I'm working on small tool to encrypt and decrypt data base on RSA Algo. I used openSSL to create private and public key. then import to java code and encrypt and decrypt data. Fisrt, I use follow command to generate public and private key
openssl genrsa -out private_key.pem 2048
openssl req -new -x509 -sha256 -key private_key.pem -out public_key.cer -days 3650
Next, get public key from file:
private static PublicKey getPublicKey(String publicKey) throws IOException, GeneralSecurityException {
String publicKeyPEM = getKey(publicKey);
return getPublicKeyFromString(publicKeyPEM);
}
private static PublicKey getPublicKeyFromString(String key) throws IOException, GeneralSecurityException {
String publicKeyPEM = key;
publicKeyPEM = publicKeyPEM.replace("-----BEGIN CERTIFICATE-----\n", "");
publicKeyPEM = publicKeyPEM.replace("-----END CERTIFICATE-----", "");
byte[] encoded = Base64.decodeBase64(publicKeyPEM);
CertificateFactory fact = CertificateFactory.getInstance("X.509");
InputStream is = new ByteArrayInputStream(encoded);
X509Certificate cer = (X509Certificate) fact.generateCertificate(is);
return cer.getPublicKey();
}
And private key from file
private static PrivateKey getPrivateKey(String privateKey) throws IOException, GeneralSecurityException {
String privateKeyPEM = getKey(privateKey);
return getPrivateKeyFromString(privateKeyPEM);
}
private static PrivateKey getPrivateKeyFromString(String key) throws IOException, GeneralSecurityException {
String privateKeyPEM = key;
privateKeyPEM = privateKeyPEM.replace("-----BEGIN RSA PRIVATE KEY-----\n", "");
privateKeyPEM = privateKeyPEM.replace("\n-----END RSA PRIVATE KEY-----\n", "");
KeyFactory kf = KeyFactory.getInstance("RSA");
byte[] data = DatatypeConverter.parseBase64Binary(privateKeyPEM);
ASN1Sequence primitive = (ASN1Sequence) ASN1Sequence
.fromByteArray(data);
Enumeration<?> e = primitive.getObjects();
BigInteger v = ((DERInteger) e.nextElement()).getValue();
int version = v.intValue();
if (version != 0 && version != 1) {
throw new IllegalArgumentException("wrong version for RSA private key");
}
/**
* In fact only modulus and private exponent are in use.
*/
BigInteger modulus = ((DERInteger) e.nextElement()).getValue();
BigInteger publicExponent = ((DERInteger) e.nextElement()).getValue();
BigInteger privateExponent = ((DERInteger) e.nextElement()).getValue();
BigInteger prime1 = ((DERInteger) e.nextElement()).getValue();
BigInteger prime2 = ((DERInteger) e.nextElement()).getValue();
BigInteger exponent1 = ((DERInteger) e.nextElement()).getValue();
BigInteger exponent2 = ((DERInteger) e.nextElement()).getValue();
BigInteger coefficient = ((DERInteger) e.nextElement()).getValue();
RSAPrivateKeySpec spec = new RSAPrivateKeySpec(modulus, privateExponent);
PrivateKey pk = kf.generatePrivate(spec);
return pk;
}
Then encrypt
private static byte[] encrypt(String text, PublicKey key) {
byte[] cipherText = null;
try {
// get an RSA cipher object and print the provider
final Cipher cipher = Cipher.getInstance(ALGORITHM);
// encrypt the plain text using the public key
cipher.init(Cipher.ENCRYPT_MODE, key);
cipherText = cipher.doFinal(text.getBytes());
} catch (Exception e) {
e.printStackTrace();
}
return cipherText;
}
And decrypt
private static String decrypt(byte[] text, PrivateKey key) {
try {
// get an RSA cipher object and print the provider
final Cipher cipher = Cipher.getInstance(ALGORITHM);
// decrypt the text using the private key
cipher.init(Cipher.DECRYPT_MODE, key);
byte[] decryptTxt = cipher.doFinal(text);
return new String(decryptTxt);
} catch (Exception ex) {
ex.printStackTrace();
return null;
}
}
So, encryption success, but in decrypt, I got following exception:
javax.crypto.BadPaddingException: Decryption error
at sun.security.rsa.RSAPadding.unpadV15(RSAPadding.java:380)
at sun.security.rsa.RSAPadding.unpad(RSAPadding.java:291)
at com.sun.crypto.provider.RSACipher.doFinal(RSACipher.java:363)
at com.sun.crypto.provider.RSACipher.engineDoFinal(RSACipher.java:389)
at javax.crypto.Cipher.doFinal(Cipher.java:2165)
at pgp.RSAUtil.decrypt(RSAUtil.java:46)
at pgp.RSAUtil.getDecryptData(RSAUtil.java:67)
at pgp.PGPForm$2.actionPerformed(PGPForm.java:109)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2022)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2348)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
at java.awt.Component.processMouseEvent(Component.java:6533)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3324)
at java.awt.Component.processEvent(Component.java:6298)
at java.awt.Container.processEvent(Container.java:2236)
at java.awt.Component.dispatchEventImpl(Component.java:4889)
at java.awt.Container.dispatchEventImpl(Container.java:2294)
at java.awt.Component.dispatchEvent(Component.java:4711)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4888)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4525)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4466)
at java.awt.Container.dispatchEventImpl(Container.java:2280)
at java.awt.Window.dispatchEventImpl(Window.java:2746)
at java.awt.Component.dispatchEvent(Component.java:4711)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758)
at java.awt.EventQueue.access$500(EventQueue.java:97)
at java.awt.EventQueue$3.run(EventQueue.java:709)
at java.awt.EventQueue$3.run(EventQueue.java:703)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:90)
at java.awt.EventQueue$4.run(EventQueue.java:731)
at java.awt.EventQueue$4.run(EventQueue.java:729)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:728)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at java.util.Base64$Decoder.decode(Base64.java:549)
at pgp.PGPForm$2.actionPerformed(PGPForm.java:110)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2022)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2348)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
at java.awt.Component.processMouseEvent(Component.java:6533)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3324)
at java.awt.Component.processEvent(Component.java:6298)
at java.awt.Container.processEvent(Container.java:2236)
at java.awt.Component.dispatchEventImpl(Component.java:4889)
at java.awt.Container.dispatchEventImpl(Container.java:2294)
at java.awt.Component.dispatchEvent(Component.java:4711)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4888)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4525)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4466)
at java.awt.Container.dispatchEventImpl(Container.java:2280)
at java.awt.Window.dispatchEventImpl(Window.java:2746)
at java.awt.Component.dispatchEvent(Component.java:4711)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758)
at java.awt.EventQueue.access$500(EventQueue.java:97)
at java.awt.EventQueue$3.run(EventQueue.java:709)
at java.awt.EventQueue$3.run(EventQueue.java:703)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:90)
at java.awt.EventQueue$4.run(EventQueue.java:731)
at java.awt.EventQueue$4.run(EventQueue.java:729)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:728)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)
So, without -sha256 in public key when run openSSL, this source code work fine. When I add it, I got exceptions above.
Any solutions? Thanks and regards.
