I am trying to decrypt an AES encrypted string from Java, in C#. When I decrypt, it returns gibberish and does not match the original plain text, which was encrypted via Java code. Pls guide me on what is going wrong here.
Attached the Java code for encryption and the C# code for decryption. Pls let me know if you need more details.
I tried AesCryptoServiceProvider as well and it did not work either. You can see the code tried in the commented code in C#.
Pls note that I can make changes on my C# code only to match the Java code and can not make any edits to Java side.
Java code for Encryption:
/** encrypt cipher */
private static final Cipher ENCRYPT_CIPHER = generateCipher(Cipher.ENCRYPT_MODE);
private static String ENCRYPT_KEY = "key";
/**
* #param val
* #return encrypted value
* #throws Exception
*/
public String encrypt(final String val) throws Exception {
return new String(Base64.encodeBase64(ENCRYPT_CIPHER.doFinal(val.getBytes()), true)).toString();
}
/**
* #param encrypt
* #return cipher
*/
protected static Cipher generateCipher(final int encrypt) {
try {
final Cipher cipher = Cipher.getInstance("AES");
cipher.init(encrypt, SecretKeyFactory.getInstance("AES").generateSecret(new IBMAESKeySpec(Base64.decodeBase64(ENCRYPT_KEY.getBytes()))));
return cipher;
} catch (final Exception e) {
return null;
}
}
C# code for decryption:
private static String ENCRYPT_KEY = "key";
public String decodeString (String encodedStr)
{
/*using (var aesCryptoProvider = new AesCryptoServiceProvider())
{
aesCryptoProvider.BlockSize = 128;
aesCryptoProvider.KeySize = 256;
aesCryptoProvider.Key = Convert.FromBase64String(ENCRYPT_KEY.ToString());
aesCryptoProvider.Padding = PaddingMode.Zeros;
aesCryptoProvider.Mode = CipherMode.ECB;
using (var decryptor = aesCryptoProvider.CreateDecryptor())
using (var memoryStream = new MemoryStream(Convert.FromBase64String(encodedStr)))
using (var cryptoStream = new CryptoStream(memoryStream, decryptor, CryptoStreamMode.Read))
using (var streamReader = new StreamReader(cryptoStream, Encoding.UTF8))
{
decodedStr = streamReader.ReadToEnd();
}
}
*/
using (AesManaged aesAlg = new AesManaged())
{
aesAlg.Key = Convert.FromBase64String(ENCRYPT_KEY.ToString()); ;
aesAlg.BlockSize = 128;
aesAlg.KeySize = 256;
aesAlg.Mode = CipherMode.ECB;
aesAlg.Padding = PaddingMode.Zeros;
// Create a decrytor to perform the stream transform.
ICryptoTransform decryptor = aesAlg.CreateDecryptor();
// Create the streams used for decryption.
using (MemoryStream msDecrypt = new MemoryStream(Convert.FromBase64String(encodedStr)))
{
using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))
{
using (StreamReader srDecrypt = new StreamReader(csDecrypt))
{
// Read the decrypted bytes from the decrypting stream
// and place them in a string.
decodedStr = srDecrypt.ReadToEnd();
}
}
}
}
}
This is just a quick answer. Haven't done a ton of research into it, but have you checked to see if the endian-ness matches? It looks like C# (.NET) is little-endian, but the JVM is big-endian. I'm not sure if it swaps it for network transmission, however (then it would just match the hardware). Just an idea. If I find anything additional, I'll update my answer.
Related
I ran the Trible DES Encryption in Java, with null IV (I have run cipher.getIV() method and indeed it's IV is null) and the same string ran the Triple DES Encryption in PHP with null IV, but I get a different result. Why is that?
Java Code:
private static final String model = "DESede/ECB/PKCS5Padding";
public static String desEncrypt(String message, String key) throws Exception {
byte[] keyBytes = null;
if(key.length() == 16){
keyBytes = newInstance8Key(ByteUtil.convertHexString(key));
} else if(key.length() == 32){
keyBytes = newInstance16Key(ByteUtil.convertHexString(key));
} else if(key.length() == 48){
keyBytes = newInstance24Key(ByteUtil.convertHexString(key));
}
SecretKey deskey = new SecretKeySpec(keyBytes, "DESede");
Cipher cipher = Cipher.getInstance(model);
cipher.init(1, deskey);
return ByteUtil.toHexString(cipher.doFinal(message.getBytes("UTF-8")));
}
PHP Code:
// composer require phpseclib/phpseclib
use phpseclib\Crypt\TripleDES;
function desEncrypt($str,$key){
$cipher = new TripleDES();
$cipher->setKey(hex2bin($key));
$cryptText = $cipher->encrypt($str);
return unpack("H*",$cryptText)[1];
}
I want to modify my PHP code to fit the Java Encryption Process，how should I do? where is the proplem?
Java Encrypt Result:
before: 622700300000
key: 0123456789ABCDEFFEDCBA98765432100123456789ABCDEF
after: c9aa8ebfcc12ce13e22a33b05d4c18cf
PHP Encrypt Result:
before: 622700300000
key: 0123456789ABCDEFFEDCBA98765432100123456789ABCDEF
after: a6e7a000d4ce79ac8b3db9f6acf73de3
Fixed PHP Code:
/**
* Triple DES (ECB) Encryption Function
* PKCS5Padding
*
* #param string $message String needed to be encode
* #param string $key Hex encoded key
* #return string Hex Encoded
*/
function desEncrypt($message,$key){
$cipher = new TripleDES(TripleDES::MODE_ECB);
$cipher->setKey(hex2bin($key));
$cryptText = $cipher->encrypt($message);
return bin2hex($cryptText);
}
You forgot to hex decode the key before using it. You're also using CBC mode instead of ECB mode, but as your IV is all zero's, that amounts to the same thing for the first block of data that is encrypted.
All,I am posting some encrypted xml data(Using AES-128 ) to another application that uses Java to decrypt.When the Java code decrypts the xml,the start tag of the xml is getting truncated and fails validation.I don't have access to their code base .I can decrypt the same data using C# without any data loss.Please see the code I use to encrypt and Decrypt the data . I have researched this and based on the research ,I added the FlushFinalBlocks() and Close() to the CryptoStream in the encryption logic ,but this doesnt seem to fix the issue.
Encryption Code:
public static string Aes128Encrypt(string plainText)
{
string encodedPayload = null;
string base64Iv = null;
string base64Key = null;
byte[] plainBytes = Encoding.UTF8.GetBytes(plainText);
using (RijndaelManaged aesAlg = new RijndaelManaged())
{
aesAlg.KeySize = 128;
aesAlg.Mode = CipherMode.CBC;
aesAlg.Padding = PaddingMode.PKCS7;
aesAlg.BlockSize = 128;
base64Iv = Convert.ToBase64String(aesAlg.IV);
base64Key = Convert.ToBase64String(aesAlg.Key);
// Create a decrytor to perform the stream transform.
ICryptoTransform encryptor = aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.IV);
// Create the streams used for encryption.
using (MemoryStream msEncrypt = new MemoryStream())
{
using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
{
csEncrypt.Write(plainBytes, 0, plainBytes.Length);
csEncrypt.FlushFinalBlock();
encodedPayload = Convert.ToBase64String(msEncrypt.ToArray());
csEncrypt.Close();
}
msEncrypt.Flush();
msEncrypt.Close();
}
}
return encodedPayload ;
}
Decryption Code:
public static string Aes128Decrypt(string base64Key, string base64IV, string encodedPayload)
{
string plainText = null;
byte[] key = Convert.FromBase64String(base64Key);
byte[] iv = Convert.FromBase64String(base64IV);
byte[] encryptedBytes = Convert.FromBase64String(encodedPayload);
using (RijndaelManaged aesAlg = new RijndaelManaged())
{
aesAlg.KeySize = 128;
aesAlg.Mode = CipherMode.CBC;
aesAlg.BlockSize = 128;
aesAlg.Padding = PaddingMode.PKCS7;
aesAlg.Key = key;
aesAlg.IV = iv;
// Create a decrytor to perform the stream transform.
ICryptoTransform decryptor = aesAlg.CreateDecryptor(aesAlg.Key, aesAlg.IV);
// Create the streams used for decryption.
using (MemoryStream msDecrypt = new MemoryStream(encryptedBytes))
{
using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))
{
using (StreamReader srDecrypt = new StreamReader(csDecrypt))
{
plainText = srDecrypt.ReadToEnd();
}
}
}
}
return plainText;
}
Testing Code:
string textXml = #"<person>
<firstName>Rennish</firstName>
<lastName>Joseph</lastName>
<accountNumber>12345678910</accountNumber>
<ssn>123456</ssn>
</person>";
Aes128Encrypt(textXml);
string encodedPayload = "4p6uU7SiqB0uCzsrWXMOStP02HM7mKA6QVzcKoNdu3w1+MYLjYVbW/Ig3XPKRRafeu+WKDMuKJJaEREkrZt/Ycvc50wfe2naJ9d0UT5B7Fre1gIsNfZUIK3SF304+WF8zX730mVsluJABKT3JCkk9AkOGCQWPYzcZvH9dojIqGP7V+2j1+IMOPMWWFIitkAi8B7ALxMuMcepzX2/cxHxH7NeID0ytEGUzGfJXSAzQcvBX9dWwUqdMX3Eip5SRPMsotnWWsFTjDuOiZk/q5fuxxWbS6cuYn/64C/vQjEIuheQKn0ZOIDLNPCUavvWD2u6PWNKMNgW/qUIq13W9PQxzIiQxrT7ZqPFJu75C1KdXXUG5lghU7EBAGehHC/5BqFjs9SuYJkV1RrchMEzytrJIQ7Zp4CnOU6Q1rEhFTaMk/s=";
string encodedKey = "2zpVbIxqvjSfJo7zkXzl2A==";
string encodedIV = "5WOQPdmB/BkECmuPdNTaLw==";
Aes128Decrypt(encodedKey, encodedIV, encodedPayload);
Data after encryption at the JAVA application looks like this
<rson>
<firstName>Rennish</firstName>
<lastName>Joseph</lastName>
<accountNumber>12345678910</accountNumber>
<ssn>123456</ssn>
</person>
Interesting problem.
I think the encryption and decryption works fine on both sides.
If part of the encrypted message was lost in transmission you would not be able to decrypt it due to the avalanche effect. So it appears that characters go missing in the plain text.
This might be an encoding issue in the plain text message. The bytes you have encoded and the bytes they decoded are probably the same. The way they are interpreted might not be.
Now there are two options here:
Either <person> becomes <rson> or it becomes rson> and there was a copy-paste mistake.
If the latter case is true then we're missing 3 bytes. This makes me think that the protocol might presume the presence of a byte order marker andsimply removes the first 3 bytes to get rid of it.
If the former case you'd have some very weird encoding issues. As all missing characters appear to be in the ascii range so they shouldn't have these issues.
Easy to test though:
1. Try sending with a byte order marker.
2. Try sending with <XXperson>
3. Try sending some characters with accents and the like.
I have the following JAVA and I am trying to convert into C# using ChilKat (or BouncyCastle) I have a working version in ChilKat, but not sure how to validate Here is the JAVA code:
private SecretKey symmKey = null;
public String encrypt(String strToEncrypt) throws Exception
{
String symmEncryptMode = "DESede";
String encString= null;
KeyGenerator keyGen = KeyGenerator.getInstance(symmEncryptMode);
symmKey = keyGen.generateKey();
byte dataToEncrypt[] = strToEncrypt.getBytes();
Cipher symmCipher = Cipher.getInstance(symmEncryptMode);
symmCipher.init(Cipher.ENCRYPT_MODE, symmKey);
byte[] encrypted = symmCipher.doFinal(dataToEncrypt);
encString= new String(Base64.encode(encrypted));
encString = URLEncoder.encode(encString, "UTF-8");
return(encString);
} //end method create Signature
Here is what I have so far (It returns a value, but I don't know how to validate as this is one of three steps of my encyption process - step 3 works, 1 and 2 are suspect, so I figured I'd ask one at a time...) This uses ChilKat and it returns a value, but I am not sure if it is correct:
private static string EncryptStringSymmetric(string data2Encrypt, ref string passKey)
{
//Init Encryptor
Crypt2 encryptor = new Crypt2();
bool success = encryptor.UnlockComponent("Anything for 30 - day trial");
if (success != true)
{ throw (new Exception("Crypt component unlock failed")); }
//Encryptor Settings
encryptor.CryptAlgorithm = "3des";
encryptor.KeyLength = 192;
encryptor.EncodingMode = "base64";
encryptor.PaddingScheme = 0;
encryptor.Charset = "utf-8";
encryptor.CipherMode = "ecb";
encryptor.RandomizeKey();
passKey = encryptor.GetEncodedKey("base64");
string eStr;
//byte[] bytesToEncrypt = Encoding.ASCII.GetBytes(data2Encrypt);
//eStr = encryptor.EncryptBytesENC(bytesToEncrypt);//??
eStr = encryptor.EncryptStringENC(data2Encrypt);
return eStr;
}
I am having some problems decrypting some text sent from PHP in Java. I have already written code that does this for a windows version of the program in C# but I am unfamiliar with Java so this might be more simple than I am making it.
The encryption code in PHP:
function encryptString($plain)
{
$iv = "12347112549354892543218565456541";
$ftpSalt = "hjjuoelkdploida";
$block = mcrypt_get_block_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_CBC);
$padding = $block - (strlen($plain) % $block);
$plain .= str_repeat(chr($padding), $padding);
$crypttext = mcrypt_encrypt(MCRYPT_RIJNDAEL_256, $ftpSalt, $plain, MCRYPT_MODE_CBC, $iv);
$crypttext64 = base64_encode($crypttext);
return $crypttext64;
}
The C# function that decrypts:
static public String doDecryptRJ256(string cypher)
{
var sRet = "";
var cypherByte = Decode(cypher);
var encoding = new UTF8Encoding();
var Key = encoding.GetBytes(mKey);
var IV = encoding.GetBytes(mIv);
using (var rj = new RijndaelManaged())
{
try
{
rj.Padding = PaddingMode.PKCS7;
rj.Mode = CipherMode.CBC;
rj.KeySize = 256;
rj.BlockSize = 256;
rj.Key = Key;
rj.IV = IV;
var ms = new MemoryStream(cypherByte);
using (var cs = new CryptoStream(ms, rj.CreateDecryptor(Key, IV), CryptoStreamMode.Read))
{
using (var sr = new StreamReader(cs))
{
sRet = sr.ReadLine();
}
}
}
finally
{
rj.Clear();
}
}
return sRet;
}
}
I have tried various suggestions from the internet but not found any that actually work. THe latest suggestion I tried to another answer was:
byte[] cipherText = encryptedText.getBytes("UTF-8");
Cipher cipher = Cipher.getInstance("AES/CBC/NoPadding");
SecretKeySpec key = new SecretKeySpec(KEY.getBytes("UTF-8"), "AES");
cipher.init(Cipher.DECRYPT_MODE, key,new IvParameterSpec(IV.getBytes("UTF-8")));
return new String(cipher.doFinal(cipherText),"UTF-8");
I know similar questions have been asked previously but the solutions (possibly due to my own ignorance) haven't helped me to get this working. I haven't done any encryption work before so there is probably something that I am just not getting.
The code to encrypt and decrypt are within my control so if someone wants to suggest an alternative method for all three languages I am open to changing the encryption method.
In this code, this line is causing an exception:
clearText = c.doFinal(Base64.decode(encryptedText, Base64.DEFAULT));
javax.crypto.BadPaddingException: pad block corrupted
I got the code from:
http://www.techrepublic.com/blog/software-engineer/attention-android-developers-keep-user-data-safe/
Any ideas?
private String decrypt (String encryptedText) {
byte[] clearText = null;
try {
SecretKeySpec ks = new SecretKeySpec(getKey(), "AES");
Cipher c = Cipher.getInstance("AES");
c.init(Cipher.DECRYPT_MODE, ks);
clearText = c.doFinal(Base64.decode(encryptedText, Base64.DEFAULT));
return new String(clearText, "UTF-8");
} catch (Exception e) {
return null;
}
}
Details: I am encrypting it on the android as well
owlstead's advice was helpful, but for this case when using the code in
Attention Android developers: Keep user data safe
http://www.techrepublic.com/blog/software-engineer/attention-android-developers-keep-user-data-safe/
I made some changes to the code that might be helpful for other people in the future. I completely deleted the getkey method.
private static String seed;
/**
* Encrypts the text.
* #param clearText The text you want to encrypt
* #return Encrypted data if successful, or null if unsucessful
*/
protected String encrypt(String clearText) {
byte[] encryptedText = null;
try {
byte[] keyData = seed.getBytes();
SecretKey ks = new SecretKeySpec(keyData, "AES");
Cipher c = Cipher.getInstance("AES");
c.init(Cipher.ENCRYPT_MODE, ks);
encryptedText = c.doFinal(clearText.getBytes("UTF-8"));
return Base64.encodeToString(encryptedText, Base64.DEFAULT);
} catch (Exception e) {
return null;
}
}
/**
* Decrypts the text
* #param encryptedText The text you want to encrypt
* #return Decrypted data if successful, or null if unsucessful
*/
protected String decrypt (String encryptedText) {
byte[] clearText = null;
try {
byte[] keyData = seed.getBytes();
SecretKey ks = new SecretKeySpec(keyData, "AES");
Cipher c = Cipher.getInstance("AES");
c.init(Cipher.DECRYPT_MODE, ks);
clearText = c.doFinal(Base64.decode(encryptedText, Base64.DEFAULT));
return new String(clearText, "UTF-8");
} catch (Exception e) {
return null;
}
}
Java + Android + Encryption + Exception means just one thing normally, somebody is using the SecureRandom class again as a key derivation function. This fails when the SecureRandom implementation of "SHA1PRNG" does not behave as the one in Sun's implementation in Java SE. Especially if the seed is added to the state of the random number generator instead of the seed being used as a starting point of the PRNG.
Basically, simply use SecretKey aesKey = new SecretKeySpec(byte[] keyData, "AES") instead, or - if you start off with a password - try and generate the key using PBKDF2.
For me, the problem is in getKey()
Make sure that two invocation of getKey() return the same value.
I used new SecureRandom(password.getBytes()) to generate key. It worked on Windows, but on Android, it returned different value for different call.
I Reffred From this : https://androidfreetutorial.wordpress.com/2017/03/14/android-encryptiondecryption-with-aes-algorithm/
Change to "AES" From "AES/ECB/PKCS7Padding";