module Digest

Digest: message digests (SHA-256, MD5), HMAC-SHA-256 and PBKDF2.

require "digest"
Digest::SHA256.hexdigest("abc")[0, 16]        # => "ba7816bf8f01cfea"
Digest::HMAC.sha256("key", "message").size   # => 32

Each function takes its data as Bytes or as a String (its UTF-8 bytes) and gives the digest as Bytes, or as lowercase hexadecimal from hexdigest.

<std:digest>:12

Classes and modules

• Digest::HMAC HMAC (RFC 2104).
• Digest::MD5 MD5 (RFC 1321). Broken as a cryptographic hash: here for protocols that still use it, such as PostgreSQL's md5 authentication.
• Digest::PBKDF2 PBKDF2 (RFC 8018), the key derivation of SCRAM and of password storage.
• Digest::SHA256 SHA-256 (FIPS 180-4).