So, I am having an issue with decrypting the decoded base64 aes string. Is this possible? I wrote a small console program to work this out but no luck. Here is my example:
As depicted, I have successfully converted the base64 back the aes encrypted string, but when I try to decrypt it I get more junk. If a code snippet is need let me. Thank you all for your help :)
UPDATE: Code snippet for decrypting method
static void Main(string[] args)
{
string plainText;
string decrypted;
string decryptedFromB64EncodedDecoded;
string fromBase64ToEncryptedText;
string encryptedText;
string encryptedTextBase64;
byte[] encryptedBytes;
byte[] encryptedBytes2;
byte[] encryptedBytesBase64;
RijndaelManaged crypto = new RijndaelManaged();
UTF8Encoding UTF = new UTF8Encoding();
Console.WriteLine("Please put in the text to be encrypted.");
plainText = Console.ReadLine();
try
{
encryptedBytes = encrypt(plainText, crypto.Key, crypto.IV);
encryptedText = Encoding.ASCII.GetString(encryptedBytes);
//encryptedBytes2 = Encoding.ASCII.GetBytes(encryptedText);
encryptedTextBase64 = toBase64String(encryptedText);
encryptedBytesBase64 = fromBase64String(encryptedTextBase64);
fromBase64ToEncryptedText = Encoding.ASCII.GetString(encryptedBytesBase64);
encryptedBytes2 = Encoding.ASCII.GetBytes(fromBase64ToEncryptedText);
decrypted = decrypt(encryptedBytes, crypto.Key, crypto.IV);
decryptedFromB64EncodedDecoded = decrypt(encryptedBytes2, crypto.Key, crypto.IV);
Console.WriteLine("Start: {0}", plainText);
Console.WriteLine("Encrypted: {0}", encryptedText);
Console.WriteLine("Encrypted Base64: {0}", encryptedTextBase64);
Console.WriteLine("From Base64 To AES Encypted Text: {0}", fromBase64ToEncryptedText);
Console.WriteLine("Decrypted: {0}", decrypted);
Console.WriteLine("Decrypted From Encode and then Decode Base64 Text: {0}", decryptedFromB64EncodedDecoded);
}
catch (Exception ex)
{
Console.WriteLine("Exception: {0}", ex.Message);
}
Console.ReadLine();
}
public static string decrypt (byte[] textToDecrypt, byte[] key, byte[] IV)
{
RijndaelManaged crypto = new RijndaelManaged();
MemoryStream stream = new MemoryStream(textToDecrypt) ;
ICryptoTransform decryptor = null;
CryptoStream cryptoStream = null;
StreamReader readStream = null;
string text = string.Empty;
try
{
crypto.Key = key;
crypto.IV = IV;
crypto.Padding = PaddingMode.None;
decryptor = crypto.CreateDecryptor(crypto.Key, crypto.IV);
cryptoStream = new CryptoStream(stream, decryptor, CryptoStreamMode.Read);
//cryptoStream.Read(textToDecrypt, 0, textToDecrypt.Length);
readStream = new StreamReader(cryptoStream);
text = readStream.ReadToEnd();
cryptoStream.Close();
byte[] decodedValue = stream.ToArray();
return text;
}
catch (Exception)
{
throw;
}
finally
{
if (crypto != null)
{
crypto.Clear();
}
stream.Flush();
stream.Close();
}
}
public static byte[] encrypt(string text, byte[] key, byte[] IV)
{
RijndaelManaged crypto = null;
MemoryStream stream = null;
//ICryptoTransform is used to perform the actual decryption vs encryption, hash function are a version crypto transforms
ICryptoTransform encryptor = null;
//CryptoStream allows for encrption in memory
CryptoStream cryptoStream = null;
UTF8Encoding byteTransform = new UTF8Encoding();
byte[] bytes = byteTransform.GetBytes(text);
try
{
crypto = new RijndaelManaged();
crypto.Key = key;
crypto.IV = IV;
stream = new MemoryStream();
encryptor = crypto.CreateEncryptor(crypto.Key, crypto.IV);
cryptoStream = new CryptoStream(stream, encryptor, CryptoStreamMode.Write);
cryptoStream.Write(bytes, 0, bytes.Length);
}
catch (Exception)
{
throw;
}
finally
{
if (crypto != null)
{
crypto.Clear();
}
cryptoStream.Close();
}
return stream.ToArray();
}
public static string toBase64String(string value)
{
UTF8Encoding UTF = new UTF8Encoding();
byte[] myarray = UTF.GetBytes(value);
return Convert.ToBase64String(myarray);
}
public static byte[] fromBase64String(string mystring)
{
//UTF8Encoding UTF = new UTF8Encoding();
//byte[] myarray = UTF.GetBytes(value);
return Convert.FromBase64String(mystring);
}
I don't know how you're decrypting but before you decrypt, you should convert the base 64 string to a byte array before sending it into the decryption.
byte[] encryptedStringAsBytes = Convert.FromBase64String(base64EncodedEncryptedValue);
Then with the byte array you can pass to the CryptoStream via a MemoryStream.
UPDATE
I believe the issue is how you're setting up your streams
using (RijndaelManaged rijndaelManaged = new RijndaelManaged())
{
rijndaelManaged.Padding = paddingMode;
rijndaelManaged.Key = key;
rijndaelManaged.IV = initVector;
MemoryStream memoryStream = null;
try
{
memoryStream = new MemoryStream(valueToDecrypt);
using (ICryptoTransform cryptoTransform = rijndaelManaged.CreateDecryptor())
{
using (CryptoStream cryptoStream = new CryptoStream(memoryStream, cryptoTransform, CryptoStreamMode.Read))
{
using (StreamReader streamReader = new StreamReader(cryptoStream))
{
return streamReader.ReadToEnd();
}
}
}
}
finally
{
if (memoryStream != null)
memoryStream.Dispose();
}
}
UPDATE 2
This is how you should basically perform the steps.
To encrypt
Encode your plain text string using the Encoding.GetBytes(stringToEncrypt)
pass the byte[] into the crypto API (via memory stream, etc.)
get the bytes from the encrypted stream and encode the results as Base64
To Decrypt (do the reverse)
Convert the base64 encoded string to bytes using Convert.FromBase64String(base64EncodedEncryptedValue)
pass that byte array into your decryption function above
Try:
encryptedBytes2 = Encoding.ASCII.GetBytes(encryptedText);
Based on your comment. The bytes are just that bytes, so in order to decrypt the ciphertext you need to undo any encoding or series of encodings you have done.
If you really want to go from Encrypted Bytes -> Base64String -> ASCII string -> then decrypt that ASCII string? you would need to base64 decode the ascii string then convert that string to bytes using
Encoding.ASCII.GetBytes(yourdecodedstring);
Note that base 64 decoding is not the same as using Convert.FromBase84String.
Related
I wrote this code to encrypt a text and write the encrypted text to a file and then decrypt it from the file. But I get this exception: System.Security.Cryptography.CryptographicException: 'The input data is not a complete block.' When I use a byte[] for storing data, it works perfect but it seems that it cant correctly convert a file to byte[]. I also tried File.ReadAllBytes but I got the same error. Please Help me.
class Program
{
static void Main(string[] args)
{
string decrypted;
byte[] encrypted;
Console.Write("Enter a text to encrypt : ");
string plaintext = Console.ReadLine();
using (Aes aes = Aes.Create())
{
encrypted = AesEncryption.Encrypt(plaintext, aes);
File.WriteAllText(#"C:\Users\sepita\Desktop\My.txt", Encoding.UTF8.GetString(encrypted), Encoding.UTF8);
decrypted = AesEncryption.Decrypt(Encoding.UTF8.GetBytes(File.ReadAllText(#"C:\Users\sepita\Desktop\My.txt")), aes);
}
Console.WriteLine($"Encrypted : {Encoding.UTF8.GetString(encrypted)}");
Console.WriteLine($"Decrypted : {decrypted}");
}
}
static class AesEncryption
{
public static byte[] Encrypt(string plaintext, Aes aes)
{
byte[] encrypted;
ICryptoTransform encryptor = aes.CreateEncryptor();
using (MemoryStream memoryStream = new MemoryStream())
{
using (CryptoStream stream = new CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write))
{
using (StreamWriter writer = new StreamWriter(stream))
{
writer.Write(plaintext);
}
encrypted = memoryStream.ToArray();
}
}
return encrypted;
}
public static string Decrypt(byte[] encrypted, Aes aes)
{
string decrypted = null;
ICryptoTransform decryptor = aes.CreateDecryptor();
using (MemoryStream memoryStream = new MemoryStream(encrypted))
{
using (CryptoStream stream = new CryptoStream(memoryStream, decryptor, CryptoStreamMode.Read))
{
using (StreamReader reader = new StreamReader(stream))
{
decrypted = reader.ReadToEnd();
}
}
}
return decrypted;
}
}
The result of your Encrypt function is binary data. It would be pure luck if this were a valid UTF8 string, so Encoding.UTF8.GetString(encrypted) will not work in general.
Replacing it by
File.WriteAllBytes(#"C:\Users\sepita\Desktop\My.bin", encrypted);
decrypted = AesEncryption.Decrypt(File.ReadAllBytes(#"C:\Users\sepita\Desktop\My.bin"), aes);
will work.
If you want a text file, use BASE64 conversion on the binary data:
File.WriteAllText(#"C:\Users\sepita\Desktop\My.txt", Convert.ToBase64String(encrypted));
decrypted = AesEncryption.Decrypt(Convert.FromBase64String(File.ReadAllText(#"C:\Users\sepita\Desktop\My.txt")), aes);
I try to build simple AES encryption helper to encrypt/decrypt some strings
Fist, I have an issue with Padding mode wherein decryption it only accepts if Zero otherwise an error about padding occurs!
The second issue is when I try to encrypt simple string "Hello World," it got encrypted, and I have the base64 string, but when trying to decrypt, there's no error, but a weird unknown character is shown! like 㡲啁䎰廾ử靱㡲啁䎰廾ử靱
My code:
private static int keySizes = 256;
private static int blockSize = 128;
private static PaddingMode pMode = PaddingMode.Zeros;
private static CipherMode cMode = CipherMode.ECB;
private static byte[] key = GenEncryptionKey();
private const string passphrase = #"StartYourMorningWithASmile";
private static byte[] GenEncryptionKey()
{
HashAlgorithm hash = MD5.Create();
return hash.ComputeHash(Encoding.Unicode.GetBytes(passphrase));
}
private static AesManaged CreateCryptor()
{
AesManaged cryptor = new AesManaged();
cryptor.KeySize = keySizes;
cryptor.BlockSize = blockSize;
cryptor.Padding = pMode;
cryptor.Key = key;
cryptor.Mode = cMode;
cryptor.GenerateIV();
return cryptor;
}
public static string EncryptParams(string reqVal)
{
string cipherText = "";
if (string.IsNullOrEmpty(reqVal) || reqVal.Length < 1)
throw new ArgumentNullException();
byte[] plainBytes = Encoding.Unicode.GetBytes(reqVal);
using (var cryptor = CreateCryptor())
{
ICryptoTransform encryptor = cryptor.CreateEncryptor();
using (MemoryStream ms = new MemoryStream())
{
using (CryptoStream cs = new CryptoStream(ms, encryptor, CryptoStreamMode.Write))
{
cs.Write(plainBytes, 0, plainBytes.Length);
}
byte[] cipherBytes = ms.ToArray();
cipherText = Convert.ToBase64String(cipherBytes);
}
cryptor.Clear();
}
return cipherText;
}
public static string DecryptParams(string resVal)
{
var data = Convert.FromBase64String(resVal);
byte[] cipherBytes = new byte[data.Length];
string plainText = "";
using (var crypto = CreateCryptor())
{
ICryptoTransform Dec = crypto.CreateDecryptor();
using (MemoryStream ms = new MemoryStream())
{
using (var cs = new CryptoStream(ms, Dec, CryptoStreamMode.Write))
{
cs.Write(cipherBytes, 0, cipherBytes.Length);
plainText = Encoding.Unicode.GetString(ms.ToArray());
}
}
crypto.Clear();
}
return plainText;
}
UPDATE 1:
Please set also the IV yourself to achieve successful decryption, as #maarten-bodewes pointed out. I missed that part and the decryption somehow worked (?) with your existing code, but you always should provide the same key and IV to a symmetric encryption algorithm to have it work both ways.
ORIGINAL ANSWER:
Your decryption fails (produces incorrect results) because you implemented the decryption part incorrectly (by using CryptoStreamMode.Write instead of CryptoStreamMode.Read) and besides feeding the decryption stream all zero bytes
At the point of execution of
cs.Write(cipherBytes, 0, cipherBytes.Length);
the variable cipherBytes is all zero. The real encrypted buffer is in the data variable which you only use to set the length of cipherBytes
So change your decryption method to this.
BONUS: After correcting the decryption part, you can specify the padding as you wish! I tested with PKCS7 and it is ok.
public static string DecryptParams(string resVal)
{
var cipherBytes = Convert.FromBase64String(resVal);
string plainText = "";
using (var crypto = CreateCryptor())
{
ICryptoTransform Dec = crypto.CreateDecryptor();
using (MemoryStream ms = new MemoryStream(cipherBytes))
{
using (var cs = new CryptoStream(ms, Dec, CryptoStreamMode.Read))
{
byte[] decryptBlock = new byte[4096];
MemoryStream decryptStream = new MemoryStream();
int readBytes;
while ((readBytes = cs.Read(decryptBlock, 0, 4096)) > 0)
{
decryptStream.Write(decryptBlock, 0, readBytes);
}
plainText = Encoding.Unicode.GetString(decryptStream.ToArray());
}
}
crypto.Clear();
}
return plainText;
}
Hope this helps.
Thanks to Oguz
Below is my description method after edit
public static string DecryptParams(string resVal)
{
var data = Convert.FromBase64String(resVal);
byte[] cipherBytes = new byte[data.Length];
string plainText = "";
using (var crypto = CreateCryptor())
{
ICryptoTransform Dec = crypto.CreateDecryptor();
using (MemoryStream ms = new MemoryStream(data))
{
using (var cs = new CryptoStream(ms, Dec, CryptoStreamMode.Read))
{
cs.Read(cipherBytes, 0, cipherBytes.Length);
plainText = Encoding.Unicode.GetString(cipherBytes.ToArray());
}
}
crypto.Clear();
}
return plainText;
}
one more thing about the return result after the decryption I got the original string plus \0\0\0\0 so I use myString.TrimEnd('\0') to solve that.
Whenever I decrypt a file I end up with \0 in between each character (this is a text file) The original is fine, and the decryption is successful without errors.
When I do open the file ; "hello" would become "h\0e\0l\0..."
Here is my decryption function: (I came up with a fix of converting the byte array to utf8 then manually removing the nulls, this is obviously not a solution. )
public static void DecryptFileToFile(String fromFile, String toFile, byte[] Key)
{
byte[] encryptedFile = IO.convertFileToByte(fromFile);
using (Aes aesAlg = Aes.Create())
{
byte[] dataIV = encryptedFile.Take(16).ToArray(); //first 16 bytes is iv
byte[] encryptedData = encryptedFile.Skip(16).Take(encryptedFile.Length-16).ToArray();
aesAlg.Key = Key;
using (var decryptor = aesAlg.CreateDecryptor(Key, dataIV))
{
byte[] final = PerformCryptography(decryptor, encryptedData);
string result = System.Text.Encoding.UTF8.GetString(final);
result = result.Replace("\0", string.Empty);
IO.writeStringToFile(result,toFile);
}
}
}
private static byte[] PerformCryptography(ICryptoTransform cryptoTransform, byte[] data)
{
using (var memoryStream = new MemoryStream())
{
using (var cryptoStream = new CryptoStream(memoryStream, cryptoTransform, CryptoStreamMode.Write))
{
cryptoStream.Write(data, 0, data.Length);
cryptoStream.FlushFinalBlock();
return memoryStream.ToArray();
}
}
}
to encrypt:
public static void EncryptFileToFile(String fromFile, String toFile, byte[] Key){
byte[] original = IO.convertFileToByte(fromFile);
using (Aes aesAlg = Aes.Create())
{
aesAlg.GenerateIV();
aesAlg.Key = Key;
using (var encryptor = aesAlg.CreateEncryptor(Key, aesAlg.IV))
{
byte[] encryptedData = PerformCryptography(encryptor, original);
byte[] final = Combine(aesAlg.IV,encryptedData);
IO.writeByteToFile(final, toFile);
}
}
}
I'm creating a TCP based chat client. I'm trying to Encrypt some of the data with AES (more security) I have a AES encryption class and it uses UTF-8 by default as the out going and incoming Encoding type. But for some reason when i pass the information over the TCPClient (using UTF-8) and get it the other side it is throwing an error:
`System.Security.Cryptography.CryptographicException: Length of the data to decrypt is invalid.
at System.Security.Cryptography.RijndaelManagedTransform.TransformFinalBlock(Byte[] inputBuffer, Int32 inputOffset, Int32 inputCount)
at System.Security.Cryptography.CryptoStream.FlushFinalBlock()`
So I recreated the problem without using the TCP client, just taking the AES encrypted data and putting it through a UTF-8 Encoding system that gets the string of the byte array then re-gets the byte array all using UTF-8 (basically the same thing as what happens over the network (without the string))
This method works:
string dataToEncrypt = "Hello World";
byte[] key = Encryption.AesEncryption.GenerateKey(32);
byte[] iv = Encryption.AesEncryption.GenerateKey(16);
byte[] encrypted = Encryption.AesEncryption.EncryptString(dataToEncrypt, key, iv);
string decrypted = Encryption.AesEncryption.DecryptedBytes(encrypted, key, iv);
The method doesn't work (throws the error from above)
Encoding encoding = Encoding.UTF8;
string dataToEncrypt = "Hello World";
byte[] key = Encryption.AesEncryption.GenerateKey(32);
byte[] iv = Encryption.AesEncryption.GenerateKey(16);
byte[] encrypted = Encryption.AesEncryption.EncryptString(dataToEncrypt, key, iv);
string encstring = encoding.GetString(encrypted);
byte[] utf8encrypted = encoding.GetBytes(encstring);
string decrypted = Encryption.AesEncryption.DecryptedBytes(utf8encrypted, key, iv);
What am i doing wrong?
This is my Encryption Class:
public sealed class AesEncryption
{
private byte[] Key;
public Encoding Encoder = Encoding.UTF8;
public AesEncryption(byte[] key)
{
Key = key;
}
public byte[] Encrypt(string text, byte[] iv)
{
var bytes = Encoder.GetBytes(text);
var rm = new RijndaelManaged();
var encrypter = rm.CreateEncryptor(Key, iv);
var ms = new MemoryStream();
var cs = new CryptoStream(ms, encrypter, CryptoStreamMode.Write);
cs.Write(bytes, 0, bytes.Length);
cs.FlushFinalBlock();
var output = ms.ToArray();
cs.Close();
ms.Close();
return output;
}
public string Decrypt(byte[] encrypted, byte[] iv)
{
var ms = new MemoryStream();
var cs = new CryptoStream(ms,
new RijndaelManaged().CreateDecryptor(Key, iv),
CryptoStreamMode.Write);
cs.Write(encrypted, 0, encrypted.Length);
cs.FlushFinalBlock();
var output = ms.ToArray();
cs.Close();
ms.Close();
return Encoder.GetString(output);
}
public static byte[] EncryptString(string text, byte[] key, byte[] iv)
{
var ec = new AesEncryption(key);
return ec.Encrypt(text, iv);
}
public static string DecryptedBytes(byte[] encrypted, byte[] key, byte[] iv)
{
var ec = new AesEncryption(key);
return ec.Decrypt(encrypted, iv);
}
public static byte[] GenerateKey(int length)
{
Random rnd = new Random();
var chars = "1!2#3#4$5%6^7&8*9(0)-_=+qQwWeErRtTyYuUiIoOpP[{]}\\|aAsSdDfFgGhHjJkKlL;:'\"zZxXcCvVbBnNmM,<.>/?".ToCharArray();
string randomizedKey = "";
for (int i = 0; i < length; i++)
{
randomizedKey += chars[rnd.Next(0, chars.Length)];
}
return randomizedKey.ToByteArray();
}
}
UTF-8 does not perfectly represent the bytes. The short and simple answer is: Transmit bytes, not a UTF-8 string. If you must have a string, encode it in Base64.
I have a DLL in C# that encrypts and decrypts string texts (something basic), but now I need to implement the same encryption method in Java, so that some applications can encrypt data and send it to the library.
I can't modify the C# code, because it's already in production, but the Java don't, so please, any suggestion must be done at the Java side.
Basically I'm trying to implement the same C# encryption method in Java. Here are my C# codes:
NOTE: the passphrase, salt, etc. values obviously are just referential.
const string PassPhrase = "IhDyHz6bgQyS0Ff1/1s=";
const string SaltValue = "0A0Qvv09OXd3GsYHVrA=";
const string HashAlgorithm = "SHA1";
const int PasswordIterations = 3;
const string InitVector = "GjrlRZ6INgNckBqv";
const int KeySize = 256;
public static string Encrypt(string plainText)
{
byte[] initVectorBytes = Encoding.ASCII.GetBytes(InitVector);
byte[] saltValueBytes = Encoding.ASCII.GetBytes(SaltValue);
byte[] plainTextBytes = Encoding.UTF8.GetBytes(plainText);
PasswordDeriveBytes password = new PasswordDeriveBytes(
PassPhrase,
saltValueBytes,
HashAlgorithm,
PasswordIterations);
byte[] keyBytes = password.GetBytes(KeySize / 8);
RijndaelManaged symmetricKey = new RijndaelManaged();
symmetricKey.Mode = CipherMode.CBC;
ICryptoTransform encryptor = symmetricKey.CreateEncryptor(
keyBytes,
initVectorBytes);
MemoryStream memoryStream = new MemoryStream();
CryptoStream cryptoStream = new CryptoStream(memoryStream,
encryptor,
CryptoStreamMode.Write);
cryptoStream.Write(plainTextBytes, 0, plainTextBytes.Length);
cryptoStream.FlushFinalBlock();
byte[] cipherTextBytes = memoryStream.ToArray();
memoryStream.Close();
cryptoStream.Close();
string cipherText = Convert.ToBase64String(cipherTextBytes);
return cipherText;
}
public static string Decrypt(string cipherText)
{
byte[] initVectorBytes = Encoding.ASCII.GetBytes(InitVector);
byte[] saltValueBytes = Encoding.ASCII.GetBytes(SaltValue);
byte[] cipherTextBytes = Convert.FromBase64String(cipherText);
PasswordDeriveBytes password = new PasswordDeriveBytes(
PassPhrase,
saltValueBytes,
HashAlgorithm,
PasswordIterations);
byte[] keyBytes = password.GetBytes(KeySize / 8);
RijndaelManaged symmetricKey = new RijndaelManaged();
symmetricKey.Mode = CipherMode.CBC;
ICryptoTransform decryptor = symmetricKey.CreateDecryptor(
keyBytes,
initVectorBytes);
MemoryStream memoryStream = new MemoryStream(cipherTextBytes);
CryptoStream cryptoStream = new CryptoStream(memoryStream,
decryptor,
CryptoStreamMode.Read);
byte[] plainTextBytes = new byte[cipherTextBytes.Length];
int decryptedByteCount = cryptoStream.Read(plainTextBytes,
0,
plainTextBytes.Length);
memoryStream.Close();
cryptoStream.Close();
string plainText = Encoding.UTF8.GetString(plainTextBytes,
0,
decryptedByteCount);
return plainText;
}
Here is my java code, it encrypts the data, but not at the same way as the C# encryption code, so when I try to decrypt it using the C# library it throws the exception: "Length of the data to decrypt is invalid"
static final String PassPhrase = "IhDyHz6bgQyS0Ff1/1s=";
static final String SaltValue = "0A0Qvv09OXd3GsYHVrA=";
static final String HashAlgorithm = "SHA1";
static final int PasswordIterations = 3;
static final String InitVector = "GjrlRZ6INgNckBqv";
static final int KeySize = 256;
public static String encrypt(String plainText)
{
char[] password = PassPhrase.toCharArray();
byte[] salt = SaltValue.getBytes();
byte[] iv = InitVector.getBytes();
byte[] ciphertext = new byte[0];
SecretKeyFactory factory;
try {
factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
KeySpec spec = new PBEKeySpec(password, salt, PasswordIterations, 256);
SecretKey tmp;
tmp = factory.generateSecret(spec);
SecretKey secret = new SecretKeySpec(tmp.getEncoded(), "AES");
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
cipher.init(Cipher.ENCRYPT_MODE, secret);
AlgorithmParameters params = cipher.getParameters();
//iv = params.getParameterSpec(IvParameterSpec.class).getIV();
ciphertext = cipher.doFinal(plainText.getBytes("UTF-8"));
} catch (NoSuchAlgorithmException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InvalidKeySpecException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (NoSuchPaddingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InvalidKeyException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//catch (InvalidParameterSpecException e) {
// // TODO Auto-generated catch block
// e.printStackTrace();
//}
catch (IllegalBlockSizeException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (BadPaddingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return Base64.encode(new String(ciphertext));
}
EDIT 1: I fixed the final byte array conversion to String in the Java code, as Jon Skeet suggested.
This is what's wrong, in the Java code:
return Base64.encode(ciphertext.toString());
You're calling toString() on the byte array, which will always give a string such as [B#3e25a5.
EDIT: Ooh, just noticed that you can change the Java side. Hooray.
Basically, you need to use a Base64 API which allows:
return Base64.encode(ciphertext);
I'm always disappointed in Base64 APIs which allow you to "encode" a string, to be honest... base64 fundamentally encodes binary data to text, and decodes text data to binary. Oh well...
Anyway, use this API (the encodeBytes method) if you need one which allows you to pass in a byte array.
I haven't checked over the actual encryption part in detail, but the C# code at least looks like it's doing the right thing in terms of encodings. It could do with using statements though :)
Here is a C# example, you need the IterationCount and PaddingMode.None
protected void Page_Load(object sender, EventArgs e)
{
string value = "";
string password = "";
string salt = "";
string iv = "";
byte[] vectorBytes = Convert.FromBase64String(Server.UrlDecode(iv));
byte[] cipherText = Convert.FromBase64String(Server.UrlDecode(value));
Rfc2898DeriveBytes key1 = new Rfc2898DeriveBytes(password, StringToByteArray(salt)); //same as PBKDF2WithHmacSHA1
key1.IterationCount = 32;
byte[] keyBytes = key1.GetBytes(16);
string Answer = DecryptDataAES(cipherText, keyBytes, vectorBytes); //vectorBytes is good
//litAnswer.Text = Answer;
}
public static string DecryptDataAES(byte[] cipherText, byte[] key, byte[] iv)
{
string plaintext = null;
using (Rijndael rijndael = Rijndael.Create())
{
rijndael.Key = key;
rijndael.IV = iv;
rijndael.Padding = PaddingMode.None;
ICryptoTransform decryptor = rijndael.CreateDecryptor(rijndael.Key, rijndael.IV);
// Create the streams used for decryption.
using (MemoryStream msDecrypt = new MemoryStream(cipherText))
{
using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))
{
using (StreamReader srDecrypt = new StreamReader(csDecrypt))
{
plaintext = srDecrypt.ReadToEnd();
}
}
}
}
return plaintext;
}
public static byte[] StringToByteArray(String hex)
{
int NumberChars = hex.Length / 2;
byte[] bytes = new byte[NumberChars];
using (var sr = new StringReader(hex))
{
for (int i = 0; i < NumberChars; i++)
bytes[i] =
Convert.ToByte(new string(new char[2] { (char)sr.Read(), (char)sr.Read() }), 16);
}
return bytes;
}