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| # Prevent HTTP requests to be made into private network (in Ruby!) | |
| # Just an example, don't use it in production! | |
| require 'http' | |
| require 'resolv' | |
| class StaticResolveTCPSocket | |
| def initialize(lookup) | |
| @lookup = lookup.dup | |
| @lookup.default_proc = proc do |_h, host| | |
| raise "Unresolvable host #{host}!" | |
| end | |
| end | |
| def open(host, port) | |
| TCPSocket.open(@lookup[host], port) | |
| end | |
| end | |
| IPV4_PRIVATE_BLOCKS = %w[ | |
| 10.0.0.0/8 | |
| 172.16.0.0/12 | |
| 192.168.0.0/16 | |
| ].map(&IPAddr.method(:new)).freeze | |
| def validate_addr!(addr) | |
| addr = IPAddr.new(addr) if addr.is_a? String | |
| raise "#{addr} belongs to a private network!" if IPV4_PRIVATE_BLOCKS.any? { |b| b.include? addr } | |
| end | |
| def safe_post(uri, body) | |
| uri = URI.parse(uri) if uri.is_a? String | |
| host = uri.host | |
| addr = Resolv.getaddress(host) | |
| validate_addr!(addr) | |
| socket_class = StaticResolveTCPSocket.new(host => addr) | |
| HTTP.post(uri, socket_class: socket_class, body: body) | |
| end |
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