doFinal() javax.crypto.IllegalBlockSizeException: last block incomplete in decryption - encryption

Sorry if this has been answered. I see several similar but not one I can identify as my issue.
I am getting the following error:
javax.crypto.IllegalBlockSizeException: last block incomplete in decryption
at org.bouncycastle.jce.provider.JCEBlockCipher.engineDoFinal(Unknown Source)
at javax.crypto.Cipher.doFinal
public static String encryptAES(String key, String source) {
String encrypted = "";
try {
SecretKeySpec keySpec = new SecretKeySpec(key.getBytes(), "AES");
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
IvParameterSpec iv = new IvParameterSpec(new byte[16]);
cipher.init(Cipher.ENCRYPT_MODE, keySpec, iv);
byte[] bXml = source.getBytes("UTF8");
byte[] enc = cipher.doFinal(bXml);
encrypted = new sun.misc.BASE64Encoder().encode(enc);
} catch (Exception e) { /** removed **/ }
return encrypted;
}
public static String decryptAES(String key, String source) {
String decrypted = "";
try {
SecretKeySpec keySpec = new SecretKeySpec(key.getBytes(), "AES");
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
IvParameterSpec iv = new IvParameterSpec(new byte[16]);
cipher.init(Cipher.DECRYPT_MODE, keySpec, iv);
byte[] dec = new sun.misc.BASE64Decoder().decodeBuffer(source);
byte[] bDecrypted = cipher.doFinal(dec); /** Error occurs here **/
decrypted = new String(bDecrypted, "UTF8");
} catch (Exception e) { /** removed **/ }
return decrypted;
}

Related

AES 256 Encryption Decryption,

Decryption logic is missing something can you please assist.
Output is not completely decrypted.
Java Encryption Logic:
public static void main(String[] args) throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, ShortBufferException, IllegalBlockSizeException, BadPaddingException {
try {
String in ="This is a text message";
byte[] input = in.toString().getBytes("utf-8");
String ENCRYPTION_KEY = "RW50ZXIgS2V5IEhlcmU=";
MessageDigest md = MessageDigest.getInstance("SHA-256");
byte[] thedigest = md.digest(ENCRYPTION_KEY.getBytes("UTF-8"));
// SecretKeySpec skc = new SecretKeySpec(thedigest, "AES/ECB/PKCS5Padding");
SecretKeySpec skc = new SecretKeySpec(thedigest, "AES");
Cipher cipher = Cipher.getInstance("AES");
cipher.init(Cipher.ENCRYPT_MODE, skc);
byte[] cipherText = new byte[cipher.getOutputSize(input.length)];
int ctLength = cipher.update(input, 0, input.length, cipherText, 0);
ctLength += cipher.doFinal(cipherText, ctLength);
// String query = Base64.encodeToString(cipherText, Base64.DEFAULT);
String query = new String(java.util.Base64.getEncoder().encode(cipherText));
System.out.println("query " + query);
// String query = new String(encode(cipherText), StandardCharsets.ISO_8859_1);
} catch(UnsupportedEncodingException e) { // TODO Auto-generated catch block
e.printStackTrace();
}
}
Nodejs Decryption Logic:
let crypto = require('crypto');
var decipher = crypto.createDecipher('aes-256-ecb', "RW50ZXIgS2V5IEhlcmU=");
decipher.setAutoPadding(false);
console.log(decipher.update("EncyptedText", 'base64', 'utf8') + decipher.final('utf8'));

Invalid Key Exception

I am retrieving a text password as input from a file and applying AES encryption over that and later on, decrypting that.
When I did it for the first time, every 4 out of 5 times it was running correctly (encryption decryption successful) but 1 time, it was throwing BadPaddingException. Following is what I wrote :
//ABCD is class name
public static void enc(String fileName, String pwd) {
try {
Properties prop = new Properties();
InputStream input = ABCD.class.getClassLoader().getResourceAsStream(fileName);
prop.load(input);
input.close();
URL url = ABCD.class.getClassLoader().getResource(fileName);
FileOutputStream outputStream = new FileOutputStream(url.getPath());
KeyGenerator key = KeyGenerator.getInstance("AES");
key.init(128);
SecretKey aesKey = key.generateKey();
String newkey = new String(Base64.encode(aesKey.getEncoded()).getBytes("UTF-8"));
Cipher aesCipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
aesCipher.init(Cipher.ENCRYPT_MODE, aesKey);
byte[] clear = pwd.getBytes("UTF-8");
byte[] cipher = aesCipher.doFinal(clear);
String encPwd = new String(cipher);
prop.setProperty("password", encPwd);
prop.setProperty("secKey", newkey);
prop.store(outputStream, null);
outputStream.close();
} catch (Exception e) {
System.out.println(e);
}
}
public static String dec(Properties prop, String fileName) {
String decPwd = ABCD.map.get(fileName);
try {
String newkey = prop.getProperty("secKey");
StringBuilder pwd;
byte[] newkeybuff = Base64.decode(newkey.getBytes("UTF-8"));
SecretKey key = new SecretKeySpec(newkeyuff, "AES");
Cipher aesCipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
aesCipher.init(Cipher.DECRYPT_MODE, key);
pwd = new StringBuilder(prop.getProperty("password"));
byte[] cipher = aesCipher.doFinal(pwd.toString().getBytes());
decPwd = new String(cipher);
} catch (Exception e) {
System.out.println(e);
}
ABCD.map.put(fileName, decPwd);
return decPwd;
}
I needed to fix this. Somewhere, I read that BadPaddingExcpetion occurs since of the operations done with String, in place of where actually byte should be used. Hence, I changed my code to the following :
public static void enc(String fileName, String pwd) {
try {
Properties prop = new Properties();
InputStream input = ABCD.class.getClassLoader().getResourceAsStream(fileName);
prop.load(input);
input.close();
URL url = ABCD.class.getClassLoader().getResource(fileName);
FileOutputStream outputStream = new FileOutputStream(url.getPath());
KeyGenerator key = KeyGenerator.getInstance("AES");
key.init(128);
SecretKey aesKey = key.generateKey();
byte[] newkey=(Base64.encode(aesKey.getEncoded())).getBytes("UTF-8");
Cipher aesCipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
aesCipher.init(Cipher.ENCRYPT_MODE, aesKey,new IvParameterSpec(new byte[16]));
byte[] clear = pwd.getBytes("UTF-8");
byte[] cipher = aesCipher.doFinal(clear);
prop.setProperty("password", Arrays.toString(cipher));
prop.setProperty("secKey", Arrays.toString(newkey));
prop.store(outputStream, null);
outputStream.flush();
outputStream.close();
} catch (Exception e) {
System.out.println(e);
}
}
public static String dec(Properties prop, String fileName) {
String decPwd = ABCD.map.get(fileName);
try {
byte[] newkey=prop.getProperty("secKey").getBytes("UTF-8");
byte[] pwd;
byte[] newkeybuff = Base64.decode(newkey);
SecretKeySpec key = new SecretKeySpec(newkeybuff, "AES");
Cipher aesCipher=Cipher.getInstance("AES/CBC/PKCS5Padding");
aesCipher.init(Cipher.DECRYPT_MODE, key,new IvParameterSpec(new byte[16]));
pwd = prop.getProperty("password").getBytes();
byte[] cipher = aesCipher.doFinal(pwd);
decPwd=new String(cipher);
System.out.println("Decrypted pwd " + decPwd);
}
catch (Exception e) {
System.out.println(e);
}
ABCD.map.put(fileName, decPwd);
return decPwd;
}
Now, I am getting InvalidKeyException. This time, I read that the size of the key should be 16 bytes. But I don't know how to apply this. Need a fix for this!
You should check your IV (Initialization Vector) which must be the same for encryption and decryption.
A padding error usually means the decryption failed.
Check that the key is a full length (16, 24 or 32 bytes), the IV is full length (16-bytes). If the key or IV is to short it will be padded with "something"and that man not be consistent, there is no standard for such padding.
getBytes("UTF-8") may return different length of bytes depending on the characters used.
Using new IvParameterSpec(new byte[16]) for the IV is incorrect, the IV should be a random bytes. A usual method of handling the IV is to create a random IV on encryption and prepend it to the encrypted data, it does not need to be secret and by prepending it will be available for decryption.

Bouncy castle light weight api encryption for j2me - Given final block not properly padded

i have used sha256 for secret key generation and took first 16 digit for AES 128 encryption. i am getting correct encrypted and decrypted data when it is 16 or below 16 string. if it is above 16 char string i am getting 16 char with some unwanted characters. (Eg: abcdefghijklmnop5#�D�!�&M�\~C��) can anybody help me to sort this issue. please see below for code.
i have encrypted using j2me code and tried to decrypt using the given online aes crypto site (http://aesencryption.net/). i guess it is having some padding issue but i am not able to figure it out.
public static String getSHA256(String key) {
SHA256Digest digester = new SHA256Digest();
byte[] retValue = new byte[digester.getDigestSize()];
digester.update(key.getBytes(), 0, key.length());
digester.doFinal(retValue,0);
byteToStr = new String(Hex.encode(retValue));
System.out.println("byteToStr === " + byteToStr);
byteToStr = byteToStr.substring(0, 16);
System.out.println("byteToStr after subString === " + byteToStr);
return byteToStr;
}
public static byte[] cipherData(BufferedBlockCipher cipher, byte[] data)
throws Exception {
int minSize = cipher.getOutputSize(data.length);
System.out.println("min Size = "+minSize);
byte[] outBuf = new byte[minSize];
int length1 = cipher.processBytes(data, 0, data.length, outBuf, 0);
int length2 = cipher.doFinal(outBuf, length1);
System.out.println("length1 = "+length1 +"/ length2 = "+length2);
int actualLength = length1 + length2;
System.out.println("actualLength = "+actualLength);
byte[] result = new byte[actualLength];
System.arraycopy(outBuf, 0, result, 0, result.length);
return result;
}
public static byte[] decrypt(byte[] cipher, byte[] key/* , byte[] iv */)
throws Exception {
/*
* PaddedBufferedBlockCipher aes = new PaddedBufferedBlockCipher( new
* CBCBlockCipher(new AESEngine())); CipherParameters ivAndKey = new
* ParametersWithIV(new KeyParameter(key), iv); aes.init(false,
* ivAndKey); return cipherData(aes, cipher);
*/
BufferedBlockCipher decryptCipher = new PaddedBufferedBlockCipher(
new CBCBlockCipher(new AESEngine()));
KeyParameter keyDecrypt = new KeyParameter(key);
decryptCipher.init(false, keyDecrypt);
return cipherData(decryptCipher, cipher);
}
public static byte[] encrypt(byte[] plain, byte[] key/* , byte[] iv */)
throws Exception {
/*
* PaddedBufferedBlockCipher aes = new PaddedBufferedBlockCipher( new
* CBCBlockCipher(new AESEngine())); CipherParameters ivAndKey = new
* ParametersWithIV(new KeyParameter(key), iv);
*/
BufferedBlockCipher encryptCipher = new PaddedBufferedBlockCipher(
new CBCBlockCipher(new AESEngine()));
KeyParameter keyEncrypt = new KeyParameter(key);
encryptCipher.init(true, keyEncrypt);
return cipherData(encryptCipher, plain);
}
public static String encryptMe(String plain) {
byte[] plainStr = plain.getBytes();
byte[] keyStr = getSHA256(key).getBytes();
// byte[] ivStr = iv.getBytes();//
System.out.println("key str = "+Strings.fromByteArray(keyStr));
try {
byte[] encBytes = encrypt(plainStr, keyStr/*
* , ivStr
*/);
strEncResult= Base64.toBase64String(encBytes);
//byte[] encbase = Base64.encode(encBytes);
//strEncResult = new String(encbase,"ISO-8859-1");
} catch (Exception e) {
e.printStackTrace();
}
return strEncResult;
}
public static String decryptMe(String cipherText) {
try {
byte[] dcrByte = Base64.decode(cipherText);
byte[] dec = decrypt(dcrByte, getSHA256(key).getBytes()/*
* ,iv.getBytes
* ()
*/);
strDcrResult = Strings.fromByteArray(dec);
//strDcrResult = new String(dec,"ISO-8859-1");
} catch (Exception e) {
e.printStackTrace();
}
return strDcrResult;
}

Encryption / decryption for j2me app with AES 128 encryption using sha256 hashing

I have to use encryption / decryption mechanism for a j2me application and lots of searching I found that Bouncy Castle is most suitable for j2me apps.
Below are the steps that I follow to perform encryption:
Get a string needed to create a hash key using sha256 algorithm;
With that hash key perform AES-128 encryption for a plain text.
Below is the sample code. It is using key and IV (Initialization Vector) for encryption key generation. Is it same as sha256 hashing?
static String strEnc = "String for encryption";
final static String strPassword = "2345678978787878"; // AES 128 -
String encrypted;
public static String strEncResult;
public static String strDcrResult;
public static String keyStr;
String dcrtpt;
String enc1;
//Key key;
/*public static byte[] getSHA256(String key) {
SHA256Digest digester = new SHA256Digest();
byte[] retValue = new byte[digester.getDigestSize()];
digester.update(key.getBytes(), 0, key.length());
digester.doFinal(retValue, 0);
System.out.println("retValue === "+retValue);
return retValue;
}*/
public static byte[] cipherData(PaddedBufferedBlockCipher cipher,
byte[] data) throws Exception {
int minSize = cipher.getOutputSize(data.length);
byte[] outBuf = new byte[minSize];
int length1 = cipher.processBytes(data, 0, data.length, outBuf, 0);
int length2 = cipher.doFinal(outBuf, length1);
int actualLength = length1 + length2;
byte[] result = new byte[actualLength];
System.arraycopy(outBuf, 0, result, 0, result.length);
return result;
}
public static byte[] decrypt(byte[] cipher, byte[] key, byte[] iv)
throws Exception {
PaddedBufferedBlockCipher aes = new PaddedBufferedBlockCipher(
new CBCBlockCipher(new AESEngine()));
CipherParameters ivAndKey = new ParametersWithIV(new KeyParameter(key),
iv);
aes.init(false, ivAndKey);
return cipherData(aes, cipher);
}
public static byte[] encrypt(byte[] plain, byte[] key, byte[] iv)
throws Exception {
PaddedBufferedBlockCipher aes = new PaddedBufferedBlockCipher(
new CBCBlockCipher(new AESEngine()));
CipherParameters ivAndKey = new ParametersWithIV(new KeyParameter(key),
iv);
aes.init(true, ivAndKey);
return cipherData(aes, plain);
}
public static String encryptMe(String plain){
byte[] plainStr = plain.getBytes();
byte[] keyStr = strPassword.getBytes();//getSHA256(strPassword);
byte[] ivStr = strPassword.getBytes();//getSHA256(strPassword);
try {
byte[] encBytes = encrypt(plainStr, keyStr,
ivStr);
byte[] encbase = Base64.encode(encBytes);
strEncResult = new String(encbase, "UTF-8");
} catch (Exception e) {
e.printStackTrace();
}
return strEncResult;
}
public static String decryptMe(String encrtptedStr){
try {
byte[] dcrByte = Base64.decode(encrtptedStr.getBytes());
byte[] dec = decrypt(dcrByte, strPassword.getBytes()/*getSHA256(strPassword)*/,
strPassword.getBytes()/*getSHA256(strPassword)*/);
strDcrResult = new String(dec, "UTF-8");
} catch (Exception e) {
e.printStackTrace();
}
return strDcrResult;
}
protected void destroyApp(boolean unconditional)
throws MIDletStateChangeException {
}
protected void pauseApp() {
}
protected void startApp() throws MIDletStateChangeException {
byte[] enc;
try {
enc = encrypt(strEnc.getBytes(), /*getSHA256(strPassword)*/strPassword.getBytes(),
/*getSHA256(strPassword)*/strPassword.getBytes());
byte[] encbase = Base64.encode(enc);
encrypted = new String(encbase, "UTF-8");
enc1= encryptMe ("String for encryption");
System.out.println("Encrypted is:" + encbase + "/// "+enc1);
} catch (Exception e) {
e.printStackTrace();
}
byte[] decbase = Base64.decode(encrypted.getBytes());
byte[] dec;
try {
dec = decrypt(decbase, /*getSHA256(strPassword)*/strPassword.getBytes(),
/*getSHA256(strPassword)*/strPassword.getBytes());
dcrtpt = decryptMe(enc1);
System.out.println("Decrypted file is:" + new String(dec, "UTF-8")+"///"+dcrtpt);
} catch (Exception e) {
e.printStackTrace();
}
}
i got it worked!!. i have used sha256 for secret key generation and took first 16 digit for AES 128 encryption. i am getting correct encrypted and decrypted data when it is 16 or below 16 string. if it is above 16 char string i am getting 16 char with some unwanted characters. (Eg: abcdefghijklmnop5#�D�!�&M�\~C��) can anybody help me to sort this issue. please see below for code
public static String getSHA256(String key) {
SHA256Digest digester = new SHA256Digest();
byte[] retValue = new byte[digester.getDigestSize()];
digester.update(key.getBytes(), 0, key.length());
digester.doFinal(retValue,0);
byteToStr = new String(Hex.encode(retValue));
System.out.println("byteToStr === " + byteToStr);
byteToStr = byteToStr.substring(0, 16);
System.out.println("byteToStr after subString === " + byteToStr);
return byteToStr;
}
public static byte[] cipherData(BufferedBlockCipher cipher, byte[] data)
throws Exception {
int minSize = cipher.getOutputSize(data.length);
System.out.println("min Size = "+minSize);
byte[] outBuf = new byte[minSize];
int length1 = cipher.processBytes(data, 0, data.length, outBuf, 0);
int length2 = cipher.doFinal(outBuf, length1);
System.out.println("length1 = "+length1 +"/ length2 = "+length2);
int actualLength = length1 + length2;
System.out.println("actualLength = "+actualLength);
byte[] result = new byte[actualLength];
System.arraycopy(outBuf, 0, result, 0, result.length);
return result;
}
public static byte[] decrypt(byte[] cipher, byte[] key/* , byte[] iv */)
throws Exception {
/*
* PaddedBufferedBlockCipher aes = new PaddedBufferedBlockCipher( new
* CBCBlockCipher(new AESEngine())); CipherParameters ivAndKey = new
* ParametersWithIV(new KeyParameter(key), iv); aes.init(false,
* ivAndKey); return cipherData(aes, cipher);
*/
BufferedBlockCipher aes = new PaddedBufferedBlockCipher(
new CBCBlockCipher(new AESEngine()));
KeyParameter secretKey = new KeyParameter(key);
aes.init(false, secretKey);
return cipherData(aes, cipher);
}
public static byte[] encrypt(byte[] plain, byte[] key/* , byte[] iv */)
throws Exception {
/*
* PaddedBufferedBlockCipher aes = new PaddedBufferedBlockCipher( new
* CBCBlockCipher(new AESEngine())); CipherParameters ivAndKey = new
* ParametersWithIV(new KeyParameter(key), iv);
*/
BufferedBlockCipher aes = new PaddedBufferedBlockCipher(
new CBCBlockCipher(new AESEngine()));
KeyParameter secretKey = new KeyParameter(key);
aes.init(true, secretKey);
return cipherData(aes, plain);
}
public static String encryptMe(String plain) {
byte[] plainStr = plain.getBytes();
byte[] keyStr = getSHA256(key).getBytes();
// byte[] ivStr = iv.getBytes();//
System.out.println("key str = "+Strings.fromByteArray(keyStr));
try {
byte[] encBytes = encrypt(plainStr, keyStr/*
* , ivStr
*/);
strEncResult= Base64.toBase64String(encBytes);
//strEncResult = new String(encbase);
} catch (Exception e) {
e.printStackTrace();
}
return strEncResult;
}
public static String decryptMe(String cipherText) {
try {
byte[] dcrByte = Base64.decode(cipherText);
byte[] dec = decrypt(dcrByte, getSHA256(key).getBytes()/*
* ,iv.getBytes
* ()
*/);
strDcrResult = Strings.fromByteArray(dec);
} catch (Exception e) {
e.printStackTrace();
}
return strDcrResult;
}

Datatype of encrypted password

I want to encrypt my password and store to my DB, SQL Server 2008 R2.
For that I took the password from text box and encrypted using proper function and want to store in back end.
Tell me which datatype I have to use for encrypted password column.
Namespace:
using System.Security.Cryptography;
Encrypt Function:
public static string Encrypt(string Message)
{
string Password = Message;
byte[] Results;
System.Text.UTF8Encoding UTF8 = new System.Text.UTF8Encoding();
MD5CryptoServiceProvider HashProvider = new MD5CryptoServiceProvider();
byte[] TDESKey = HashProvider.ComputeHash(UTF8.GetBytes(Password));
TripleDESCryptoServiceProvider TDESAlgorithm = new TripleDESCryptoServiceProvider();
TDESAlgorithm.Key = TDESKey;
TDESAlgorithm.Mode = CipherMode.ECB;
TDESAlgorithm.Padding = PaddingMode.PKCS7;
byte[] DataToEncrypt = UTF8.GetBytes(Message);
try
{
ICryptoTransform Encryptor = TDESAlgorithm.CreateEncryptor();
Results = Encryptor.TransformFinalBlock(DataToEncrypt, 0, DataToEncrypt.Length);
}
finally
{
TDESAlgorithm.Clear();
HashProvider.Clear();
}
return Convert.ToBase64String(Results);
}
Decrypt Function:
public static string Decrypt(string Message)
{
string Password = Message;
byte[] Results;
System.Text.UTF8Encoding UTF8 = new System.Text.UTF8Encoding();
MD5CryptoServiceProvider HashProvider = new MD5CryptoServiceProvider();
byte[] TDESKey = HashProvider.ComputeHash(UTF8.GetBytes(Password));
TripleDESCryptoServiceProvider TDESAlgorithm = new TripleDESCryptoServiceProvider();
TDESAlgorithm.Key = TDESKey;
TDESAlgorithm.Mode = CipherMode.ECB;
TDESAlgorithm.Padding = PaddingMode.PKCS7;
byte[] DataToDecrypt = Convert.FromBase64String(Message);
try
{
ICryptoTransform Decryptor = TDESAlgorithm.CreateDecryptor();
Results = Decryptor.TransformFinalBlock(DataToDecrypt, 0, DataToDecrypt.Length);
}
finally
{
TDESAlgorithm.Clear();
HashProvider.Clear();
}
return UTF8.GetString(Results);
}
How to use??
For Encrypt:
string encryptpassword=Encrypt(txtPassword.Text.Trim());
For Decrypt:
string decryptpassword=Decrypt(txtPassword.Text.Trim());
NOTE : txtPassword is a textbox where you can enter a password

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