com.good.daf.DAMessage Class Reference

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

Public Member Functions
	DAMessage ()
	Basic constructor. More...
DAMechanism	getMechanism ()
DADigestType	getDigestType ()
byte[]	getIV ()
byte[]	getPlaintext ()
byte[]	getCiphertext ()
void	setMechanism (DAMechanism newMech)
	Sets the mechanism. More...
void	setDigestType (DADigestType newDigest)
	Sets the digest type. More...
void	setIV (byte[] newIV)
	Sets the IV. More...
void	setPlaintext (byte[] newPt)
	Sets the plaintext. More...
void	setCiphertext (byte[] newCt)
	Sets the ciphertext. More...
boolean	setMechanismForRSAPkcs1Signature ()
	Set mechanism appropriately for RSA PKCS#1 signatures. More...
boolean	setMechanismForDSA ()
	Set mechanism appropriately for DSA algorithm. More...
boolean	setMechanismForECDSA ()
	Set mechanism appropriately for ECDSA algorithm. More...
boolean	applyDefaultDigest ()
	Ensure the DAMessage contains a pre-hashed message. More...
byte[]	getPkcs1SignatureData ()
	Create a byte string suitable for RSA PKCS#1 signature. More...
String	toString ()
	Stringifies the message contents. More...

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. More...

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.

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

• DAMessage.java