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:

• hashlib — Secure hashes and message digests
  • Hash algorithms
    • new()
    • algorithms_guaranteed
    • algorithms_available
    • hash.digest_size
    • hash.block_size
    • hash.name
    • hash.update()
    • hash.digest()
    • hash.hexdigest()
    • hash.copy()
  • SHAKE variable length digests
    • shake.digest()
    • shake.hexdigest()
  • File hashing
    • file_digest()
  • Key derivation
    • pbkdf2_hmac()
    • scrypt()
  • BLAKE2
    • Creating hash objects
      • blake2b()
      • blake2s()
    • Constants
      • blake2b.SALT_SIZE
      • blake2s.SALT_SIZE
      • blake2b.PERSON_SIZE
      • blake2s.PERSON_SIZE
      • blake2b.MAX_KEY_SIZE
      • blake2s.MAX_KEY_SIZE
      • blake2b.MAX_DIGEST_SIZE
      • blake2s.MAX_DIGEST_SIZE
    • Examples
      • Simple hashing
      • Using different digest sizes
      • Keyed hashing
      • Randomized hashing
      • Personalization
      • Tree mode
    • Credits
• hmac — Keyed-Hashing for Message Authentication
  • new()
  • digest()
  • HMAC.update()
  • HMAC.digest()
  • HMAC.hexdigest()
  • HMAC.copy()
  • HMAC.digest_size
  • HMAC.block_size
  • HMAC.name
  • compare_digest()
• secrets — Generate secure random numbers for managing secrets
  • Random numbers
    • SystemRandom
    • choice()
    • randbelow()
    • randbits()
  • Generating tokens
    • token_bytes()
    • token_hex()
    • token_urlsafe()
    • How many bytes should tokens use?
  • Other functions
    • compare_digest()
  • Recipes and best practices