we have RijndaelManaged algorithm written in .net. same thing I wanted to convert in objective c . Please help me on this.

Please find the c charp code.

private string EncryptKey(string key)
{
byte[] objIV = null;
byte[] objSecretKey = null;
string strSecretKey = GetConfigValue(MyPatients.Utils.Constants.SECRET_KEY);
string strIVKey = GetConfigValue(MyPatients.Utils.Constants.IV_KEY);
string strEncrypted = null;

if ((strSecretKey.Length > 0))
{
objSecretKey = HexToByte(strSecretKey);
}

if ((strIVKey.Length > 0))
{
objIV = HexToByte(strIVKey);
}

byte[] aibUrlArray = System.Text.Encoding.UTF8.GetBytes(key);
byte[] EncryptedStringArray = null;

// instantiate a Rijndael Object
RijndaelManaged objRijndael = new RijndaelManaged();

// initializing the Rijndael Encryptor
objRijndael.Mode = CipherMode.CBC;
objRijndael.Padding = PaddingMode.PKCS7;
objRijndael.KeySize = 256;
objRijndael.BlockSize = 128;

// Creating an encryptor
ICryptoTransform objEncryptor = objRijndael.CreateEncryptor(objSecretKey, objIV);

// Creating a memory string
System.IO.MemoryStream objMemoryStream = new System.IO.MemoryStream();
CryptoStream objCryptoStream = new CryptoStream(objMemoryStream, objEncryptor, CryptoStreamMode.Write);

objCryptoStream.Write(aibUrlArray, 0, aibUrlArray.Length);
objCryptoStream.FlushFinalBlock();

// Encrypted data to the array
EncryptedStringArray = objMemoryStream.ToArray();

// Create the encrypted string:
strEncrypted = ByteToHex(EncryptedStringArray);

return strEncrypted;
}

Thanks in advance.

I tried to download the zip but it is giving me error.

Have you solve the problem? I have the same issue. Server-side encrypted data is not get decrypt in iOS.

int x = 9;
for (int i = passcode.length; i < kChosenCipherKeySize/*16*/; i++)
{
//passcode = [passcode stringByAppendingString:@"9"];
passcode = [passcode stringByAppendingFormat:@"%d", x];
x–;
if (x 0)
[reversedStr appendString:
[NSString stringWithFormat:@"%C", [originalString characterAtIndex:–len]]];

return reversedStr;
}

Doesn't seem to make sense. It looks like it's missing a couple of brackets and some variables. Could you post the complete function? That would help me a whole tonne.

I use the following two(2) global variables:

private static int eKeySize = 32; //16
private static int cipherKeySize = eKeySize * 8;

The following routines encrypt/decrypt based on a 32bit key size:

private string EncryptString(string plainSourceStringToEncrypt, string passPhrase)
{
//Set up the encryption objects
using (AesCryptoServiceProvider acsp = GetProvider(Encoding.Default.GetBytes(passPhrase)))
{
byte[] sourceBytes = Encoding.ASCII.GetBytes(plainSourceStringToEncrypt);
ICryptoTransform ictE = acsp.CreateEncryptor();

//Set up stream to contain the encryption
MemoryStream msS = new MemoryStream();

//Perform the encrpytion, storing output into the stream
CryptoStream csS = new CryptoStream(msS, ictE, CryptoStreamMode.Write);
csS.Write(sourceBytes, 0, sourceBytes.Length);
csS.FlushFinalBlock();

//sourceBytes are now encrypted as an array of secure bytes
byte[] encryptedBytes = msS.ToArray(); //.ToArray() is important, don’t mess with the buffer

//return the encrypted bytes as a BASE64 encoded string
return Convert.ToBase64String(encryptedBytes);
}
}

///
/// Decrypts a BASE64 encoded string of encrypted data, returns a plain string
///
/// an Aes encrypted AND base64 encoded string
/// The passphrase.
/// returns a plain string
private string DecryptString(string base64StringToDecrypt, string passphrase)
{
try
{
//Set up the encryption objectsr
using (AesCryptoServiceProvider acsp = GetProvider(Encoding.Default.GetBytes(passphrase)))
{
byte[] RawBytes = Convert.FromBase64String(base64StringToDecrypt);
ICryptoTransform ictD = acsp.CreateDecryptor();

//RawBytes now contains original byte array, still in Encrypted state

//Decrypt into stream
MemoryStream msD = new MemoryStream(RawBytes, 0, RawBytes.Length);
CryptoStream csD = new CryptoStream(msD, ictD, CryptoStreamMode.Read);
//csD now contains original byte array, fully decrypted

//return the content of msD as a regular string
return (new StreamReader(csD)).ReadToEnd();
}
}
catch (Exception e)
{
throw new Exception(“Unable to Decrypt Data: [” + base64StringToDecrypt + “] –> ” + e.Message);
}
}

private AesCryptoServiceProvider GetProvider(byte[] key)
{
AesCryptoServiceProvider result = new AesCryptoServiceProvider();
result.BlockSize = 128;
result.KeySize = cipherKeySize; // 256;
result.Mode = CipherMode.CBC;
result.Padding = PaddingMode.PKCS7;

result.GenerateIV();
result.IV = new byte[] { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

byte[] RealKey = GetKey(key, result);
result.Key = RealKey;
// result.IV = RealKey;
return result;
}

private byte[] GetKey(byte[] suggestedKey, SymmetricAlgorithm p)
{
byte[] kRaw = suggestedKey;
List kList = new List();

for (int i = 0; i < cipherKeySize /* p.LegalKeySizes[0].MaxSize*//*MinSize*/; i += 8)
{
kList.Add(kRaw[(i / 8) % kRaw.Length]);
}
byte[] k = kList.ToArray();
return k;
}
}
}