curl_g2o

#!/usr/bin/env ruby

require 'net/http'
require 'digest'
require 'base64'
require 'openssl'

class ArgumentsError < Exception
    def initialize(msg)
	super(msg)
    end

    def explain
	$stderr.puts message
	$stderr.puts "usage: curl_g2o [curl options] --g2o-token token --g2o-password password url"
	$stderr.puts "url must be a fully qualified url, starting with HTTP or HTTPS"
    end
end

def parse_token_from_arguments(argv)
    args = {:args => argv}

    parse_argument(args, 'token', '--g2o-token')
    parse_argument(args, 'password', '--g2o-password')

    args[:url] = parse_url_from_arguments(args[:args])

    args
end

def parse_argument(args, arg_description, arg)
    index = args[:args].index(arg)
    if index
	value = args[:args][index + 1]

	args[:args].delete_at(index)
	args[:args].delete_at(index)

	args[arg_description.intern] = value
    else
	raise ArgumentsError.new("no #{arg_description} found")
    end
end

def parse_url_from_arguments(args)
    uri_string = args[-1]
    begin
	uri = URI.parse(uri_string)
	raise URI::InvalidURIError unless uri.host
	raise URI::InvalidURIError unless uri.path
	uri
    rescue URI::InvalidURIError
	raise ArgumentsError.new("invalid url: `#{uri_string}'")
    end
end

def g2o_data_header(token)
  "3, 69.31.17.132, 80.169.32.154, #{Time.now.to_i}, 13459971.1599924223, #{token}"
end

def get(uri)
  Net::HTTP.start(uri.host, uri.port) do |http|
    headers = {}

    data = g2o_data_header
    headers["X-Akamai-G2O-Auth-Data"] = data
    headers["X-Akamai-G2O-Auth-Sign"] = sign_data(uri, data)

    http.get(uri.path, headers)
  end
end

def sign_data(uri, data, options = {})
  key = (options[:key] or 'some password')
  digest = OpenSSL::HMAC.digest('md5', key, data + uri.path)
  Base64.encode64(digest).chomp
end

def exec_curl(data, sign, other_arguments)
    p sign
    cmd = %{curl -H "X-Akamai-G2O-Auth-Data: #{data}" -H "X-Akamai-G2O-Auth-Sign: #{sign}" #{other_arguments}}
    puts cmd
    exec cmd
end

begin
    args = parse_token_from_arguments(ARGV)
    data = g2o_data_header(args[:token])
    sign = sign_data(args[:url], data)
    exec_curl(data, sign, args[:args].join(' '))
rescue ArgumentsError => e
    e.explain
end