms. The Java Cryptography Architecture API is used for implementing the cryptographic computations.

Field Summary

Fields

Modifier and Type	Field and Description
protected java.lang.String	DEFAULT_ALGORITHM_URI_ The default algorithm URI for this algorithm implementation.
protected java.security.interfaces.RSAPublicKey	publicKey_ The public key used to verify the signature.
protected java.lang.String	RSA_JCA_ALGID_ The identifier used for the RSA algorithm within the Java Cryptography Architecture.

Fields inherited from class iaik.ixsil.algorithms.SignatureAlgorithm

input_, jCEProviderName_, privateKey_

Fields inherited from class iaik.ixsil.algorithms.Algorithm

uri_

Constructor Summary

Constructors

Constructor and Description
SignatureAlgorithmImplRSA() Standard constructor.
SignatureAlgorithmImplRSA(java.lang.String URI, java.lang.String RsaAlg) Constructor that allows specific RSA algorithms to be defined.

Method Summary

Modifier and Type	Method and Description
void	setSignerKey(java.security.interfaces.RSAPrivateKey signerKey) Sets the private key, which is used to compute the signature for the algorithm's input.
void	setVerifierKey(java.security.Key verifierKey) Sets the public key, which is used to verify the signature for the algorithm's input.
java.io.InputStream	sign() Computes the signature value for the input previously provided by means of method SignatureAlgorithm.setInput(java.io.InputStream).
org.w3c.dom.Element	toElement(org.w3c.dom.Document signatureDOMDoc) Returns the DOM element representation of the algorithm.
boolean	verifierKeyUnknown() Gets the information, if this signature algorithm knows about the verification key.
boolean	verify(java.io.InputStream signature) Verifies the specified signature for the input data previously set with method SignatureAlgorithm.setInput(java.io.InputStream).

Methods inherited from class iaik.ixsil.algorithms.SignatureAlgorithm

setInput, setJCEProviderName, setSignerKey

Methods inherited from class iaik.ixsil.algorithms.Algorithm

getURI, setParameters, setURI

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_ALGORITHM_URI_

protected java.lang.String DEFAULT_ALGORITHM_URI_

The default algorithm URI for this algorithm implementation.

RSA_JCA_ALGID_

protected java.lang.String RSA_JCA_ALGID_

The identifier used for the RSA algorithm within the Java Cryptography Architecture.

publicKey_

protected java.security.interfaces.RSAPublicKey publicKey_

The public key used to verify the signature.

Constructor Detail

SignatureAlgorithmImplRSA

public SignatureAlgorithmImplRSA()

Standard constructor. Sets the default value for the algorithm URI to http://www.w3.org/2000/09/xmldsig#rsa-sha1.

SignatureAlgorithmImplRSA

public SignatureAlgorithmImplRSA(java.lang.String URI,
                                 java.lang.String RsaAlg)

Constructor that allows specific RSA algorithms to be defined. The specified URI must be the appropriate type of URI for the RsaAlg defined. For example,

For example, the default constructor uses RSA-SHA1

 
 URI:        http://www.w3.org/2000/09/xmldsig#rsa-sha1
 JCE AlgID:  SHA/RSA
 

Note: This constructor does not take any parameters, so only RSA based algorithms that do not require parameters may be used

Parameters:

URI - The URI to use for the specified signature algorithm

RsaAlg - The RSA JCA/JCE algorithm String which identifies the algorithm to use

Method Detail

toElement

public org.w3c.dom.Element toElement(org.w3c.dom.Document signatureDOMDoc)
                              throws AlgorithmException

Returns the DOM element representation of the algorithm.

Specified by:

toElement in class Algorithm

Parameters:

signatureDOMDoc - The DOM document which should be used to create necessary DOM nodes. Must not be null.

Returns:

the DOM element representation of the algorithm.

Throws:

AlgorithmException - if no identifying URI has been specified for this algorithm.

sign

public java.io.InputStream sign()
                         throws AlgorithmException

Computes the signature value for the input previously provided by means of method SignatureAlgorithm.setInput(java.io.InputStream).

Specified by:

sign in class SignatureAlgorithm

Returns:

the signature value for the input specified with method SignatureAlgorithm.setInput(java.io.InputStream). This value will NOT be base64 encoded.

Throws:

AlgorithmException - if the signer key or the input data have not been set, or if computing the signature value fails for any reason.

verify

public boolean verify(java.io.InputStream signature)
               throws AlgorithmException

Verifies the specified signature for the input data previously set with method SignatureAlgorithm.setInput(java.io.InputStream).

Specified by:

verify in class SignatureAlgorithm

Parameters:

signature - The bytes representing the signature to be verified. Must not be null.

Returns:

true, if the signature is valid, false otherwise.

Throws:

AlgorithmException - if the verifier key or the input data have not been set, or if verifying the signature fails for any reason.

setSignerKey

public void setSignerKey(java.security.interfaces.RSAPrivateKey signerKey)

Sets the private key, which is used to compute the signature for the algorithm's input.

Parameters:

signerKey - The private key for computing the signature. Must not be null.

setVerifierKey

public void setVerifierKey(java.security.Key verifierKey)
                    throws AlgorithmException

Sets the public key, which is used to verify the signature for the algorithm's input.

Specified by:

setVerifierKey in class SignatureAlgorithm

Parameters:

verifierKey - The public key for verifying the signature. Must be an instance of RSAPublicKey and must not be null.

Throws:

AlgorithmException - if the specified key is not an instance of RSAPublicKey.

verifierKeyUnknown

public boolean verifierKeyUnknown()

Gets the information, if this signature algorithm knows about the verification key. This depends on wheter the key has already been set explicitely with method setVerifierKey(java.security.Key) or not.

Specified by:

verifierKeyUnknown in class SignatureAlgorithm

Returns:

true, if this signature algorithm does not know about the verification key.