internal static void SetValue(this KeyBagEntry item, string blockIdentifier, ReadOnlySpan <byte> value)
{
switch (blockIdentifier)
{
case KeyBagConstants.UuidTag:
item.Uuid = KeyBagExtensions.ReadGuidBigEndian(value);
break;
case KeyBagConstants.ClassTag:
item.ProtectionClass = (ProtectionClass)BinaryPrimitives.ReadInt32BigEndian(value);
break;
case KeyBagConstants.WrapTag:
item.Wrap = (KeyWrapTypes)BinaryPrimitives.ReadInt32BigEndian(value);
break;
case KeyBagConstants.KeyTypeTag:
item.KeyType = (KeyType)BinaryPrimitives.ReadInt32BigEndian(value);
break;
case KeyBagConstants.WrappedKeyTag:
item.Wpky = value.ToArray();
break;
default:
throw new InvalidDataException($"Unexpected block identifier \"{blockIdentifier}\"");
}
}
public static void ConsoleWrite(this KeyBagEntry item)
{
Console.WriteLine($"UUID={item.Uuid}");
Console.WriteLine($"CLAS={item.ProtectionClass}");
Console.WriteLine($"WRAP={item.Wrap}");
Console.WriteLine($"KTYP={item.KeyType}");
Console.Write($"WPKY={CommonHelpers.ByteArrayToDebugString(item.Wpky)}");
}
private static byte[] UnwrapClassKey(KeyBagEntry item, byte[] kek)
{
byte[] result = default;
if (item.Wpky != null)
{
if ((item.Wrap & KeyWrapTypes.Passcode) == KeyWrapTypes.Passcode)
{
result = KeyWrapAlgorithm.UnwrapKey(kek, item.Wpky);
}
}
return(result);
}
public static KeyBag Read(byte[] data)
{
if (data is null)
{
throw new ArgumentNullException(nameof(data));
}
KeyBag result = default;
var state = ReaderState.Invalid;
KeyBagEntry currentKey = default;
var keys = new List <KeyBagEntry>();
var length = data.Length;
var position = 0;
while (position < length)
{
var blockIdentifier = Encoding.ASCII.GetString(data, position, 4);
position += 4;
var blockLength = BinaryPrimitives.ReadInt32BigEndian(data.AsSpan(position, 4));
position += 4;
var value = data.AsSpan(position, blockLength);
if (state == ReaderState.Invalid)
{
state = ReaderState.ReadHeader;
}
if (state == ReaderState.ReadHeader)
{
if (result is null)
{
result = new KeyBag();
}
if (blockIdentifier == KeyBagConstants.UuidTag && result.Uuid != Guid.Empty)
{
state = ReaderState.ReadKeyBagEntry;
}
else
{
result.SetValue(blockIdentifier, value);
}
}
if (state == ReaderState.ReadKeyBagEntry)
{
if (blockIdentifier == KeyBagConstants.UuidTag)
{
if (currentKey != null)
{
keys.Add(currentKey);
}
currentKey = new KeyBagEntry();
}
currentKey.SetValue(blockIdentifier, value);
}
position += blockLength;
}
if (result != null)
{
if (currentKey != null)
{
keys.Add(currentKey);
}
result.WrappedKeys = keys.ToArray();
}
return(result);
}
