org.cryptacular

Class CiphertextHeader

java.lang.Object

org.cryptacular.CiphertextHeader

Direct Known Subclasses:

CiphertextHeaderV2

Deprecated.

Superseded by CiphertextHeaderV2

@Deprecated
public class CiphertextHeader
extends Object

Cleartext header prepended to ciphertext providing data required for decryption.

Data format:

     +-----+----------+-------+------------+---------+
     | Len | NonceLen | Nonce | KeyNameLen | KeyName |
     +-----+----------+-------+------------+---------+
 

Where fields are defined as follows:

• Len - Total header length in bytes (4-byte integer)
• NonceLen - Nonce length in bytes (4-byte integer)
• Nonce - Nonce bytes (variable length)
• KeyNameLen (OPTIONAL) - Key name length in bytes (4-byte integer)
• KeyName (OPTIONAL) - Key name encoded as bytes in platform-specific encoding (variable length)

The last two fields are optional and provide support for multiple keys at the encryption provider. A common case for multiple keys is key rotation; by tagging encrypted data with a key name, an old key may be retrieved by name to decrypt outstanding data which will be subsequently re-encrypted with a new key.

Author:

Middleware Services

Field Summary

Fields

Modifier and Type	Field and Description
protected String	keyName Deprecated. Header key name field value.
protected int	length Deprecated. Header length in bytes.
protected static int	MAX_KEYNAME_LEN Deprecated. Maximum key name length in bytes.
protected static int	MAX_NONCE_LEN Deprecated. Maximum nonce length in bytes.
protected byte[]	nonce Deprecated. Header nonce field value.

Constructor Summary

Constructors

Constructor and Description
CiphertextHeader(byte[] nonce) Deprecated. Creates a new instance with only a nonce.
CiphertextHeader(byte[] nonce, String keyName) Deprecated. Creates a new instance with a nonce and named key.

Method Summary

Modifier and Type	Method and Description
protected int	computeLength() Deprecated.
static CiphertextHeader	decode(byte[] data) Deprecated. Creates a header from encrypted data containing a cleartext header prepended to the start.
static CiphertextHeader	decode(InputStream input) Deprecated. Creates a header from encrypted data containing a cleartext header prepended to the start.
byte[]	encode() Deprecated. Encodes the header into bytes.
String	getKeyName() Deprecated. Gets the encryption key name stored in the header.
int	getLength() Deprecated. Gets the header length in bytes.
byte[]	getNonce() Deprecated. Gets the bytes of the nonce/IV.

Methods inherited from class java.lang.Object

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

Field Detail

MAX_NONCE_LEN

protected static final int MAX_NONCE_LEN

Deprecated.

Maximum nonce length in bytes.

See Also:

Constant Field Values

MAX_KEYNAME_LEN

protected static final int MAX_KEYNAME_LEN

Deprecated.

Maximum key name length in bytes.

See Also:

Constant Field Values

nonce

protected final byte[] nonce

Deprecated.

Header nonce field value.

keyName

protected String keyName

Deprecated.

Header key name field value.

length

protected int length

Deprecated.

Header length in bytes.

Constructor Detail

CiphertextHeader

public CiphertextHeader(byte[] nonce)

Deprecated.

Creates a new instance with only a nonce.

Parameters:

nonce - Nonce bytes.

CiphertextHeader

public CiphertextHeader(byte[] nonce,
                        String keyName)

Deprecated.

Creates a new instance with a nonce and named key.

Parameters:

nonce - Nonce bytes.

keyName - Key name.

Method Detail

getLength

public int getLength()

Deprecated.

Gets the header length in bytes.

Returns:

Header length in bytes.

getNonce

public byte[] getNonce()

Deprecated.

Gets the bytes of the nonce/IV.

Returns:

Nonce bytes.

getKeyName

public String getKeyName()

Deprecated.

Gets the encryption key name stored in the header.

Returns:

Encryption key name.

encode

public byte[] encode()

Deprecated.

Encodes the header into bytes.

Returns:

Byte representation of header.

computeLength

protected int computeLength()

Deprecated.

Returns:

Length of this header encoded as bytes.

decode

public static CiphertextHeader decode(byte[] data)
                               throws EncodingException

Deprecated.

Creates a header from encrypted data containing a cleartext header prepended to the start.

Parameters:

data - Encrypted data with prepended header data.

Returns:

Decoded header.

Throws:

EncodingException - when ciphertext header cannot be decoded.

decode

public static CiphertextHeader decode(InputStream input)
                               throws EncodingException,
                                      StreamException

Deprecated.

Creates a header from encrypted data containing a cleartext header prepended to the start.

Parameters:

input - Input stream that is positioned at the start of ciphertext header data.

Returns:

Decoded header.

Throws:

EncodingException - when ciphertext header cannot be decoded.

StreamException - on stream IO errors.