io.jsonwebtoken.impl.crypto

Class MacProvider

java.lang.Object

io.jsonwebtoken.impl.crypto.MacProvider

Direct Known Subclasses:

MacSigner

public abstract class MacProvider
extends Object

Field Summary

Fields

Modifier and Type	Field and Description
protected SignatureAlgorithm	alg
static SecureRandom	DEFAULT_SECURE_RANDOM JJWT's default SecureRandom number generator.
protected Key	key

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	MacProvider(SignatureAlgorithm alg, Key key)

Method Summary

Modifier and Type	Method and Description
protected Signature	createSignatureInstance()
static SecretKey	generateKey() Generates a new secure-random 512 bit secret key suitable for creating and verifying HMAC signatures.
static SecretKey	generateKey(SignatureAlgorithm alg) Generates a new secure-random secret key of a length suitable for creating and verifying HMAC signatures according to the specified SignatureAlgorithm using JJWT's default SecureRandom instance.
static SecretKey	generateKey(SignatureAlgorithm alg, SecureRandom random) Generates a new secure-random secret key of a length suitable for creating and verifying HMAC signatures according to the specified SignatureAlgorithm using the specified SecureRandom number generator.
protected Signature	getSignatureInstance()
protected boolean	isBouncyCastleAvailable()

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_SECURE_RANDOM

public static final SecureRandom DEFAULT_SECURE_RANDOM

JJWT's default SecureRandom number generator. This RNG is initialized using the JVM default as follows:

 static {
     DEFAULT_SECURE_RANDOM = new SecureRandom();
     DEFAULT_SECURE_RANDOM.nextBytes(new byte[64]);
 }
 

nextBytes is called to force the RNG to initialize itself if not already initialized. The byte array is not used and discarded immediately for garbage collection.

alg

protected final SignatureAlgorithm alg

key

protected final Key key

Constructor Detail

MacProvider

protected MacProvider(SignatureAlgorithm alg,
                      Key key)

Method Detail

generateKey

public static SecretKey generateKey()

Generates a new secure-random 512 bit secret key suitable for creating and verifying HMAC signatures. This is a convenience method that immediately delegates to generateKey(SignatureAlgorithm) using SignatureAlgorithm.HS512 as the method argument.

Returns:

a new secure-random 512 bit secret key suitable for creating and verifying HMAC signatures.

Since:

0.5

See Also:

generateKey(SignatureAlgorithm), generateKey(SignatureAlgorithm, SecureRandom)

generateKey

public static SecretKey generateKey(SignatureAlgorithm alg)

Generates a new secure-random secret key of a length suitable for creating and verifying HMAC signatures according to the specified SignatureAlgorithm using JJWT's default SecureRandom instance. This is a convenience method that immediately delegates to generateKey(SignatureAlgorithm, SecureRandom).

Parameters:

alg - the desired signature algorithm

Returns:

a new secure-random secret key of a length suitable for creating and verifying HMAC signatures according to the specified SignatureAlgorithm using JJWT's default SecureRandom instance.

Since:

0.5

See Also:

generateKey(), generateKey(SignatureAlgorithm, SecureRandom)

generateKey

public static SecretKey generateKey(SignatureAlgorithm alg,
                                    SecureRandom random)

Generates a new secure-random secret key of a length suitable for creating and verifying HMAC signatures according to the specified SignatureAlgorithm using the specified SecureRandom number generator. This implementation returns secure-random key sizes as follows:

Signature Algorithm	Generated Key Size
HS256	256 bits (32 bytes)
HS384	384 bits (48 bytes)
HS512	256 bits (64 bytes)

Parameters:

alg - the signature algorithm that will be used with the generated key

random - the secure random number generator used during key generation

Returns:

a new secure-random secret key of a length suitable for creating and verifying HMAC signatures according to the specified SignatureAlgorithm using the specified SecureRandom number generator.

Since:

0.5

See Also:

generateKey(), generateKey(SignatureAlgorithm)

createSignatureInstance

protected Signature createSignatureInstance()

getSignatureInstance

protected Signature getSignatureInstance()
                                  throws NoSuchAlgorithmException

Throws:

NoSuchAlgorithmException

isBouncyCastleAvailable

protected boolean isBouncyCastleAvailable()