Authentication

All API calls are authenticated with the combination of two separate keys: API Key and API Secret.

The API Key is the public key and can be put in clear client-side. The API Secret should never be shared publicly.

To authenticate all your HTTP calls, you need to set the following headers: X-Api-Key and X-Api-Digest. The CSML Studio API uses HMAC authentication to ensure that all calls are properly signed with both the API Key and API Secret, while preventing man-in-the-middle attacks and replay attacks.

In the X-Api-Key header, concatenate the API Key and the current unix timestamp (in seconds), separated by the | character. In the X-Api-Signature header, provide the hexadecimal sha-256 hash of the X-Api-Key header value, signed with your API Secret.

The CSML server will be able to validate that both the API Key and the API Secret used are valid, without requiring you to provide the API Secret in clear text. Replay attacks are prevented by invalidating all calls a few minutes after the timestamp provided in the X-Api-Key header.

Implementation examples

Nodejs

const crypto = require('crypto');
​
const UNIX_TIMESTAMP = Math.floor(Date.now() / 1000);
​
const XApiKey = `${API_KEY}|${UNIX_TIMESTAMP}`;
const signature = crypto.createHmac('sha256', secret)
  .update(XApiKey, 'utf-8')
  .digest('hex');
const XApiSignature = `sha256=${signature}`;

Python

import time
import hmac
import hashlib
​
timestamp = str(int(time.time()))
x_api_key = ${API_KEY} + "|" + timestamp
​
signature = hmac.new(
    str.encode(${API_SECRET}),
    x_api_key.encode('utf8'),
    digestmod=hashlib.sha256
  ).hexdigest()
x_api_signature = "sha256=" + signature