Package com.dalsemi.onewire.application.sha

Class SHAiButtonUser

java.lang.Object

com.dalsemi.onewire.application.sha.SHAiButtonUser

Direct Known Subclasses:

SHAiButtonUser18, SHAiButtonUser33

public abstract class SHAiButtonUser
extends java.lang.Object

The abstract superclass for all users of a SHAiButton transaction system. The user in a SHA transaction system mainly consists of a page (or pages) of account data. The abstract superclass guarantees an interface for retrieving information about account data, as well as reading and writing that data.

SHAiButtonUser was defined for use with the DS1963S (family code 0x18) and the DS1961S (family code 0x33). The benefit to using our SHA iButtons in a transaction is for device authentication. Using a challenge-response protocol, the DS1961S and the DS1963S can authenticate themselves to the system before their actual account data is verified. But, if device authentication isn't important to your transaction, the SHAiButtonUser can be extended to support any 1-Wire memory device.

The format of user's account data is not specified by this class, only the interface for accessing it. Each different SHATransaction is free to implement whatever format is appropriate for the transaction type.

See Also:

SHATransaction, SHAiButtonCopr, SHAiButtonUser18, SHAiButtonUser33

Field Summary

Fields

Modifier and Type	Field	Description
protected byte[]	accountData	local cache of accountData
protected int	accountPageNumber	page number account data is stored on
protected byte[]	address	Cache of 1-Wire Address
protected boolean	forceOverdrive	force 1-wire container into overdrive speed
protected byte[]	fullBindCode	maintains a cache of the fullBindCode, for later binding of coprocessor.
protected byte[]	serviceFile	used to construct appropriate string for OWFile constructor
protected java.lang.String	strServiceFilename	stores string name of user's service file
protected int	writeCycleCounter	local cache of writeCycleCounter for data page

Constructor Summary

Constructors

Constructor	Description
SHAiButtonUser()

Method Summary

Modifier and Type	Method	Description
protected boolean	checkAccountPageInfo(OneWireContainer ibc)	Asserts that proper account info exists for this SHAiButtonUser and establishes a buffer for caching account data.
protected boolean	createServiceFile(OneWireContainer owc, java.lang.String filename, boolean formatDevice)	Create's empty service file for the user with the given filename.
java.lang.String	getAccountFilename()	Returns the TMEX filename of the user's account data file.
int	getAccountPageNumber()	Returns the page number of the first memory page where account data is stored.
byte[]	getAddress()	Returns the 8 byte address of the OneWireContainer this SHAiButton refers to.
void	getAddress(byte[] data, int offset)	Copies the 8 byte address of the OneWireContainer into the provided array starting at the given offset.
void	getAddress(byte[] data, int offset, int cnt)	Copies the specified number of bytes from the address of the OneWireContainer into the provided array starting at the given offset.
abstract byte	getAuthorizationCommand()	Returns a byte representing the appropriate authorization command for the coprocessor to use to authenticate this user.
boolean	getForceOverdrive()	Reports whether or not the container is forced into overdrive.
abstract void	getFullBindCode(byte[] l_fullBindCode, int offset)	This function creates the full 15-byte binding data for the coprocessor to use to recreate this user's secret on the copr's workspace page.
abstract int	getWriteCycleCounter()	Returns the value of the write cycle counter for the page where the account data is stored.
abstract boolean	hasWriteCycleCounter()	Returns true if this buttons account data is stored on a page that has a write cycle counter.
abstract boolean	readAccountData(byte[] dataBuffer, int offset)	Reads the account data off the SHAiButton using a standard READ command.
abstract int	readAccountData(byte[] chlg, int chlgStart, byte[] dataBuffer, int dataStart, byte[] mac, int macStart)	Reads the account data off the SHAiButton using a READ_AUTHENTICATE command.
boolean	refreshDevice()	Refreshes eeprom SHA devices in case of weakly-programmed bits on the account page.
void	setForceOverdrive(boolean value)	Sets whether or not the container should be forced into overdrive.
abstract boolean	setiButtonUser(byte[] address)	Modifies this SHA iButton so that it refers to another device.
abstract boolean	setiButtonUser(DSPortAdapter adapter, byte[] address)	Modifies this SHA iButton so that it refers to another device.
java.lang.String	toString()	Returns a string representing this SHAiButton.
abstract boolean	writeAccountData(byte[] dataBuffer, int offset)	Writes the account data to the SHAiButton.

Methods inherited from class java.lang.Object

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

Field Detail

address

protected byte[] address

Cache of 1-Wire Address

accountData

protected final byte[] accountData

local cache of accountData

accountPageNumber

protected int accountPageNumber

page number account data is stored on

serviceFile

protected final byte[] serviceFile

used to construct appropriate string for OWFile constructor

strServiceFilename

protected java.lang.String strServiceFilename

stores string name of user's service file

fullBindCode

protected final byte[] fullBindCode

maintains a cache of the fullBindCode, for later binding of coprocessor.

writeCycleCounter

protected int writeCycleCounter

local cache of writeCycleCounter for data page

forceOverdrive

protected boolean forceOverdrive

force 1-wire container into overdrive speed

Constructor Detail

SHAiButtonUser

public SHAiButtonUser()

Method Detail

getAccountPageNumber

public int getAccountPageNumber()

Returns the page number of the first memory page where account data is stored.

Returns:

page number where account data is stored.

getAccountFilename

public java.lang.String getAccountFilename()

Returns the TMEX filename of the user's account data file.

Returns:

filename of user's account data file

getAddress

public byte[] getAddress()

Returns the 8 byte address of the OneWireContainer this SHAiButton refers to.

Returns:

8 byte array containing family code, address, and crc8 of the OneWire device.

getAddress

public void getAddress(byte[] data,
                       int offset)

Copies the 8 byte address of the OneWireContainer into the provided array starting at the given offset.

Parameters:

data - array with at least 8 bytes after offset

offset - the index at which copying starts

getAddress

public void getAddress(byte[] data,
                       int offset,
                       int cnt)

Copies the specified number of bytes from the address of the OneWireContainer into the provided array starting at the given offset.

Parameters:

data - array with at least cnt bytes after offset

offset - the index at which copying starts

cnt - the number of bytes to copy

setForceOverdrive

public void setForceOverdrive(boolean value)

Sets whether or not the container should be forced into overdrive.

Parameters:

value - if true, the container will be forced to overdrive

getForceOverdrive

public boolean getForceOverdrive()

Reports whether or not the container is forced into overdrive.

Returns:

if true, the container will be forced to overdrive

createServiceFile

protected boolean createServiceFile(OneWireContainer owc,
                                    java.lang.String filename,
                                    boolean formatDevice)

Create's empty service file for the user with the given filename. Also, it populates accountPageNumber with the page that the service file is stored on.

Parameters:

owc - the 1-wire device where the service file will be created.

filename - the filename of the service file.

formatDevice - if true, the device is formatted before creating the service file.

checkAccountPageInfo

protected boolean checkAccountPageInfo(OneWireContainer ibc)

Asserts that proper account info exists for this SHAiButtonUser and establishes a buffer for caching account data.

Parameters:

ibc - the OneWireContainer whose account info is checked

Returns:

whether or not the device is initialized properly

setiButtonUser

public abstract boolean setiButtonUser(DSPortAdapter adapter,
                                       byte[] address)
                                throws OneWireException,
                                       OneWireIOException

Modifies this SHA iButton so that it refers to another device. If this object already has an appropriate instance of OneWireContainer, that instance is updated with the new address.

Parameters:

adapter - The adapter that the device can be found on.

address - The address of the 1-Wire device

Returns:

true if a valid account service file exists on this OneWireContainer18.

Throws:

OneWireIOException - on a 1-Wire communication error such as reading an incorrect CRC from a 1-Wire device. This could be caused by a physical interruption in the 1-Wire Network due to shorts or a newly arriving 1-Wire device issuing a 'presence pulse'.

OneWireException - on a communication or setup error with the 1-Wire adapter

setiButtonUser

public abstract boolean setiButtonUser(byte[] address)
                                throws OneWireException,
                                       OneWireIOException

Modifies this SHA iButton so that it refers to another device. If this object does not already has an appropriate instance of OneWireContainer, it returns false immediately, because there is no adapter info available. Otherwise, it reuses the same adapter.

Parameters:

address - The address of the 1-Wire device

Returns:

true if a valid account service file exists on this OneWireContainer18.

Throws:

OneWireIOException - on a 1-Wire communication error such as reading an incorrect CRC from a 1-Wire device. This could be caused by a physical interruption in the 1-Wire Network due to shorts or a newly arriving 1-Wire device issuing a 'presence pulse'.

OneWireException - on a communication or setup error with the 1-Wire adapter

getWriteCycleCounter

public abstract int getWriteCycleCounter()
                                  throws OneWireException,
                                         OneWireIOException

Returns the value of the write cycle counter for the page where the account data is stored. If the write cycle counter has ever been retrieved, this returns the cached value. Otherwise, this method reads the value from the part.

For devices that do not support write cycle counters, this method always returns -1.

Returns:

the value of the write cycle counter for the account data page.

Throws:

OneWireIOException - on a 1-Wire communication error such as reading an incorrect CRC from a 1-Wire device. This could be caused by a physical interruption in the 1-Wire Network due to shorts or a newly arriving 1-Wire device issuing a 'presence pulse'.

OneWireException - on a communication or setup error with the 1-Wire adapter

hasWriteCycleCounter

public abstract boolean hasWriteCycleCounter()

Returns true if this buttons account data is stored on a page that has a write cycle counter.

Returns:

true if account page has write cycle counter.

getFullBindCode

public abstract void getFullBindCode(byte[] l_fullBindCode,
                                     int offset)

This function creates the full 15-byte binding data for the coprocessor to use to recreate this user's secret on the copr's workspace page. This function is located in the SHAiButtonUser class to support binding codes for user buttons who use alternate techniques (such as the DS1961S) for secret computation.

Parameters:

bindCode - the 7-byte binding code from coprocessor's service file

fullBindCode - the 15-byte full binding code to to be copied into the coprocessor's scratchpad. There should be 15 bytes available starting from the offset.

offset - the offset into fullBindCode where copying should begin.

getAuthorizationCommand

public abstract byte getAuthorizationCommand()

Returns a byte representing the appropriate authorization command for the coprocessor to use to authenticate this user. For a DS1961S, the authentication command is AUTH_HOST, but for a DS1963S, the authentication command is VALIDATE_PAGE.

Returns:

byte indicating appropriate command for authenticating user

writeAccountData

public abstract boolean writeAccountData(byte[] dataBuffer,
                                         int offset)
                                  throws OneWireException,
                                         OneWireIOException

Writes the account data to the SHAiButton. First, this function asserts that the account page number is known. The account data is copied from dataBuffer starting at the offset. If there are less than 32 bytes available to copy, this function only copies the bytes that are available.

Parameters:

dataBuffer - the buffer to copy the account data from

offset - the index into the buffer where copying should begin

Returns:

whether or not the data write succeeded

Throws:

OneWireIOException - on a 1-Wire communication error such as reading an incorrect CRC from a 1-Wire device. This could be caused by a physical interruption in the 1-Wire Network due to shorts or a newly arriving 1-Wire device issuing a 'presence pulse'.

OneWireException - on a communication or setup error with the 1-Wire adapter

readAccountData

public abstract boolean readAccountData(byte[] dataBuffer,
                                        int offset)
                                 throws OneWireException,
                                        OneWireIOException

Reads the account data off the SHAiButton using a standard READ command. First, this function asserts that the account page number is known as well as the length of the account file. The 32 byte account data page is copied into dataBuffer starting at the given offset.

Parameters:

dataBuffer - the buffer to copy the account data into

offset - the index into the buffer where copying should begin

Returns:

whether or not the read was successful

Throws:

OneWireIOException - on a 1-Wire communication error such as reading an incorrect CRC from a 1-Wire device. This could be caused by a physical interruption in the 1-Wire Network due to shorts or a newly arriving 1-Wire device issuing a 'presence pulse'.

OneWireException - on a communication or setup error with the 1-Wire adapter

readAccountData

public abstract int readAccountData(byte[] chlg,
                                    int chlgStart,
                                    byte[] dataBuffer,
                                    int dataStart,
                                    byte[] mac,
                                    int macStart)
                             throws OneWireException,
                                    OneWireIOException

Reads the account data off the SHAiButton using a READ_AUTHENTICATE command. First, this function asserts that the account page number is known as well as the length of the account file. Then it copies the 3 byte challenge to the scratchpad before sending the command for READ_AUTHENTICATE. The 32 byte account data page is copied into dataBuffer starting at dataStart.

In addition to the account data, this function also returns a calculated MAC. The MAC requires 20 bytes after the start index. The return value is the write cycle counter value for the account data page

Parameters:

chlg - the buffer containing a 3-byte random challenge.

chlgStart - the index into the buffer where the 3 byte challenge begins.

dataBuffer - the buffer to copy the account data into

dataStart - the index into the buffer where copying should begin

mac - the buffer to copy the resulting Message Authentication Code

macStart - the index into the mac buffer to start copying

Returns:

the value of the write cycle counter for the page

Throws:

OneWireIOException - on a 1-Wire communication error such as reading an incorrect CRC from a 1-Wire device. This could be caused by a physical interruption in the 1-Wire Network due to shorts or a newly arriving 1-Wire device issuing a 'presence pulse'.

OneWireException - on a communication or setup error with the 1-Wire adapter

refreshDevice

public boolean refreshDevice()
                      throws OneWireException,
                             OneWireIOException

Refreshes eeprom SHA devices in case of weakly-programmed bits on the account page.

Returns:

true if the refresh was successful

Throws:

OneWireException

OneWireIOException

toString

public java.lang.String toString()

Returns a string representing this SHAiButton.

Overrides:

toString in class java.lang.Object

Returns:

a string containing the 8-byte address of this 1-Wire device.