C# Class OpenStory.Cryptography.RollingIv

Represents an AES encryption transformer.

Public Methods

Method	Description
ConstructHeader ( int length ) : byte[]	Constructs a packet header.
GetPacketLength ( byte header ) : int	Reads a packet header from an array and extracts the packet's length.
GetVersion ( byte header, byte iv ) : ushort	Extracts a version from the header using a specified IV.
RollingIv ( ICryptoAlgorithm algorithm, byte initialIv, ushort versionMask ) : System	Initializes a new instance of the RollingIv class.
Transform ( byte data ) : void	Transforms the specified data in-place.
TryGetLength ( byte header, int &length ) : bool	Attempts to extract the length of a packet from its header. When overriding this method in a derived class, do not call the base implementation.
ValidateHeader ( byte header ) : bool	Determines whether the start of an array is a valid packet header.

Method	Description
GetVersionInternal ( byte header, byte iv ) : ushort
ValidateHeaderInternal ( byte header, byte iv, ushort versionMask ) : bool

Constructs a packet header.

/// Thrown if is less than 2. ///

public ConstructHeader ( int length ) : byte[]
length	int	The length of the packet to make a header for.
return	byte[]

Reads a packet header from an array and extracts the packet's length.

/// Thrown if is . /// /// Thrown if has less than 4 elements. ///

public static GetPacketLength ( byte header ) : int
header	byte	The array to read from.
return	int

Extracts a version from the header using a specified IV.

/// Thrown if /// or are . /// /// Thrown if has less than 4 elements or /// if doesn't have exactly 4 elements. ///

public static GetVersion ( byte header, byte iv ) : ushort
header	byte	The header byte array.
iv	byte	The IV to use for the decoding.
return	ushort

Initializes a new instance of the RollingIv class.

/// Thrown if or is . /// /// Thrown if does not have exactly 4 elements. ///

public RollingIv ( ICryptoAlgorithm algorithm, byte initialIv, ushort versionMask ) : System
algorithm	ICryptoAlgorithm	The instance for this session.
initialIv	byte	The initial IV for this instance.
versionMask	ushort	The version mask used for header creation.
return	System

Transforms the specified data in-place.

Thrown if is .

public Transform ( byte data ) : void
data	byte	The array to transform. This array will be directly modified.
return	void

Attempts to extract the length of a packet from its header.

When overriding this method in a derived class, do not call the base implementation.

/// Thrown if is . /// /// Thrown if has less than 4 elements. ///

public TryGetLength ( byte header, int &length ) : bool
header	byte	The header byte array to process.
length	int	A variable to hold the result.
return	bool

Determines whether the start of an array is a valid packet header.

public ValidateHeader ( byte header ) : bool
header	byte	The raw packet data to validate.
return	bool