GitHub Action Gotchas

I started with GitHub Actions a couple years ago. Recently I came across a few interesting use cases while I was trying to setup Terraform workflow with GitHub actions. These use cases prompted me to make use some new features in GitHub Action. So I put them in a post here. Runners can assume IAM … Read moreGitHub Action Gotchas

Istio Authentication and Authorization

Applications running on Kubernetes platform seeks to offload common non-business features to the platform. Istio helps Kubernetes bridge that gap. It can enforce mTLS communication, which is known as Peer Authentication. It can help with two other things with the use of JWT token: when a web request presents a JWT token, it can validate … Read moreIstio Authentication and Authorization

NTLM and Kerberos protocols

This article explains how two most common authentication mechanisms (NTLM and Kerberos) work. Both authentication protocols are based on symmetric key cryptography. The protocols themselves are platform independent. NTLM Authentication NTLM is the default authentication protocol prior to Windows 2000 and still prevalent today as backup to Kerberos. It is based on challenge/response mechanism. User … Read moreNTLM and Kerberos protocols

Introduction to Authentication Frameworks (PAM and SSPI)

This article gives a very brief high-level introduction to PAM (Pluggable Authentication Module) and SSPI (Security Support Provider Interface) as authentication frameworks in Linux and Windows respectively. PAM The Pluggable Authentication Module (PAM) architecture provides a powerful abstraction for user IAM using pluggable authentication model Unix platforms. It defines a generic API for authentication and … Read moreIntroduction to Authentication Frameworks (PAM and SSPI)

OAuth and OpenID Connect

OAuth 2.0 and OpenID Connect (OIDC 1.0) are different but highly related protocols and they are often confused. When we talk about IAM (identity and access management), we should first distinguish between Authentication (AuthN) and Authorization (AuthZ): AutheNtication (AuthN, aka Identity Management) is about validating user’s identity by verifying that the user trying to connect … Read moreOAuth and OpenID Connect

Security Assertion Markup Language (SAML)

SAML is an XML-based standard for exchanging authentication and authorization data between IdP (identity provider) and service provider. We can compare SAML with LDAP (as authentication protocol) as both are to provide single-sign-on (SSO) feature. LDAP is considered traditional configuration in on-premise operation for organizations. The configuration can be complex and administrators needs to complete … Read moreSecurity Assertion Markup Language (SAML)