iaik.security.rsa
Class ShaRSASignature

java.lang.Object
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  +--java.security.SignatureSpi
        |
        +--java.security.Signature
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              +--iaik.security.rsa.RSAPkcs1Signature
                    |
                    +--iaik.security.rsa.RSASignature
                          |
                          +--iaik.security.rsa.ShaRSASignature

public class ShaRSASignature

extends RSASignature

This class implements the RSA PKCS#1v1.5 digital signature algorithm (RSASSA-PKCS1-v1_5) using the Secure Hash Algorithm (SHA1) as message digest algorithm.

The PKCS#1v1.5 "SHA1 with RSA" signature algorithm is described in PKCS#1.

An application wishing to sign some message or to verify some signature using the "SHA1 with RSA" algorithm, generally has to perform three steps:

• First an instance of the desired signature algorithm has to be created using a proper getInstance method, e.g.

   Signature sha_rsa = Signature.getInstance("SHA1withRSA");
   

• Second, the Signature object just created has to be properly initialized for signing a message respectively verifying a signature using a RSA private respectively RSA public key, e.g.:
  • Initialize for Signing: sha_rsa.initSign(rsaPrivateKey);
  • Initialize for Verifying: sha_rsa.initVerify(rsaPublicKey);

• Finally, if the Signature object has been initialized for signing, the data to be signed is supplied to it and subsequently the signature is created by calling the sign method returning the signature as byte array. Otherwise, if the Signature object has been initialized for verifying, first the data to be verified is supplied to the Signature object, and subsequently the signature is verified by calling the verify method, supplied with the byte array holding the corresponding signature value:
  • Supply the data to be signed, and subsequently sign it:

     sha_rsa.update(data);
     byte[] signature = sha_rsa.sign();
     

  • Supply the data to be verified, and verify the signature:

     sha_rsa.update(data);
     System.out.println("Signature " + (sha_rsa.verify(signature) ? "correct!" : "not correct!"));
     

Version:

File Revision 16

See Also:

SHA, RSASignature, Signature

Fields inherited from class iaik.security.rsa.RSASignature

hash

Fields inherited from class java.security.Signature

SIGN, state, UNINITIALIZED, VERIFY

Fields inherited from class java.security.SignatureSpi

appRandom

Constructor Summary

ShaRSASignature()
Default Constructor.

Methods inherited from class iaik.security.rsa.RSASignature

engineGetParameter, engineInitSign, engineInitSign, engineInitVerify, engineSetParameter, engineSetParameter, engineSign, engineUpdate, engineUpdate, engineVerify

Methods inherited from class java.security.Signature

clone, getAlgorithm, getInstance, getInstance, getParameter, getProvider, initSign, initSign, initVerify, initVerify, setParameter, setParameter, sign, sign, toString, update, update, update, verify

Methods inherited from class java.security.SignatureSpi

engineSign

Methods inherited from class java.lang.Object

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

Constructor Detail

ShaRSASignature

public ShaRSASignature()

Default Constructor.

Applications do not call this constructor. They shall use one of the getInstance methods of the java.security.Signature class for obtaining a ShaRSASignature object.

See Also:

Signature.getInstance(java.lang.String)