Instead, look for the option to "Sign in with Google," which is a safer way to sync your mail to other apps. Learn about Sign in with Google.

Authorization scopes are a way to determine to what extent the client can use resources located in the provider. When the client requests the authorization it specifies in which scope they would like to be authorized. This information is then displayed to the user - resource owner - and they can decide whether or not they accept the given application to be able to act in specified scopes.

aud

https://accounts.google.com/o/oauth2/v2/auth?

Web server applications

Sign in with Google is based on OAuth 2.0.

OAuth 2.0 is also the industry-standard protocol for authorization. It provides for a set of endpoints with which relying parties integrate using HTTP.

The OAuth 2.0 Authorization Framework: Bearer Token Usage

Unlike access tokens, refresh tokens are intended for use only with authorization servers and are never sent to resource servers.

Spring Cloud Gateway + Jwt + Oauth2 实现网关的鉴权操作

Refresh tokens are bearer tokens. It's impossible for the authorization server to know who is legitimate or malicious when receiving a new access token request. We could then treat all users as potentially malicious.

But what about a Refresh Token flow? When using a refresh token, confidential clients also have to authenticate. Public clients, such as browser-based applications, do not authenticate during the Refresh Token flow. So in a typical frontend application, refresh tokens issued to frontend web applications are bearer tokens.   In practice, this means that if an attacker manages to steal a refresh token from a frontend application, they can use that token in a Refresh Token flow. To counter such attacks, the OAuth 2.0 specifications mandate that browser-based applications apply a security measure known as refresh token rotation.

Grant Types

For example, if I make an application (Client) that allows a user (Resource Owner) to make notes and save them as a repo in their GitHub account (Resource Server), then my application will need to access their GitHub data. It's not secure for the user to directly supply their GitHub username and password to my application and grant full access to the entire account. Instead, using OAuth 2.0, they can go through an authorization flow that will grant limited access to some resources based on a scope, and I will never have access to any other data or their password.

Proof of Key Code Exchange is an OAuth2 extension that recently been adopted as the standard for both OAuth 2.1 and IndieAuth, and provides additional security for attacks on the Authorization Code flow.

Here’s what this flow looks like:

The process used to create an OAuth wrapper client is very simple.

This document defines how a JWT Bearer Token can be used to request an access token when a client wishes to utilize an existing trust relationship, expressed through the semantics of the JWT, without a direct user-approval step at the authorization server.

the OAuth 2.0 grant type, Authorization Code Flow with Proof Key for Code Exchange (PKCE).

If the Client is a Single-Page App (SPA), an application running in a browser using a scripting language like JavaScript, there are two grant options: the Authorization Code Flow with Proof Key for Code Exchange (PKCE) and the Implicit Flow with Form Post. For most cases, we recommend using the Authorization Code Flow with PKCE because the Access Token is not exposed on the client side, and this flow can return Refresh Tokens.

Which OAuth 2.0 Flow Should I Use?

If the Client is a regular web app executing on a server, then the Authorization Code Flow is the flow you should use. Using this the Client can retrieve an Access Token and, optionally, a Refresh Token.

The first decision point is about whether the party that requires access to resources is a machine. In the case of machine-to-machine authorization, the Client is also the Resource Owner, so no end-user authorization is needed.

We want to use the Doorkeeper gem to implement an OAuth provider in our app. However, we use 2 factor auth in the login process, so we need a way to modify the password grant to accept email, password and a 2fa token (and respond with an appropriate error if the 2fa token is required and missing).

is there a more official way to deal hook in OmniAuth so we can authenticate with Facebook, Twitter, or Google?

If the application credentials check out, the authorization server returns an access token to the application. Now the application is authorized to use its own account.

OAuth, or Open Authorization is a protocol for users to authorize websites to access their information without handing over a password.

A combination of good cross-site scripting hygiene, a secure HTTP only cookie for authentication and a CSRF token is a good combination for building a secure ecosystem for your PWA and web API.

An end-user (resource owner 👤) grants a printing service (app 📦) access to their photo (resource 🖼) hosted in a photo-sharing service (resource server 📚), without sharing their username and password. Instead, they authenticate directly with a server trusted by the photo-sharing service (authorization server 🛡), which issues the printing service delegation-specific credentials (access token 🔑).

OAuth can be many things. It is most commonly used to allow an application (the consumer) to access data or services that the user (the resource owner) has with another service (the provider), and this is done in a way that prevents the consumer from knowing the login credentials that the user has with the provider

For each call to your API, user should send token with every API request and you should validate the encoded toke and either deny or send back the response.

Application credentials provide the required information about the caller making a request to a GCP API. Valid credential types include API keys, OAuth 2.0 client credentials, or service account keys.

it's not that there are new vulnerabilities that have been identified in the implicit flow, just that PKCE offers a more secure alternative that you should use if you have the option

PKCE (which stands for "Proof Key for Code Exchange" and is pronounced "pixie") was originally developed to solve a problem specific to native mobile apps using OAuth 2.0

While this has worked and continues to work for a wide range of web applications, security experts had (and continue to have) concerns that it leaves open some potential attack vectors

click a button that says "Sign in with GitHub." I am then sent to GitHub to sign in and, if this is my first time, grant permissions

A locally unique and never reassigned identifier within the Issuer for the End-User, which is intended to be consumed by the Client

o ensure that the "redirect_uri" parameter is present if the "redirect_uri" parameter was included in the initial authorization request as described in Section 4.1.1, and if included ensure that their values are identical.

If an authorization request is missing the "response_type" parameter, or if the response type is not understood, the authorization server MUST return an error response as described in Section 4.1.2.1.

The authorization server MAY fully or partially ignore the scope requested by the client, based on the authorization server policy or the resource owner's instructions. If the issued access token scope is different from the one requested by the client, the authorization server MUST include the "scope" response parameter to inform the client of the actual scope granted.

This should only be one per client as each grant type has different security properties and it is best to keep them separate to avoid mistakes.

A delegated solution means that one site is simply outsourcing its authentication needs to another pre-selected site. If your site uses Facebook Connect, you are delegating your authentication facilities to Facebook. Visitors to your site cannot use any other accounts, only accounts from the vendors you have pre-selected. A federated solution means that visitors to your site can use any account they have, as long as it is compatible. It makes no difference to the site which account is being used, as long as it can interoperate. At its core, OpenID is a federated solution because its most important feature is the ability to use any OpenID account with any OpenID-enabled service. A good example is stores accepting credit cards. A store that accepts any Visa card is using federated payments – payments from any account that “speaks Visa”. But a store that accepts only credit cards issued by a specific vendor, for example, a department store branded card, use delegated payments. The reason why you no longer see many stores accepting only their own credit cards, is because it is bad for business. But not every OpenID implementation is federated, and this is the big dilemma OpenID has to resolve. The question is, can users use any account they want? If a site uses the Yahoo! OpenID service by using the Yahoo! button: but does not offer the ability to use other vendors, it is really just another delegated solution, even if it is powered by OpenID under the hood. In this case, OpenID becomes just a technical detail of the implementation, not part of its design. Much of the recent discussion about OpenID usability centers around using brands as a way to make the service more usable. But the problem with this approach is that is takes away most of the federated value out of OpenID, leaving it simply as a common protocol to implement proprietary delegated services. When implemented this way, OpenID adds no real value to services with an OAuth API. The question which solution to use for sign-in, OpenID or OAuth, is very much application specific. If you are building a brand new site that needs accounts, and want to leverage existing accounts from services such as Google, Yahoo!, and Microsoft, OpenID is a great option that will give your users a lot of flexibility. But if you are extending an existing service, implementing a specific API and building a site that has great dependencies on another service, OAuth gives you everything you need, for very little extra work. It is all about using the right tool for the job.

Single Sign-on With Rails, WordPress and Oauth2

Last week we talked about giving away your passwords and how you should never do it. When a website wants to use the services of another—such as Bitly posting to your Twitter stream—instead of asking you to share your password, they should use OAuth instead. OAuth is an authentication protocol that allows you to approve one application interacting with another on your behalf without giving away your password. This is a quick guide to illustrate, as simply as possible, how OAuth works. The Actors There are 3 main players in an OAuth transaction: the user, the consumer, and the service provider. This triumvirate has been affectionately deemed the OAuth Love Triangle. In our example, Joe is the user, Bitly is the consumer, and Twitter is the service provided who controls Joe’s secure resource (his Twitter stream). Joe would like Bitly to be able to post shortened links to his stream. Here’s how it works: Step 1 – The user shows intent Joe (User): “Hey, Bitly, I would like you to be able to post links directly to my Twitter stream.” Bitly (Consumer): “Great! Let me go ask for permission.” Step 2 – The consumer gets permission Bitly: “I have a user that would like me to post to his stream. Can I have a request token?” Twitter (Service Provider): “Sure. Here’s a token and a secret.” The secret is used to prevent request forgery. The consumer uses the secret to sign each request so that the service provider can verify it is actually coming from the consumer application. Step 3 – The user is redirected to the service provider Bitly: “OK, Joe. I’m sending you over to Twitter so you can approve. Take this token with you.” Joe: “OK!” <Bitly directs Joe to Twitter for authorization> Note: This is the scary part. If Bitly were super-shady Evil Co. it could pop up a window that looked like Twitter but was really phishing for your username and password. Always be sure to verify that the URL you’re directed to is actually the service provider (Twitter, in this case). Step 4 – The user gives permission Joe: “Twitter, I’d like to authorize this request token that Bitly gave me.” Twitter: “OK, just to be sure, you want to authorize Bitly to do X, Y, and Z with your Twitter account?” Joe: “Yes!” Twitter: “OK, you can go back to Bitly and tell them they have permission to use their request token.” Twitter marks the request token as “good-to-go,” so when the consumer requests access, it will be accepted (so long as it’s signed using their shared secret). Step 5 – The consumer obtains an access token Bitly: “Twitter, can I exchange this request token for an access token?” Twitter: “Sure. Here’s your access token and secret.” Step 6 – The consumer accesses the protected resource Bitly: “I’d like to post this link to Joe’s stream. Here’s my access token!” Twitter: “Done!” Recap In our scenario, Joe never had to share his Twitter credentials with Bitly. He simply delegated access using OAuth in a secure manner. At any time, Joe can login to Twitter and review the access he has granted and revoke tokens for specific applications without affecting others. OAuth also allows for granular permission levels. You can give Bitly the right to post to your Twitter account, but restrict LinkedIn to read-only access. OAuth Isn’t Perfect…Yet OAuth is a solid solution for browser based applications and is a huge improvement over HTTP basic authentication. However, there are limitations, specifically with OAuth 1.0, that make it far less secure and less user-friendly in native and mobile applications. OAuth 2.0 is a newer, more secure version of the protocol which introduces different “flows” for web, mobile, and desktop applications. It also has the notion of token expiration (similar to cookie expiration), requires SSL, and reduces the complexity for developers by no longer requiring signing.

Satellizer is a simple to use, end-to-end, token-based authentication module for AngularJS with built-in support for Google, Facebook, LinkedIn, Twitter, Yahoo, Windows Live authentication providers, as well as Email and Password sign-in.

JavaScript oAuth

OpenID Connect 1.0 is a simple identity layer on top of the OAuth 2.0 protocol.