src/main/java/org/imsglobal/lti/launch/LtiOauthVerifier.java
@Override
    public LtiVerificationResult verify(HttpServletRequest request, String secret) throws LtiVerificationException {
        OAuthMessage oam = OAuthServlet.getMessage(request, OAuthServlet.getRequestURL(request));
        String oauth_consumer_key = null;
        try {
            oauth_consumer_key = oam.getConsumerKey();
        } catch (Exception e) {
            return new LtiVerificationResult(false, LtiError.BAD_REQUEST, "Unable to find consumer key in message");
        }

        OAuthValidator oav = new SimpleOAuthValidator();
        OAuthConsumer cons = new OAuthConsumer(null, oauth_consumer_key, secret, null);
        OAuthAccessor acc = new OAuthAccessor(cons);

        try {
            oav.validateMessage(oam, acc);
        } catch (Exception e) {
            return new LtiVerificationResult(false, LtiError.BAD_REQUEST, "Failed to validate: " + e.getLocalizedMessage());
        }
        return new LtiVerificationResult(true, new LtiLaunch(request));
    }
@Override
    public LtiVerificationResult verify(HttpServletRequest request, String secret) throws LtiVerificationException {
        OAuthMessage oam = OAuthServlet.getMessage(request, OAuthServlet.getRequestURL(request));
        String oauth_consumer_key = null;
        try {
            oauth_consumer_key = oam.getConsumerKey();
        } catch (Exception e) {
            return new LtiVerificationResult(false, LtiError.BAD_REQUEST, "Unable to find consumer key in message");
        }

        OAuthValidator oav = new SimpleOAuthValidator();
        OAuthConsumer cons = new OAuthConsumer(null, oauth_consumer_key, secret, null);
        OAuthAccessor acc = new OAuthAccessor(cons);

        try {
            oav.validateMessage(oam, acc);
        } catch (Exception e) {
            return new LtiVerificationResult(false, LtiError.BAD_REQUEST, "Failed to validate: " + e.getLocalizedMessage());
        }
        return new LtiVerificationResult(true, new LtiLaunch(request));
    }
This method verifies the signed HttpServletRequest
@param request the HttpServletRequest that will be verified
@param secret the secret to verify the properties with
@return the result of the verification, along with contextual
information
@throws LtiVerificationException