pygar.zoneable
Class FieldCrypto

java.lang.Object
  pygar.zoneable.FieldCrypto

Direct Known Subclasses:

FieldCryptoXmlTxt0

public abstract class FieldCrypto
extends java.lang.Object

Perform the innermost encryption step: the encryption of fields but not the semantic tags of the statements.

According to the original plan, this class is abstract because there may be alternative document encodings during development and perhaps even in deployment. Thus, we introduce this abstract class and work is done in a subclass: FieldCryptoXmlTxt0

See Also:

A potential alternative method would use document tree structures that are stored and transmitted in binary. In order to supply that alternative, it will be necessary write a new implementation in a subclass.

Field Summary

protected int	cipherBlockSize
protected javax.crypto.Cipher	cipherDecrypt
protected javax.crypto.Cipher	cipherEncrypt
protected int	cipherOutputSize
protected CryptoEngine	crypto
protected java.security.Key	key
protected EncryptedFieldTable	table

Constructor Summary

FieldCrypto(CryptoEngine crypto, java.security.Key key, EncryptedFieldTable table)
Create an object initializing it for encryption using the table definitions of the fields.

Method Summary

abstract boolean	compareStreams(java.io.InputStream inStream1, java.io.InputStream inStream2, java.lang.Double tolerance, EncryptedFieldTable table) Compare two streams containing XML documents containing fields described by the field table.
abstract void	decode(java.io.InputStream in, java.io.OutputStream out) Decode the in stream applying the encryption algorithm to the fields as specified in the table and placing the results on the out stream.
abstract java.lang.String	decodeField(EncryptedFieldTable.EFTYPE ftype, java.lang.String name, byte[] value) Decode a single encrypted field according to its type creating a clear text string for the value.
abstract java.lang.String	decodeField(EncryptedFieldTable.Row row, java.lang.String value) Decode a single encrypted field according to its type creating a clear text string for the value.
abstract void	decryptPartiallyEncryptedStream(java.io.InputStream inStream, java.io.OutputStream outStream, EncryptedFieldTable table) Decrypt the document on the inStream assuming it was partially encrypted with the current session encryption key.
abstract void	encode(java.io.InputStream in, java.io.OutputStream out) Encode the in stream applying the encryption algorithm to the fields as specified in the table and placing results on the out stream.
abstract java.lang.String	encodeField(EncryptedFieldTable.Row row, java.lang.String value) Encode a single field represented as a string creating an encrypted byte array using the field type specified.
protected abstract java.lang.String	encodeString(java.lang.String s) Encode a string with a symmetric session key and return it as a string representation in hexadecimal.
abstract void	partiallyEncryptStream(java.io.InputStream inStream, java.io.OutputStream outStream, EncryptedFieldTable table) Partially encrypt the input stream according to the specifications of the EncryptedFieldTable and using the current session key.
abstract boolean	verifyField(EncryptedFieldTable.Row row, java.lang.Double tolerance, java.lang.String value1, java.lang.String value2)

Methods inherited from class java.lang.Object

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

Field Detail

cipherEncrypt

protected javax.crypto.Cipher cipherEncrypt

cipherDecrypt

protected javax.crypto.Cipher cipherDecrypt

crypto

protected CryptoEngine crypto

cipherBlockSize

protected int cipherBlockSize

cipherOutputSize

protected int cipherOutputSize

table

protected volatile EncryptedFieldTable table

key

protected java.security.Key key

Constructor Detail

FieldCrypto

public FieldCrypto(CryptoEngine crypto,
                   java.security.Key key,
                   EncryptedFieldTable table)
            throws java.security.NoSuchAlgorithmException,
                   javax.crypto.NoSuchPaddingException,
                   java.security.InvalidKeyException

Create an object initializing it for encryption using the table definitions of the fields.

Parameters:

crypto - the CryptoEngine object for this configuration

key - the symmetric encryption key

table - the definitions of the fields

Throws:

java.security.NoSuchAlgorithmException

javax.crypto.NoSuchPaddingException

java.security.InvalidKeyException

Method Detail

encode

public abstract void encode(java.io.InputStream in,
                            java.io.OutputStream out)
                     throws DocumentError

Encode the in stream applying the encryption algorithm to the fields as specified in the table and placing results on the out stream.

Parameters:

in -

out -

Throws:

DocumentError

decode

public abstract void decode(java.io.InputStream in,
                            java.io.OutputStream out)
                     throws CryptoException

Decode the in stream applying the encryption algorithm to the fields as specified in the table and placing the results on the out stream.

Parameters:

in -

out -

Throws:

CryptoException

encodeField

public abstract java.lang.String encodeField(EncryptedFieldTable.Row row,
                                             java.lang.String value)
                                      throws CryptoException

Encode a single field represented as a string creating an encrypted byte array using the field type specified.

Parameters:

row - - from EncryptedFieldTable that describes the field

value -

Returns:

encoded value as string of hexadecimal

Throws:

CryptoException

decodeField

public abstract java.lang.String decodeField(EncryptedFieldTable.EFTYPE ftype,
                                             java.lang.String name,
                                             byte[] value)
                                      throws CryptoException

Decode a single encrypted field according to its type creating a clear text string for the value.

Parameters:

ftype - the type of the field

name - the name of the field

value -

Returns:

the decoded value as a string

Throws:

CryptoException

decodeField

public abstract java.lang.String decodeField(EncryptedFieldTable.Row row,
                                             java.lang.String value)
                                      throws CryptoException

Decode a single encrypted field according to its type creating a clear text string for the value.

Parameters:

row - the description of the field

value -

Returns:

the decoded value as a string

Throws:

CryptoException

partiallyEncryptStream

public abstract void partiallyEncryptStream(java.io.InputStream inStream,
                                            java.io.OutputStream outStream,
                                            EncryptedFieldTable table)
                                     throws javax.xml.stream.XMLStreamException,
                                            CryptoException

Partially encrypt the input stream according to the specifications of the EncryptedFieldTable and using the current session key.

Throws:

javax.xml.stream.XMLStreamException

CryptoException

decryptPartiallyEncryptedStream

public abstract void decryptPartiallyEncryptedStream(java.io.InputStream inStream,
                                                     java.io.OutputStream outStream,
                                                     EncryptedFieldTable table)
                                              throws javax.xml.stream.XMLStreamException,
                                                     CryptoException

Decrypt the document on the inStream assuming it was partially encrypted with the current session encryption key.

Parameters:

inStream -

outStream -

table -

Throws:

javax.xml.stream.XMLStreamException

CryptoException

compareStreams

public abstract boolean compareStreams(java.io.InputStream inStream1,
                                       java.io.InputStream inStream2,
                                       java.lang.Double tolerance,
                                       EncryptedFieldTable table)
                                throws javax.xml.stream.XMLStreamException,
                                       java.lang.Exception

Compare two streams containing XML documents containing fields described by the field table. Check each field for equality. Allow a tolerance in the comparison of real value fields. Other fields are compared for exact identity. This test procedure is provided to check the results a round-trip encryption and decryption.

Parameters:

inStream1 - first xml document to compare

inStream2 - second xml document

tolerance - allowable difference between two real values as a fraction of value

table - description of fields

Returns:

true if the documents and equal in every field within the tolerance

Throws:

javax.xml.stream.XMLStreamException

java.lang.Exception

verifyField

public abstract boolean verifyField(EncryptedFieldTable.Row row,
                                    java.lang.Double tolerance,
                                    java.lang.String value1,
                                    java.lang.String value2)
                             throws CryptoException

Throws:

CryptoException

encodeString

protected abstract java.lang.String encodeString(java.lang.String s)
                                          throws CryptoException

Encode a string with a symmetric session key and return it as a string representation in hexadecimal.

Parameters:

s - - clear text string

Returns:

encoded string

Throws:

CryptoException