MAC string is not generated in correct order for Aktia

thank you for working on the tests! In general this looks pretty good already. Just some code style / documentation comments.

1. +++ b/tupas_registration.module
   @@ -335,29 +335,32 @@ function tupas_registration_return_rej($transaction_id = '') {
   +  foreach ($mac_order as $key) {
   

   It would be useful to document here why do we need to set these in specific order

2. +++ b/tupas_registration.module
   @@ -384,6 +387,27 @@ function tupas_registration_active_session($transaction_id) {
   + * Generate mac hash.
   

   This could be more describive, i.e. "Generates mac hash based on chosen encryption algorithm."

3. +++ b/tupas_registration.module
   @@ -384,6 +387,27 @@ function tupas_registration_active_session($transaction_id) {
   + * @param $encryption_alg
   + * @param $mac_string
   

   These are missing description as per Drupal documentation coding standards

4. +++ b/tupas_registration.module
   @@ -384,6 +387,27 @@ function tupas_registration_active_session($transaction_id) {
   + * @return string
   

   There shold be empty line before @return statement

5. +++ b/tupas_registration.module
   @@ -384,6 +387,27 @@ function tupas_registration_active_session($transaction_id) {
   +function tupas_registration_hash_mac($encryption_alg, $mac_string) {
   

   Could we rename this to "tupas_registration_generate_mac_hash"

6. +++ b/tupas_registration.module
   @@ -384,6 +387,27 @@ function tupas_registration_active_session($transaction_id) {
   +  if ($encryption_alg == 01) {
   ...
   +  elseif ($encryption_alg == 03) {
   ...
   +  else {
   

   It might be more obvious to transfer this to use switch instead of if

7. +++ b/tupas_registration.test
   @@ -68,4 +68,56 @@ class TupasRegistrationTests extends DrupalWebTestCase {
   +   * Make sure that mac calculation is same regardless of what order url arguments
   +   * were given.
   

   According to Drupal documentation standards this should be on single line

8. +++ b/tupas_registration.test
   @@ -68,4 +68,56 @@ class TupasRegistrationTests extends DrupalWebTestCase {
   +  protected function generateBankMac($bank, $transaction_id) {
   

   We should document the parameteres on the docblock

Thanks for the fix & writing the tests!