How to set up user authentication for a Chrome Extension using the Chrome Identity API

_chrome-ext-auth-identity.md

How to set up user authentication for a Chrome Extension using the Chrome Identity API

1. Create a private key file, from which you can create the manifest key and Application ID, as detailed here: https://stackoverflow.com/questions/23873623/obtaining-chrome-extension-id-for-development
2. Add the manifest key to "key" in manifest.json
3. Create a new project in Google Developer Console https://console.developers.google.com/project
4. Go to "APIs & auth > Credentials" and create new client id for a Chrome Application using the Application ID generated in step 3.
5. Copy the Client ID to oauth2.client_id in the manifest.json

Deprecated?

1. Create a new app on the Chrome Web Store Developer Dashboard https://chrome.google.com/webstore/developer/dashboard
2. Click on "more info" and copy the public key to "key" in manifest.json. (or not needed because of next step...?)

Resources

• http://stackoverflow.com/questions/25044936/chrome-identity-user-authentication-in-a-chrome-extension

background.js

chrome.identity.getAuthToken({
    interactive: true
}, function(token) {
    if (chrome.runtime.lastError) {
        alert(chrome.runtime.lastError.message);
        return;
    }
    var x = new XMLHttpRequest();
    x.open('GET', 'https://www.googleapis.com/oauth2/v1/userinfo?alt=json&access_token=' + token);
    x.onload = function() {
        alert(x.response);
    };
    x.send();
});

manifest.json

{
    "key": "<Application ID>",
    "name": "Identity test",
    "version": "1",
    "manifest_version": 2,
    "background": {
        "scripts": ["background.js"]
    },
    "permissions": [
        "identity"
    ],
    "oauth2": {
        "client_id": "<Client ID>",
        "scopes": [
            "https://www.googleapis.com/auth/userinfo.email"
        ]
    }
}

@mikeyyyzhao that is specific to chrome.
If you want to continue your thenable promise, you can use a polyfill:
https://github.com/mozilla/webextension-polyfill#using-the-promise-based-apis