com.nimbusds.jose.crypto

Class MACSigner

java.lang.Object

com.nimbusds.jose.crypto.MACSigner

All Implemented Interfaces:

JCAAware<JCAContext>, JOSEProvider, JWSProvider, JWSSigner

@ThreadSafe
public class MACSigner
extends Object
implements JWSSigner

Message Authentication Code (MAC) signer of JWS objects. Expects a secret key.

See RFC 7518 section 3.2 for more information.

This class is thread-safe.

Supports the following algorithms:

• JWSAlgorithm.HS256
• JWSAlgorithm.HS384
• JWSAlgorithm.HS512

Version:

2016-07-27

Author:

Vladimir Dzhuvinov

Field Summary

Fields

Modifier and Type	Field and Description
static Set<JWSAlgorithm>	SUPPORTED_ALGORITHMS The supported JWS algorithms by the MAC provider class.

Constructor Summary

Constructors

Constructor and Description
MACSigner(byte[] secret) Creates a new Message Authentication (MAC) signer.
MACSigner(OctetSequenceKey jwk) Creates a new Message Authentication (MAC) signer.
MACSigner(SecretKey secretKey) Creates a new Message Authentication (MAC) signer.
MACSigner(String secretString) Creates a new Message Authentication (MAC) signer.

Method Summary

Modifier and Type	Method and Description
static Set<JWSAlgorithm>	getCompatibleAlgorithms(int secretLength) Returns the compatible JWS HMAC algorithms for the specified secret length.
protected static String	getJCAAlgorithmName(JWSAlgorithm alg) Gets the matching Java Cryptography Architecture (JCA) algorithm name for the specified HMAC-based JSON Web Algorithm (JWA).
JCAContext	getJCAContext() Returns the Java Cryptography Architecture (JCA) context.
static int	getMinRequiredSecretLength(JWSAlgorithm alg) Returns the minimal required secret length for the specified HMAC JWS algorithm.
byte[]	getSecret() Gets the secret bytes.
SecretKey	getSecretKey() Gets the secret key.
String	getSecretString() Gets the secret as a UTF-8 encoded string.
Base64URL	sign(JWSHeader header, byte[] signingInput) Signs the specified input of a JWS object.
Set<JWSAlgorithm>	supportedJWSAlgorithms() Returns the names of the supported algorithms by the JWS provider instance.

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.nimbusds.jose.JWSProvider

supportedJWSAlgorithms

Methods inherited from interface com.nimbusds.jose.jca.JCAAware

getJCAContext

Field Detail

SUPPORTED_ALGORITHMS

public static final Set<JWSAlgorithm> SUPPORTED_ALGORITHMS

The supported JWS algorithms by the MAC provider class.

Constructor Detail

MACSigner

public MACSigner(byte[] secret)
          throws KeyLengthException

Creates a new Message Authentication (MAC) signer.

Parameters:

secret - The secret. Must be at least 256 bits long and not null.

Throws:

KeyLengthException - If the secret length is shorter than the minimum 256-bit requirement.

MACSigner

public MACSigner(String secretString)
          throws KeyLengthException

Creates a new Message Authentication (MAC) signer.

Parameters:

secretString - The secret as a UTF-8 encoded string. Must be at least 256 bits long and not null.

Throws:

KeyLengthException - If the secret length is shorter than the minimum 256-bit requirement.

MACSigner

public MACSigner(SecretKey secretKey)
          throws KeyLengthException

Creates a new Message Authentication (MAC) signer.

Parameters:

secretKey - The secret key. Must be at least 256 bits long and not null.

Throws:

KeyLengthException - If the secret length is shorter than the minimum 256-bit requirement.

MACSigner

public MACSigner(OctetSequenceKey jwk)
          throws KeyLengthException

Creates a new Message Authentication (MAC) signer.

Parameters:

jwk - The secret as a JWK. Must be at least 256 bits long and not null.

Throws:

KeyLengthException - If the secret length is shorter than the minimum 256-bit requirement.

Method Detail

getMinRequiredSecretLength

public static int getMinRequiredSecretLength(JWSAlgorithm alg)
                                      throws JOSEException

Returns the minimal required secret length for the specified HMAC JWS algorithm.

Parameters:

alg - The HMAC JWS algorithm. Must be supported and not null.

Returns:

The minimal required secret length, in bits.

Throws:

JOSEException - If the algorithm is not supported.

getCompatibleAlgorithms

public static Set<JWSAlgorithm> getCompatibleAlgorithms(int secretLength)

Returns the compatible JWS HMAC algorithms for the specified secret length.

Parameters:

secretLength - The secret length in bits. Must not be negative.

Returns:

The compatible HMAC algorithms, empty set if the secret length is too short for any algorithm.

sign

public Base64URL sign(JWSHeader header,
                      byte[] signingInput)
               throws JOSEException

Description copied from interface: JWSSigner

Signs the specified input of a JWS object.

Specified by:

sign in interface JWSSigner

Parameters:

header - The JSON Web Signature (JWS) header. Must specify a supported JWS algorithm and must not be null.

signingInput - The input to sign. Must not be null.

Returns:

The resulting signature part (third part) of the JWS object.

Throws:

JOSEException - If the JWS algorithm is not supported, if a critical header parameter is not supported or marked for deferral to the application, or if signing failed for some other internal reason.

getJCAAlgorithmName

protected static String getJCAAlgorithmName(JWSAlgorithm alg)
                                     throws JOSEException

Gets the matching Java Cryptography Architecture (JCA) algorithm name for the specified HMAC-based JSON Web Algorithm (JWA).

Parameters:

alg - The JSON Web Algorithm (JWA). Must be supported and not null.

Returns:

The matching JCA algorithm name.

Throws:

JOSEException - If the algorithm is not supported.

getSecretKey

public SecretKey getSecretKey()

Gets the secret key.

Returns:

The secret key.

getSecret

public byte[] getSecret()

Gets the secret bytes.

Returns:

The secret bytes.

getSecretString

public String getSecretString()

Gets the secret as a UTF-8 encoded string.

Returns:

The secret as a UTF-8 encoded string.

supportedJWSAlgorithms

public Set<JWSAlgorithm> supportedJWSAlgorithms()

Description copied from interface: JWSProvider

Returns the names of the supported algorithms by the JWS provider instance. These correspond to the alg JWS header parameter.

Specified by:

supportedJWSAlgorithms in interface JWSProvider

Returns:

The supported JWS algorithms, empty set if none.

getJCAContext

public JCAContext getJCAContext()

Description copied from interface: JCAAware

Returns the Java Cryptography Architecture (JCA) context. May be used to set a specific JCA security provider or secure random generator.

Specified by:

getJCAContext in interface JCAAware<JCAContext>

Returns:

The JCA context. Not null.