Web Development

Re: ASP.Net Core Web API Exception - Can't Find System.Data.Linq

11-Oct-21 6:40

I have an existing WPF app with a BL and DAL all written in .Net 4.5.2,

I'm now trying to call the DAL from a new Asp.Net Core 5.0 Web API. I pass through the Controller into the BL fine, but when I hit the line that calls into the DAL it throws

System.IO.FileNotFoundException: 'Could not load file or assembly 'System.Data.Linq, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'. The system cannot find the file specified.'

System.Data.Linq isn't in the WPF app's bin folder because it's a .net assembly. I tried copying it into the Web API's Bin folder but that didn't work.

Is there some problem with me calling a .Net 5 Core Wab API from a WPF app?

If it's not broken, fix it until it is.
Everything makes sense in someone's mind.
Ya can't fix stupid.

Dave Kreskowiak11-Oct-21 8:01

Dave Kreskowiak

11-Oct-21 8:01

As far as I know, no, you cannot use a .NET Framework 4.5.2 .DLL in a .NET Core 5 app.

You could migrate the 4.5.2 code to .NET Standard 2, then you could use it in both Framework and Core apps, but this solution is not ideal.

You best solution would be to migrate your WPF and libraries to .NET Core 5.

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Dave Kreskowiak

Re: ASP.Net Core Web API Exception - Can't Find System.Data.Linq

Kevin Marois11-Oct-21 8:33

Re: ASP.Net Core Web API Exception - Can't Find System.Data.Linq

11-Oct-21 8:33

Wow, that $ucks.

The end goal is to stand up an API so I can hit it from both the WPF app and a Xamarin Forms app. I could still do this using a .Net Framework Web API.

If it's not broken, fix it until it is.
Everything makes sense in someone's mind.
Ya can't fix stupid.

#realJSOP2-Nov-21 0:43

#realJSOP

2-Nov-21 0:43

I'm convinced that Core is a steaming pile of shit. But that's just me.

Now, instead of having one common assembly, I have to have two - one for framework, and one for ~~whore~~ core, which defeats the purpose of having a common library.

".45 ACP - because shooting twice is just silly" - JSOP, 2010
-----
You can never have too much ammo - unless you're swimming, or on fire. - JSOP, 2010
-----
When you pry the gun from my cold dead hands, be careful - the barrel will be very hot. - JSOP, 2013

Re: ASP.Net Core Web API Exception - Can't Find System.Data.Linq

Richard Deeming2-Nov-21 1:14

Re: ASP.Net Core Web API Exception - Can't Find System.Data.Linq

2-Nov-21 1:14

#realJSOP wrote:
Now, instead of having one common assembly, I have to have two

Or have one that targets .NET Standard 2.0, which should generally work in .NET Framework 4.7.2 or later, .NET Core 2.0 or later, and .NET 5/6/etc.

.NET Standard | Microsoft Docs[^]

And if you really need to use features which aren't available in .NET Standard, you can target multiple frameworks in a single project[^] (so long as it's a new "SDK"-style project). It's a PITA, but it works.

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

Kevin Marois2-Nov-21 4:34

Re: ASP.Net Core Web API Exception - Can't Find System.Data.Linq

2-Nov-21 4:34

I just need to get an API up & running. I have no reason to target .Net Core, so .Net Framework would be fine.

If it's not broken, fix it until it is.
Everything makes sense in someone's mind.
Ya can't fix stupid.

Richard Deeming11-Oct-21 22:11

Re: ASP.Net Core Web API Exception - Can't Find System.Data.Linq

11-Oct-21 22:11

LINQ to SQL has been effectively end-of-life since 2009. It was never ported to .NET Core or .NET 5/6/...

The recommended workaround is to switch to using Entity Framework Core. But that's obviously a huge change, and will require a lot of testing, since some of your queries may no longer work, and the behaviour will be different in some cases.

There's a third-party clone of L2S which is marked as .NET Standard 2.0, so it might work for you:
NuGet Gallery | Mindbox.Data.Linq 5.0.0[^]
GitHub - mindbox-moscow/data-linq: A clone of Microsoft System.Data.Linq to allow multi-DLL extensibility and EF compatibility.[^]

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

Kevin Marois12-Oct-21 7:34

Re: ASP.Net Core Web API Exception - Can't Find System.Data.Linq

12-Oct-21 7:34

I could stand up a .Net Core API using a new DAL with EF and slowly port things over.

If it's not broken, fix it until it is.
Everything makes sense in someone's mind.
Ya can't fix stupid.

#realJSOP2-Nov-21 1:01

#realJSOP

2-Nov-21 1:01

Instead of doing all that, just roll your own DAL and do either sql queries or stored procs to get/put data. You have much more control in a smaller package without having to understand or deal with how Microsoft thinks the world of database access should work.

Generally speaking all ORM tools are garbage.

Securing A Web API

Kevin Marois20-Sep-21 11:51

20-Sep-21 11:51

I'm working on an ASP.Net Web API.

I found this article. It seems pretty straightforward, but it's a few years old. Is this still the way to secure a Web API? If not, can someone point me in the right direction?

If it's not broken, fix it until it is.
Everything makes sense in someone's mind.
Ya can't fix stupid.

Re: Securing A Web API

#realJSOP2-Nov-21 1:06

#realJSOP

2-Nov-21 1:06

You could set up a table in your database that contains authorization data (like an GUID that serves as an api key, and even further, api method name(s) that can be used by the key.

You'd have to manually maintain the table unless you took the time to write a tool to assist you.

Re: Securing A Web API

Kevin Marois2-Nov-21 4:35

Laravel 8 how to add elements to navbar app.blade

2-Nov-21 4:35

Thanks!

If it's not broken, fix it until it is.
Everything makes sense in someone's mind.
Ya can't fix stupid.

paradox0215-Sep-21 2:01

paradox02

15-Sep-21 2:01

i have add elements to navbar app.blade view after login

Link 1 link 2 link 3 --------------------User<>

SSL Certificate

Kevin Marois26-Aug-21 7:23

26-Aug-21 7:23

I'm trying to set up a Web API and connect to it from a Xamarin Forms app. The API works, but the Xamarin Forms app wants the Web API to HTTPS.

So, I created a Self-Signed cert in IIS and installed my Web API using HTTPS and that cert.

When I click Browse in IIS, I get

There is a problem with this website’s security certificate.
The security certificate presented by this website was issued for a different website's address.

I click Continue and everything seems fine, and I can hit the API with Postman.

But when I try to hit it from my Xamarin Forms app, I get

Javax.Net.Ssl.SSLHandshakeException: 
'java.security.cert.CertPathValidatorException: Trust anchor for certification path not found.'

I'm out of my league here. I really know nothing about certs and setting up HTTPS. Can someone help a blind man?

If it's not broken, fix it until it is.
Everything makes sense in someone's mind.
Ya can't fix stupid.

Richard Deeming26-Aug-21 21:52

26-Aug-21 21:52

When your API is published, you should use a valid SSL certificate. Assuming it's public, you should be able to get a free certificate from "Let's Encrypt".

For development purposes, you should be able to extract the public key of your self-signed certificate, and use the ServicePointManager.ServerCertificateValidationCallback to compare the public key of the certificate to the public key you extracted.
ServicePointManager.ServerCertificateValidationCallback Property (System.Net) | Microsoft Docs[^]

Apparently, there are also options to enable calling HTTP services - again, you'd only want to do this in the debug build:
Certificate Pinning in Android Application with Xamarin[^]

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

Kevin Marois20-Sep-21 9:23

20-Sep-21 9:23

Richard Deeming wrote:
...."Let's Encrypt".

I'm just now getting back to this...

On that page you linked I read both the "With Shell Access" and the "Without Shell Access" sections and I'm thoroughly confused.

I created a .Net ASP.Net Web API and hosted it in IIS on my client's server. I'm not sure which of these two options I need.

The bottom line here is that I'm completely clueless about certifications and how to enable things in my Xamarin Forms app. I don't even know where to start learning. I've been Googling but the results are all over the board.

If it's not broken, fix it until it is.
Everything makes sense in someone's mind.
Ya can't fix stupid.

modified 20-Sep-21 15:38pm.

Richard Deeming20-Sep-21 21:47

20-Sep-21 21:47

I can't find any reference to "shell" on either of the links I posted. Confused | :confused:

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

Kevin Marois21-Sep-21 4:22

21-Sep-21 4:22

Richard Deeming wrote:
I can't find any reference to "shell" on either of the links I posted.

I don't understand

If it's not broken, fix it until it is.
Everything makes sense in someone's mind.
Ya can't fix stupid.

Richard Deeming21-Sep-21 5:36

21-Sep-21 5:36

Kevin Marois wrote:
On that page you linked I read both the "With Shell Access" and the "Without Shell Access" sections

There were two pages I linked to:

ServicePointManager.ServerCertificateValidationCallback Property (System.Net) | Microsoft Docs[^]
Searching the page for "shell": zero hits

Certificate Pinning in Android Application with Xamarin[^]
Searching the page for "shell": zero hits

So I'm confused. Which page that I linked to had sections titled "With Shell Access" and "Without Shell Access"? Confused | :confused:

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

Kevin Marois21-Sep-21 6:02

21-Sep-21 6:02

I'm sorry. My mistake. I Googled "Let's Encrypt" and got this page.

I'm up to my neck in Google results, and I inadvertently referenced the wrong page.

If it's not broken, fix it until it is.
Everything makes sense in someone's mind.
Ya can't fix stupid.

Richard Deeming21-Sep-21 6:37

21-Sep-21 6:37

If you're using Windows, and you can connect to the server's desktop and run applications on it, then this client is probably the easiest option to set up a "Let's Encrypt" certificate in IIS:

GitHub - win-acme/win-acme: A simple ACME client for Windows (for use with Let's Encrypt et al.)[^]

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

Kevin Marois21-Sep-21 6:53

21-Sep-21 6:53

Thanks I'll give it a try

If it's not broken, fix it until it is.
Everything makes sense in someone's mind.
Ya can't fix stupid.