Package com.ongres.scram.client

Class ScramClient

java.lang.Object

com.ongres.scram.client.ScramClient

public class ScramClient
extends Object

A class that can be parametrized to generate ScramSessions. This class supports the channel binding and string preparation mechanisms that are provided by module scram-common. The class is fully configurable, including options to selected the desired channel binding, automatically pick the best client SCRAM mechanism based on those supported (advertised) by the server, selecting an externally-provided SecureRandom instance or an external nonceProvider, or choosing the nonce length. This class is thread-safe if the two following conditions are met:

• The SecureRandom used (SecureRandom by default) are thread-safe too. The contract of Random marks it as thread-safe, so inherited classes are also expected to maintain it.
• No external nonceSupplier is provided; or if provided, it is thread-safe.

So this class, once instantiated via the ScramClient.Builder.setup()} method, can serve for multiple users and authentications.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	ScramClient.Builder	This class is not meant to be used directly.
static enum	ScramClient.ChannelBinding	Select whether this client will support channel binding or not
static class	ScramClient.PreBuilder1	This class is not meant to be used directly.
static class	ScramClient.PreBuilder2	This class is not meant to be used directly.

Field Summary

Fields

Modifier and Type	Field	Description
private final ScramClient.ChannelBinding	channelBinding
static final int	DEFAULT_NONCE_LENGTH	Length (in characters, bytes) of the nonce generated by default (if no nonce supplier is provided)
private final NonceSupplier	nonceSupplier
private final ScramMechanism	scramMechanism
private final SecureRandom	secureRandom
private final StringPreparation	stringPreparation

Constructor Summary

Constructors

Modifier	Constructor	Description
private	ScramClient(ScramClient.ChannelBinding channelBinding, StringPreparation stringPreparation, ScramMechanism nonChannelBindingMechanism, ScramMechanism channelBindingMechanism, SecureRandom secureRandom, NonceSupplier nonceSupplier)

Method Summary

Modifier and Type	Method	Description
static ScramClient.PreBuilder1	channelBinding(ScramClient.ChannelBinding channelBinding)	Selects for the client whether to use channel binding.
ScramMechanism	getScramMechanism()
StringPreparation	getStringPreparation()
ScramSession	scramSession(String user)	Instantiates a ScramSession for the specified user and this parametrized generator.
static List<String>	supportedMechanisms()	List all the supported SCRAM mechanisms by this client implementation

Methods inherited from class java.lang.Object

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

Field Details

DEFAULT_NONCE_LENGTH

public static final int DEFAULT_NONCE_LENGTH

Length (in characters, bytes) of the nonce generated by default (if no nonce supplier is provided)

See Also:

• Constant Field Values

channelBinding

private final ScramClient.ChannelBinding channelBinding

stringPreparation

private final StringPreparation stringPreparation

scramMechanism

private final ScramMechanism scramMechanism

secureRandom

private final SecureRandom secureRandom

nonceSupplier

private final NonceSupplier nonceSupplier

Constructor Details

ScramClient

private ScramClient(ScramClient.ChannelBinding channelBinding,
 StringPreparation stringPreparation,
 ScramMechanism nonChannelBindingMechanism,
 ScramMechanism channelBindingMechanism,
 SecureRandom secureRandom,
 NonceSupplier nonceSupplier)

Method Details

channelBinding

public static ScramClient.PreBuilder1 channelBinding(ScramClient.ChannelBinding channelBinding)
                                              throws IllegalArgumentException

Selects for the client whether to use channel binding. Refer to ScramClient.ChannelBinding documentation for the description of the possible values.

Parameters:

channelBinding - The channel binding setting

Returns:

The next step in the chain (PreBuilder1).

Throws:

IllegalArgumentException - If channelBinding is null

getStringPreparation

public StringPreparation getStringPreparation()

getScramMechanism

public ScramMechanism getScramMechanism()

supportedMechanisms

public static List<String> supportedMechanisms()

List all the supported SCRAM mechanisms by this client implementation

Returns:

A list of the IANA-registered, SCRAM supported mechanisms

scramSession

public ScramSession scramSession(String user)

Instantiates a ScramSession for the specified user and this parametrized generator.

Parameters:

user - The username of the authentication exchange

Returns:

The ScramSession instance