class ActiveRecord::Encryption::KeyGenerator

# File activerecord/lib/active_record/encryption/key_generator.rb, line 32
def derive_key_from(password, length: key_length)
  ActiveSupport::KeyGenerator.new(password).generate_key(ActiveRecord::Encryption.config.key_derivation_salt, length)
end

Derives a key from the given password. The key will have a size in bytes of :length (configured Cipher's length by default)

The generated key will be salted with the value of ActiveRecord::Encryption.key_derivation_salt

# File activerecord/lib/active_record/encryption/key_generator.rb, line 24
def generate_random_hex_key(length: key_length)
  generate_random_key(length: length).unpack("H*")[0]
end

Returns a random key in hexadecimal format. The key will have a size in bytes of :length (configured Cipher's length by default)

Hexadecimal format is handy for representing keys as printable text. To maximize the space of characters used, it is good practice including not printable characters. Hexadecimal format ensures that generated keys are representable with plain text

To convert back to the original string with the desired length:

[ value ].pack("H*")

# File activerecord/lib/active_record/encryption/key_generator.rb, line 10
def generate_random_key(length: key_length)
  SecureRandom.random_bytes(length)
end

Returns a random key. The key will have a size in bytes of :length (configured Cipher's length by default)