private SymmetricKey GetMasterKey()
{
V1KeyWrap1HeaderBlock keyHeaderBlock = _headers.FindHeaderBlock <V1KeyWrap1HeaderBlock>();
VersionHeaderBlock versionHeaderBlock = _headers.FindHeaderBlock <VersionHeaderBlock>();
byte[] unwrappedKeyData = keyHeaderBlock.UnwrapMasterKey(_keyEncryptingKey.DerivedKey, versionHeaderBlock.FileVersionMajor);
if (unwrappedKeyData.Length == 0)
{
return(null);
}
return(new SymmetricKey(unwrappedKeyData));
}
public void EnsureFileFormatVersion(int lowestMajorVersion, int highestMajorVersion)
{
VersionHeaderBlock versionHeaderBlock = FindHeaderBlock <VersionHeaderBlock>();
if (versionHeaderBlock.FileVersionMajor > highestMajorVersion)
{
throw new FileFormatException("Too new file format.", ErrorStatus.TooNewFileFormatVersion);
}
if (versionHeaderBlock.FileVersionMajor < lowestMajorVersion)
{
throw new FileFormatException("Too old file format.", ErrorStatus.TooOldFileFormatVersion);
}
}
private static AxCryptReader CreateVersionedReader(LookAheadStream inputStream, IList <HeaderBlock> headers)
{
AxCryptReader reader;
VersionHeaderBlock versionHeaderBlock = FindHeaderBlock <VersionHeaderBlock>(headers);
switch (versionHeaderBlock.FileVersionMajor)
{
case 1:
case 2:
case 3:
reader = new V1AxCryptReader(inputStream);
break;
case 4:
reader = new V2AxCryptReader(inputStream);
break;
default:
throw new FileFormatException("Too new file format. You need a more recent version.");
}
return(reader);
}
public override object Clone()
{
VersionHeaderBlock block = new VersionHeaderBlock((byte[])GetDataBlockBytesReference().Clone());
return(block);
}
