Downloading Platform Certificate API
WeChat Pay will change the platform certificate from time to time due to certificate validity and for transaction security. WeChat Pay provides a range of APIs to help merchant backend system replace the certificate easily.
Tips：
Instructions：
• It is recommended that developers use the central control server (i.e., unified management and distribution. Pay attention to the confidentiality and security of the certificate) to uniformly download and manage the WeChat Pay platform certificate. Other service logic servers conduct the signature verification and decryption of messages via the central control server.
• Before WeChat Pay replaces the platform certificate, the certificate to be replaced will be added to the merchant's platform certificate list 24 hours in advance. The central control server needs to view the merchant's platform certificate list periodically and download the latest platform certificate in time.
• When WeChat Pay replaces the platform certificate, different certificate serial numbers may exist in response requests and callback notifications received by the merchant, and the merchant should process it properly.
• Rate limit rules for the API obtaining platform certificates: For a single Merchant ID, it is 1000/s.
• For sensitive information encryption, it is recommended to use the latest platform certificate (that is, a certificate with a longer valid period).
Best practice：
• Call the API on the central control server list.
• Call regularly, with an interval of less than 12 hours.
• Compare with the local certificate serial number list. A new certificate serial number indicates a certificate to be replaced.The old certificate needs to be cleaned up before being deprecated.
• After obtaining the certificate, distribute it to each service API server.
1. API intro
Applicable object:Common modeInstitutional mode
Request URL:https://apihk.mch.weixin.qq.com/v3/global/certificates
Request method: GET
Pathparameter is a path parameter.
Queryparameter needs to be passed in the request URL.
Bodyparameter needs to be passed in the request JSON.
2. Request Parameters
None
3. Response Parameters
Response for successful request:
| Name |
Variable Name |
Type |
Required |
Description |
| Certificate serial number |
serial_no |
string(40) |
Yes |
Serial numbers of certificates
Example: 5157F09EFDC096DE15EBE81A47057A7232F1B8E1 |
| Certificate enabling time |
effective_time |
string(32) |
Yes |
The time when the certificate took effect, in RFC3339 format. The enabling time for each platform certificate is fixed.
Example: 2018-06-08T10:34:56+08:00 |
| Certificate deprecation time |
expire_time |
string(32) |
Yes |
The time when the certificate expired, in RFC3339 format.
Before replacing the platform certificate, the deprecation time of the old certificate will be modified 24 hours in advance, and the API returns both the new and the old platform certificates. After the replacement is complete, the API returns the latest platform certificate.
Example: 2018-06-08T10:34:56+08:00 |
| Certificate information |
encrypt_certificate |
object |
Yes |
Certificate information. For more information, see the description below. |
| Name |
Variable Name |
Type |
Required |
Description |
| Algorithm of encrypted certificate |
algorithm |
string(32) |
Yes |
Certificate encryption algorithm, with the key of API KEY, which needs to be set on the merchant platform.
Example: AEAD_AES_256_GCM |
| Random string of the encrypted certificate |
nonce |
string(12) |
Yes |
Random string of encrypted certificate
Example: 61f9c719728a |
| Additional data of encrypted certificate |
associated_data |
string(32) |
Yes |
Fixed value： certificate
Example: certificate |
| Encrypted certificate content |
ciphertext |
string(344) |
Yes |
With the API KEY and the above parameters, you can decrypt the plaintext of the platform certificate.The certificate plaintext is in PEM format.（Note：
he certificate expiration time in PEM format may be inconsistent with the certificate deprecation time returned by the API when the certificate is replaced.)
Example: Y1IPF0kyRe+aJ7TK6cw08r1g/agxl16o |
|
he procedure of how to decrypt the certificate is described as follows.
1、Obtain the merchant's key from the merchant platform and record it as "key".
2、For the algorithm described in "algorithm" (which is AEAD_AES_256_GCM), obtain the corresponding parameters "nonce" and "associated_data".
3、Use "key", "nonce" and "associated_data" to decrypt "ciphertext" (decode ciphertext with base64 before decrypting) to get the certificate content.
Tips：
For the API information of the "AEAD_AES_256_GCM" algorithm, see
rfc5116。
Response for failed request:
| Name |
Variable Name |
Type |
Required |
Description |
| Returned status code |
code |
string[1,32] |
Yes |
Error code. See the error code list for the enumerated values. |
| Returned information |
message |
string[1,256] |
Yes |
Returned message. It indicates the reason for the error if not empty. |
| Detailed error description |
detail |
object |
No |
It is returned when code is PARAM_ERROR. Details will be described below. |
| Name |
Variable Name |
Type |
Required |
Description |
| The location of incorrect parameter |
field |
string[1,256] |
Yes |
If the incorrect parameter is in the JSON for request body, it is populated with the JSON Pointer pointing to this parameter. If the incorrect parameter is in the request URL or querystring, it is populated with the variable name of this parameter. |
| Value of the incorrect parameter |
value |
string[1,256] |
Yes |
Value of the incorrect parameter |
| Cause of error |
issue |
string[1,256] |
Yes |
Cause of error |
| Location of the incorrect parameter |
location |
string[1,256] |
No |
body: The incorrect parameter is in the JSON for request body
url: The incorrect parameter is in the request URL
query: The incorrect parameter is in the querystring of the request |
|
Response Example:
{
"data": [{
"serial_no": "5157F09EFDC096DE15EBE81A47057A7232F1B8E1",
"effective_time ": "2018-06-08T10:34:56+08:00",
"expire_time ": "2018-12-08T10:34:56+08:00",
"encrypt_certificate": {
"algorithm": "AEAD_AES_256_GCM",
"nonce": "61f9c719728a",
"associated_data": "certificate",
"ciphertext": "sRvt… "
}
},
{
"serial_no": "50062CE505775F070CAB06E697F1BBD1AD4F4D87",
"effective_time ": "2018-12-07T10:34:56+08:00",
"expire_time ": "2020-12-07T10:34:56+08:00",
"encrypt_certificate": {
"algorithm": "AEAD_AES_256_GCM",
"nonce": "35f9c719727b",
"associated_data": "certificate",
"ciphertext": "aBvt… "
}
}
]
}
{
"code": "INVALID_REQUEST",
"message": "Parameter format verification error",
"detail": {
"field": "#/properties/payer",
"value": "1346177081915535577",
"issue": "与ALLOF schema不符",
"location": "body"
}
}
4. Error Codes
| Error Message |
Description |
Solution |
| SYSTEM_ERROR |
System error |
System error. Please call the API again to initiate the query. |
