Keyboard shortcuts

Press ← or → to navigate between chapters

Press S or / to search in the book

Press ? to show this help

Press Esc to hide this help

TLS from Scratch

Build TLS from its cryptographic primitives. Each lesson introduces one concept with real-life analogies, shell commands, ASCII diagrams, and hands-on Rust exercises.

You’ll go from hashing a file to building an encrypted, authenticated communication channel — then use real TLS libraries and build production tools.

Course overview

Phase 1: Cryptographic Building Blocks
  Hashing → Encryption → Signatures → Key Exchange
  + Projects: TOTP Authenticator, Signed Git Commits

Phase 2: Putting Primitives Together
  Key Derivation → Password KDFs → Certificates → Cert Generation
  + Projects: Certificate Inspector, Password Manager Vault

Phase 3: Build a Mini-TLS
  Encrypted Echo → Authenticated Echo → mTLS → Replay Defense → Handshake Deep Dive
  + Project: Encrypted File Transfer

Phase 4: Real TLS
  tokio-rustls → HTTPS Client
  + Projects: HTTPS Server, TLS Scanner

Phase 5: Capstone Projects
  Certificate Authority, mTLS Service Mesh, TLS Proxy, Intercepting Proxy

What you’ll build

Lessons (16 total):

  • SHA-256 file hasher
  • ChaCha20-Poly1305 encryption with tamper detection
  • Ed25519 digital signatures
  • X25519 Diffie-Hellman key exchange
  • HKDF key derivation + password-based KDFs (Argon2)
  • X.509 certificate parsing + generation with rcgen
  • Encrypted echo server (your own mini-TLS)
  • Authenticated echo server, mutual TLS, replay defense
  • TLS 1.3 handshake deep dive
  • Real TLS with tokio-rustls, HTTPS client

Projects (11 total):

  • TOTP authenticator (Google Authenticator clone)
  • Signed git commits
  • Certificate inspector (check any website’s cert chain)
  • Password manager vault
  • Encrypted file transfer (mini scp)
  • HTTPS server
  • TLS scanner (probe server configurations)
  • Certificate authority
  • mTLS service mesh
  • TLS termination proxy
  • HTTPS intercepting proxy (mini mitmproxy)

Prerequisites

  • Rust fundamentals (ownership, traits, generics)
  • Basic networking (TCP/UDP)

Source code

git clone https://github.com/its-saeed/learn-by-building.git
cd learn-by-building
cargo run -p tls --bin 1-hash -- --file-path Cargo.toml