Lo siguiente es del The CSharp Cookbook. Es tan sencillo como un ejemplo. Por supuesto, tendrá que portar la parte de cifrado al Objetivo C, pero siempre que use la misma Clave, debería generar el mismo resultado.
Es necesario utilizar Rijndael cifrado que está disponible here in ObjC compatible code
public static void EncDecString()
{
string encryptedString = CryptoString.Encrypt("MyPassword");
Console.WriteLine("encryptedString: " + encryptedString);
// get the key and IV used so you can decrypt it later
byte [] key = CryptoString.Key;
byte [] IV = CryptoString.IV;
CryptoString.Key = key;
CryptoString.IV = IV;
string decryptedString = CryptoString.Decrypt(encryptedString);
Console.WriteLine("decryptedString: " + decryptedString);
}
public sealed class CryptoString
{
private CryptoString() {}
private static byte[] savedKey = null;
private static byte[] savedIV = null;
public static byte[] Key
{
get { return savedKey; }
set { savedKey = value; }
}
public static byte[] IV
{
get { return savedIV; }
set { savedIV = value; }
}
private static void RdGenerateSecretKey(RijndaelManaged rdProvider)
{
if (savedKey == null)
{
rdProvider.KeySize = 256;
rdProvider.GenerateKey();
savedKey = rdProvider.Key;
}
}
private static void RdGenerateSecretInitVector(RijndaelManaged rdProvider)
{
if (savedIV == null)
{
rdProvider.GenerateIV();
savedIV = rdProvider.IV;
}
}
public static string Encrypt(string originalStr)
{
// Encode data string to be stored in memory
byte[] originalStrAsBytes = Encoding.ASCII.GetBytes(originalStr);
byte[] originalBytes = {};
// Create MemoryStream to contain output
MemoryStream memStream = new MemoryStream(originalStrAsBytes.Length);
RijndaelManaged rijndael = new RijndaelManaged();
// Generate and save secret key and init vector
RdGenerateSecretKey(rijndael);
RdGenerateSecretInitVector(rijndael);
if (savedKey == null || savedIV == null)
{
throw (new NullReferenceException(
"savedKey and savedIV must be non-null."));
}
// Create encryptor, and stream objects
ICryptoTransform rdTransform =
rijndael.CreateEncryptor((byte[])savedKey.Clone(),
(byte[])savedIV.Clone());
CryptoStream cryptoStream = new CryptoStream(memStream, rdTransform,
CryptoStreamMode.Write);
// Write encrypted data to the MemoryStream
cryptoStream.Write(originalStrAsBytes, 0, originalStrAsBytes.Length);
cryptoStream.FlushFinalBlock();
originalBytes = memStream.ToArray();
// Release all resources
memStream.Close();
cryptoStream.Close();
rdTransform.Dispose();
rijndael.Clear();
// Convert encrypted string
string encryptedStr = Convert.ToBase64String(originalBytes);
return (encryptedStr);
}
public static string Decrypt(string encryptedStr)
{
// Unconvert encrypted string
byte[] encryptedStrAsBytes = Convert.FromBase64String(encryptedStr);
byte[] initialText = new Byte[encryptedStrAsBytes.Length];
RijndaelManaged rijndael = new RijndaelManaged();
MemoryStream memStream = new MemoryStream(encryptedStrAsBytes);
if (savedKey == null || savedIV == null)
{
throw (new NullReferenceException(
"savedKey and savedIV must be non-null."));
}
// Create decryptor, and stream objects
ICryptoTransform rdTransform =
rijndael.CreateDecryptor((byte[])savedKey.Clone(),
(byte[])savedIV.Clone());
CryptoStream cryptoStream = new CryptoStream(memStream, rdTransform,
CryptoStreamMode.Read);
// Read in decrypted string as a byte[]
cryptoStream.Read(initialText, 0, initialText.Length);
// Release all resources
memStream.Close();
cryptoStream.Close();
rdTransform.Dispose();
rijndael.Clear();
// Convert byte[] to string
string decryptedStr = Encoding.ASCII.GetString(initialText);
return (decryptedStr);
}
}
No puedo hablar acerca de la aplicación Objective C de Rijndael cifrado, pero he utilizado este (C#) código de la base de la parte de la producción trabajo y ha funcionado maravillosamente.
funciona bien ... – nbojja