b24acb9f47fd930d3e77bcce3b18797718e77292
2 # MessageVerifier makes it easy to generate and verify messages which are signed
3 # to prevent tampering.
5 # This is useful for cases like remember-me tokens and auto-unsubscribe links where the
6 # session store isn't suitable or available.
9 # cookies[:remember_me] = @verifier.generate([@user.id, 2.weeks.from_now])
11 # In the authentication filter:
13 # id, time = @verifier.verify(cookies[:remember_me])
15 # self.current_user = User.find(id)
19 class InvalidSignature
< StandardError
; end
21 def initialize(secret
, digest
= 'SHA1')
26 def verify(signed_message
)
27 data, digest
= signed_message
.split("--")
28 if digest
!= generate_digest(data)
29 raise InvalidSignature
31 Marshal
.load(ActiveSupport
::Base64.decode64(data))
36 data = ActiveSupport
::Base64.encode64s(Marshal
.dump(value
))
37 "#{data}--#{generate_digest(data)}"
41 def generate_digest(data)
42 require 'openssl' unless defined?(OpenSSL
)
43 OpenSSL
::HMAC.hexdigest(OpenSSL
::Digest::Digest.new(@digest), @secret, data)