OAuth 2.0

In the modern digital landscape, secure authentication and authorization are critical for protecting user data and enabling seamless access to applications. Three key protocols—SAML, OpenID Connect (OIDC), and OAuth 2.0—play pivotal roles in identity and access management. While they share some similarities, each serves distinct purposes and operates differently. This post explores these protocols in depth, highlighting their use cases, workflows, and differences. What is SAML? Security Assertion Markup Language (SAML) is an XML-based standard for exchanging authentication and authorization data between parties, particularly between an Identity Provider (IdP) and a Service Provider (SP). SAML is widely used in enterprise Single Sign-On (SSO) solutions, allowing users to log in once and access multiple services without re-entering credentials. ...

OAuth 2.0 is a widely used authorization framework that enables applications to access user data on behalf of the user without requiring the user to share their credentials. It provides a secure and standardized approach to delegating access control, ensuring that applications can interact with various services while keeping user information private. The Authorization Code Flow is one of the core grant types in OAuth 2.0, designed for scenarios where both the client and the authorization server need to exchange information securely. ...

OAuth 2.0 is a widely used authorization framework that allows applications to obtain limited access to user resources without handling user credentials directly. The Authorization Code Flow with PKCE (Proof Key for Code Exchange) is a security-enhanced version of the Authorization Code Flow, specifically designed to address vulnerabilities in public clients like mobile apps and single-page applications (SPAs) that cannot safely store a client secret. Why PKCE Is Needed Traditional Authorization Code Flow relies on a client_secret to authenticate the client when exchanging an authorization code for a token. In public clients (like browser apps or mobile apps), this secret cannot be safely stored. Without proper safeguards, attackers could intercept the authorization code during redirection and exchange it for tokens. ...

OAuth 2.0 is a widely used authorization framework that enables applications to obtain limited access to user accounts on an HTTP service. Among its several grant types, the Client Credentials Flow is uniquely designed for machine-to-machine (M2M) communication where no user is involved. What is the Client Credentials Flow? The Client Credentials Flow is used when applications (typically backend services, daemons, or microservices) need to access resources or APIs on their own behalf, rather than on behalf of a user. This flow is ideal for internal services, automation scripts, or server-to-server communication where the resource owner is the application itself. ...