At the moment, I'm working on a project that involves encryption. Therefore, I have a class, which worked fine in .NET 4.0, but now that I changed it so it would work in .NET 2.0, it fails to encrypt almost any string... I don't know why, but it fails every time and throws a CryptographicException. Decrypting works fine as far as I can tell, and everything else too.
Anyway, here's the code:
public class Encryption
{
static readonly string PasswordHash = "P##Sw0rd";
static readonly string SaltKey = "S#LT&KEY";
static readonly string VIKey = "#1B2c3D4e5F6g7H8";
public static string Encrypt(string plainText, string passwordHash)
{
byte[] plainTextBytes = Encoding.UTF8.GetBytes(plainText);
byte[] keyBytes = new Rfc2898DeriveBytes(passwordHash, Encoding.ASCII.GetBytes(SaltKey)).GetBytes(256 / 8);
RijndaelManaged symmetricKey = new RijndaelManaged();
symmetricKey.Mode = CipherMode.CBC;
symmetricKey.Padding = PaddingMode.None;
ICryptoTransform encryptor = symmetricKey.CreateEncryptor(keyBytes, Encoding.ASCII.GetBytes(VIKey));
byte[] cipherTextBytes;
using (MemoryStream memoryStream = new MemoryStream())
{
using (CryptoStream cryptoStream = new CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write))
{
cryptoStream.Write(plainTextBytes, 0, plainTextBytes.Length);
cryptoStream.FlushFinalBlock();
cipherTextBytes = memoryStream.ToArray();
cryptoStream.Close();
}
memoryStream.Close();
}
return Convert.ToBase64String(cipherTextBytes);
}
public static string Decrypt(string encryptedText, string passwordHash)
{
byte[] cipherTextBytes = Convert.FromBase64String(encryptedText);
byte[] keyBytes = new Rfc2898DeriveBytes(passwordHash, Encoding.ASCII.GetBytes(SaltKey)).GetBytes(256 / 8);
RijndaelManaged symmetricKey = new RijndaelManaged();
symmetricKey.Mode = CipherMode.CBC;
symmetricKey.Padding = PaddingMode.None;
ICryptoTransform decryptor = symmetricKey.CreateDecryptor(keyBytes, Encoding.ASCII.GetBytes(VIKey));
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();
return Encoding.UTF8.GetString(plainTextBytes, 0, decryptedByteCount).TrimEnd("\0".ToCharArray());
}
}
The error message is (translated from German):
CryptographicException: Length of the data to encrypt is invalid. at System.Security.Cryptography.RijndaelManagedTransform.TransformFinalBlock(Byte[] inputBuffer, Int32 inputOffset, Int32 inputCount) at System.Security.Cryptography.CryptoStream.FlushFinalBlock() at System.Security.Cryptography.CryptoStream.Dispose(Boolean disposing)
Encryption.Encrypt("Client connected!", "elit3Nase") does not work
"Client connected!" is not long enough to fully fill a block (16 bytes) and you are not using padding:
symmetricKey.Padding = PaddingMode.None;
Change to symmetricKey.Padding = PaddingMode.PKCS7; to ensure padding is applied.
Related
I am trying to decrypt a byte[] the length of 30601 with the following method
public static byte[] DecryptObject(byte[] recObj, byte[] aesKey, byte[] aesIV) {
using (Aes aes = Aes.Create()) {
aes.BlockSize = 128;
aes.Mode = CipherMode.ECB;
aes.Padding = PaddingMode.PKCS7;
aes.Key = aesKey;
aes.IV = aesIV;
using (ICryptoTransform decryptor = aes.CreateDecryptor(aes.Key, aes.IV)) {
using (MemoryStream ms = new MemoryStream())
using (CryptoStream cs = new CryptoStream(ms, decryptor, CryptoStreamMode.Write)) {
cs.Write(recObj, 0, recObj.Length);
cs.FlushFinalBlock();
return ms.ToArray();
}
}
}
}
I have confirmed the key and iv is the same in which I used to encrypt with, but its throwing the error on cs.FlushFinalBlock(); with error
System.Security.Cryptography.CryptographicException: 'The input data is not a complete block.'
I have tried other methods to get this resolved but they are not working.
I am using this to encrypt
public static byte[] EncryptAes(byte[] data, byte[] key, byte[] iv) {
using (var aes = Aes.Create()) {
aes.Padding = PaddingMode.PKCS7;
aes.Key = key;
aes.IV = iv;
using (var ms = new MemoryStream()) {
using (var cs = new CryptoStream(ms, aes.CreateEncryptor(), CryptoStreamMode.Write)) {
cs.Write(data, 0, data.Length);
cs.FlushFinalBlock();
return ms.ToArray();
}
}
}
}
In ms SQL server, I have a field text with data look like below:
"!"$$$$$$!#$$$$!!!!! !!!!!!!!!!!!!! "!! ! " !" ! !" !!!! ! !!"!".
I belive that from a plain text string, they using a Rijndael algorithm to encrypted this string. from encrypted string, it was transform to string above.
Can anyone recognize what the algorithm to decrypt from string above to the encrypted string of Rijndael algorithm?
thanks
Hi me drona please find the below code. It will useful from you.
public static class Encrypt
{
// This size of the IV (in bytes) must = (keysize / 8). Default keysize is 256, so the IV must be
// 32 bytes long. Using a 16 character string here gives us 32 bytes when converted to a byte array.
private const string initVector = "pemgail9uzpgzl88";
// This constant is used to determine the keysize of the encryption algorithm
private const int keysize = 256;
//Encrypt
public static string EncryptString(string plainText, string passPhrase)
{
byte[] initVectorBytes = Encoding.UTF8.GetBytes(initVector);
byte[] plainTextBytes = Encoding.UTF8.GetBytes(plainText);
PasswordDeriveBytes password = new PasswordDeriveBytes(passPhrase, null);
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();
return Convert.ToBase64String(cipherTextBytes);
}
//Decrypt
public static string DecryptString(string cipherText, string passPhrase)
{
byte[] initVectorBytes = Encoding.ASCII.GetBytes(initVector);
byte[] cipherTextBytes = Convert.FromBase64String(cipherText);
PasswordDeriveBytes password = new PasswordDeriveBytes(passPhrase, null);
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();
return Encoding.UTF8.GetString(plainTextBytes, 0, decryptedByteCount);
}
enter code here
I am using a Rijndeal algorithm to encrypt and decrypt a string value. This method works fine in most of the cases, but in same cases on one machine I'm missing characters after decryption.
Here is my sample code
public static string Decrypt(string cipherText)
{
try
{
string incoming = cipherText.Replace('_', '/').Replace('-', '+');
switch (cipherText.Length % 4)
{
case 2: incoming += "=="; break;
case 3: incoming += "="; break;
}
byte[] initVectorBytes = Encoding.ASCII.GetBytes(initVector);
byte[] cipherTextBytes = Convert.FromBase64String(incoming);
PasswordDeriveBytes password = new PasswordDeriveBytes(passPhrase, null);
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();
return Encoding.UTF8.GetString(plainTextBytes, 0, decryptedByteCount);
}
catch (Exception ex)
{
return "Exception";
}
}
This question already has an answer here:
Decrypt/Decrypt Arabic string
(1 answer)
Closed 7 years ago.
How to Encrypt/Decrypt Arabic string in C# using these methods ????
Wheni try to decrypt any arabic string its return "????" question marks.. How can use Encoding UTF8 through this code ??
Any help please ..
thanks in advance
public static string Encrypt(string pDataToEncrypt)
{
ASCIIEncoding textConverter = new ASCIIEncoding();
RijndaelManaged myRijndael = new RijndaelManaged();
byte[] toEncrypt;
ICryptoTransform encryptor = myRijndael.CreateEncryptor(key, IV);
MemoryStream msEncrypt = new MemoryStream();
CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write);
toEncrypt = textConverter.GetBytes(pDataToEncrypt);
csEncrypt.Write(toEncrypt, 0, toEncrypt.Length);
csEncrypt.FlushFinalBlock();
return Convert.ToBase64String(msEncrypt.GetBuffer(), 0, (int)msEncrypt.Length);
}
public static string Decrypt(string pDataToDecrypt)
{
RijndaelManaged myRijndael = new RijndaelManaged();
byte[] fromEncrypt;
//Encoding asciiEncoding = Encoding.ASCII;
fromEncrypt = Convert.FromBase64String(pDataToDecrypt);
ICryptoTransform decryptor = myRijndael.CreateDecryptor(key, IV);
MemoryStream msDecrypt = new MemoryStream(fromEncrypt, 0, fromEncrypt.Length);
CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read);
StreamReader sr = new StreamReader(csDecrypt);
return sr.ReadToEnd();
}
Using UTF-8 your code should be like this:
public static string Encrypt(string pDataToEncrypt)
{
RijndaelManaged myRijndael = new RijndaelManaged();
ICryptoTransform encryptor = myRijndael.CreateEncryptor(key, IV);
MemoryStream msEncrypt = new MemoryStream();
CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor,CryptoStreamMode.Write);
byte[] toEncrypt = Encoding.UTF8.GetBytes(pDataToEncrypt);
csEncrypt.Write(toEncrypt, 0, toEncrypt.Length);
csEncrypt.FlushFinalBlock();
return Convert.ToBase64String(msEncrypt.GetBuffer(), 0, (int)msEncrypt.Length);
}
public static string Decrypt(string pDataToDecrypt)
{
RijndaelManaged myRijndael = new RijndaelManaged();
byte[] fromEncrypt = Convert.FromBase64String(pDataToDecrypt);
ICryptoTransform decryptor = myRijndael.CreateDecryptor(key, IV);
MemoryStream msDecrypt = new MemoryStream(fromEncrypt, 0, fromEncrypt.Length);
CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read);
byte[] plainTextBytes = new byte[fromEncrypt.Length];
int decryptedByteCount = csDecrypt.Read(plainTextBytes, 0, plainTextBytes.Length);
return Encoding.UTF8.GetString(plainTextBytes, 0, decryptedByteCount);
}
when i use this code to encrypt and decrypt i got an error said
Padding is invalid and cannot be removed.
any idea
public static class Crypto
{
private static readonly byte[] initVectorBytes = Encoding.ASCII.GetBytes("tu89geji340t89u2");
// This constant is used to determine the keysize of the encryption algorithm.
private const int keysize = 256;
public static string Encrypt(string plainText, string passPhrase)
{
byte[] plainTextBytes = Encoding.UTF8.GetBytes(plainText);
using (PasswordDeriveBytes password = new PasswordDeriveBytes(passPhrase, null))
{
byte[] keyBytes = password.GetBytes(keysize / 8);
using (RijndaelManaged symmetricKey = new RijndaelManaged())
{
symmetricKey.Mode = CipherMode.CBC;
using (ICryptoTransform encryptor = symmetricKey.CreateEncryptor(keyBytes, initVectorBytes))
{
using (MemoryStream memoryStream = new MemoryStream())
{
using (CryptoStream cryptoStream = new CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write))
{
cryptoStream.Write(plainTextBytes, 0, plainTextBytes.Length);
cryptoStream.FlushFinalBlock();
byte[] cipherTextBytes = memoryStream.ToArray();
return Convert.ToBase64String(cipherTextBytes);
}
}
}
}
}
}
public static string Decrypt(string cipherText, string passPhrase)
{
byte[] cipherTextBytes = Convert.FromBase64String(cipherText);
using (PasswordDeriveBytes password = new PasswordDeriveBytes(passPhrase, null))
{
byte[] keyBytes = password.GetBytes(keysize / 8);
using (RijndaelManaged symmetricKey = new RijndaelManaged())
{
symmetricKey.Mode = CipherMode.CBC;
using (ICryptoTransform decryptor = symmetricKey.CreateDecryptor(keyBytes, initVectorBytes))
{
using (MemoryStream memoryStream = new MemoryStream(cipherTextBytes))
{
using (CryptoStream cryptoStream = new CryptoStream(memoryStream, decryptor, CryptoStreamMode.Read))
{
byte[] plainTextBytes = new byte[cipherTextBytes.Length];
int decryptedByteCount = cryptoStream.Read(plainTextBytes, 0, plainTextBytes.Length);
return Encoding.UTF8.GetString(plainTextBytes, 0, decryptedByteCount);
}
}
}
}
}
}
}
I tried the following using your methods and it worked fine:
var passPhrase = "123456";
var e = Encrypt("testtesttesttest", passPhrase);
Console.WriteLine(e); // YEtSJshcn686ZO+JlEQ48ap/odhuvIGalbAT1XhinqQ=
var d = Decrypt(e, passPhrase);
Console.WriteLine(d); // testtesttesttest
This suggests that you're either passing a different passPhrase to Decrypt() to the one you passed to Encrypt(), or that you are somehow corrupting the ciphertext prior to decryption. (Are you perhaps calling Decrypt with the ciphertext and passphrase parameters reversed?)
It's also worth noting that essentially everything in the comments at the top of your code is wrong:
You're not passing any salt to PasswordDeriveBytes.
The size of the IV must be equal to the block size (16 bytes), it is unrelated to the key size used.
Passing a 16 character string through Encoding.ASCII.GetBytes() results in a 16 byte output, not 32 bytes. (This rather coincidentally means that your initVectorBytes is in fact the correct length for the IV).
Furthermore, PasswordDeriveBytes is deprecated and should not be used. You should be using Rfc2898DeriveBytes instead, and you should be using a proper salt value. The IV should also not be a static value, and definitely not one derived from an ASCII string!