B4J Question HMAC SHA256

[LordZenzo]

hello forum
one of my applications needs to query APIs that require a signature in HMAC SHA256
I saw the SIGNATURE library but I don't know how to use it and I'm not sure it's the right way

 

[DonManfred]

I saw the SIGNATURE library

?? probably a library to draw a SIGNATURE on a Canvas and has nothing to do with HMAC SHA256

Which Library are you speaking of?

 

[LordZenzo]

?? probably a library to draw a SIGNATURE on a Canvas and has nothing to do with HMAC SHA256

Which Library are you speaking of?

HI
sorry, I was stuck trying
signature is part of the Encription library

 

[aeric]

You will need ByteConverter (or StringUtils) and Encryption libraries.

 

[LordZenzo]

You will need ByteConverter (or StringUtils) and Encryption libraries.

I had guessed it but as I said in the first post I have no idea how

 

[aeric]

I had guessed it but as I said in the first post I have no idea how

Check the Similar Threads below.

 

[LordZenzo]

I've been searching for hours but nothing has cleared up my mind, which is why I'm writing here

 

[aeric]

The last thread is a good example.

Sign the nonce with secret using HMAC-SHA256

Hi there, I am trying to access the blinktrade bitcoin platform API. I am trying to do the following curl request within B4J, but I am having a hard time. I keep getting invalid APIKey, but I think the problem is with the formating of the code. Here is instructions on the site...

www.b4x.com

 

[LordZenzo]

Thanks, I'll try to put it into practice now

 

[LordZenzo]

I tried to implement the solution but I'm not sure it works, let me explain
using PHP I have
$hmac = hash_hmac('sha256', $message, $secretKey);
which returns a value
using the suggested code I get another value, I don't think PHP is wrong

 

[aeric]

I think the value will be different every time it is executed. Does PHP return same value every time?

 

[LordZenzo]

the value depends on the text and the key I don't think it should always be different
php always returns the same value if it starts from the same data

 

[aeric]

I just tested. I got the same results as PHP.

<?php
echo hash_hmac('sha256', 'The quick brown fox jumped over the lazy dog.', 'secret');
?>

Example taken from https://www.php.net/manual/en/function.hash-hmac.php

Dim results As String = HMACSHA256("The quick brown fox jumped over the lazy dog.", "secret")
Log(results)

Public Sub HMACSHA256 (str As String, key As String) As String
    Dim data() As Byte
    Dim MC As Mac
    Dim KG As KeyGenerator
    Dim BC As ByteConverter
    
    KG.Initialize("HMACSHA256")
    KG.KeyFromBytes(key.GetBytes("UTF8"))
    
    MC.Initialise("HMACSHA256", KG.Key)
    MC.Update(str.GetBytes("UTF8"))
    
    data = MC.Sign
    Return BC.HexFromBytes(data).ToLowerCase
End Sub

Results: 9c5c42422b03f0ee32949920649445e417b2c634050833c5165704b825c2a53b

 

[LordZenzo]

Ho appena testato. Ho ottenuto gli stessi risultati di PHP.

[CODICE=php]<?php
echo hash_hmac('sha256', 'La veloce volpe marrone saltò sopra il cane pigro.', 'segreto');
?>[/CODICE]
Esempio tratto da https://www.php.net/manual/en/function.hash-hmac.php

Dim results As String = HMACSHA256("La veloce volpe marrone saltò sopra il cane pigro.", "segreto")
Registro(risultati)

Sub pubblico HMACSHA256 (str come stringa, chiave come stringa) come stringa
    Dim data() come byte
    Dim MC come Mac
    Dim KG come generatore di chiavi
    Dim BC come ByteConverter
  
    KG.Inizializza("HMACSHA256")
    KG.KeyFromBytes(chiave.GetBytes("UTF8"))
  
    MC.Inizializza("HMACSHA256", KG.Chiave)
    MC.Aggiornamento(str.GetBytes("UTF8"))
  
    dati = MC.Segno
    Restituisce BC.HexFromBytes(dati).ToLowerCase
Fine Sotto

Risultati: 9c5c42422b03f0ee32949920649445e417b2c634050833c5165704b825c2a53b

Thank you