The example HMAC calculation does not work !!

[MiesSuomesta]

Following code does not provide same hash that exmaple should produce?

Code to test:

package main import( "crypto/hmac" "crypto/sha256" "encoding/hex" "sort" "fmt" )

var PaytrailOfficialRequestSignature = "3708f6497ae7cc55a2e6009fc90aa10c3ad0ef125260ee91b19168750f6d74f6"

func headersToBytesSorted(headers map[string]string) (sortedHeaders []byte) { var keys []string for key := range headers { fmt.Println("headersToBytesSorted/for :", key) if len(key) >= 9 { if key[:9] == "checkout-" { fmt.Println("headersToBytesSorted/added :", key) keys = append(keys, key) } } } sort.Strings(keys) for _, key := range keys { sortedHeaders = append(sortedHeaders, []byte(key+":"+headers[key]+"\n")...) } return sortedHeaders }

func CalculateHmac(secret, body []byte, headers map[string]string) string {

payload := headersToBytesSorted(headers)
payload = append(payload, body...)
hash := hmac.New(sha256.New, secret)
hash.Write(payload)
return hex.EncodeToString(hash.Sum(nil))

}

var PaytrailOfficialRequestHeaders = map[string]string{ "checkout-account": "375917", "checkout-algorithm": "sha256", "checkout-method": "POST", "checkout-nonce": "564635208570151", "checkout-timestamp": "2018-07-06T10:01:31.904Z", }

var PaytrailOfficialRequestBody = []byte({ "stamp": "unique-identifier-for-merchant", "reference": "3759170", "amount": 1525, "currency": "EUR", "language": "FI", "items": [ { "unitPrice": 1525, "units": 1, "vatPercentage": 24, "productCode": "#1234", "deliveryDate": "2018-09-01" } ], "customer": { "email": ["test.customer@example.com"](mailto:test.customer@example.com) }, "redirectUrls": { "success": ["https://ecom.example.com/cart/success"](https://ecom.example.com/cart/success), "cancel": ["https://ecom.example.com/cart/cancel"](https://ecom.example.com/cart/cancel) } })

func main() { signatureStrOut := CalculateHmac([]byte("SAIPPUAKAUPPIAS"), PaytrailOfficialRequestBody, PaytrailOfficialRequestHeaders) fmt.Println("Const :", PaytrailOfficialRequestSignature) fmt.Println("Got :", signatureStrOut) }

Output for me:

Const : 3708f6497ae7cc55a2e6009fc90aa10c3ad0ef125260ee91b19168750f6d74f6 Got : c7340510147ab5fe988fcf27f755b374f370aba2c612484f0fe3878936f961d6

[MiesSuomesta]

The function would be bit better as:

func CalculateHmac(secret, body []byte, headers map[string]string) string {

    bufBody := new(bytes.Buffer)
        json.Compact(bufBody, body)

    payload := headersToBytesSorted(headers)
    payload = append(payload, bufBody.Bytes() ...)
    hash := hmac.New(sha256.New, secret)
    hash.Write(payload)
    return hex.EncodeToString(hash.Sum(nil))
}

.. Just for future refrence :D

[loueranta-paytrail]

I assume the problem was solved.