com.good.daf.DAMessage Class Reference

This type contains the inputs and outputs of a cryptographic transform. More...

List of all members.

Public Member Functions
	DAMessage ()
	Basic constructor.
DAMechanism	getMechanism ()
DADigestType	getDigestType ()
byte[]	getIV ()
byte[]	getPlaintext ()
byte[]	getCiphertext ()
void	setMechanism (DAMechanism newMech)
	Sets the mechanism.
void	setDigestType (DADigestType newDigest)
	Sets the digest type.
void	setIV (byte[] newIV)
	Sets the IV.
void	setPlaintext (byte[] newPt)
	Sets the plaintext.
void	setCiphertext (byte[] newCt)
	Sets the ciphertext.
boolean	setMechanismForRSAPkcs1Signature ()
	Set mechanism appropriately for RSA PKCS#1 signatures.
boolean	setMechanismForDSA ()
	Set mechanism appropriately for DSA algorithm.
boolean	setMechanismForECDSA ()
	Set mechanism appropriately for ECDSA algorithm.
boolean	applyDefaultDigest ()
	Ensure the DAMessage contains a pre-hashed message.
byte[]	getPkcs1SignatureData ()
	Create a byte string suitable for RSA PKCS#1 signature.
String	toString ()
	Stringifies the message contents.
Static Public Member Functions
static DAMessage	build (byte[] plain, byte[] cipher, byte[] iv, byte[] mechoid, int digest)
	This is a one-shot constructor from a set of byte strings.

---

Detailed Description

This type contains the inputs and outputs of a cryptographic transform.

An instance of this type can contain a mechanism, digest type, iv, plaintext and ciphertext. All items are optional. A new instance of this class starts with none present and a digest type of 'none'.

---

Constructor & Destructor Documentation

com.good.daf.DAMessage.DAMessage

(

)

Basic constructor.

The instance starts without any mechanism, iv, plaintext or ciphertext.

---

Member Function Documentation

boolean com.good.daf.DAMessage.applyDefaultDigest

(

)

Ensure the DAMessage contains a pre-hashed message.

If the digest type is already set, does nothing and returns false. Otherwise, applies a default hash algorithm (SHA-256 in the current release) to the plaintext field, and sets the digest type accordingly. Returns true if the DAMessage was changed.

static DAMessage com.good.daf.DAMessage.build	(	byte[]	plain,
		byte[]	cipher,
		byte[]	iv,
		byte[]	mechoid,
		int	digest
	)		[static]

This is a one-shot constructor from a set of byte strings.

This constructor is mainly for the benefit of JNI calling code.

Parameters:

plain	plaintext, may be null
cipher	ciphertext, may be null
iv	iv, may be null
mechoid	mechanism encoded OID, may be null
digest	digest type ordinal (in DADigestType enumeration)

Returns:

a DAMessage

byte [] com.good.daf.DAMessage.getCiphertext

(

)

Returns:

ciphertext, or null if no ciphertext is present

DADigestType com.good.daf.DAMessage.getDigestType

(

)

Returns:

digest type

byte [] com.good.daf.DAMessage.getIV

(

)

Returns:

iv, or null if no iv is present

DAMechanism com.good.daf.DAMessage.getMechanism

(

)

Returns:

mechanism, or null if no mechanism is present

byte [] com.good.daf.DAMessage.getPkcs1SignatureData

(

)

Create a byte string suitable for RSA PKCS#1 signature.

Returns:

null if the DAMessage is invalid/unsuitable

This is the DER encoding of a SEQUENCE containing the OID of the hash function followed by the hash value. See e.g. RFC 3447 section 9.2. This function will also apply a default hash function if the message doesn't have a digest type set.

byte [] com.good.daf.DAMessage.getPlaintext

(

)

Returns:

plaintext, or null if no plaintext is present

void com.good.daf.DAMessage.setCiphertext

(

byte[]

newCt

)

Sets the ciphertext.

Parameters:

newCt

new ciphertext value, may be null to unset ciphertext

void com.good.daf.DAMessage.setDigestType

(

DADigestType

newDigest

)

Sets the digest type.

Parameters:

newDigest

new digest type, may be null to reset to default (none)

void com.good.daf.DAMessage.setIV

(

byte[]

newIV

)

Sets the IV.

Parameters:

newIV

new IV value, may be null to unset IV

void com.good.daf.DAMessage.setMechanism

(

DAMechanism

newMech

)

Sets the mechanism.

Parameters:

newMech

new mechanism value, may be null to unset mechanism

boolean com.good.daf.DAMessage.setMechanismForDSA

(

)

Set mechanism appropriately for DSA algorithm.

Chooses a suitable DAMechanism (see DAMechanism.Preset) for the hash algorithm identified by the digest type field, and sets it as the mechanism field.

Returns:

false if unhandled digest in digest type field.

boolean com.good.daf.DAMessage.setMechanismForECDSA

(

)

Set mechanism appropriately for ECDSA algorithm.

Chooses a suitable DAMechanism (see DAMechanism.Preset) for the hash algorithm identified by the digest type field, and sets it as the mechanism field.

Returns:

false if invalid mechanism in digest type field.

boolean com.good.daf.DAMessage.setMechanismForRSAPkcs1Signature

(

)

Set mechanism appropriately for RSA PKCS#1 signatures.

Choose a suitable DAMechanism (see DAMechanism.Preset) for the hash algorithm identified by the digest type field, and sets it as the mechanism field.

Returns:

false if unhandled digest in digest type field.

void com.good.daf.DAMessage.setPlaintext

(

byte[]

newPt

)

Sets the plaintext.

Parameters:

newPt

new plaintext value, may be null to unset plaintext

String com.good.daf.DAMessage.toString

(

)

Stringifies the message contents.

Note that this can contain sensitive plaintext content.

---

The documentation for this class was generated from the following file:

• DAMessage.java