Bitstamp API Authentication

Ruby
#1

Greetings. Im a ruby fan and i am also buying/selling bitcoins on the bitstamp exchange. I have used the bitstamp api successfully in the past with python and i also want to try ruby for that task. I have not been successfull with that though.

Here is a python code that works

import hashlib
import hmac
import time
import requests
import uuid
import sys

api_key = 'some api key'
API_SECRET = b'some secret api key'

timestamp = str(int(round(time.time() * 1000)))
nonce = str(uuid.uuid4())
content_type = 'application/x-www-form-urlencoded'
payload = {'offset': '1'}

if sys.version_info.major >= 3:
    from urllib.parse import urlencode
else:
    from urllib import urlencode

payload_string = urlencode(payload)

# '' (empty string) in message represents any query parameters or an empty string in case there are none
message = 'BITSTAMP ' + api_key + \
    'POST' + \
    'www.bitstamp.net' + \
    '/api/v2/user_transactions/' + \
    '' + \
    content_type + \
    nonce + \
    timestamp + \
    'v2' + \
    payload_string
message = message.encode('utf-8')
signature = hmac.new(API_SECRET, msg=message, digestmod=hashlib.sha256).hexdigest()
headers = {
    'X-Auth': 'BITSTAMP ' + api_key,
    'X-Auth-Signature': signature,
    'X-Auth-Nonce': nonce,
    'X-Auth-Timestamp': timestamp,
    'X-Auth-Version': 'v2',
    'Content-Type': content_type
}
r = requests.post(
    'https://www.bitstamp.net/api/v2/user_transactions/',
    headers=headers,
    data=payload_string
    )
if not r.status_code == 200:
    raise Exception('Status code not 200')

string_to_sign = (nonce + timestamp + r.headers.get('Content-Type')).encode('utf-8') + r.content
signature_check = hmac.new(API_SECRET, msg=string_to_sign, digestmod=hashlib.sha256).hexdigest()

if not r.headers.get('X-Server-Auth-Signature') == signature_check:
    raise Exception('Signatures do not match')

print(r.content)

And here is my ruby code

require "awesome_print"
require "json"
require "securerandom"
require "openssl"
require "uri"
require "net/http"

api_key = 'Some api key'
API_SECRET = 'Some api_secret key'

nonce = SecureRandom.uuid
timestamp = Time.new.strftime('%s%L')
content_type = 'application-x-www-form-urlencoded'

params= {'offset' => '1'}
params_string = URI.encode_www_form(params)

message = 'BITSTAMP' + '' + api_key + 'POST' + 'www.bitstamp.net' + 'api/v2/balance' + '' +
           content_type + nonce + timestamp + 'v2' + params_string
message.encode("UTF-8")

signature = OpenSSL::HMAC.hexdigest("SHA256", API_SECRET, message)

headers = { 'X-Auth' => 'BITSTAMP ' + api_key,
            'X-Auth-Signature' => signature,
            'X-Auth-Nonce' => nonce,
            'X-Auth-Timestamp' => timestamp,
            'X-Auth-Version' => 'V2',
            'Content-Type' => content_type
          } 



uri = URI("https://www.bitstamp.net/api/v2/balance/")

res = Net::HTTP.post_form(uri, {"headers" => headers})

puts res.body

The api gives me back an error. The error is
{“status”: “error”, “reason”: “Missing key, signature and nonce parameters”, “code”: “API0000”}

Im a novice programmer so i don’t have deep skills in this. If anyone has an idea to get this ruby code to work that would
be highly appreciated. Thanx for reading.

Regards.
Primtala