Package io.github.hapjava.server.impl.pairing

Class HomekitSRP6ServerSession

  • public class HomekitSRP6ServerSession
extends com.nimbusds.srp6.SRP6Session
    This is a slightly modified version of the SRP6ServerSession class included with nimbus. The only change made for homekit compatability is a change to the size of the b key. HomeKit pairing fails if b is not 3072 bytes.

    Stateful server-side Secure Remote Password (SRP-6a) authentication session. Handles the computing and storing of SRP-6a variables between the protocol steps as well as timeouts.

    Usage:

    • Create a new SRP-6a server session for each client authentication attempt.
    • If you wish to use custom routines for the server evidence message 'M1' and / or the client evidence message 'M2' specify them at this point.
    • Proceed to step one on receiving a valid user identity 'I' from the authenticating client. Respond with the server public value 'B' and password salt 's'. If the SRP-6a crypto parameters 'N', 'g' and 'H' were not agreed in advance between server and client append them to the response.
    • Proceed to step two on receiving the public client value 'A' and evidence message 'M1'. If the client credentials are valid signal success and return the server evidence message 'M2'. The established session key 'S' may be retrieved to encrypt further communication with the client. Else signal an authentication failure to the client.
    Author:
    Vladimir Dzhuvinov

    • Constructor Detail

      • HomekitSRP6ServerSession

        public HomekitSRP6ServerSession​(com.nimbusds.srp6.SRP6CryptoParams config,
                                int timeout)
        Creates a new server-side SRP-6a authentication session and sets its state to HomekitSRP6ServerSession.State.INIT.
        Parameters:
        config - The SRP-6a crypto parameters configuration. Must not be null.
        timeout - The SRP-6a authentication session timeout in seconds. If the authenticating counterparty (server or client) fails to respond within the specified time the session will be closed. If zero timeouts are disabled.

      • HomekitSRP6ServerSession

        public HomekitSRP6ServerSession​(com.nimbusds.srp6.SRP6CryptoParams config)
        Creates a new server-side SRP-6a authentication session and sets its state to HomekitSRP6ServerSession.State.INIT. Session timeouts are disabled.
        Parameters:
        config - The SRP-6a crypto parameters configuration. Must not be null.

    • Method Detail

      • mockStep1

        public BigInteger mockStep1​(String userID,
                            BigInteger s,
                            BigInteger v)
        Increments this SRP-6a authentication session to HomekitSRP6ServerSession.State.STEP_1 indicating a non-existing user identity 'I' with mock (simulated) salt 's' and password verifier 'v' values.

        This method can be used to avoid informing the client at step one that the user identity is bad and throw instead a guaranteed general "bad credentials" SRP-6a exception at step two.

        Argument origin:

        • From client: user identity 'I'.
        • Simulated by server, preferably consistently for the specified identity 'I': salt 's' and password verifier 'v' values.
        Parameters:
        userID - The identity 'I' of the authenticating user. Must not be null or empty.
        s - The password salt 's'. Must not be null.
        v - The password verifier 'v'. Must not be null.
        Returns:
        The server public value 'B'.
        Throws:
        IllegalStateException - If the method is invoked in a state other than HomekitSRP6ServerSession.State.INIT.

      • step2

        public BigInteger step2​(BigInteger A,
                        BigInteger M1)
                 throws com.nimbusds.srp6.SRP6Exception
        Increments this SRP-6a authentication session to HomekitSRP6ServerSession.State.STEP_2.

        Argument origin:

        • From client: public value 'A' and evidence message 'M1'.
        Parameters:
        A - The client public value. Must not be null.
        M1 - The client evidence message. Must not be null.
        Returns:
        The server evidence message 'M2'.
        Throws:
        com.nimbusds.srp6.SRP6Exception - If the session has timed out, the client public value 'A' is invalid or the user credentials are invalid.
        IllegalStateException - If the method is invoked in a state other than HomekitSRP6ServerSession.State.STEP_1.

      • getState

        public HomekitSRP6ServerSession.State getState()
        Returns the current state of this SRP-6a authentication session.
        Returns:
        The current state.