Gemini API: "InvalidSignature" in App Scripts

Question

I am attempting to call Gemini API using App Scripts but I am consistently getting the 'InvalidSignature' error message. The code that I am using is a conversion of the python code from their documentation for Private API Invocation.

Code:

function createHeaders(payload) {
  var geminiApiKey = API_KEY
  var geminiApiSecret = SECRET_KEY
  var encodedApiSecret = Utilities.newBlob(geminiApiSecret, 'UTF-8').getBytes()

  var payloadNonce = new Date().getTime() / 1000;
  payload["nonce"] = Math.round(payloadNonce);

  var encodedPayload = Utilities.newBlob(JSON.stringify(payload), 'UTF-8').getBytes()
  var b64 = Utilities.base64Encode(encodedPayload) //string

  var signature = Utilities.computeHmacSignature(
    Utilities.MacAlgorithm.HMAC_SHA_384,
    b64,
    geminiApiSecretAuditor 
  ) //bytes

  return {
    "Content-Type": "text/plain",
    "X-GEMINI-APIKEY": geminiApiKeyAuditor,
    "X-GEMINI-PAYLOAD": b64,
    "X-GEMINI-SIGNATURE": Utilities.base64Encode(signature), //string
    "Cache-Control": "no-cache"
  };
}

function fetchGeminiData() {
  var baseUrl = "https://api.gemini.com";
  var url = baseUrl + "/v1/mytrades";

  var payload = {
    "request": "/v1/mytrades"
  };

  var headers = createHeaders(payload);
  var options = {
    "method": "post",
    "headers": headers,
  };

  var response = UrlFetchApp.fetch(url, options);
  var responseData = response.getContentText();
  var jsonResponse = JSON.parse(responseData);
  Logger.log(jsonResponse);
}

The error messages:

Exception: Request failed for https://api.gemini.com returned code 400. Truncated server response: {"result":"error","reason":"InvalidSignature","message":"InvalidSignature"}

I have ensured that the object types are as per what is expected from each methods, but I still get the above error messages. What am I missing?

score 0 · Accepted Answer · answered Aug 20 '23 at 07:29

I believe your goal is as follows.

You want to convert the following Python script to Google Apps Script. Ref

import requests
import json
import base64
import hmac
import hashlib
import datetime, time

url = "https://api.gemini.com/v1/mytrades"
gemini_api_key = "mykey"
gemini_api_secret = "1234abcd".encode()

t = datetime.datetime.now()
payload_nonce = time.time()
payload =  {"request": "/v1/mytrades", "nonce": payload_nonce}
encoded_payload = json.dumps(payload).encode()
b64 = base64.b64encode(encoded_payload)
signature = hmac.new(gemini_api_secret, b64, hashlib.sha384).hexdigest()

request_headers = {
    'Content-Type': "text/plain",
    'Content-Length': "0",
    'X-GEMINI-APIKEY': gemini_api_key,
    'X-GEMINI-PAYLOAD': b64,
    'X-GEMINI-SIGNATURE': signature,
    'Cache-Control': "no-cache"
    }

response = requests.post(url, headers=request_headers)

my_trades = response.json()
print(my_trades)

In this case, how about the following sample script?

Sample script:

function myFunction() {
  API_KEY = "mykey"; // Please set your api key.
  SECRET_KEY = "1234abcd"; // Please set your secret.

  var gemini_api_key = API_KEY;
  var gemini_api_secret = SECRET_KEY;

  var baseUrl = "https://api.gemini.com";
  var url = baseUrl + "/v1/mytrades";
  var nonce = (new Date().getTime() / 1000).toString();
  var payload = `{"request": "/v1/mytrades", "nonce": "${nonce}"}`;
  var b64 = Utilities.base64Encode(payload);
  var signature = Utilities.computeHmacSignature(Utilities.MacAlgorithm.HMAC_SHA_384, b64, gemini_api_secret).map(b => ('0' + (b & 0xFF).toString(16)).slice(-2)).join('');
  var request_headers = {
    'Content-Type': "text/plain",
    'X-GEMINI-APIKEY': gemini_api_key,
    'X-GEMINI-PAYLOAD': b64,
    'X-GEMINI-SIGNATURE': signature,
    'Cache-Control': "no-cache"
  };
  var options = { method: "post", headers: request_headers };
  var response = UrlFetchApp.fetch(url, options);
  var responseData = response.getContentText();
  var jsonResponse = JSON.parse(responseData);
  console.log(jsonResponse);
}

Note:

I think that the request of this sample script is the same as the above Python script. But, unfortunately, I cannot test this script. So, if an error occurs, please confirm your API key, your secret, and the URL again.

Reference:

fetch(url, params)

thanks for the code, your code works. But would you be able to explain `Utilities.computeHmacSignature().map(b => ('0' + (b & 0xFF).toString(16)).slice(-2)).join('');`? Why do we need to map? — Koh, Aug 20 '23 at 07:46
@Koh Thank you for replying. I'm glad your issue was resolved. About `Utilities.computeHmacSignature().map(b => ('0' + (b & 0xFF).toString(16)).slice(-2)).join('');`, `Utilities.computeHmacSignature()` returns the byte array. In your API, I thought that it is required to use the hex string value. So, in order to convert the byte array to the hex string value, I used `map(b => ('0' + (b & 0xFF).toString(16)).slice(-2)).join('')`. If this explanation was not useful, I apologize. — Tanaike, Aug 20 '23 at 07:50

Gemini API: "InvalidSignature" in App Scripts

1 Answers1

Sample script:

Note:

Reference: