HCP OpenAPI's Headers Configuration

This page is writing about the correct steps to configure the required request headers before sending an API request at HCP OpenAPI.

HikCentral Professional (HCP) v2.4.1 is used.

Prerequisite

APPkey (header: X-Ca-Key)
APPsecret (used for the formation of signature string)
Signature String (header: X-Ca-Signature)

APPkey and APPsecret

Both APPkey and APPsecret can be found after creating a partner at Open Platform (https://IPaddress/artemis-web > Partner Management).

APPkey is included in the request header, while APPsecret is used for the calculation of signature string.

Signature String

Form a string with the request method, header’s Accept, header’s Content-Type and URI, separated by “\n“

Example 1: POST /artemis/api/example?qa=value1&qb=value2&qc ; Accept = */* ; Content-Type=application/json

String: “POST\n*/*\napplication/json\n/artemis/api/example?qa=value1&qb=value2&qc“

Example 2: POST /artemis/api/example ; Accept = application/json ; Content-Type=application/json

String: “POST\napplication/json\napplication/json\n/artemis/api/example“

URI must start with “/“, containing the endpoint and request parameters.

Convert the string with HmacSHA256 algorithm and APPsecret as the key, to generate message digest.
Encode the message digest in Base64, to generate the signature string.

Prepare the request header

Use the APPkey and Signature String to form the request header.

{
    'X-Ca-Key': <APPkey>,
    'X-Ca-Signature': <Signature String>
}

Sample Code

Calculating Signature String

def generate_signature(app_key, app_secret, method, path):
    message = "POST\n*/*\napplication/json\n/artemis/api/example" # Initial string

    key_bytes = bytes(app_secret, 'utf-8') # key
    message_bytes = bytes(message, 'utf-8') # msg
    signature = hmac.new(key_bytes, msg=message_bytes, digestmod=hashlib.sha256).digest() # message digest

    encoded_signature = base64.b64encode(signature).decode('utf-8') # signature string

    return encoded_signature

Creating the request header

headers = {
    'X-Ca-Key': app_key,                  # Get from Open Platform
    'X-Ca-Signature': encoded_signature   # Get from calculation
}
response = requests.request("POST", url, headers=headers, json=request_body)

Calculation of signature and making the request’s header