com.amazon.speech.speechlet.verifier

Class TimestampSpeechletRequestVerifier

java.lang.Object

com.amazon.speech.speechlet.verifier.TimestampSpeechletRequestVerifier

All Implemented Interfaces:

SpeechletRequestVerifier

public class TimestampSpeechletRequestVerifier
extends Object
implements SpeechletRequestVerifier

Verifies whether or not timestamps are valid within a certain tolerance.

Every request sent by Alexa includes a timestamp. This information is part of the signed portion of the request, so it cannot be changed without also invalidating the request signature. Using this timestamp to verify the freshness of the request before responding protects the client's service from attackers attempting a "replay" attack in which they acquire a properly signed request and then repeatedly resend it to disrupt your service.

See Also:

Checking the Timestamp of the Request

Constructor Summary

Constructors

Constructor and Description
TimestampSpeechletRequestVerifier(long tolerance, TimeUnit unit) Constructs a new timestamp verifier with the provided tolerance (in the provided units).

Method Summary

Modifier and Type	Method and Description
boolean	verify(SpeechletRequest request, Session session) Returns true if the provided date is inclusively within the verifier tolerance, either in the past or future, of the current system time.

Methods inherited from class java.lang.Object

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

Constructor Detail

TimestampSpeechletRequestVerifier

public TimestampSpeechletRequestVerifier(long tolerance,
                                         TimeUnit unit)

Constructs a new timestamp verifier with the provided tolerance (in the provided units).

Parameters:

tolerance - the tolerance of this verifier

unit - the time unit of the tolerance parameter

Method Detail

verify

public boolean verify(SpeechletRequest request,
                      Session session)

Returns true if the provided date is inclusively within the verifier tolerance, either in the past or future, of the current system time. This method will return false if SpeechletRequest or SpeechletRequest.getTimestamp() is null.

Specified by:

verify in interface SpeechletRequestVerifier

Parameters:

request - SpeechletRequest to validate

session - Session context within which to validate the call

Returns:

true if the provided date is within the verifier tolerance, false otherwise