Package: zc.authorizedotnet
Authorize.Net provides credit card (henceforth “CC”) processing via a protocol
on top of HTTPS.  Authorize.Net’s customers are “merchants”.  The merchant is
the entity accepting a CC as payment.  This package provides a simple
interface to Authorize.Net’s “Advanced Integration Method” (AIM).Several terms used in this document:authorize: check validity of CC information and for sufficient balancecapture: the approval of transfer of funds from the CC holder to the
merchantsettlement: the actual transfer of funds from the CC holder
to the merchantcredit: issuing a refund from the merchant to the card holdervoiding: canceling a previous transactionSettlement is performed in daily batches.  The cut-off time for which is
specified in the merchant’s settings available on the Authorize.Net merchant
interface.There are many other settings which can be configured via the merchant
interface, but this module attempts to work independently of most of them.
Where specific settings are required they will be marked with the phrase
“required merchant interface setting”.Transaction KeysEach AIM transaction must be accompanied by a merchant login and a
“transaction key”.  This key is obtained from the merchant interface.  After
importing the CcProcessor class you must pass it your login and transaction
key:>>> from zc.authorizedotnet.processing import CcProcessor
>>> from zc.creditcard import (AMEX, DISCOVER, MASTERCARD,
...                            VISA, UNKNOWN_CARD_TYPE)
>>> cc = CcProcessor(server=SERVER_NAME, login=LOGIN, key=KEY)AuthorizingTo authorize a charge use theauthorizemethod.  It returns aTransactionobject.>>> result = cc.authorize(amount='2.00', card_num='4007000000027',
...                       exp_date='0530')The result object contains details about the transaction.>>> result.response
'approved'
>>> result.response_reason
'This transaction has been approved.'
>>> result.approval_code
'123456'
>>> auth_trans_id = result.trans_id
>>> result.trans_id
'123456789'When the card_num is sent in, the result also contains the type of credit card:>>> result.card_type == VISA
TrueIf no credit card number is provided, card_type is None:>>> result2 = cc.authorize(amount='2.00', exp_date='0530')
>>> result2.card_type == None
True>>> result2 = cc.authorize(amount='2.00', card_num='', exp_date='0530')
>>> result2.card_type == None
TrueCapturing Authorized TransactionsNow if we want to capture the transaction that was previously authorized, we
can do so.>>> result = cc.captureAuthorized(trans_id=result.trans_id)
>>> result.response
'approved'Credit (refund) transactionsA previosly credited transaction can be refunded.  The amount of the
refund cannot exceed the amount captured.  At least the last four
digits of the credit card number must be provided, along with the
transaction id.Credit will only work when the transaction has been settled by the
banks, that is if we try refunding immediately, it will fail:>>> result = cc.credit(trans_id=auth_trans_id,
...                    card_num='4007000000027',
...                    exp_date='0530',
...                    amount='1.00',
...                    )
>>> result.response_reason
'The referenced transaction does not meet the criteria for issuing a credit.'
>>> result.response
'error'Voiding TransactionsIf we need to stop a transaction that has not yet been completed (like the
crediting of the captured transaction above) we can do so with thevoidmethod.>>> result = cc.void(trans_id=auth_trans_id)
>>> result.response
'approved'Transaction ErrorsIf something about the transaction is erroneous, the transaction results
indicate so.>>> result = cc.authorize(amount='2.50', card_num='4007000000027',
...                       exp_date='0599')The result object reflecs the error.>>> result.response
'error'
>>> result.response_reason
'The credit card has expired.'The valid values for theresponseattribute are ‘approved’, ‘declined’,
and ‘error’.Address Verification System (AVS)AVS is used to assert that the billing information provided for a transaction
must match (to some degree or another) the cardholder’s actual billing data.
The gateway can be configured to disallow transactions that don’t meet certain
AVS criteria.>>> result = cc.authorize(amount='27.00', card_num='4222222222222',
...                       exp_date='0530', address='000 Bad Street',
...                       zip='90210')
>>> result.response
'declined'
>>> result.response_reason
'The transaction resulted in an AVS mismatch...'Duplicate WindowThe gateway provides a way to detect and reject duplicate transactions within
a certain time window.  Any transaction with the same CC information (card
number and expiration date) and amount duplicated within the window will be
rejected.The first transaction will work.>>> result = cc.authorize(amount='3.00', card_num='4007000000027',
...                       exp_date='0530', invoice_num='123')
>>> result.response
'approved'A duplicate transaction will fail with an appropriate message.>>> result2 = cc.authorize(amount='3.00', card_num='4007000000027',
...                       exp_date='0530', invoice_num='123')
>>> result2.response
'error'
>>> result2.response_reason
'A duplicate transaction has been submitted.'Similar transactions can be unaliased by including a unique invoice_num
field:>>> result3 = cc.authorize(amount='3.00', card_num='4007000000027',
...                        exp_date='0530', invoice_num='124')
>>> result3.response
'approved'The default window size is 120 seconds, but any other value (including 0) can
be provided by passingduplicate_windowto the transaction method.>>> cc.captureAuthorized(trans_id=result.trans_id).response
'approved'>>> cc.captureAuthorized(trans_id=result.trans_id).response_reason
'This transaction has already been captured.'>>> cc.captureAuthorized(trans_id=result.trans_id, duplicate_window=0
...                     ).response
'approved'But voiding doesn’t report errors if the same transaction is voided inside
the duplicate window.>>> cc.void(trans_id=result.trans_id).response
'approved'>>> cc.void(trans_id=result.trans_id).response
'approved'Line itemsAn itemized listing of the order can be included in the authorization
data as a sequcence of sequences.>>> result = cc.authorize(amount='2.98', card_num='4007000000027',
...                       exp_date='0530',
...                       line_items=[
...                       # id  name      description qty  unit price tax
...                       ('1', 'G-1000', 'Gadget',   '1', '1.99',    'Y'),
...                       ('2', 'A-150',  'Accessory','1', '0.99',    'Y'),
...                       ])
>>> result.response
'approved'the result will have a card_type attribute.>>> result.card_type == VISA
TrueThe MD5 Hash Security FeatureAuthorize.Net provides for validating transaction responses via an MD5 hash.
The required merchant interface setting to use this feature is under
“Settings and Profile” and then “MD5 Hash”.  Enter a “salt” value in the
fields provided and submit the form.  You may then provide thesaltparameter to the CcProcessor constructor to enable response validation.WARNING: The format of the “amount” field is very important for this feature
to work correctly.  The field must be formatted in the “canonical” way for the
currency in use.  For the US dollar that means no leading zeros and two (and
only two) decimal places.  If the amount is not formatted properly in the
request, the hashes will not match and the transaction will raise an exception.If you want to enable hash checking, provide asaltvalue to theCcProcessorconstructor.  If an incorrect salt value is used, or the
hash given in the transaction doesn’t match the true hash value an exception
is raised.>>> cc = CcProcessor(server=SERVER_NAME, login=LOGIN, key=KEY,
...                  salt='wrong')
>>> result = cc.authorize(amount='10.00', card_num='4007000000027',
...                       exp_date='0530')
Traceback (most recent call last):
    ...
ValueError: MD5 hash is not valid (trans_id = ...)Error CheckingIf you don’t pass a string for the amount when doing an authorization, an
exception will be raised.  This is to avoid charging the wrong amount due to
floating point representation issues.>>> cc.authorize(amount=5.00, number='4007000000027', expiration='0530')
Traceback (most recent call last):
    ...
ValueError: amount must be a string