我编写了简单的java类来创建双重签名并由商家方验证。当我尝试运行java类时，我在解密点上遇到异常。
javax.crypto.IllegalBlockSizeException: Data must not be longer than 256 bytes
at com.sun.crypto.provider.RSACipher.doFinal(RSACipher.java:344)
at com.sun.crypto.provider.RSACipher.engineDoFinal(RSACipher.java:389)
at javax.crypto.Cipher.doFinal(Cipher.java:2165)
at com.ucsc.raji.DualSignatureSample.convert(DualSignatureSample.java:43)
at com.ucsc.raji.DualSignatureSample.decrypt(DualSignatureSample.java:31)
at com.ucsc.raji.DualSignatureSample.verifyDualByMerchant(DualSignatureSample.java:128)
at com.ucsc.raji.DualSignatureSample.main(DualSignatureSample.java:175)
java.lang.NullPointerException
at java.lang.String.<init>(String.java:566)
at com.ucsc.raji.DualSignatureSample.verifyDualByMerchant(DualSignatureSample.java:129)
at com.ucsc.raji.DualSignatureSample.main(DualSignatureSample.java:175)
请注意，我已通过命令行使用Java密钥工具创建了密钥存储区 Java key tool basic commands
下面是java代码
package com.ucsc.raji;
import java.io.File;
import java.io.FileInputStream;
import java.security.Key;
import java.security.KeyPair;
import java.security.KeyStore;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.cert.Certificate;
import java.util.Base64;
import javax.crypto.Cipher;
import javax.crypto.NoSuchPaddingException;
public class DualSignatureSample {
public static byte[] encrypt(String original, Key privateKey) {
if (original != null && privateKey != null) {
byte[] bs = original.getBytes();
byte[] encData = convert(bs, privateKey, Cipher.ENCRYPT_MODE);
return encData;
}
return null;
}
public static byte[] decrypt(byte[] encrypted, Key publicKey) {
if (encrypted != null && publicKey != null) {
byte[] decData = convert(encrypted, publicKey, Cipher.DECRYPT_MODE);
return decData;
}
return null;
}
private static byte[] convert(byte[] data, Key key, int mode) {
try {
//Cipher cipher = Cipher.getInstance("RSA");
Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
cipher.init(mode, key);
byte[] newData = cipher.doFinal(data);
byte[] datax = org.apache.commons.codec.binary.Base64.encodeBase64(newData);
return datax;
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
public static KeyPair getPrivateKey() throws Exception {
FileInputStream is = new FileInputStream("C:" + File.separator
+ "Users" + File.separator + "rsatkunam" + File.separator
+ "Documents" + File.separator + "Rajeenthini" + File.separator
+ "MCS" + File.separator + "keystore.jks");
KeyStore keystore = KeyStore.getInstance(KeyStore.getDefaultType());
keystore.load(is, "password".toCharArray());
PublicKey publicKey = null;
String alias = "rajeenthini";
Key key = keystore.getKey(alias, "2015mcs070".toCharArray());
if (key instanceof PrivateKey) {
// Get certificate of public key
Certificate cert = keystore.getCertificate(alias);
// Get public key
publicKey = cert.getPublicKey();
// Return a key pair
}
return new KeyPair(publicKey, (PrivateKey) key);
}
public static PublicKey getPublicKey() throws Exception {
FileInputStream is = new FileInputStream("C:" + File.separator
+ "Users" + File.separator + "rsatkunam" + File.separator
+ "Documents" + File.separator + "Rajeenthini" + File.separator
+ "MCS" + File.separator + "keystore.jks");
KeyStore keystore = KeyStore.getInstance(KeyStore.getDefaultType());
keystore.load(is, "password".toCharArray());
PublicKey publicKey = null;
String alias = "rajeenthini";
Key key = keystore.getKey(alias, "password".toCharArray());
// Get certificate of public key
Certificate cert = keystore.getCertificate(alias);
// Get public key
publicKey = cert.getPublicKey();
return publicKey;
}
public static String getSha1(String input) throws NoSuchAlgorithmException {
MessageDigest mDigest = MessageDigest.getInstance("SHA1");
byte[] result = mDigest.digest(input.getBytes());
StringBuffer sb = new StringBuffer();
for (int i = 0; i < result.length; i++) {
sb.append(Integer.toString((result[i] & 0xff) + 0x100, 16).substring(1));
}
return sb.toString();
}
public static byte[] fromHexString(String s) {
int len = s.length();
byte[] data = new byte[len / 2];
for (int i = 0; i < len; i += 2) {
data[i / 2] = (byte) ((Character.digit(s.charAt(i), 16) << 4)
+ Character.digit(s.charAt(i+1), 16));
}
return data;
}
public static boolean verifyDualByMerchant(String ds, String oi, String hpi, PublicKey pubKey) throws NoSuchAlgorithmException{
boolean isVerified = false;
// String hOI = hash(oi);
// String hoihpi = hoi + hpi;
// String originalHash = decrypt(ds, pubKey);
// if (hoihpi.equals(originalHash)) {
// isVerified = true;
// }
System.out.println(ds.length());
byte[] ostr = decrypt(ds.getBytes(), pubKey);
System.out.println(new String(ostr).toString());
String xtr = new String(ostr);
System.out.println(xtr);
String x = getSha1(oi);
String cx = x + hpi;
String cxx = getSha1(cx);
System.out.println(cxx);
return isVerified;
}
public static void main(String args[]) {
String OI = "One Laptop Computer";
String PI = "4465-5342-2344-1009";
try {
/*System.out.println("---------1"+getPrivateKey().getPrivate());
byte[] cipherTxt = encrypt(OI, getPrivateKey().getPrivate());
System.out.println("---------2"+cipherTxt.toString());
System.out.println("---------3"+getPublicKey());
byte[] plainTxt = decrypt(cipherTxt, getPublicKey());
String s = new String(plainTxt);
System.out.println("---------4"+s);*/
String hashOI = getSha1(OI);
System.out.println("---------"+hashOI);
String hashPI = getSha1(PI);
System.out.println("---------"+hashPI);
String concatOIPI = hashOI + hashPI;
System.out.println("---------"+concatOIPI);
String hashconcatOIPI = getSha1(concatOIPI);
System.out.println("---------"+hashconcatOIPI);
byte[] dualSignature = encrypt(hashconcatOIPI, getPrivateKey().getPrivate());
String s = new String(dualSignature);
PublicKey pubKey = getPublicKey();
verifyDualByMerchant(s, OI, hashPI, pubKey);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
我正在获取保存在PC上本地文件夹中的密钥存储文件的公钥和私钥。 有人可以帮我解决这个例外吗？