org.bouncycastle.tls.crypto.impl

Class TlsSuiteHMac

java.lang.Object

org.bouncycastle.tls.crypto.impl.TlsSuiteHMac

All Implemented Interfaces:

TlsSuiteMac

public class TlsSuiteHMac
extends java.lang.Object
implements TlsSuiteMac

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

Field Summary

Fields

Modifier and Type	Field and Description
protected TlsCryptoParameters	cryptoParams
protected int	digestBlockSize
protected int	digestOverhead
protected TlsHMAC	mac
protected int	macSize

Constructor Summary

Constructors

Constructor and Description
TlsSuiteHMac(TlsCryptoParameters cryptoParams, TlsHMAC mac) Generate a new instance of a TlsMac.

Method Summary

Modifier and Type	Method and Description
byte[]	calculateMac(long seqNo, short type, byte[] msg, int msgOff, int msgLen) Calculate the MAC for some given data.
byte[]	calculateMacConstantTime(long seqNo, short type, byte[] msg, int msgOff, int msgLen, int fullLength, byte[] dummyData) Constant time calculation of the MAC for some given data with a given expected length.
protected int	getDigestBlockCount(int inputLength)
protected static int	getMacSize(TlsCryptoParameters cryptoParams, TlsMAC mac)
int	getSize() Return the output length (in bytes) of this MAC.
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

cryptoParams

protected final TlsCryptoParameters cryptoParams

mac

protected final TlsHMAC mac

digestBlockSize

protected final int digestBlockSize

digestOverhead

protected final int digestOverhead

macSize

protected final int macSize

Constructor Detail

TlsSuiteHMac

public TlsSuiteHMac(TlsCryptoParameters cryptoParams,
                    TlsHMAC mac)

Generate a new instance of a TlsMac.

Parameters:

cryptoParams - the TLS client context specific crypto parameters.

mac - The MAC to use.

Method Detail

getMacSize

protected static int getMacSize(TlsCryptoParameters cryptoParams,
                                TlsMAC mac)

getSize

public int getSize()

Description copied from interface: TlsSuiteMac

Return the output length (in bytes) of this MAC.

Specified by:

getSize in interface TlsSuiteMac

Returns:

The output length of this MAC.

calculateMac

public byte[] calculateMac(long seqNo,
                           short type,
                           byte[] msg,
                           int msgOff,
                           int msgLen)

Description copied from interface: TlsSuiteMac

Calculate the MAC for some given data.

Specified by:

calculateMac in interface TlsSuiteMac

Parameters:

seqNo - The sequence number of the record.

type - The content type of the message.

msg - A byte array containing the message.

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

msgLen - The length of the message.

Returns:

A new byte array containing the MAC value.

calculateMacConstantTime

public byte[] calculateMacConstantTime(long seqNo,
                                       short type,
                                       byte[] msg,
                                       int msgOff,
                                       int msgLen,
                                       int fullLength,
                                       byte[] dummyData)

Description copied from interface: TlsSuiteMac

Constant time calculation of the MAC for some given data with a given expected length.

Specified by:

calculateMacConstantTime in interface TlsSuiteMac

Parameters:

seqNo - The sequence number of the record.

type - The content type of the message.

msg - A byte array containing the message.

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

msgLen - The length of the message.

fullLength - The expected length of the full message.

dummyData - Random data for padding out the MAC calculation if required.

Returns:

A new byte array containing the MAC value.

getDigestBlockCount

protected int getDigestBlockCount(int inputLength)

truncate

protected byte[] truncate(byte[] bs)