Closed KamranShahid closed 5 years ago
Found out some help at [(https://stackoverflow.com/questions/53580563/c-sharp-encrypt-decrypt-from-java-aes-cbc-pkcs5padding)] Looking for more
C# may have the same algorithm implementation, you can look for details of what I'm using here I think it is all I can help you because I have no expertise in C#. Good luck!
Following is Full C# class which i were able to work as it is like java class At the moment i have only checked encryption part
public sealed class MyCryptoClass
{
protected AesManaged myRijndael;
private static string encryptionKey = "MyKey";
private static string salt = "Mysalt";
private static byte[] initialisationVector = new byte[16];
//private static byte[] initialisationVector = Encoding.UTF8.GetBytes("l4iG63jN9Dcg6537");
private static byte[] secretKey = GetSecretKey();
// Singleton pattern used here with ensured thread safety
protected static readonly MyCryptoClass _instance = new MyCryptoClass();
public static MyCryptoClass Instance
{
get { return _instance; }
}
public MyCryptoClass()
{
}
public string DecryptText(string encryptedString)
{
using (myRijndael = new AesManaged())
{
myRijndael.Key = Convert.FromBase64String(encryptionKey);
myRijndael.IV = new byte[16];
myRijndael.Mode = CipherMode.CBC;
myRijndael.Padding = PaddingMode.PKCS7;
Byte[] ourEnc = Convert.FromBase64String(encryptedString);
string ourDec = DecryptStringFromBytes(ourEnc, myRijndael.Key, myRijndael.IV);
return ourDec;
}
}
public string EncryptText(string plainText)
{
using (myRijndael = new AesManaged())
{
myRijndael.Key = secretKey;
myRijndael.IV = initialisationVector;
myRijndael.Mode = CipherMode.CBC;
myRijndael.Padding = PaddingMode.PKCS7;
byte[] encrypted = EncryptStringToBytes(plainText, myRijndael.Key, myRijndael.IV);
string encString = Convert.ToBase64String(encrypted);
return encString;
}
}
protected byte[] EncryptStringToBytes(string plainText, byte[] Key, byte[] IV)
{
// Check arguments.
if (plainText == null || plainText.Length <= 0)
throw new ArgumentNullException("plainText");
if (Key == null || Key.Length <= 0)
throw new ArgumentNullException("Key");
if (IV == null || IV.Length <= 0)
throw new ArgumentNullException("Key");
byte[] encrypted;
// Create an RijndaelManaged object
// with the specified key and IV.
using (RijndaelManaged rijAlg = new RijndaelManaged())
{
rijAlg.Key = Key;
rijAlg.IV = IV;
// Create a decrytor to perform the stream transform.
ICryptoTransform encryptor = rijAlg.CreateEncryptor(rijAlg.Key, rijAlg.IV);
// Create the streams used for encryption.
using (MemoryStream msEncrypt = new MemoryStream())
{
using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
{
using (StreamWriter swEncrypt = new StreamWriter(csEncrypt))
{
//Write all data to the stream.
swEncrypt.Write(plainText);
}
encrypted = msEncrypt.ToArray();
}
}
}
// Return the encrypted bytes from the memory stream.
return encrypted;
}
protected string DecryptStringFromBytes(byte[] cipherText, byte[] Key, byte[] IV)
{
// Check arguments.
if (cipherText == null || cipherText.Length <= 0)
throw new ArgumentNullException("cipherText");
if (Key == null || Key.Length <= 0)
throw new ArgumentNullException("Key");
if (IV == null || IV.Length <= 0)
throw new ArgumentNullException("Key");
// Declare the string used to hold
// the decrypted text.
string plaintext = null;
// Create an RijndaelManaged object
// with the specified key and IV.
using (RijndaelManaged rijAlg = new RijndaelManaged())
{
rijAlg.Key = Key;
rijAlg.IV = IV;
// Create a decrytor to perform the stream transform.
ICryptoTransform decryptor = rijAlg.CreateDecryptor(rijAlg.Key, rijAlg.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))
{
// Read the decrypted bytes from the decrypting stream
// and place them in a string.
plaintext = srDecrypt.ReadToEnd();
}
}
}
}
return plaintext;
}
public static void GenerateKeyAndIV()
{
// This code is only here for an example
AesManaged myRijndaelManaged = new AesManaged();
myRijndaelManaged.Mode = CipherMode.CBC;
myRijndaelManaged.Padding = PaddingMode.PKCS7;
myRijndaelManaged.GenerateIV();
myRijndaelManaged.GenerateKey();
string newKey = ByteArrayToHexString(myRijndaelManaged.Key);
string newinitVector = ByteArrayToHexString(myRijndaelManaged.IV);
}
protected static byte[] HexStringToByte(string hexString)
{
try
{
int bytesCount = (hexString.Length) / 2;
byte[] bytes = new byte[bytesCount];
for (int x = 0; x < bytesCount; ++x)
{
bytes[x] = Convert.ToByte(hexString.Substring(x * 2, 2), 16);
}
return bytes;
}
catch
{
throw;
}
}
public static string ByteArrayToHexString(byte[] ba)
{
StringBuilder hex = new StringBuilder(ba.Length * 2);
foreach (byte b in ba)
hex.AppendFormat("{0:x2}", b);
return hex.ToString();
}
private static byte[] GetSecretKey()
{
string hashedKey = GetHashedKey();
byte[] saltBytes = Encoding.UTF8.GetBytes(salt); // builder.mCharsetName = "UTF8";
int iterations = 1; // builder.mIterationCount = 1
byte[] secretKey = null;
using (Rfc2898DeriveBytes rfc2898 = new Rfc2898DeriveBytes(hashedKey, saltBytes, iterations)) // builder.mSecretKeyType = "PBKDF2WithHmacSHA1";
{
secretKey = rfc2898.GetBytes(16); // builder.mKeyLength = 128;
//Console.WriteLine("Key: " + ByteArrayToHexString(secretKey));
}
return secretKey;
}
private static string GetHashedKey()
{
string hashBase64 = String.Empty;
using (SHA1Managed sha1 = new SHA1Managed()) // builder.mDigestAlgorithm = "SHA1";
{
byte[] hash = sha1.ComputeHash(Encoding.UTF8.GetBytes(encryptionKey)); // builder.mCharsetName = "UTF8";
hashBase64 = Base64ThirdPartAndroid(hash, true);
//hashBase64 = Base64ThirdPartAndroid(hash, true);
//Console.WriteLine("Hash (base64): " + hashBase64);
}
return hashBase64;
}
private static string Base64ThirdPartAndroid(byte[] arr, bool withoutPadding)
{
string base64String = System.Convert.ToBase64String(arr);
if (withoutPadding) base64String = base64String.TrimEnd('='); // Remove trailing "="-characters
base64String += "\n"; // Append LF (10)
//Console.WriteLine("Array as base64 encoded string: " + base64String);
return base64String;
}
}
Great progress @KamranShahid it will be nice if you create a repo and provide your code as a library.
I am porting some of my server code from java to C# which uses this library. Can any body help me conversion or equivalent logic in C#