com.hfg.util

Class CryptoUtil

java.lang.Object

com.hfg.util.CryptoUtil

public class CryptoUtil
extends Object

Cryptology-related methods for key & signature handling.

Constructor Summary

Constructors

Constructor and Description
CryptoUtil()

Method Summary

Modifier and Type	Method and Description
static KeyPair	generateEllipticCurveKeyPair() Generates an Elliptic Curve key pair using the default elliptic curve spec.
static KeyPair	generateEllipticCurveKeyPair(String inEllipticCurveSpec) Generates an Elliptic Curve key pair.
static byte[]	generateSignatureWithECDSA(PrivateKey inPrivateKey, String inText) Generates a signature give a private key and the text to sign.
static String	getDefaultEllipticCurveSpec() Returns the default SunEC-implemented elliptic curve spec used.
static PrivateKey	readPrivateEllipticCurveKeyFile(File inPrivateKeyFile)
static PublicKey	readPublicEllipticCurveKeyFile(File inPublicKeyFile)
static void	setDefaultEllipticCurveSpec(String inValue) Sets the default SunEC-implemented elliptic curve spec used.
static boolean	verifySignatureWithECDSA(PublicKey inPublicKey, String inText, byte[] inSignature) Verifies a signature give a public key, the signed text, and the signature.
static void	writePrivateEllipticCurveKeyToFile(PrivateKey inPrivateKey, File inFile)
static void	writePublicEllipticCurveKeyToFile(PublicKey inPublicKey, File inFile)

Methods inherited from class java.lang.Object

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

Constructor Detail

CryptoUtil

public CryptoUtil()

Method Detail

setDefaultEllipticCurveSpec

public static void setDefaultEllipticCurveSpec(String inValue)

Sets the default SunEC-implemented elliptic curve spec used. Surely there is a better way to find the possible values but here is one url: http://www.docjar.com/html/api/sun/security/ec/SunECEntries.java.html. Also see "Implementing ECC with Java Standard Edition 7" by V. Martinez.

Parameters:

inValue - String spec for the SunEC-implemented elliptic curve to use.

getDefaultEllipticCurveSpec

public static String getDefaultEllipticCurveSpec()

Returns the default SunEC-implemented elliptic curve spec used.

Returns:

Default String spec for the SunEC-implemented elliptic curve to use

generateEllipticCurveKeyPair

public static KeyPair generateEllipticCurveKeyPair()
                                            throws Exception

Generates an Elliptic Curve key pair using the default elliptic curve spec.

Returns:

KeyPair which can be written out to public and private key files.

Throws:

Exception

generateEllipticCurveKeyPair

public static KeyPair generateEllipticCurveKeyPair(String inEllipticCurveSpec)
                                            throws Exception

Generates an Elliptic Curve key pair.

Parameters:

inEllipticCurveSpec - String spec for the SunEC-implemented elliptic curve to use.

Returns:

KeyPair which can be written out to public and private key files.

Throws:

Exception

writePrivateEllipticCurveKeyToFile

public static void writePrivateEllipticCurveKeyToFile(PrivateKey inPrivateKey,
                                                      File inFile)
                                               throws Exception

Throws:

Exception

readPrivateEllipticCurveKeyFile

public static PrivateKey readPrivateEllipticCurveKeyFile(File inPrivateKeyFile)
                                                  throws Exception

Throws:

Exception

writePublicEllipticCurveKeyToFile

public static void writePublicEllipticCurveKeyToFile(PublicKey inPublicKey,
                                                     File inFile)
                                              throws Exception

Throws:

Exception

readPublicEllipticCurveKeyFile

public static PublicKey readPublicEllipticCurveKeyFile(File inPublicKeyFile)
                                                throws Exception

Throws:

Exception

generateSignatureWithECDSA

public static byte[] generateSignatureWithECDSA(PrivateKey inPrivateKey,
                                                String inText)
                                         throws Exception

Generates a signature give a private key and the text to sign. Uses the SHA512withECDSA signature algorithm.

Parameters:

inPrivateKey - private Elliptic Curve key

inText - text to sign

Returns:

signature as a byte[]

Throws:

Exception

verifySignatureWithECDSA

public static boolean verifySignatureWithECDSA(PublicKey inPublicKey,
                                               String inText,
                                               byte[] inSignature)
                                        throws Exception

Verifies a signature give a public key, the signed text, and the signature. Uses the SHA512withECDSA signature algorithm.

Parameters:

inPublicKey - public Elliptic Curve key

inText - text that was signed

inSignature - signature as a byte[]

Returns:

whether the signature is valid

Throws:

Exception