gnu.java.zrtp.packets

Class ZrtpPacketHello

java.lang.Object

gnu.java.zrtp.packets.ZrtpPacketBase

gnu.java.zrtp.packets.ZrtpPacketHello

public class ZrtpPacketHello
extends ZrtpPacketBase

Implement the Hello packet. The ZRTP message Hello. The implementation sends this to start the ZRTP negotiation sequence. The Hello message offers crypto methods and parameters to the other party. The other party selects methods and parameters it can support and uses the Commit message to commit these.

Author:

Werner Dittmann <Werner.Dittmann@t-online.de>

Field Summary

Fields inherited from class gnu.java.zrtp.packets.ZrtpPacketBase

CLIENT_ID_SIZE, CRC_SIZE, HASH_IMAGE_SIZE, HMAC_SIZE, HVI_SIZE, packetBuffer, ZID_SIZE, ZRTP_HEADER_LENGTH, ZRTP_WORD_SIZE

Constructor Summary

Constructors

Constructor and Description
ZrtpPacketHello()
ZrtpPacketHello(byte[] data)

Method Summary

Modifier and Type	Method and Description
boolean	checkMultiStream()
void	configureHello(ZrtpConfigure config)
ZrtpConstants.SupportedAuthLengths	findBestAuthLen(ZrtpConfigure config)
ZrtpConstants.SupportedSymCiphers	findBestCipher(ZrtpConfigure config, ZrtpConstants.SupportedPubKeys pk)
ZrtpConstants.SupportedHashes	findBestHash(ZrtpConfigure config) Find matching algorithms in Hello packet.
ZrtpConstants.SupportedPubKeys	findBestPubkey(ZrtpConfigure config)
ZrtpConstants.SupportedSASTypes	findBestSASType(ZrtpConfigure config)
byte[]	getH3()
ZrtpConstants.SupportedSymCiphers	getSelectedCipher()
ZrtpConstants.SupportedHashes	getSelectedHash()
byte[]	getVersion()
int	getVersionInt()
byte[]	getZid()
boolean	isLengthOk()
boolean	isMitmMode()
boolean	isSameVersion(byte[] data) Check if version data matches.
boolean	isSasSign()
void	setAuthLen(int n, byte[] data)
void	setCipherType(int n, byte[] data)
void	setClientId(String text)
void	setH3(byte[] data)
void	setHashType(int n, byte[] data)
void	setHMAC(byte[] data)
void	setMitmMode()
void	setPubKeyType(int n, byte[] data)
void	setSasSign()
void	setSasType(int n, byte[] data)
void	setVersion(byte[] data)
void	setZid(byte[] data)

Methods inherited from class gnu.java.zrtp.packets.ZrtpPacketBase

getHeaderBase, getLength, getMessageType, isZrtpPacket, setLength, setMessageType, setZrtpId

Methods inherited from class java.lang.Object

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

Constructor Detail

ZrtpPacketHello

public ZrtpPacketHello()

ZrtpPacketHello

public ZrtpPacketHello(byte[] data)

Method Detail

configureHello

public void configureHello(ZrtpConfigure config)

setClientId

public final void setClientId(String text)

setH3

public final void setH3(byte[] data)

getH3

public final byte[] getH3()

setZid

public final void setZid(byte[] data)

getZid

public final byte[] getZid()

setVersion

public final void setVersion(byte[] data)

getVersion

public final byte[] getVersion()

getVersionInt

public final int getVersionInt()

setHashType

public final void setHashType(int n,
                              byte[] data)

setCipherType

public final void setCipherType(int n,
                                byte[] data)

setAuthLen

public final void setAuthLen(int n,
                             byte[] data)

setPubKeyType

public final void setPubKeyType(int n,
                                byte[] data)

setSasType

public final void setSasType(int n,
                             byte[] data)

setHMAC

public final void setHMAC(byte[] data)

setMitmMode

public final void setMitmMode()

isMitmMode

public final boolean isMitmMode()

setSasSign

public final void setSasSign()

isSasSign

public final boolean isSasSign()

isLengthOk

public final boolean isLengthOk()

isSameVersion

public final boolean isSameVersion(byte[] data)

Check if version data matches.

Parameters:

data - The data to compare against.

Returns:

true if data matches the packet version data, false other wise.

findBestHash

public final ZrtpConstants.SupportedHashes findBestHash(ZrtpConfigure config)

Find matching algorithms in Hello packet. The next functions look up and return a prefered algorithm. These functions work as follows: - If the Hello packet does not contain an algorithm (number of algorithms is zero) then return our prefered algorithm. This prefered algorithm must be one of the mandatory algorithms specified in chapter 6.1.x. - If the functions find a match return the found algorithm. - If the functions do not find a match return a prefered, mandatory algorithm. This guarantees that we always return a supported alogrithm. The mandatory algorithms are: (internal enums are our prefered algoritms) Hash: S256 (SHA 256) (internal enum Sha256) Symmetric Cipher: AES1 (AES 128) (internal enum Aes128) SRTP Authentication: HS32 and HS80 (32/80 bits) (internal enum AuthLen32) Key Agreement: DH3k (3072 Diffie-Helman) (internal enum Dh3072) Find macthing Hash type.

Returns:

found matching hash or default SHA 256.

findBestCipher

public final ZrtpConstants.SupportedSymCiphers findBestCipher(ZrtpConfigure config,
                                                              ZrtpConstants.SupportedPubKeys pk)

getSelectedHash

public ZrtpConstants.SupportedHashes getSelectedHash()

getSelectedCipher

public ZrtpConstants.SupportedSymCiphers getSelectedCipher()

findBestPubkey

public final ZrtpConstants.SupportedPubKeys findBestPubkey(ZrtpConfigure config)

findBestSASType

public final ZrtpConstants.SupportedSASTypes findBestSASType(ZrtpConfigure config)

findBestAuthLen

public final ZrtpConstants.SupportedAuthLengths findBestAuthLen(ZrtpConfigure config)

checkMultiStream

public final boolean checkMultiStream()