mirror of https://github.com/Siphonay/mastodon
88 lines
2.4 KiB
Ruby
88 lines
2.4 KiB
Ruby
# frozen_string_literal: true
|
|
|
|
# Implemented according to HTTP signatures (Draft 6)
|
|
# <https://tools.ietf.org/html/draft-cavage-http-signatures-06>
|
|
module SignatureVerification
|
|
extend ActiveSupport::Concern
|
|
|
|
def signed_request?
|
|
request.headers['Signature'].present?
|
|
end
|
|
|
|
def signed_request_account
|
|
return @signed_request_account if defined?(@signed_request_account)
|
|
|
|
unless signed_request?
|
|
@signed_request_account = nil
|
|
return
|
|
end
|
|
|
|
raw_signature = request.headers['Signature']
|
|
signature_params = {}
|
|
|
|
raw_signature.split(',').each do |part|
|
|
parsed_parts = part.match(/([a-z]+)="([^"]+)"/i)
|
|
next if parsed_parts.nil? || parsed_parts.size != 3
|
|
signature_params[parsed_parts[1]] = parsed_parts[2]
|
|
end
|
|
|
|
if incompatible_signature?(signature_params)
|
|
@signed_request_account = nil
|
|
return
|
|
end
|
|
|
|
account = ResolveRemoteAccountService.new.call(signature_params['keyId'].gsub(/\Aacct:/, ''))
|
|
|
|
if account.nil?
|
|
@signed_request_account = nil
|
|
return
|
|
end
|
|
|
|
signature = Base64.decode64(signature_params['signature'])
|
|
compare_signed_string = build_signed_string(signature_params['headers'])
|
|
|
|
if account.keypair.public_key.verify(OpenSSL::Digest::SHA256.new, signature, compare_signed_string)
|
|
@signed_request_account = account
|
|
@signed_request_account
|
|
else
|
|
@signed_request_account = nil
|
|
end
|
|
end
|
|
|
|
private
|
|
|
|
def build_signed_string(signed_headers)
|
|
signed_headers = 'date' if signed_headers.blank?
|
|
|
|
signed_headers.split(' ').map do |signed_header|
|
|
if signed_header == Request::REQUEST_TARGET
|
|
"#{Request::REQUEST_TARGET}: #{request.method.downcase} #{request.path}"
|
|
else
|
|
"#{signed_header}: #{request.headers[to_header_name(signed_header)]}"
|
|
end
|
|
end.join("\n")
|
|
end
|
|
|
|
def matches_time_window?
|
|
begin
|
|
time_sent = DateTime.httpdate(request.headers['Date'])
|
|
rescue ArgumentError
|
|
return false
|
|
end
|
|
|
|
(Time.now.utc - time_sent).abs <= 30
|
|
end
|
|
|
|
def to_header_name(name)
|
|
name.split(/-/).map(&:capitalize).join('-')
|
|
end
|
|
|
|
def incompatible_signature?(signature_params)
|
|
signature_params['keyId'].blank? ||
|
|
signature_params['signature'].blank? ||
|
|
signature_params['algorithm'].blank? ||
|
|
signature_params['algorithm'] != 'rsa-sha256' ||
|
|
!signature_params['keyId'].start_with?('acct:')
|
|
end
|
|
end
|