'I want know Google Home Account Linking detail step (with OAuth)

I followed step this link : https://developers.google.com/assistant/smarthome/develop/implement-oauth

but there are a few things that I can't understand.

First of all, here's what I've been through.

Account linking add (A) Authorization URL, (B) Token URL
Deploy spring boot server for OAuth

(A) Html file & source like this (Authorization URL side)
- oauth.html

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>google login</title>

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script>
<script>
function press() {
    var email = document.getElementById("email");
    var id = document.getElementById("id");
    
    $.ajax({
        url: '/api/getMemberInfo.do',
        async: true,
        type: 'POST',
        data:JSON.stringify({
            email: id.value
        }),
        contentType: 'application/json',
        dataType:"json",
        success: function(res){
            email.innerText = res.member_email;
        },
        error: function(res){
            alert("error");
        }
    })
}

function getParam(sname) {

    var params = location.search.substr(location.search.indexOf("?") + 1);

    var sval = "";

    params = params.split("&");

    for (var i = 0; i < params.length; i++) {

        temp = params[i].split("=");

        if ([temp[0]] == sname) { sval = temp[1]; }

    }

    return sval;

}

window.onload = function(){

    var client_id = document.getElementById("client_id");
    var redirect_uri = document.getElementById("redirect_uri");
    var state = document.getElementById("state");
    var scope = document.getElementById("scope");
    var response_type = document.getElementById("response_type");
    var user_locale = document.getElementById("user_locale");

    const url = window.location.href;
    const urlParams = url.searchParams;

    client_id.innerText = getParam("client_id");
    redirect_uri.innerText = getParam("redirect_uri");
    state.innerText = getParam("state");
    scope.innerText = getParam("scope");
    response_type.innerText = getParam("response_type");
    user_locale.innerText = getParam("user_locale");

}

function redirect(){
    var state = getParam("state");
    var redirect_uri = getParam("redirect_uri");
    var url = redirect_uri + "?code=asdf1234&state=" + state;
    window.location.href = url;
}


</script>

</head>
<body>
    <input type="text" id="id">
    <input type="button" value="redirect" onclick="redirect()">

    <table border="1">
        <tr>
            <th>client_id</th>
            <td id="client_id"></td>
        </tr>
        <tr>
            <th>redirect_uri</th>
            <td id="redirect_uri"></td>
        </tr>
        <tr>
            <th>state</th>
            <td id="state"></td>
        </tr>
        <tr>
            <th>scope</th>
            <td id="scope"></td>
        </tr>
        <tr>
            <th>response_type</th>
            <td id="response_type"></td>
        </tr>
        <tr>
            <th>user_locale</th>
            <td id="user_locale"></td>
        </tr>
    </table>
</body>
</html>

[1] In this part I have a question here.

//who generate code parameter? (me? or google?) 
var url = redirect_uri + "?code=asdf1234&state=" + state;
window.location.href = url;

(B) /tokenExcange.do (Token URL side)

indexController.java

@Controller
@ComponentScan({"com.ramax.ramaxloadtestserver"})
public class IndexController {
    
    @Autowired
    meberServiceImpl service;
    
    @ResponseBody
    @PostMapping("/tokenExcange.do")
    public HashMap<String, String> tokenExcange(@RequestBody MultiValueMap<String, String> param) {
        System.out.print(param.toString());
        HashMap<String, String> map = new HashMap<String, String>();
        map.put("token_type", "Bearer");
        map.put("access_token", "dpvm9412");    // I write Any Value
        map.put("refresh_token", "dpvm0217");   // I write Any Value
        map.put("expires_in", "3600");
        
        return map;
    }
}

[2] In this part I have a second question here.

map.put("access_token", "dpvm9412");    // I write Any Value  <-- who make this token?
map.put("refresh_token", "dpvm0217");   // I write Any Value  <-- who make this token?

[3] The third question is, is this really the end that /tokenExcange.do return them?

I did the linking account process with Google Home app.

[4] But I found this error.

{
  "insertId": "16qlk2of7t19ol",
  "jsonPayload": {
    "syncLog": {
      "syncs": [
        {
          "httpLatencyMsec": "553",
          "status": "json_response_invalid_format",
          "requestId": "17655534332433302029"
        }
      ]
    }
  },
  "resource": {
    "type": "assistant_action_project",
    "labels": {
      "project_id": "hometrigger-7ec6d"
    }
  },
  "timestamp": "2021-08-17T06:25:48.498293954Z",
  "severity": "ERROR",
  "logName": "projects/hometrigger-7ec6d/logs/assistant_smarthome%2Fassistant_smarthome_logs",
  "receiveTimestamp": "2021-08-17T06:25:48.498293954Z"
}

I want to know the answer to those questions. [1], [2], [3], [4]

Please help me, and I'm sorry about my English.

Thank you for read my thread.

Solution 1:^[1]

[1] Google send (generates) the state and redirectURL to partner, and partner return the "code" to Google. Please refer to the following link for more information https://developers.google.com/identity/account-linking/oauth-linking?oauth=code .

[2] Partner generates these values

[3] Yes, once Google receives the token the account linking has been created.

[4] You did not handle sync intent correctly. You need to return the correct sync response.

Sources

This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.

Source: Stack Overflow

Solution	Source
Solution 1	Siddhant Priyadarshi

'I want know Google Home Account Linking detail step (with OAuth)

Solution 1:[1]

Sources

Related Questions

Solution 1:^[1]