Need some help on how to implement an restfull api app based on golang

My coding skills are a bit low
Recently i started learning golang and how to handle an Api communication app. Have been having a great time learning it by myself, golang is revealing itself as a challenging language with great rewards in the end (code sense ^^).

Have been trying to create a cryptsy api lib for golang based on their API V2 (BETA) which is a restfull api. They have a python lib on their api website https://github.com/ScriptProdigy/CryptsyPythonV2/blob/master/Cryptsy.py.

So far have been able to get the public access working but am having a really hard time at the private access because of the authentication part.. I find that the info they give on their website on how to implement it is a bit confusing

> Authorization is performed by sending the following variables into the request header Key
>
> - Public API key.
> - All query data (nonce=blahblah&limit=blahblah) signed by a secret key according to HMAC-SHA512 method. Your secret key and public keys can be generated from your account settings page. Every request requires a unique nonce. (Suggested to use unix timestamp with microseconds)

For this authentication part the python code goes as:

def _query(self, method, id=None, action=None, query=[], get_method="GET"):
    query.append(('nonce', time.time()))
    queryStr = urllib.urlencode(query)
    
    link = 'https://' + self.domain + route
    
    sign = hmac.new(self.PrivateKey.encode('utf-8'), queryStr, hashlib.sha512).hexdigest()
            
    headers = {'Sign': sign, 'Key': self.PublicKey.encode('utf-8')}

Got this far in golang:

package main

import(

    "crypto/hmac"
    "crypto/sha512"
    "encoding/hex"
    "encoding/json"
    "errors"
    "fmt"
    "io/ioutil"
    "net/http"
    "strings"
    "time"

)

const (

    API_BASE_CRY    = "https://api.cryptsy.com/api/"
    API_VERSION_CRY = "v2"
    API_KEY_CRY     = "xxxxx"
    API_SECRET_CRY  = "xxxxxxxxxxxx"
    DEFAULT_HTTPCLIENT_TIMEOUT = 30 // HTTP client timeout
)

type clientCry struct {
    apiKey     string
    apiSecret  string
    httpClient *http.Client
}

type Cryptsy struct {
    clientCry *clientCry
}

type CryptsyApiRsp struct {
    Success bool            `json:"success"`
    Data    json.RawMessage `json:"data"`
}

func NewCry(apiKey, apiSecret string) *Cryptsy {
    clientCry := NewClientCry(apiKey, apiSecret)
    return &Cryptsy{clientCry}
}

func NewClientCry(apiKey, apiSecret string) (c *clientCry) {
    return &clientCry{apiKey, apiSecret, &http.Client{}}
}

func ComputeHmac512Hex(secret, payload string) string {
    h := hmac.New(sha512.New, []byte(secret))
    h.Write([]byte(payload))
    return hex.EncodeToString(h.Sum(nil))
}

func (c *clientCry) doTimeoutRequestCry(timer *time.Timer, req *http.Request) (*http.Response, error) {

    type data struct {
	   resp *http.Response
	   err  error
    }

    done := make(chan data, 1)
    go func() {
	   resp, err := c.httpClient.Do(req)
	   done <- data{resp, err}
    }()

    select {
       case r := <-done:
	   return r.resp, r.err
       case <-timer.C:
	      return nil, errors.New("timeout on reading data from Bittrex API")
    }
}

func (c *clientCry) doCry(method string, ressource string, payload string, authNeeded bool) (response []byte, err error) {
    connectTimer := time.NewTimer(DEFAULT_HTTPCLIENT_TIMEOUT * time.Second)

    var rawurl string        

    nonce := time.Now().UnixNano()
    result :=  fmt.Sprintf("nonce=%d", nonce)
    rawurl = fmt.Sprintf("%s%s/%s?%s", API_BASE_CRY ,API_VERSION_CRY , ressource, result )
    req, err := http.NewRequest(method, rawurl, strings.NewReader(payload))

    sig := ComputeHmac512Hex(API_SECRET_CRY, result)
    
    req.Header.Add("Sign", sig)
    req.Header.Add("Key", API_KEY_CRY )
    
    resp, err := c.doTimeoutRequestCry(connectTimer, req)
    defer resp.Body.Close()
    
    response, err = ioutil.ReadAll(resp.Body)
    fmt.Println(fmt.Sprintf("reponse %s", response), err)
    return response, err
}

func main() {

    crypsy := NewCry(API_KEY_CRY, API_SECRET_CRY)
    r, _ := crypsy.clientCry.doCry("GET", "info", "", true) 
    fmt.Println(r)
}

and my output is :

response {"success":false,"error":["Must be authenticated"]} <nil>

not getting why im passing the public key and the signature in the header, the signature.. i think im doing it right in the hmac-sha512.
I'm quering the user info url https://www.cryptsy.com/pages/apiv2/user, which as stated in the api site doesn't have any extra query variables so the nonce is the only one needed..

Have googled about restfull api's but haven't been able to find any answer starting to not let me sleep at night since i think that what im doing is kinda right.. really cant spot the error..

Anyone out there that could try and help me with this?

Thxs a lot

I see the issue with result := fmt.Sprintf("%d", nonce). The code that corresponds to the Python code should be something like

result :=  fmt.Sprintf("nonce=%d", nonce)

Could you please check it with this fix?

I also can observe a major difference in how the request is sending. The Python version is (link):

        ret = requests.get(link,
                           params=query,
                           headers=headers,
                           verify=False)

but your code is does not send params with added nonce, etc. I think it should be something like

rawurl = fmt.Sprintf("%s%s/%s?%s", API_BASE_CRY ,API_VERSION_CRY , ressource, queryStr)

where queryStr should contain nonce, etc.