diff options
Diffstat (limited to 'activesupport/lib/active_support/message_verifier.rb')
| -rw-r--r-- | activesupport/lib/active_support/message_verifier.rb | 85 |
1 files changed, 78 insertions, 7 deletions
diff --git a/activesupport/lib/active_support/message_verifier.rb b/activesupport/lib/active_support/message_verifier.rb index 8419e858c6..83c39c0a86 100644 --- a/activesupport/lib/active_support/message_verifier.rb +++ b/activesupport/lib/active_support/message_verifier.rb @@ -1,6 +1,10 @@ +# frozen_string_literal: true + require "base64" require "active_support/core_ext/object/blank" require "active_support/security_utils" +require "active_support/messages/metadata" +require "active_support/messages/rotator" module ActiveSupport # +MessageVerifier+ makes it easy to generate and verify messages which are @@ -27,10 +31,76 @@ module ActiveSupport # # +MessageVerifier+ creates HMAC signatures using SHA1 hash algorithm by default. # If you want to use a different hash algorithm, you can change it by providing - # `:digest` key as an option while initializing the verifier: + # +:digest+ key as an option while initializing the verifier: # # @verifier = ActiveSupport::MessageVerifier.new('s3Krit', digest: 'SHA256') + # + # === Confining messages to a specific purpose + # + # By default any message can be used throughout your app. But they can also be + # confined to a specific +:purpose+. + # + # token = @verifier.generate("this is the chair", purpose: :login) + # + # Then that same purpose must be passed when verifying to get the data back out: + # + # @verifier.verified(token, purpose: :login) # => "this is the chair" + # @verifier.verified(token, purpose: :shipping) # => nil + # @verifier.verified(token) # => nil + # + # @verifier.verify(token, purpose: :login) # => "this is the chair" + # @verifier.verify(token, purpose: :shipping) # => ActiveSupport::MessageVerifier::InvalidSignature + # @verifier.verify(token) # => ActiveSupport::MessageVerifier::InvalidSignature + # + # Likewise, if a message has no purpose it won't be returned when verifying with + # a specific purpose. + # + # token = @verifier.generate("the conversation is lively") + # @verifier.verified(token, purpose: :scare_tactics) # => nil + # @verifier.verified(token) # => "the conversation is lively" + # + # @verifier.verify(token, purpose: :scare_tactics) # => ActiveSupport::MessageVerifier::InvalidSignature + # @verifier.verify(token) # => "the conversation is lively" + # + # === Making messages expire + # + # By default messages last forever and verifying one year from now will still + # return the original value. But messages can be set to expire at a given + # time with +:expires_in+ or +:expires_at+. + # + # @verifier.generate(parcel, expires_in: 1.month) + # @verifier.generate(doowad, expires_at: Time.now.end_of_year) + # + # Then the messages can be verified and returned upto the expire time. + # Thereafter, the +verified+ method returns +nil+ while +verify+ raises + # <tt>ActiveSupport::MessageVerifier::InvalidSignature</tt>. + # + # === Rotating keys + # + # MessageVerifier also supports rotating out old configurations by falling + # back to a stack of verifiers. Call +rotate+ to build and add a verifier to + # so either +verified+ or +verify+ will also try verifying with the fallback. + # + # By default any rotated verifiers use the values of the primary + # verifier unless specified otherwise. + # + # You'd give your verifier the new defaults: + # + # verifier = ActiveSupport::MessageVerifier.new(@secret, digest: "SHA512", serializer: JSON) + # + # Then gradually rotate the old values out by adding them as fallbacks. Any message + # generated with the old values will then work until the rotation is removed. + # + # verifier.rotate old_secret # Fallback to an old secret instead of @secret. + # verifier.rotate digest: "SHA256" # Fallback to an old digest instead of SHA512. + # verifier.rotate serializer: Marshal # Fallback to an old serializer instead of JSON. + # + # Though the above would most likely be combined into one rotation: + # + # verifier.rotate old_secret, digest: "SHA256", serializer: Marshal class MessageVerifier + prepend Messages::Rotator::Verifier + class InvalidSignature < StandardError; end def initialize(secret, options = {}) @@ -77,11 +147,12 @@ module ActiveSupport # # incompatible_message = "test--dad7b06c94abba8d46a15fafaef56c327665d5ff" # verifier.verified(incompatible_message) # => TypeError: incompatible marshal file format - def verified(signed_message) + def verified(signed_message, purpose: nil, **) if valid_message?(signed_message) begin data = signed_message.split("--".freeze)[0] - @serializer.load(decode(data)) + message = Messages::Metadata.verify(decode(data), purpose) + @serializer.load(message) if message rescue ArgumentError => argument_error return if argument_error.message.include?("invalid base64") raise @@ -101,8 +172,8 @@ module ActiveSupport # # other_verifier = ActiveSupport::MessageVerifier.new 'd1ff3r3nt-s3Krit' # other_verifier.verify(signed_message) # => ActiveSupport::MessageVerifier::InvalidSignature - def verify(signed_message) - verified(signed_message) || raise(InvalidSignature) + def verify(*args) + verified(*args) || raise(InvalidSignature) end # Generates a signed message for the provided value. @@ -112,8 +183,8 @@ module ActiveSupport # # verifier = ActiveSupport::MessageVerifier.new 's3Krit' # verifier.generate 'a private message' # => "BAhJIhRwcml2YXRlLW1lc3NhZ2UGOgZFVA==--e2d724331ebdee96a10fb99b089508d1c72bd772" - def generate(value) - data = encode(@serializer.dump(value)) + def generate(value, expires_at: nil, expires_in: nil, purpose: nil) + data = encode(Messages::Metadata.wrap(@serializer.dump(value), expires_at: expires_at, expires_in: expires_in, purpose: purpose)) "#{data}--#{generate_digest(data)}" end |