15. Cryptographic Services

The modules described in this chapter implement various algorithms of a cryptographic nature. They are available at the discretion of the installation. On Unix systems, the crypt module may also be available. Here’s an overview:

• 15.1. hashlib — Secure hashes and message digests
  • 15.1.1. Hash algorithms
  • 15.1.2. SHAKE variable length digests
  • 15.1.3. Key derivation
  • 15.1.4. BLAKE2
    • 15.1.4.1. Creating hash objects
    • 15.1.4.2. Constants
    • 15.1.4.3. Examples
      • 15.1.4.3.1. Simple hashing
      • 15.1.4.3.2. Using different digest sizes
      • 15.1.4.3.3. Keyed hashing
      • 15.1.4.3.4. Randomized hashing
      • 15.1.4.3.5. Personalization
      • 15.1.4.3.6. Tree mode
    • 15.1.4.4. Credits
• 15.2. hmac — Keyed-Hashing for Message Authentication
• 15.3. secrets — Generate secure random numbers for managing secrets
  • 15.3.1. Random numbers
  • 15.3.2. Generating tokens
    • 15.3.2.1. How many bytes should tokens use?
  • 15.3.3. Other functions
  • 15.3.4. Recipes and best practices