/// <summary>
/// Create a KeyWrap instance for wrapping or unwrapping
/// </summary>
/// <param name="salt">A salt. This is required by AxCrypt, although the algorithm supports not using a salt.</param>
/// <param name="keyWrapIterations">The number of wrapping iterations, at least 6</param>
/// <param name="mode">Use original specification mode or AxCrypt mode (only difference is that 't' is little endian in AxCrypt mode)</param>
public KeyWrap(Salt salt, long keyWrapIterations, KeyWrapMode mode)
{
if (salt == null)
{
throw new ArgumentNullException("salt");
}
if (keyWrapIterations < 6)
{
throw new InternalErrorException("Key wrap iterations must be at least 6.");
}
if (mode != KeyWrapMode.Specification && mode != KeyWrapMode.AxCrypt)
{
throw new InternalErrorException("mode");
}
_salt = salt;
_mode = mode;
_keyWrapIterations = keyWrapIterations;
}
/// <summary>
/// Create a KeyWrap instance for wrapping or unwrapping
/// </summary>
/// <param name="key">The key wrapping key</param>
/// <param name="salt">An optional salt, or null if none. AxCrypt uses a salt.</param>
/// <param name="iterations">The number of wrapping iterations, at least 6</param>
/// <param name="mode">Use original specification mode or AxCrypt mode (only difference is that 't' is little endian in AxCrypt mode)</param>
public KeyWrap(AesKey key, KeyWrapSalt salt, long iterations, KeyWrapMode mode)
{
if (key == null)
{
throw new ArgumentNullException("key");
}
if (salt == null)
{
throw new ArgumentNullException("salt");
}
if (salt.Length != 0 && salt.Length != key.Length)
{
throw new InternalErrorException("salt length is incorrect");
}
if (iterations < 6)
{
throw new InternalErrorException("iterations");
}
if (mode != KeyWrapMode.Specification && mode != KeyWrapMode.AxCrypt)
{
throw new InternalErrorException("mode");
}
_mode = mode;
_key = key;
_salt = salt;
_iterations = iterations;
byte[] saltedKey = _key.GetBytes();
saltedKey.Xor(_salt.GetBytes());
_aes.Mode = CipherMode.ECB;
_aes.KeySize = _key.Length * 8;
_aes.Key = saltedKey;
_aes.Padding = PaddingMode.None;
}
/// <summary>
/// Create a KeyWrap instance for wrapping or unwrapping
/// </summary>
/// <param name="key">The key wrapping key</param>
/// <param name="salt">An optional salt, or null if none. AxCrypt uses a salt.</param>
/// <param name="iterations">The number of wrapping iterations, at least 6</param>
/// <param name="mode">Use original specification mode or AxCrypt mode (only difference is that 't' is little endian in AxCrypt mode)</param>
public KeyWrap(AesKey key, KeyWrapSalt salt, long iterations, KeyWrapMode mode)
{
if (key == null)
{
throw new ArgumentNullException("key");
}
if (salt == null)
{
throw new ArgumentNullException("salt");
}
if (salt.Length != 0 && salt.Length != key.Length)
{
throw new InternalErrorException("salt length is incorrect");
}
if (iterations < 6)
{
throw new InternalErrorException("iterations");
}
if (mode != KeyWrapMode.Specification && mode != KeyWrapMode.AxCrypt)
{
throw new InternalErrorException("mode");
}
_mode = mode;
_key = key;
_salt = salt;
_iterations = iterations;
byte[] saltedKey = _key.GetBytes();
saltedKey.Xor(_salt.GetBytes());
_aes.Mode = CipherMode.ECB;
_aes.KeySize = _key.Length * 8;
_aes.Key = saltedKey;
_aes.Padding = PaddingMode.None;
}
/// <summary>
/// Create a KeyWrap instance for wrapping or unwrapping
/// </summary>
/// <param name="key">The key wrapping key</param>
/// <param name="iterations">The number of wrapping iterations, at least 6</param>
/// <param name="mode">Use original specification mode or AxCrypt mode (only difference is that 't' is little endian in AxCrypt mode)</param>
public KeyWrap(AesKey key, long iterations, KeyWrapMode mode)
: this(key, KeyWrapSalt.Zero, iterations, mode)
{
}
/// <summary>
/// Create a KeyWrap instance for wrapping or unwrapping
/// </summary>
/// <param name="key">The key wrapping key</param>
/// <param name="iterations">The number of wrapping iterations, at least 6</param>
/// <param name="mode">Use original specification mode or AxCrypt mode (only difference is that 't' is little endian in AxCrypt mode)</param>
public KeyWrap(AesKey key, long iterations, KeyWrapMode mode)
: this(key, KeyWrapSalt.Zero, iterations, mode)
{
}
/// <summary>
/// Create a KeyWrap instance for wrapping or unwrapping
/// </summary>
/// <param name="keyWrapIterations">The number of wrapping iterations, at least 6</param>
/// <param name="mode">Use original specification mode or AxCrypt mode (only difference is that 't' is little endian in AxCrypt mode)</param>
public KeyWrap(long keyWrapIterations, KeyWrapMode mode)
: this(Salt.Zero, keyWrapIterations, mode)
{
}
