Pull data from a REST API Authentication with a nonce field

[mahonni]

Hi, I'm trying to use this API, following posts like this one but I keep getting "invalid arguments" error. The idea is to get info like the "balance", so I need to use POST instead of GET.

I barely understand how APIs work, but looking at the documentation, it looks like I need to send a nonce which I understand it has to be an increasing number every time and that I can't repeat it. The problem is that this nonce field has to be send in the POST data, but I only know how to send data as a header.

How should I do that?

Thanks!!

[v-yuezhe-msft]

@mahonni,

Based on my research, the above error could occur when you enter wrong API-Key or API-Sign, please find correct API-Key and API-Sign following the guide in the similar threads below, then enter them in Power BI Desktop.


https://superuser.com/questions/1123526/curl-example-for-accessing-authenticated-kraken-api
https://stackoverflow.com/questions/43722037/kraken-eapi-invalid-key

Regards,
Lydia

[mahonni]

Thanks for your answer, @v-yuezhe-msft.

I was doing it in the same was as you put it, but without the "Accept" part in the header. However, it still didn't work.

The API-Key and API-Sign are correct, but here's my doubt: is PowerBI doing the rest of the process (using a nonce, doing hmac signature...), or do I have to manually create that? And, in case I have to do it myself, is it possible to HMAC-SHA512?

Thanks in advance,

Marc

[v-yuezhe-msft]

@mahonni,

You would need  to manually create the rest of the process.  Power BI doesn’t offer a function to calculate a HMAC-SHA512 hash, the entire HMAC-SHA512 algorithm has to be reproduced from scratch using M code. There is a similar blog about reproduce HMAC-SHA1 algorithm in M code for your reference.

https://chris.koester.io/index.php/2016/07/15/post-twitter-using-power-query/

Regards,
Lydia

[mahonni]

Sounds like it'll take too much effort to get that. PowerBI is quite behind when it comes to APIs, most of them are using this kind of algotyhms, so the implementation is almost impossible. I'll see if I can solve it with some Python + SQL and then get the source from this database.

Anyway, thanks @v-yuezhe-msft for the help!

[wodraeve]

Hi, did you manage to do this in the end?