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How to auth with node-red against UM3 REST API

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Posted · How to auth with node-red against UM3 REST API

Hey everybody,


I am desperate. Here in short what I want to do:

Using node-red as platform for crosslinking different IOT devices with different services. Like a MQTT Broker, Telegram and other.

What I'm using right now is: RedBot for asking my UM3+ what is going on with the current print job, how the print looks like (grabbing an image from the integrated camera and sending it to the chat via the Telegram bot). 

What I want to do now is, if I see the printjob is failing right now after image checking, to stop the print via the bot. For this action, node-red needs to be authenticated in the REST API. I have an id and key generated which is valid and ready for use. 

So how do I do this, any ideas or suggestions? Would be very helpfull. 


Thanks ;)


curl -X GET --header 'Accept: application/json' 'http://um3ip/api/v1/auth/check/fad462df155f52ceb0e6ce8ed64845ed'

Request URL

Response Body
  "message": "authorized"


[{"id":"1300e776.abe2f1","type":"change","z":"5674bd4d.d67064","name":"Set Headers","rules":[{"t":"set","p":"headers","pt":"msg","to":"{}","tot":"json"},{"t":"set","p":"headers.content-type","pt":"msg","to":"application/json","tot":"str"},{"t":"set","p":"headers.Authorization","pt":"msg","to":"Digest username=\"fad462df155f52ceb0e6ce8ed64845ed\", password=\"2789fb63914e0fac010b2489e4358becdd22886997151e093894e518a198a264\", uri=\"/api/v1/auth/verify\", realm=\"Jedi-API\", qop=auth","tot":"str"}],"action":"","property":"","from":"","to":"","reg":false,"x":360,"y":1297,"wires":[["d710857b.bc85f","bf1c1cce.74dc98"]]},{"id":"d710857b.bc85f","type":"http request","z":"5674bd4d.d67064","name":"","method":"GET","ret":"obj","url":"http://um3ip/api/v1/auth/verify","tls":"","x":568,"y":1296,"wires":[["caad6ed4.e755a"]]},{"id":"bf1c1cce.74dc98","type":"debug","z":"5674bd4d.d67064","name":"","active":true,"console":"false","complete":"true","x":633,"y":1397,"wires":[]},{"id":"f0c9e7a5.d0cd68","type":"inject","z":"5674bd4d.d67064","name":"","topic":"","payload":"","payloadType":"date","repeat":"","crontab":"","once":false,"x":197,"y":1249,"wires":[["1300e776.abe2f1"]]},{"id":"caad6ed4.e755a","type":"debug","z":"5674bd4d.d67064","name":"","active":true,"console":"false","complete":"true","x":737,"y":1259,"wires":[]}]


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    Posted · How to auth with node-red against UM3 REST API

    I have no experience with node-red. So I cannot help you on that part. I did post a python example in my topic about the API, that might help?


    But the UM3 API requires HTTP Digest with "auth" quality-of-protection. (The Digest standard makes this optional, but that completely ruins the security, and thus we made it required) most libraries handle this seamlessly.


    Part of the "auth" quiality-of-protection are one-time-use tokens, called "nonce". Which I'm not sure if node-red is handling for you or not.

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    Posted · How to auth with node-red against UM3 REST API

    You might also try the Cura Connect API (on newer firmware versions) which currently has not authentication. Docs are available on http://{PRINTER_IP}/cluster-api/v1/.

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    Posted · How to auth with node-red against UM3 REST API

    There's a little more information right here (images seem to be missing, but everything should be clear):


    I would first try to get the /verify call working with cURL. I believe it should be as simple as adding a "--digest" parameter:



    Next, you need to get it into Node-red. From what I know about this (= not much), it's based on node, so JavaScript. It looks like some of the libraries don't completely support digest authentication, so if it doesn't work, probably best to try another library. This is just the first thing that comes up:




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