Package com.nimbusds.jose.crypto.impl

Class PBKDF2

java.lang.Object

com.nimbusds.jose.crypto.impl.PBKDF2

public class PBKDF2
extends Object

Password-Based Key Derivation Function 2 (PBKDF2) utilities. Provides static methods to generate Key Encryption Keys (KEK) from passwords. Adopted from jose4j by Brian Campbell.

Version:

2021-07-03

Author:

Brian Campbell, Yavor Vassilev, Vladimir Dzhuvinov

Field Summary

Fields

Modifier and Type	Field	Description
static int	MIN_SALT_LENGTH	The minimum salt length (8 bytes).

Method Summary

Modifier and Type	Method	Description
static SecretKey	deriveKey(byte[] password, byte[] formattedSalt, int iterationCount, PRFParams prfParams)	Derives a PBKDF2 key from the specified password and parameters.
static byte[]	formatSalt(JWEAlgorithm alg, byte[] salt)	Formats the specified cryptographic salt for use in PBKDF2.

Methods inherited from class java.lang.Object

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

Field Detail

MIN_SALT_LENGTH

public static final int MIN_SALT_LENGTH

The minimum salt length (8 bytes).

See Also:

Constant Field Values

Method Detail

formatSalt

public static byte[] formatSalt(JWEAlgorithm alg,
                                byte[] salt)
                         throws JOSEException

Formats the specified cryptographic salt for use in PBKDF2.

 UTF8(JWE-alg) || 0x00 || Salt Input
 

Parameters:

alg - The JWE algorithm. Must not be null.

salt - The cryptographic salt. Must be at least 8 bytes long.

Returns:

The formatted salt for use in PBKDF2.

Throws:

JOSEException - If formatting failed.

deriveKey

public static SecretKey deriveKey(byte[] password,
                                  byte[] formattedSalt,
                                  int iterationCount,
                                  PRFParams prfParams)
                           throws JOSEException

Derives a PBKDF2 key from the specified password and parameters.

Parameters:

password - The password. Must not be null.

formattedSalt - The formatted cryptographic salt. Must not be null.

iterationCount - The iteration count. Must be a positive integer.

prfParams - The Pseudo-Random Function (PRF) parameters. Must not be null.

Returns:

The derived secret key (with "AES" algorithm).

Throws:

JOSEException - If the key derivation failed.