Authentication
What is OAuth? OAuth is an open-standard authorization protocol or framework that describes how unrelated servers and services can safely allow authenticated access to their assets without actually sharing the initial, related, single logon credential.
Give an example of what using OAuth would look like. The simplest example of OAuth is when you go to log onto a website and it offers one or more opportunities to log on using another website’s/service’s logon. You then click on the button linked to the other website, the other website authenticates you, and the website you were originally connecting to logs you on itself afterward using permission gained from the second website.
How does OAuth work? What are the steps that it takes to authenticate the user?
- the first website connects to the second website on behalf of the user, providing the user’s verified identity.
- The second site generates a one-time token and a one-time secret unique to the request.
- The first site gives this token and secret to the user’s client software.
- The client’s software presents the request token and secret to their authorization provider.
- If not already authenticated to the authorization provider, the client may be asked to authenticate. After that, the client is asked to approve the authorization transaction to the second website.
- The client approves a particular transaction type at the first website.
- The user is given an approved access token.
- The user gives the approved access token to the first website.
- The first website gives the access token to the second website as proof of authentication on behalf of the user.
- The second website lets the first website access their site on behalf of the user.
- The user receives a successfully completed transaction occurring.
What is OpenID? it is about authentication: as a commenter on StackOverflow pithily put it: “OpenID is for humans logging into machines, OAuth is for machines logging into machines on behalf of humans.”
Authorization and Authentication flows What is the difference between authorization and authentication? What is Authorization Code Flow? What is Authorization Code Flow with Proof Key for Code Exchange (PKCE)? What is Implicit Flow with Form Post? What is Client Credentials Flow? What is Device Authorization Flow? What is Resource Owner Password Flow?