WeChat Pay (via PPRO)

1. About WeChat Pay(via PPRO)

1.1 General information about WeChat Pay

InfoTyp
WeChat is a free, cross-platform and instant messaging application developed by Tencent. It was first released in January 2011 and was one of the largest standalone messaging apps by monthly active users. As of May 2016, WeChat has over a billion created accounts, 700 million active users; with more than 70 million outside of China (as of December 2015). In 2016, WeChat reached 864 million active users.Payments by Wallet

WeChat Pay is a payment solution completely integrated inside the social and messaging application WeChat. WeChat payment functionality appears in the “Wallet” section of the application.

WeChat supports Payment and Money Transfer

Users can perform a variety of transactions using WeChat Pay, including and not limited to:

  • Transferring money to friends (especially as “red envelopes” shared during Chinese festivals)
  • Performing transactions on e-commerce websites
  • Topping up their mobile

1.2 Process flow chart

2 1cs Online Payment System-interface

2.1 Definitions

Data formats:

FormatDescription
aalphabetical
asalphabetical with special characters
nnumeric
analphanumeric
ansalphanumeric with special characters
nsnumeric with special characters
boolboolean expression (true or false)
3fixed length with 3 digits/characters
..3variable length with maximum 3 digits/characters
enumenumeration of allowed values
dttmISODateTime (YYYY-MM-DDThh:mm:ss)

Abbreviations:

AbbreviationDescriptionComment
CNDcondition
MmandatoryIf a parameter is mandatory, then it must be present
OoptionalIf a parameter is optional, then it can be present, but it is not required
CconditionalIf a parameter is conditional, then there is a conditional rule which specifies whether it is mandatory or optional

Notice: Please note that the names of parameters can be returned in upper or lower case.

2.2 Payment with Blik via 1cs OPS form interface

To make a payment with WeChat Pay, please use the following URL:

https://www.computop-paygate.com/wechat.aspx

Notice: For security reasons, the 1cs Online Payment System rejects all payment requests with formatting errors. Therefore, please use the correct data type for each parameter.

The following table describes the encrypted payment request parameters:

KeyFormatCNDDescription
MerchantIDans..30MMerchantID, assigned by First Cash Solution. Additionally this parameter has to be passed in plain language too.
TransIDans..64M
TransactionID provided by you which should be unique for each payment
RefNrans..40OMerchant’s unique reference number. Only characters a-zA-Z0-9,-_ are allowed.
Amountn..10MAmount in the smallest currency unit (e.g. EUR Cent). Please contact the 1cs Support, if you want to capture amounts <100 (smallest currency unit).
Currencya3M
Currency, three digits DIN / ISO 4217, e.g. EUR, USD, GBP. Only PLN and EUR is permissible. Please find an overview here: Currency table
MACan64MHash Message Authentication Code (HMAC) with SHA-256 algorithm. Details can be found here:
HMAC Authentication (Request)
HMAC Authentication (Notify)
OrderDescans..768MDescription of goods and prices. Intended purpose on the statement of account.
URLSuccessans..256MComplete URL which calls up 1cs Online Payment System if payment has been successful. The URL may be called up only via port 443. This URL may not contain parameters: In order to exchange values between 1cs Online Payment Systemand shop, please use the parameter UserData.
Common notes: We recommend to use parameter “response=encrypt” to get an encrypted response by 1cs OPS.
However, fraudster may just copy the encrypted DATA-element which are sent to URLFailure and send the DATA to URLSuccess. Therefore ensure to check the “code”-value which indicates success/failure of the action. Only a result of “code=00000000” should be considered successful.
URLFailureans..256M
Complete URL which calls up 1cs Online Payment System if payment has been unsuccessful. The URL may not be called up only via port 443. In order to exchange values between 1cs OPS and shop, please use the parameter User Data.
Common notes: We recommend to use parameter “response=encrypt” to get an encrypted response by 1cs OPS.
However, fraudster may just copy the encrypted DATA-element which are sent to URLFailure and send the DATA to URLSuccess/URLNotify. Therefore ensure to check the “code”-value which indicates success/failure of the action. Only a result of “code=00000000” should be considered successful.
Responsea7OStatus response sent by 1cs OPS to URLSuccess and URLFailure, should be encrypted. For this purpose, transmit Response=encrypt parameter.
URLNotifyans..256MComplete URL which 1cs OPS calls up in order to notify the shop about the payment result. The URL may be called up only via port 443. It may not contain parameters: Use the UserData parameter instead.
Common notes: We recommend to use parameter “response=encrypt” to get an encrypted response by 1cs OPS.
However, fraudster may just copy the encrypted DATA-element which are sent to URLFailure and send the DATA to URLSuccess/URLNotify. Therefore ensure to check the “code”-value which indicates success/failure of the action. Only a result of “code=00000000” should be considered successful.
UserDataans..1024OIf specified at request, 1cs OPS forwards the parameter with the payment result to the shop.
ReqIdans..32OTo avoid double payments or actions (e.g. by ETM), enter an alphanumeric value which identifies your transaction and may be assigned only once. If the transaction or action is submitted again with the same ReqID, 1cs Online Payment System will not carry out the payment or new action, but will just return the status of the original transaction or action.
Please note that the 1cs OPS must have a finalized transaction status for the first initial action (authentication/authorisation). This does not apply to 3-D Secure authentications that are terminated by a timeout. The 3-D Secure Timeout status does not count as a completed status in which the ReqID functionality on 1cs OPS does not take effect. Submissions with identical ReqID for an open status will be processed regularly.
Notice: Please note that a ReqID is only valid for 12 month, then it gets deleted at the 1cs OPS.
SellingPointans..50OSelling point
Serviceans..50Oproducts or service sold
Channelans..64OConfiguration channel of the PPRO contract (account and ContractID are stored in the system). If it exists, it may overwrite channels stored in the system.
Languagea2O2-letter language code (e.g. de) that should be preferred when presenting payment pages to the consumer
AccOwnerans3..50MName of account holder
AddrCountryCodea2MCountry code for the account holder’s invoicing address, 2 characters according to ISO 3166. Only PL allowed, defined within the code.
Plainans..50OA single value to be set by the merchant to return some information unencrypted in response/notify, e.g. the MID. 
“Plain”-parameter is part of encrypted “Data” in 1cs OPS and therefore protected against manipulation. 
Customans..1024O“Custom”-parameter is added to the request data before encryption and is part of encrypted “Data” in 1cs OPS request. By this they are protected against manipulation by a consumer. 
The Custom-value is added to the 1cs OPS response in plain text and the “|” is replaced by a “&”. By this you can put a single value into Custom-parameter and get multiple key-value-pairs back in response for your own purpose. 
Please find a samples here: Custom
Parameters for payments with WeChat Pay

The following table gives the result parameters which 1cs Online Payment System transmits to URLSuccess or URLFailure and URLNotify. If you have specified the Response=encrypt parameter, the following parameters are sent Blowfish encrypted to your system:

(info) pls. be prepared to receive additional parameters at any time and do not check the order of parameters

(info) the key (e.g. MerchantId, RefNr) should not be checked case-sentive

ParameterFormatCNDDescription
midans..30MMerchantID, assigned by the First Cash Solution
PayIDan32M
ID assigned by 1cs OPS for the payment, e.g. for referencing in batch files as well as for capture or credit request.
XIDan32MID for all single transactions (authorisation, capture, credit note) for one payment assigned by the 1cs OPS
TransIDans..64MTransactionID provided by you which should be unique for each payment
refnrans..40O
Merchant’s unique reference number. Only characters a-zA-Z0-9,-_ are allowed.
Statusa…50M
OK or AUTHORIZE_REQUEST (URLSuccess) as well as FAILED (URLFailure)
Descriptionans..1024MFurther details in the event that payment is rejected. Please do not use the Description but the Code parameter for the transaction status analysis!
Coden8MError code according to 1cs OPS Response Codes (Error codes)
MACan64MHash Message Authentication Code (HMAC) with SHA-256 algorithm. Details can be found here:
HMAC Authentication (Request)
HMAC Authentication (Notify)
UserDataans..1024OIf specified at request, 1cs OPS forwards the parameter with the payment result to the shop.
PaymentPurposeans..26OPurpose of payment
PaymentGuaranteea..12OValue+ Description:
NONE – no payment guarantee
VALIDATED – customer account valid, but no payment guarantee
FULL – payment guarantee

Notice: This parameter is only returned if the Status=OK.
ErrorTextans..128CDetailed PPRO error message.
Notice: Is returned only if Status=FAILED. Use is possible only in agreement with the First Cash Solution
TransactionIDan..20OUnique transaction number with PPRO
Plainans..50OA single value to be set by the merchant to return some information unencrypted in response/notify, e.g. the MID. 
“Plain”-parameter is part of encrypted “Data” in the 1cs OPS and therefore protected against manipulation. 
Customans..1024O“Custom”-parameter is added to the request data before encryption and is part of encrypted “Data” in 1cs OPS request. By this they are protected against manipulation by a consumer. 
The Custom-value is added to 1cs OPS response in plain text and the “|” is replaced by a “&”. By this you can put a single value into Custom-parameter and get multiple key-value-pairs back in response for your own purpose. 
Please find a samples here: Custom
Return parameters for URLSuccess, URLFailure and URLNotify with WeChat Pay

2.3 Credit with reference

Credits (refunds) are possible via a Server-to-Server connection. For a Credit with reference to a capture the amount of the Credit is limited to the amount of the previous capture. To carry out a credit with a reference transaction, please use the following URL:

https://www.computop-paygate.com/credit.aspx

Notice: For security reasons, 1cs OPS rejects all payment requests with formatting errors. Therefore, please use the correct data type for each parameter.

The following table describes the encrypted payment request parameters:

ParameterFormatCNDDescription
MerchantIDans..30MMerchantID, assigned by the First Cash Solution. Additionally this parameter has to be passed in plain language too.
PayIDan32M
ID assigned by 1cs OPS for the payment to be credited
TransIDans..64MTransactionID provided by you which should be unique for each payment
refnrans..40OMerchant’s unique reference number. Only characters a-zA-Z0-9,-_ are allowed.
Amountn..10MAmount in the smallest currency unit (e.g. EUR Cent). Please contact the First Cash Solution, if you want to capture amounts <100 (smallest currency unit).
Currencya3MCurrency, three digits DIN / ISO 4217, e.g. EUR, USD, GBP. Please find an overview here: Currency table
MACan64MHash Message Authentication Code (HMAC) with SHA-256 algorithm. Details can be found here:
HMAC Authentication (Request)
HMAC Authentication (Notify)
ReqIdans..32OTo avoid double payments or actions (e.g. by ETM), enter an alphanumeric value which identifies your transaction and may be assigned only once. If the transaction or action is submitted again with the same ReqID, 1cs Online Payment System will not carry out the payment or new action, but will just return the status of the original transaction or action.
Please note that the 1cs OPS must have a finalized transaction status for the first initial action (authentication/authorisation). This does not apply to 3-D Secure authentications that are terminated by a timeout. The 3-D Secure Timeout status does not count as a completed status in which the ReqID functionality on 1cs OPS does not take effect. Submissions with identical ReqID for an open status will be processed regularly.
Notice: Please note that a ReqID is only valid for 12 month, then it gets deleted at the 1cs OPS.
Parameters for credit payments with WeChat Pay via socket connection

The following table describes the result parameters with which the 1cs OPS responds to your system

(info) pls. be prepared to receive additional parameters at any time and do not check the order of parameters

(info) the key (e.g. MerchantId, RefNr) should not be checked case-sentive

ParameterFormatCNDDescription
midans..30MMerchantID, assigned by the First Cash Solution
PayIDan32M
ID assigned by 1cs OPS for the payment, e.g. for referencing in batch files as well as for capture or credit request.
XIDan32MID for all single transactions (authorisation, capture, credit note) for one payment assigned by the 1cs OPS
TransIDans..64MTransactionID provided by you which should be unique for each payment
Statusa…50MOK or /URLSuccess) or FAILED (URLFailure)
Descriptionans..1024MFurther details in the event that payment is rejected. Please do not use the Description but the Code parameter for the transaction status analysis!
Coden8MError code according to 1cs OPS Response Codes (Error codes)
refnrans..40OMerchant’s unique reference number. Only characters a-zA-Z0-9,-_ are allowed.
ErrorTextans..128CDetailed PPRO error message.
Notice: Is returned only if Status=FAILED. Use is possible only in agreement with the First Cash Solution
Response parameters for credit payments with WeChat Pay via socket connection