de.fuberlin.wiwiss.ng4j.swp.util
Class SWPSignatureUtilities

java.lang.Object
  de.fuberlin.wiwiss.ng4j.swp.util.SWPSignatureUtilities

public class SWPSignatureUtilities
extends Object

Last commit info : $Author: zedlitz $ $Date: 2007/03/07 09:44:19 $ $Revision: 1.9 $ SWPSignatureUtilities

This class contains a lot of supporting methods for manipulating digital signatures in the context of SWP.

We now support:

• X.509 "Identity" Certificates
• OpenPGP Certificates

We are investigating supporting other PKIs including:

• Simple Public Key Infrastructure (SPKI)

If you have any questions, please contact me at: erw@it-innovation.soton.ac.uk

Author:

Rowland Watkins Certificate and Chain verification code based on code by Svetlin Nakov

Constructor Summary

SWPSignatureUtilities()

Method Summary

static String	calculateDigest(NamedGraph graph, Node digestMethod)
static String	calculateDigest(NamedGraphSet set, Node digestMethod)
static String	calculateSignature(NamedGraph graph, Node signatureMethod, Object key)
static String	calculateSignature(NamedGraphSet set, Node signatureMethod, PrivateKey key)
static String	getCanonicalGraph(NamedGraph graph) Takes a NamedGraph and returns its canonical form.
static String	getCanonicalGraphSet(NamedGraphSet set) Takes a NamedGraphSet and returns its canonical form.
static Signature	getSignatureAlgorithm(Node signatureMethod)
static boolean	isEverySignatureValid(NamedGraph verifiedSignatures) Check if all signatures in a verifiedSignatures graph are avlid.
static boolean	validateSignature(NamedGraph graph, Node signatureMethod, String signatureValue, String pem)
static boolean	validateSignature(NamedGraph graph, Node signatureMethod, String signatureValue, X509Certificate certificate)
static boolean	validateSignature(NamedGraph graph, Node signatureMethod, String signatureValue, X509Certificate certificate, ArrayList trustedCertificates)
static boolean	validateSignature(NamedGraph graph, Node signatureMethod, String signatureValue, X509Certificate certificate, ArrayList trustedCertificates, ArrayList otherCertificates)
static void	verifyCertificate(X509Certificate aCertificate, ArrayList aTrustedCertificates) Verifies a certificate.

Methods inherited from class java.lang.Object

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

Constructor Detail

SWPSignatureUtilities

public SWPSignatureUtilities()

Method Detail

getCanonicalGraph

public static String getCanonicalGraph(NamedGraph graph)

Takes a NamedGraph and returns its canonical form.

This method fixes the flaw where the graph name is excluded from the canonical form.

Parameters:

Named - Graph graph

Returns:

canonicalString

getCanonicalGraphSet

public static String getCanonicalGraphSet(NamedGraphSet set)

Takes a NamedGraphSet and returns its canonical form.

Parameters:

NamedGraphSet - set

Returns:

canonicalString

calculateDigest

public static String calculateDigest(NamedGraph graph,
                                     Node digestMethod)
                              throws SWPNoSuchDigestMethodException

Parameters:

graph -

digestMethod -

Returns:

digest

Throws:

SWPNoSuchDigestMethodException

calculateDigest

public static String calculateDigest(NamedGraphSet set,
                                     Node digestMethod)
                              throws SWPNoSuchDigestMethodException

Parameters:

set -

digestMethod -

Returns:

digest

Throws:

SWPNoSuchDigestMethodException

calculateSignature

public static String calculateSignature(NamedGraph graph,
                                        Node signatureMethod,
                                        Object key)
                                 throws SWPNoSuchAlgorithmException,
                                        SWPSignatureException,
                                        SWPInvalidKeyException,
                                        SWPAlgorithmNotSupportedException

Parameters:

graph -

signatureMethod -

key -

Returns:

signature

Throws:

SWPNoSuchAlgorithmException

SWPSignatureException

SWPInvalidKeyException

SWPAlgorithmNotSupportedException

calculateSignature

public static String calculateSignature(NamedGraphSet set,
                                        Node signatureMethod,
                                        PrivateKey key)
                                 throws SWPNoSuchAlgorithmException,
                                        SWPSignatureException,
                                        SWPInvalidKeyException

Parameters:

set -

signatureMethod -

key -

Returns:

signature

Throws:

SWPNoSuchAlgorithmException

SWPSignatureException

SWPInvalidKeyException

getSignatureAlgorithm

public static Signature getSignatureAlgorithm(Node signatureMethod)
                                       throws SWPNoSuchAlgorithmException

Throws:

SWPNoSuchAlgorithmException

validateSignature

public static boolean validateSignature(NamedGraph graph,
                                        Node signatureMethod,
                                        String signatureValue,
                                        String pem)
                                 throws SWPNoSuchAlgorithmException,
                                        SWPValidationException,
                                        SWPInvalidKeyException,
                                        SWPSignatureException

Parameters:

graph -

signatureMethod -

signatureValue -

pem -

Returns:

boolean

Throws:

SWPNoSuchAlgorithmException

SWPValidationException

SWPInvalidKeyException

SWPSignatureException

validateSignature

public static boolean validateSignature(NamedGraph graph,
                                        Node signatureMethod,
                                        String signatureValue,
                                        X509Certificate certificate)
                                 throws SWPNoSuchAlgorithmException,
                                        SWPValidationException,
                                        SWPInvalidKeyException,
                                        SWPSignatureException,
                                        SWPCertificateException

Parameters:

graph -

signatureMethod -

signatureValue -

certificate -

Returns:

boolean

Throws:

SWPNoSuchAlgorithmException

SWPValidationException

SWPInvalidKeyException

SWPSignatureException

SWPCertificateException

validateSignature

public static boolean validateSignature(NamedGraph graph,
                                        Node signatureMethod,
                                        String signatureValue,
                                        X509Certificate certificate,
                                        ArrayList trustedCertificates)
                                 throws SWPNoSuchAlgorithmException,
                                        SWPValidationException,
                                        SWPInvalidKeyException,
                                        SWPSignatureException

Parameters:

graph -

signatureMethod -

signatureValue -

certificate -

trustedCertificates -

Returns:

boolean

Throws:

SWPNoSuchAlgorithmException

SWPValidationException

SWPInvalidKeyException

SWPSignatureException

validateSignature

public static boolean validateSignature(NamedGraph graph,
                                        Node signatureMethod,
                                        String signatureValue,
                                        X509Certificate certificate,
                                        ArrayList trustedCertificates,
                                        ArrayList otherCertificates)
                                 throws SWPNoSuchAlgorithmException,
                                        SWPValidationException,
                                        SWPInvalidKeyException,
                                        SWPSignatureException

Parameters:

graph -

signatureMethod -

signatureValue -

certificate -

trustedCertificates -

otherCertificates -

Returns:

boolean

Throws:

SWPNoSuchAlgorithmException

SWPValidationException

SWPInvalidKeyException

SWPSignatureException

verifyCertificate

public static void verifyCertificate(X509Certificate aCertificate,
                                     ArrayList aTrustedCertificates)
                              throws GeneralSecurityException,
                                     CertificateExpiredException,
                                     CertificateNotYetValidException

Verifies a certificate. Checks its validity period and tries to find a trusted certificate from given list of trusted certificates that is directly signed given certificate. The certificate is valid if no exception is thrown.

Parameters:

aCertificate - the certificate to be verified.

aTrustedCertificates - a list of trusted certificates to be used in the verification process.

Throws:

CertificateExpiredException - if the certificate validity period is expired.

CertificateNotYetValidException - if the certificate validity period is not yet started.

SWPCertificateValidationException - if the certificate is invalid (can not be validated using the given set of trusted certificates.

GeneralSecurityException

isEverySignatureValid

public static boolean isEverySignatureValid(NamedGraph verifiedSignatures)

Check if all signatures in a verifiedSignatures graph are avlid. After invoking SWPNamedGraphSet.verifyAllSignatures() a new graph called will be added to the graphset. This methods checks if all signatures in this graph are valid.

Parameters:

verifiedSignatures -