gitlab-org--gitlab-foss/lib/gitlab/jwt_authenticatable.rb

43 lines
1.2 KiB
Ruby

# frozen_string_literal: true
module Gitlab
module JwtAuthenticatable
# Supposedly the effective key size for HMAC-SHA256 is 256 bits, i.e. 32
# bytes https://tools.ietf.org/html/rfc4868#section-2.6
SECRET_LENGTH = 32
def self.included(base)
base.extend(ClassMethods)
end
module ClassMethods
include Gitlab::Utils::StrongMemoize
def decode_jwt_for_issuer(issuer, encoded_message)
JWT.decode(
encoded_message,
secret,
true,
{ iss: issuer, verify_iss: true, algorithm: 'HS256' }
)
end
def secret
strong_memoize(:secret) do
Base64.strict_decode64(File.read(secret_path).chomp).tap do |bytes|
raise "#{secret_path} does not contain #{SECRET_LENGTH} bytes" if bytes.length != SECRET_LENGTH
end
end
end
def write_secret
bytes = SecureRandom.random_bytes(SECRET_LENGTH)
File.open(secret_path, 'w:BINARY', 0600) do |f|
f.chmod(0600) # If the file already existed, the '0600' passed to 'open' above was a no-op.
f.write(Base64.strict_encode64(bytes))
end
end
end
end
end