Signature クラスを使用して署名を検証しようとすると、 Signature.verify() メソッドは常に false を返します。私のコードは以下の通りです。
package test;
import com.sun.org.apache.xerces.internal.impl.dv.util.Base64;
import java.io.UnsupportedEncodingException;
import java.math.BigInteger;
import java.security.*;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.RSAPublicKeySpec;
import java.util.logging.Level;
import java.util.logging.Logger;
/* this method converts the string into hash using SHA1 encryption algorithm */
public class SignatureTest {
static byte[] sha1(String input) throws NoSuchAlgorithmException {
MessageDigest mDigest = MessageDigest.getInstance("SHA1");
byte[] result = mDigest.digest(input.getBytes());
System.out.println("sha1 hashed data" + result);
return result;
}
public static void main(String[] args) throws InvalidKeySpecException {
try {
String dataString = "70:F3:95:11:14:B3" + "AIG_OCR" + "5";
byte[] data = sha1(dataString);
System.out.println(dataString);
System.out.println("data::::::::::::" + data);
String data2 = Base64.encode(data);
System.out.println(data2);
/* here goes ur signed data */
byte[] signedData =
Base64.decode("Q2BD1bPUKcs/iWpsBlvFtcJfrnzofucHIhc+m3qvKibLO13Z7FLSUQyOUUL9oh5KKpxiQY6b4mcLKYP2N9UPNZlCB6WBowJyDTEGajKNNyBgnn6nm7I/7X+eboQkEEqmSsGC0WA1XFXE+QQD6EXWzEkXzPornC3RnNJoR/fEIc8=");
System.out.println(" lenghtof signedData:::::" +
signedData.length);
/* here is the modulus reqired to generate the public key*/
byte[] modulusBytes =
Base64.decode("pggfRN033/0G9HA5/x5v257h5Zdb13Lown8MTYDVF4ItZRuA6mC148omMvAdOO6wdaak/4atCvrIFrsNlFK8NSY8eb7WKN8WCdamXvHQ6G7FUDMOWs0WNokbhJRabUey/cXtG5b7ODTSr1VX2lV9uEfZEruw5YhmLXof39uftWc=");
/* here is the exponentBytes reqired to generate the public key*/
byte[] exponentBytes = Base64.decode("AQAB");
System.out.println(" lenghtof modulusBytes:::::" +
modulusBytes.length);
BigInteger modulus = new BigInteger(1, modulusBytes);
BigInteger exponent = new BigInteger(1, exponentBytes);
RSAPublicKeySpec rsaPubKey =
new RSAPublicKeySpec(modulus, exponent);
KeyFactory fact = KeyFactory.getInstance("RSA");
PublicKey rsaPublicKey = fact.generatePublic(rsaPubKey);
Signature sig = Signature.getInstance("SHA1withRSA");
sig.initVerify(rsaPublicKey); // initiate the signature with public key
sig.update(data); // update signature with the data that was signed by the card
Boolean flag =
sig.verify(signedData); // Test card signature - this always returns false
System.out.println("flag:::::::::::::" + flag);
} catch (SignatureException ex) {
Logger.getLogger(SignatureTest.class.getName()).log(Level.SEVERE,
null, ex);
} catch (InvalidKeyException ex) {
Logger.getLogger(SignatureTest.class.getName()).log(Level.SEVERE,
null, ex);
} catch (NoSuchAlgorithmException ex) {
Logger.getLogger(SignatureTest.class.getName()).log(Level.SEVERE,
null, ex);
} catch (Exception ex) {
Logger.getLogger(SignatureTest.class.getName()).log(Level.SEVERE,
null, ex);
}
}
}