amazon-web-services - Postman 请求 Amazon Alexa Smart Home Skill LWA 时客户端身份验证失败

Question

我指的是 Amazon documentation用于客户身份验证。目前，我正在使用 LWA。

我遵循的步骤:

1. 我在“构建”>“权限”页面中从 Alexa 开发人员控制台启用了“发送 Alexa 事件权限”。

2. 我从 cloudwatch 日志中的请求中获取了授权代码，该请求是在我使用 Alexa 配套应用登录时发送的。

例子:-

    {
     "directive": {
         "header": {
             "messageId": "Example",
             "name": "AcceptGrant",
             "namespace": "Alexa.Authorization",
             "payloadVersion": "3"
         },
         "payload": {
            "grant": {
                "code": "Example2",
                "type": "OAuth2.AuthorizationCode"
            },
            "grantee": {
                "token": "Example3",
                "type": "BearerToken"
            }
         }
      }
    }

1. 在 Alexa Developer 控制台上构建的权限页面给了我客户端 ID 和客户端密码，我用它来向 https://api.amazon.com/auth/o2/token 发出发布请求.

例子:-

 POST /auth/o2/token HTTP/l.l
 Host: api.amazon.com
 Content-Type: application/x-www-form-urlencoded;charset=UTF-8 
 grant_type=authorization_code&code=&client_id=&client_secret=

我在上面的例子中传递了代码、client_id 和client_secret，并向这个URL https://api.amazon.com/auth/o2/token 发出了post 请求。

1. 我尝试使用 x-www-form-urlencoded;charset=UTF-8 以及 JSON 作为 Content-Type。

我按照上述文档中给出的步骤进行操作，但仍卡在错误 ( 401 Unauthorized ) 中:

{
    "error_description": "The request has an invalid grant parameter : code",
    "error": "invalid_grant"
}

我尝试同时使用 Python 代码和 Postman 来实现它。以上述相同的错误场景结束。

Answer 1

这是一个示例代码，可以帮助您和其他希望将事件发送到 alexa 网关的人。

    const AWS = require('aws-sdk');
    AWS.config.update({region: 'eu-west-1'});
    
    // Create the DynamoDB service object
    const ddb = new AWS.DynamoDB({ apiVersion: 'latest' });
    const doc = new AWS.DynamoDB.DocumentClient({
                convertEmptyValues: true,
                service: ddb
            });        
    
    // Using 'request' for http POST and GET request.
    // https://www.npmjs.com/package/requests
    // npm install --save requests 
    const r = require('request');

    //Handle Authorization. Call this method from your lambda handler whenever you get Alexa.Authorization message. You will get this message only when you select permission to 
    //send events in your Smart Home Skill.
    //Access to Event gateway allows you to enable Proactive Device Discovery and 
    //Proactive State Reporting in your skill
    //More information on Alexa.Authorization can be found on https://developer.amazon.com/docs/device-apis/alexa-authorization.html
    function handleAuthorization(request, context, user) {  
    
        //Even when you are using your own authentication, the url below will still
        //point to amazon OAuth token url. The token you obtain here has to be stored
        //separately for this user. Whenever sending an event to alexa event gateway you will
        //require this token.
        //URL below is for EU server. Look at following documentation link to identify correct url
        //for your system.
        //https://developer.amazon.com/docs/smarthome/send-events-to-the-alexa-event-gateway.html
        var url = "https://api.amazon.com/auth/o2/token";
        var body = {
            grant_type : 'authorization_code',
            code : request.directive.payload.grant.code,
            client_id : 'your client id from permissions page on developer portal where you enable alexa events. This is id different than one you specify in account linking settings',
            client_secret : 'client secret from permissions page'
        }
        
        //https://developer.amazon.com/docs/smarthome/authenticate-a-customer-permissions.html
        r.post({
          url:     url,
          form :  body
        }, function(error, response, b){    
            if (error) { return console.log(error); }
            var body = JSON.parse(b);
            var params = {
              TableName: 'Devices',
              Item: {
                'id' : user,
                'auth_token' : body.access_token,
                'refresh_token' : body.refresh_token
              }
            }
            log("DEBUG:", "Authorization Body", JSON.stringify(body));
            log("DEBUG:", "Authorization Response", JSON.stringify(response));
            log("DEBUG:", "Database Params", JSON.stringify(params));
            
            // Call DynamoDB to add the item to the table
            var putObjectPromise = doc.put(params).promise();
            //Store auth_token and refresh_token in database. We will need these
            //while sending events to event gateway.
            //Send a success response.
            putObjectPromise.then(function(data) {
                var response = {
                  event: {
                    header: {
                      messageId: request.directive.header.messageId,
                      namespace: "Alexa.Authorization",
                      name: "AcceptGrant.Response",
                      payloadVersion: "3"
                    },
                    "payload": {
                    }
                  }
                };
        
                context.succeed(response);
            }).catch(function(err) {
                //TODO - Add a Authorization error response JSON here.      
                console.log(err);
            });                         
        });                   
    }