public void SetManifestKey(byte[] wrappedKeyData)
{
if (wrappedKeyData is null)
{
throw new ArgumentNullException(nameof(wrappedKeyData));
}
_logger.LogInformation("Retrieving manifest wrapped encryption key");
_wrappedManifestKey = WrappedKeyReader.Read(wrappedKeyData);
}
public static WrappedKey Read(byte[] wrappedKeyData)
{
if (wrappedKeyData is null)
{
throw new ArgumentNullException(nameof(wrappedKeyData));
}
WrappedKey result = default;
if (wrappedKeyData.Length == 44)
{
result = new WrappedKey
{
Unknown = wrappedKeyData.AsSpan(0, 4).ToArray(),
Key = wrappedKeyData.AsSpan(4, 40).ToArray(),
};
}
return(result);
}
private WrappedKey ReadEncryptionKey(BinaryReader reader)
{
const int PrefixLength = 4;
WrappedKey result = default;
int size = reader.ReadUInt16BigEndian();
if (size != 0xFFFF && size > PrefixLength)
{
int keySize = size - PrefixLength;
result = new WrappedKey
{
Unknown = reader.ReadBytes(PrefixLength),
Key = reader.ReadBytes(keySize),
};
}
return(result);
}
public void DecryptFile(string inputFile, string outputFile, WrappedKey wrappedKey, ProtectionClass protectionClass, bool overwrite)
{
var key = UnwrapKey(wrappedKey, _classKeys, protectionClass);
DecryptFileCore(inputFile, outputFile, key, overwrite);
}
public static byte[] UnwrapKey(WrappedKey item, IReadOnlyDictionary <ProtectionClass, byte[]> classKeys, ProtectionClass protectionClass)
{
var kek = classKeys[protectionClass];
return(KeyWrapAlgorithm.UnwrapKey(kek, item.Key));
}
public static byte[] UnwrapKey(WrappedKey item, IReadOnlyDictionary <ProtectionClass, byte[]> classKeys)
{
var protectionClass = (ProtectionClass)item.Unknown[0];
return(UnwrapKey(item, classKeys, protectionClass));
}