com.absio.crypto.signature

Class SignatureHelper

java.lang.Object

com.absio.crypto.signature.SignatureHelper

public class SignatureHelper
extends Object

Use this helper class to assist with signing and signature verification operations. It uses the JCE Signature class to accomplish the signing operations. The helper works with a set SignatureHelper.SignatureAlgorithm which is defined at creation.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	SignatureHelper.SignatureAlgorithm This enumeration represents the signature algorithms that Absio knowingly supports.

Constructor Summary

Constructors

Constructor and Description
SignatureHelper() Create a helper with SignatureHelper.SignatureAlgorithm.DEFAULT for signing and signature verification.
SignatureHelper(SignatureHelper.SignatureAlgorithm algorithm) Create a helper with the given SignatureHelper.SignatureAlgorithm for signing and signature verification.

Method Summary

Modifier and Type	Method and Description
byte[]	sign(PrivateKey key, byte[] data) Sign the data with the given private key.
boolean	verify(PublicKey key, byte[] data, byte[] signature)

Methods inherited from class java.lang.Object

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

Constructor Detail

SignatureHelper

public SignatureHelper(SignatureHelper.SignatureAlgorithm algorithm)
                throws NoSuchAlgorithmException

Create a helper with the given SignatureHelper.SignatureAlgorithm for signing and signature verification.

Parameters:

algorithm - the algorithm to use for signing and signature verification

Throws:

NoSuchAlgorithmException - thrown if the given SignatureHelper.SignatureAlgorithm is not supported

SignatureHelper

public SignatureHelper()
                throws NoSuchAlgorithmException

Create a helper with SignatureHelper.SignatureAlgorithm.DEFAULT for signing and signature verification.

Throws:

NoSuchAlgorithmException - thrown if SignatureHelper.SignatureAlgorithm.DEFAULT is not supported

Method Detail

sign

public byte[] sign(PrivateKey key,
                   byte[] data)
            throws InvalidKeyException,
                   SignatureException

Sign the data with the given private key.

Parameters:

key - the key to sign with

data - the data to sign

Returns:

the signature

Throws:

InvalidKeyException - thrown if the key is not correct for the helper's SignatureHelper.SignatureAlgorithm

SignatureException - thrown is there was an issue signing the data

verify

public boolean verify(PublicKey key,
                      byte[] data,
                      byte[] signature)
               throws SignatureException,
                      InvalidKeyException

Parameters:

key - the public portion of the private key used to sign the data

data - the data that was signed

signature - the signature

Returns:

true if the signature is correct for the given data

Throws:

SignatureException - thrown if the signature is not correct

InvalidKeyException - thrown if the key is not correct for the helper's SignatureHelper.SignatureAlgorithm