topic RE: Error when making HTTP Post call using Utility VBO in Product Forum

Error when making HTTP Post call using Utility VBO

yusuf.hoosain — Mon, 30 Aug 2021 15:48:00 GMT

Hi

I am trying to make a SOAP service call to a service which requires certificate for authentication. I am able to make a call using POSTMAN which has the cert and key file loaded on POSTMAN. If I only load the cert without the key file I am unable to make the call.

I have imported the cert using the Utility VBO which returns a cert id.
Using this as an input along with the POSTMAN code stage I have copied all details of the request.
I have made a collection with one row for the headers as per postman:

--header 'Content-Type: text/plain' \

When I make the call using the Utility HTTP I receive the error :

Internal : Could not execute code stage because exception thrown by code stage: Cannot set null or blank methods on request.
Parameter name: value

If I change the method to POST I receive the error below:
Internal : Could not execute code stage because exception thrown by code stage: Object reference not set to an instance of an object.

I have attached the inputs of the request.

Kindly advise how make this call using the Utility HTTP VBO.
I tried using the WS Wizard but I am unable to locate the certificate when setting up, error :
No Certificate found matching that criteria.

Kindly advise on the steps required to call this service using Blue Prism.

Regards

Yusuf

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Yusuf Hoosain
RPA Developer
Africa/Johannesburg
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RE: Error when making HTTP Post call using Utility VBO

ewilson — Mon, 30 Aug 2021 16:33:00 GMT

@yusuf.hoosain,

Couple of things I see:

The value of Method should only be the specific HTTP verb you're trying to use (ex. "GET" or "POST").
There's no need to include Content-Type in the Headers collection because you're already setting the Content Type attribute.

Cheers,

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Eric Wilson
Director, Integrations and Enablement
Blue Prism Digital Exchange
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RE: Error when making HTTP Post call using Utility VBO

ewilson — Mon, 30 Aug 2021 17:23:00 GMT

@yusuf.hoosain,

What's the value of [Certificate ID Forum]? I assume you called the action Load Certificate before trying to call the HTTP Request action?

Cheers,

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Eric Wilson
Director, Integrations and Enablement
Blue Prism Digital Exchange
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RE: Error when making HTTP Post call using Utility VBO

EVIPUTI — Wed, 01 Sep 2021 12:55:00 GMT

Two things which i noticed :

1- The method is wrongly defined . It only takes "POST,GET , PUT.. no need of giving curl there.
2- Looks like you are not loading certificate here first .

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Vipul Tiwari
Senior Process Simplification and Optimization Designer(Solutions Architect)
Fidelity International
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RE: Error when making HTTP Post call using Utility VBO

MarekMroc — Wed, 13 Apr 2022 09:20:00 GMT

Hi @Vipul Tiwari, @ewilson

I am also dealing with the similar problem as Yusuf. I am able to make a call using POSTMAN with cert and key file loaded and I am trying to replicate the same approach by using HTTP Request VBO, but I'm getting this error:

The process sequence is following:

Header contains the information about Client-Id and Client-Secret, necessary for authentication. Details of HTTP request are following:

Would you please be so kind and could you advise how to solve this issue?

Many thanks in advance.

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Marek Mroc
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RE: Error when making HTTP Post call using Utility VBO

PabloSarabia — Wed, 13 Apr 2022 13:30:00 GMT

Hi @Marek Mroc

I think the problem is with the combination of the "Content/type" and the "Method".

First to all, the correct way to type the content type is: application/json (Take care with the correct slash that you use)

And, when you put a content type is to send information, not to receive. You can avoid this parameter cause you are using the "GET" method.

Can you try with this changes and let use know if this solves the problem?

See you in the community, bye 🙂

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Pablo Sarabia
Architect
Altamira Assets Management
Madrid
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RE: Error when making HTTP Post call using Utility VBO

MarekMroc — Wed, 13 Apr 2022 14:24:00 GMT

Hi Pablo,

thank you for your response. I tried to adjust the settings according to the call from Postman so I added content type there as well, despite I'm trying to get the data not post. Nevertheless I deleted the application/json from inputs but I'm still getting the same error.

Could the problem be with the header which is a collection I am populating before the request?

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Marek Mroc
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RE: Error when making HTTP Post call using Utility VBO

PabloSarabia — Wed, 13 Apr 2022 14:49:00 GMT

Hi @Marek Mroc

Ooops.... 😞

Never mind, let's continue checking!

Remove the "accept" value. If I'm not wrong, these "AcceptType" does not exists. (This is the list of types that you can use: text/html, text/xml, image/gif, image/jpg, application/msword)

Can you check if the action "Load Certificate" populate the Dictionary of certificates?

About the headers, I check at one of my calls to this action, and looks correct. You must to create a collection with only one row with as many columns as headers you want to add.

Hope this helps you!

Bye 🙂

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Pablo Sarabia
Architect
Altamira Assets Management
Madrid
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RE: Error when making HTTP Post call using Utility VBO

ewilson — Wed, 13 Apr 2022 17:12:00 GMT

@Marek Mroc,

So the service you're trying to invoke requires a client certificate in addition to a client ID and client secret in the headers?

Cheers,

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Eric Wilson
Director, Integrations and Enablement
Blue Prism Digital Exchange
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RE: Error when making HTTP Post call using Utility VBO

MarekMroc — Thu, 14 Apr 2022 07:09:00 GMT

Hello Pablo,

unfortunately it is still not working and I am getting the same error.
Certificate seems to be loaded successfully.

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Marek Mroc
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RE: Error when making HTTP Post call using Utility VBO

MarekMroc — Thu, 14 Apr 2022 07:34:00 GMT

Hello @ewilson,

Yes exactly. I don't have much experience with the API calls, so I'm trying to replicate the same approach I'm using in POSTMAN. Apart from client ID and client Secret authentication in headers and certificate, it is also necessary to add the private key to certificate.

Those are my setting of certificates in POSTMAN.

I deleted the try and catch from the code and I got this error:

I assume that I don't associate the private key with the crt and maybe this is causing an error?

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Marek Mroc
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RE: Error when making HTTP Post call using Utility VBO

ewilson — Thu, 14 Apr 2022 12:18:00 GMT

@Marek Mroc,

Is the API service that you're trying to call something that's publicly addressable? In other words, could I try calling it myself?

As for the private key, it's typically contained within the certificate in the form of a .PFX file (as opposed to a CRT/Key file combination). The CRT file contains just the public information about the certificate. So, it seems the HTTP VBO needs to be enhanced to handle this situation (a CRT/Key file combination) unless you have the actual PFX file?

I'll research a bit more.

Cheers,

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Eric Wilson
Director, Integrations and Enablement
Blue Prism Digital Exchange
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RE: Error when making HTTP Post call using Utility VBO

MarekMroc — Thu, 14 Apr 2022 13:57:00 GMT

Hi @@ewilson,

No it is not, the Client ID and Client Secret are associated with an application which is making a call . The application is subscribed to the API and authenticated by .crt, private key and mentioned Client ID and Secret.

I generated the .pfx file via OPENSSL using this command:

openssl pkcs12 -export -out certificate.pfx -inkey privateKey.key -in certificate.crt

Then i tried to load .pfx file but I received this error this time:

I can install pfx on windows 10 which I'm using locally, but the running resource for the BOT is a Windows Server 2016 and I am still getting invalid password message when I'm trying to install the pfx there. But if I manage to install the pfx cert, then load it by VBO, could this fix the issue?

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Marek Mroc
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RE: Error when making HTTP Post call using Utility VBO

ewilson — Thu, 14 Apr 2022 14:25:00 GMT

@Marek Mroc,

When you generated the PFX file, using OpenSSL, did you enter a password? If so, did you supply that password to the Load Certificate action when you tried loading the PFX file in the VBO?

Cheers.

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Eric Wilson
Director, Integrations and Enablement
Blue Prism Digital Exchange
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RE: Error when making HTTP Post call using Utility VBO

MarekMroc — Thu, 14 Apr 2022 14:34:00 GMT

Hi @@ewilson,

I did, I provided the pw but it was not working. So I generated the second pfx without any pw and the issue was the same.

Do I need to install the pfx first on a running resource in mmc?

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Marek Mroc
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RE: Error when making HTTP Post call using Utility VBO

ewilson — Thu, 14 Apr 2022 14:42:00 GMT

@Marek Mroc,

Silly question, but the password is not greater than 32 characters in length is it? My understanding is that you do not have to install the PFX first, but you can always try that.

Cheers,

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Eric Wilson
Director, Integrations and Enablement
Blue Prism Digital Exchange
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RE: Error when making HTTP Post call using Utility VBO

ewilson — Thu, 14 Apr 2022 14:55:00 GMT

@Marek Mroc,

I think I know what's going on here. It seems that even though the private key is contained in the PFX file, the constructor we're using in the Load Certificate actions Code stage doesn't actually seem to read that private key. So, what you can try doing is change the Code stage from this:

to this (notice the highlighted change). This also assumes you will be using a password with the PFX file.

Cheers,

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Eric Wilson
Director, Integrations and Enablement
Blue Prism Digital Exchange
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RE: Error when making HTTP Post call using Utility VBO

MarekMroc — Thu, 14 Apr 2022 15:42:00 GMT

Hi @ewilson,

unfortunately I am still getting the same error

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Marek Mroc
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RE: Error when making HTTP Post call using Utility VBO

ewilson — Thu, 14 Apr 2022 16:01:00 GMT

@Marek Mroc,

Ok, that's a bummer. There are a few other things we can try here. First, I think we might need an additional flag along with the ephemeral flag. Can you try changing the X509KeyStorageFlags.EphemeralKeySet entry to this:

X509KeyStorageFlags.EphemeralKeySet | X509KeyStorageFlags.PersistKeySet

If that one doesn't work, it might be that the key needs to actually be written to a store on disk. In that case, try changing the above to this:

X509KeyStorageFlags.UserKeySet | X509KeyStorageFlags.PersistKeySet

Cheers,

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Eric Wilson
Director, Integrations and Enablement
Blue Prism Digital Exchange
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RE: Error when making HTTP Post call using Utility VBO

MarekMroc — Thu, 14 Apr 2022 16:35:00 GMT

Hello @@ewilson,

this time I've got an compiler error 😕

I checked the NET Framework setup:

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Marek Mroc
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