src/main/java/org/imsglobal/lti/launch/LtiOauthVerifier.java
@Override
    public LtiVerificationResult verifyParameters(Map<String, String> parameters, String url, String method, String secret) throws LtiVerificationException {
        OAuthMessage oam = new OAuthMessage(method, url, parameters.entrySet());
        OAuthConsumer cons = new OAuthConsumer(null, parameters.get(OAUTH_KEY_PARAMETER), secret, null);
        OAuthValidator oav = new SimpleOAuthValidator();
        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() + ", Parameters: " + Arrays.toString(parameters.entrySet().toArray()));
        }
        return new LtiVerificationResult(true, new LtiLaunch(parameters));
    }
@Override
    public LtiVerificationResult verifyParameters(Map<String, String> parameters, String url, String method, String secret) throws LtiVerificationException {
        OAuthMessage oam = new OAuthMessage(method, url, parameters.entrySet());
        OAuthConsumer cons = new OAuthConsumer(null, parameters.get(OAUTH_KEY_PARAMETER), secret, null);
        OAuthValidator oav = new SimpleOAuthValidator();
        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() + ", Parameters: " + Arrays.toString(parameters.entrySet().toArray()));
        }
        return new LtiVerificationResult(true, new LtiLaunch(parameters));
    }
This method will verify a collection of parameters
@param parameters the parameters that will be verified. mapped by key &amp; value
@param url the url this request was made at
@param method the method this url was requested with
@param secret the secret to verify the propertihes with
@return
@throws LtiVerificationException