Package com.impossibl.postgres.protocol.sasl.scram.client

Class ScramSession

java.lang.Object

com.impossibl.postgres.protocol.sasl.scram.client.ScramSession

public class ScramSession
extends Object

A class that represents a SCRAM client. Use this class to perform a SCRAM negotiation with a SCRAM server. This class performs an authentication execution for a given user, and has state related to it. Thus, it cannot be shared across users or authentication executions.

Method Summary

Modifier and Type	Method	Description
byte[]	clientFirstMessage(String authzid)	Returns the text representation of a SCRAM client-first-message
String	getChannelBindMethod()	Selected method the client should use to generate channel-bind data
String	getScramMechanismName()	Name of the session's selected SCRAM mechanism.
void	receiveServerFinalMessage(String serverFinalMessage)
byte[]	receiveServerFirstMessage(String serverFirstMessage, byte[] channelBindData, byte[] clientKey, byte[] storedKey)	Generates a client-final-message from the received server-first-message, channel-bind data (if any), and the clientKey and storedKey which, if available, provide an optimized path versus providing the original user's passwordthe user's password.
byte[]	receiveServerFirstMessage(String serverFirstMessage, byte[] channelBindData, String password)	Generates a client-final-message from the received server-first-message, channel-bind data (if any), and the user's password.
boolean	requiresChannelBindData()	Definitive answer to whether the client should be providing channel-bind data to the receiveServerFirstMessage(java.lang.String, byte[], java.lang.String) method call.

Methods inherited from class java.lang.Object

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

Method Detail

getScramMechanismName

public String getScramMechanismName()

Name of the session's selected SCRAM mechanism.

clientFirstMessage

public byte[] clientFirstMessage(String authzid)

Returns the text representation of a SCRAM client-first-message

Parameters:

authzid - Optional authzid (may be null)

Returns:

The message

requiresChannelBindData

public boolean requiresChannelBindData()

Definitive answer to whether the client should be providing channel-bind data to the receiveServerFirstMessage(java.lang.String, byte[], java.lang.String) method call.

Returns:

True if the client should provide channel-bind data.

getChannelBindMethod

public String getChannelBindMethod()

Selected method the client should use to generate channel-bind data

Returns:

Name of channel-bind method

receiveServerFirstMessage

public byte[] receiveServerFirstMessage(String serverFirstMessage,
                                        byte[] channelBindData,
                                        String password)
                                 throws ScramException

Generates a client-final-message from the received server-first-message, channel-bind data (if any), and the user's password. A matching ScramSession.ClientFinalProcessor is stored internally for a later call to receiveServerFinalMessage(String) to complete the authentication.

Parameters:

serverFirstMessage - The message

channelBindData - Optional channel-bind data (my be null)

password - The user's password

Returns:

The generated client-final-message.

Throws:

ScramParseException - If the message is not a valid server-first-message

ScramException

receiveServerFirstMessage

public byte[] receiveServerFirstMessage(String serverFirstMessage,
                                        byte[] channelBindData,
                                        byte[] clientKey,
                                        byte[] storedKey)
                                 throws ScramException

Generates a client-final-message from the received server-first-message, channel-bind data (if any), and the clientKey and storedKey which, if available, provide an optimized path versus providing the original user's passwordthe user's password. A matching ScramSession.ClientFinalProcessor is stored internally for a later call to receiveServerFinalMessage(String) to complete the authentication.

Parameters:

serverFirstMessage - The message

channelBindData - Optional channel-bind data (my be null)

clientKey - The client key, as per the SCRAM algorithm. It can be generated with: ScramFunctions.clientKey(ScramMechanism, StringPreparation, String, byte[], int)

storedKey - The stored key, as per the SCRAM algorithm. It can be generated from the client key with: ScramFunctions.storedKey(ScramMechanism, byte[])

Returns:

The generated client-final-message.

Throws:

ScramParseException - If the message is not a valid server-first-message

ScramException

receiveServerFinalMessage

public void receiveServerFinalMessage(String serverFinalMessage)
                               throws ScramException

Throws:

ScramException