com.ongres.scram.common

Enum ScramMechanisms

java.lang.Object

java.lang.Enum<ScramMechanisms>

com.ongres.scram.common.ScramMechanisms

All Implemented Interfaces:

ScramMechanism, Serializable, Comparable<ScramMechanisms>

public enum ScramMechanisms
extends Enum<ScramMechanisms>
implements ScramMechanism

SCRAM Mechanisms supported by this library. At least, SCRAM-SHA-1 and SCRAM-SHA-256 are provided, since both the hash and the HMAC implementations are provided by the Java JDK version 6 or greater. MessageDigest: "Every implementation of the Java platform is required to support the following standard MessageDigest algorithms: MD5, SHA-1, SHA-256". Mac: "Every implementation of the Java platform is required to support the following standard Mac algorithms: HmacMD5, HmacSHA1, HmacSHA256".

See Also:

SASL SCRAM Family Mechanisms

Enum Constant Summary

Enum Constants

Enum Constant and Description
SCRAM_SHA_1
SCRAM_SHA_1_PLUS
SCRAM_SHA_256
SCRAM_SHA_256_PLUS

Method Summary

Modifier and Type	Method and Description
int	algorithmKeyLength() Returns the length of the key length of the algorithm.
static ScramMechanisms	byName(String name) Gets a SCRAM mechanism, given its standard IANA name.
byte[]	digest(byte[] message) Calculate a message digest, according to the algorithm of the SCRAM mechanism.
protected String	getHashAlgorithmName() Method that returns the name of the hash algorithm.
protected String	getHmacAlgorithmName() Method that returns the name of the HMAC algorithm.
String	getName() The name of the mechanism, which must be a value registered under IANA: SASL SCRAM Family Mechanisms
byte[]	hmac(byte[] key, byte[] message) Calculate the hmac of a key and a message, according to the algorithm of the SCRAM mechanism.
byte[]	saltedPassword(StringPreparation stringPreparation, String password, byte[] salt, int iterations) Compute the salted password
static ScramMechanism	selectMatchingMechanism(boolean channelBinding, String... peerMechanisms) This class classifies SCRAM mechanisms by two properties: whether they support channel binding; and a priority, which is higher for safer algorithms (like SHA-256 vs SHA-1).
boolean	supportsChannelBinding() Whether this mechanism supports channel binding
static ScramMechanisms	valueOf(String name) Returns the enum constant of this type with the specified name.
static ScramMechanisms[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

SCRAM_SHA_1

public static final ScramMechanisms SCRAM_SHA_1

SCRAM_SHA_1_PLUS

public static final ScramMechanisms SCRAM_SHA_1_PLUS

SCRAM_SHA_256

public static final ScramMechanisms SCRAM_SHA_256

SCRAM_SHA_256_PLUS

public static final ScramMechanisms SCRAM_SHA_256_PLUS

Method Detail

values

public static ScramMechanisms[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (ScramMechanisms c : ScramMechanisms.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static ScramMechanisms valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null

getHashAlgorithmName

protected String getHashAlgorithmName()

Method that returns the name of the hash algorithm. It is protected since should be of no interest for direct users. The instance is supposed to provide abstractions over the algorithm names, and are not meant to be directly exposed.

Returns:

The name of the hash algorithm

getHmacAlgorithmName

protected String getHmacAlgorithmName()

Method that returns the name of the HMAC algorithm. It is protected since should be of no interest for direct users. The instance is supposed to provide abstractions over the algorithm names, and are not meant to be directly exposed.

Returns:

The name of the HMAC algorithm

getName

public String getName()

Description copied from interface: ScramMechanism

The name of the mechanism, which must be a value registered under IANA: SASL SCRAM Family Mechanisms

Specified by:

getName in interface ScramMechanism

Returns:

The mechanism name

supportsChannelBinding

public boolean supportsChannelBinding()

Description copied from interface: ScramMechanism

Whether this mechanism supports channel binding

Specified by:

supportsChannelBinding in interface ScramMechanism

Returns:

True if it supports channel binding, false otherwise

algorithmKeyLength

public int algorithmKeyLength()

Description copied from interface: ScramMechanism

Returns the length of the key length of the algorithm.

Specified by:

algorithmKeyLength in interface ScramMechanism

Returns:

The length (in bits)

digest

public byte[] digest(byte[] message)

Description copied from interface: ScramMechanism

Calculate a message digest, according to the algorithm of the SCRAM mechanism.

Specified by:

digest in interface ScramMechanism

Parameters:

message - the message

Returns:

The calculated message digest

hmac

public byte[] hmac(byte[] key,
                   byte[] message)

Description copied from interface: ScramMechanism

Calculate the hmac of a key and a message, according to the algorithm of the SCRAM mechanism.

Specified by:

hmac in interface ScramMechanism

Parameters:

key - the key

message - the message

Returns:

The calculated message hmac instance

saltedPassword

public byte[] saltedPassword(StringPreparation stringPreparation,
                             String password,
                             byte[] salt,
                             int iterations)

Description copied from interface: ScramMechanism

Compute the salted password

Specified by:

saltedPassword in interface ScramMechanism

Returns:

The salted password

byName

public static ScramMechanisms byName(String name)

Gets a SCRAM mechanism, given its standard IANA name.

Parameters:

name - The standard IANA full name of the mechanism.

Returns:

An Optional instance that contains the ScramMechanism if it was found, or empty otherwise.

selectMatchingMechanism

public static ScramMechanism selectMatchingMechanism(boolean channelBinding,
                                                     String... peerMechanisms)

This class classifies SCRAM mechanisms by two properties: whether they support channel binding; and a priority, which is higher for safer algorithms (like SHA-256 vs SHA-1). Given a list of SCRAM mechanisms supported by the peer, pick one that matches the channel binding requirements and has the highest priority.

Parameters:

channelBinding - The type of matching mechanism searched for

peerMechanisms - The mechanisms supported by the other peer

Returns:

The selected mechanism, or null if no mechanism matched