带有Lambdas的Android自定义身份验证

Question

我正在尝试使用Amazon Cognito和lambda脚本实施自定义身份验证流程。触发了自定义身份验证，但是请求会话数组为空，而不是像使用javascript sdk一样触发SRP_a挑战。如果未发生SRP_a质询，则不会执行PASSWORD_VERIFIER质询，这对于用于验证用户名/密码是必需的。注意：身份验证的自定义部分在用户名/密码auth发生之后发生。

Cognito的文档说，可以在javascript，iOS和Android上实现此流程，但仅提供javascript中的示例。下面，我包括了进行身份验证的Android代码。

    CognitoHelper cognitoHelper = CognitoHelper.getInstance(getApplicationContext());
    username = loginView.getUsername();
    //Must use toLowerCase to make the username not case sensitive
    cognitoHelper.setUser(username.toLowerCase());
    password = loginView.getPassword();
    AuthFlowType authFlowType = AuthFlowType.fromValue(String.valueOf(AuthFlowType.CUSTOM_AUTH));
    HashMap<String, String> authenticationParameters = new HashMap<>();
    authenticationParameters.put(CognitoServiceConstants.AUTH_PARAM_PASSWORD,password);
    authenticationParameters.put(CognitoServiceConstants.AUTH_PARAM_USERNAME, username);

    SRP_aHelper srp_aHelper = new SRP_aHelper(cognitoHelper.getUserPoolID());
    authenticationParameters.put(CognitoServiceConstants.AUTH_PARAM_SRP_A,srp_aHelper.getA().toString(16));

    InitiateAuthRequest initiateAuthRequest = new InitiateAuthRequest();
    initiateAuthRequest.setClientId(cognitoHelper.getClientID());
    initiateAuthRequest.setAuthFlow(authFlowType);
    initiateAuthRequest.setAuthParameters(authenticationParameters);

    CognitoUser cognitoUser = cognitoHelper.getUserPool().getUser(username);
    thisDevice = cognitoUser.thisDevice();
    //getCIPClient returns a AmazonCognitoIdentityProviderClient
    InitiateAuthResult initiateAuthResult = cognitoHelper.getCipClient().initiateAuth(initiateAuthRequest);