org.spongycastle.crypto.tls

Class TlsMac

java.lang.Object

org.spongycastle.crypto.tls.TlsMac

public class TlsMac
extends java.lang.Object

A generic TLS MAC implementation, acting as an HMAC based on some underlying Digest.

Field Summary

Fields

Modifier and Type	Field and Description
protected TlsContext	context
protected int	digestBlockSize
protected int	digestOverhead
protected Mac	mac
protected int	macLength
protected byte[]	secret

Constructor Summary

Constructors

Constructor and Description
TlsMac(TlsContext context, Digest digest, byte[] key, int keyOff, int keyLen) Generate a new instance of an TlsMac.

Method Summary

Modifier and Type	Method and Description
byte[]	calculateMac(long seqNo, short type, byte[] message, int offset, int length) Calculate the MAC for some given data.
byte[]	calculateMacConstantTime(long seqNo, short type, byte[] message, int offset, int length, int fullLength, byte[] dummyData)
protected int	getDigestBlockCount(int inputLength)
byte[]	getMACSecret()
int	getSize()
protected byte[]	truncate(byte[] bs)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

context

protected TlsContext context

secret

protected byte[] secret

mac

protected Mac mac

digestBlockSize

protected int digestBlockSize

digestOverhead

protected int digestOverhead

macLength

protected int macLength

Constructor Detail

TlsMac

public TlsMac(TlsContext context,
              Digest digest,
              byte[] key,
              int keyOff,
              int keyLen)

Generate a new instance of an TlsMac.

Parameters:

context - the TLS client context

digest - The digest to use.

key - A byte-array where the key for this MAC is located.

keyOff - The number of bytes to skip, before the key starts in the buffer.

keyLen - The length of the key.

Method Detail

getMACSecret

public byte[] getMACSecret()

Returns:

the MAC write secret

getSize

public int getSize()

Returns:

The output length of this MAC.

calculateMac

public byte[] calculateMac(long seqNo,
                           short type,
                           byte[] message,
                           int offset,
                           int length)

Calculate the MAC for some given data.

Parameters:

type - The message type of the message.

message - A byte-buffer containing the message.

offset - The number of bytes to skip, before the message starts.

length - The length of the message.

Returns:

A new byte-buffer containing the MAC value.

calculateMacConstantTime

public byte[] calculateMacConstantTime(long seqNo,
                                       short type,
                                       byte[] message,
                                       int offset,
                                       int length,
                                       int fullLength,
                                       byte[] dummyData)

getDigestBlockCount

protected int getDigestBlockCount(int inputLength)

truncate

protected byte[] truncate(byte[] bs)