auth_code.rb

require 'shiparound_api/rest'
require 'rest-client'
require 'openssl'
require 'base64'
require 'json'
require 'uri'

# auth_code, error = ::ShiparoundApi::AuthCode.get(
#   password: "password",
#   api_key:  "api_key",
#   sandbox:  false
# )

module ShiparoundApi
  class AuthCode
  
    ENCRYPTION_METHOD = 'AES-128-CTR';
    ENCRYPTION_KEY    = '92~GkkXV44b}*>z}rRf^'
  
    def self.get(
        password: "",
        api_key:  "",
        sandbox:  true
      )
      json     = create_json(password, api_key)
      uri      = ::ShiparoundApi::Rest.uri_call(sandbox,true)
      uri     << create_uri_parameters(json)
      response = RestClient.get uri
      return result_of response
    end
    
    private
    
    def self.result_of(response)
      error = ""; result = nil
      if response.code == 200
        hash = JSON.parse(response.body)
        if hash["success"] == true
          result = decrypt(hash["AUTH_CODE_encrypted"])
        else
          error = hash["error"].inspect
        end
      else
        error = "ERROR: #{response.body} (#{response.code})"
      end
      [result, error]
    end
    
    def self.create_json(password,api_key)
      %Q[{"password":#{password.to_json},"SHIPAPI_AUTH_ENCRYPTION_KEY":#{api_key.to_json}}]
    end
    
    def self.create_uri_parameters(json)
      "?info=#{encrypt(json)}&"+
      "encryption_method=#{ENCRYPTION_METHOD}&"+
      "encryption_options=1"
    end
    
    def self.encrypt(str)
      cipher = OpenSSL::Cipher.new(ENCRYPTION_METHOD)
      cipher.encrypt
      cipher.key = ENCRYPTION_KEY[0..15]
      data = cipher.update(str) + cipher.final
      CGI.escape( Base64.encode64(data).gsub("\n","") )
    end
    
    def self.decrypt(str)
      data = Base64.decode64(str)
      cipher = OpenSSL::Cipher.new(ENCRYPTION_METHOD)
      cipher.decrypt
      cipher.key = ENCRYPTION_KEY[0..15]
      cipher.update(data) + cipher.final
    end
    
  end # class AuthCode
end # module ShiparoundApi

getAuthCode.php

<?php
//
// /usr/bin/php getAuthCode.php 'password' 'api-key'
//
$baseURL = "https://shiparound.de/shipAPI/getAuthCode.bridge.php";
$ENCRYPTION_METHOD = 'AES-128-CTR';
$ENCRYPTION_KEY = '92~GkkXV44b}*>z}rRf^'; 
$ENCRYPTION_OPTIONS = OPENSSL_RAW_DATA;
$password = $argv[1];
$SHIPAPI_AUTH_ENCRYPTION_KEY = $argv[2];
$info = json_encode(array('password' => $password, 'SHIPAPI_AUTH_ENCRYPTION_KEY' => $SHIPAPI_AUTH_ENCRYPTION_KEY));
$info = base64_encode(@openssl_encrypt($info, $ENCRYPTION_METHOD, $ENCRYPTION_KEY, $ENCRYPTION_OPTIONS)); 
$url = $baseURL . '?info=' . urlencode($info);
$url .= '&encryption_method=' . $ENCRYPTION_METHOD;
$url .= '&encryption_options=' . $ENCRYPTION_OPTIONS;
$request = file_get_contents($url);
$arr = json_decode($request, true);
$encrypted_auth = base64_decode($arr["AUTH_CODE_encrypted"]);
$decrypted_auth = openssl_decrypt($encrypted_auth, $ENCRYPTION_METHOD, $ENCRYPTION_KEY, $ENCRYPTION_OPTIONS);
echo $decrypted_auth;
?>