How to send multipart/mime SOAP request from ASP.NET MVC controller

Question

SOAP server requires multipart SOAP request with XML file like

    Content-type: multipart/related;boundary="MIME_boundary";type="text/xml"; start=""

    	--MIME_boundary
    	Content-Type: text/xml;charset=utf-8
    	Content-Transfer-Encoding: 8bit
    	Content-ID: 
    		
    			
    				
    					EE
    					COM
    					00000000
    					misp-client
    				
    				
    					EE
    					GOV
    					70000349
    					mkrliides
    					uploadMime
    					v1
    				
    				EE00000000000
    				4894e35d-bf0f-44a6-867a-8e51f1daa7e1
    				4.0
    			
    			
    				
    					
    						KMD2
    						Submit
    						
    						
    							et
    							TRUE
    						
    					
    				
    			
    		

--MIME_boundary
Content-Type:application/octet-stream
Content-Transfer-Encoding: binary
Content-Disposition: attachment; flename=test.xml
Content-ID: <6f55eb41-7b72-40fe-bb7f-49bffefe9ae4>
test
--MIME_boundary--

Another sample is in https://ncfailid.emta.ee/s/bS2XCJMF3KtErpC/download/example-mime-request.xml

Code to use it is generated from WSDL below in Visual Studio. Trying generated code using

 var cl = new webServiceInterfaceClient(new BasicHttpsBinding(BasicHttpsSecurityMode.Transport), new EndpointAddress("https://example.com"));
var rt = new UploadMimeRequestType()
{
  target = "target",
  operation = "operation",
  file = new UploadMimeRequestTypeFile() { href = "href", Value = Encoding.UTF8.GetBytes("xml content") },
  props = new PropertiesProp[0]
};
var ulreg = new uploadMime() { request = rt };
var tulem = await cl.uploadMimeAsync(new uploadMimeRequest(ulreg,
                                   Encoding.UTF8.GetBytes("xml xml")));

throws SOAP error body must have exactly one child element :



	
		
			Client.InvalidBody
			Malformed SOAP message: body must have exactly one child element
			
			
				1e2a2727-98f5-4d6d-ba1a-7a34dc6438fc

.NET sends requests with two child elemnts in SOAP body:



	
		
	
	
		
			
				target
				operation
				786D6C20636F6E74656E74
				
			
		
		eG1sIHhtbA==

How to create such request in ASP.NET MVC controller in .NET 8 ?

WSDL of service is in https://ncfailid.emta.ee/s/ad5sNbJtJ5RRfEK/download/uploadmime.wsdl:


    
        
            
            
                
                    
                        
                    
                
            
            
                
                    
                        
                            
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                Failide edastamise teenus
            
            
            
        
    
    
        
        
            
            v1

Answer

I'm not the SOAP guy, but here is what Copilot told me👇

To send a multipart/mime SOAP request from an ASP.NET MVC controller, you can follow these steps:

Create the Multipart/MIME Request: First, construct your SOAP request with the necessary XML content. Next, create a multipart/mime request that includes both the SOAP XML and any additional files (if needed).
Use HttpClient to Send the Request: In your ASP.NET MVC controller, use HttpClient to send the multipart/mime request. Add the SOAP XML as one part of the request and any other files (if applicable) as additional parts.
Example Code: Here’s an example of how you might send a multipart/mime SOAP request using HttpClient:

using System;
using System.Net.Http;
using System.Text;
using System.Threading.Tasks;
public class MyController : Controller
{
    public async Task SendSoapRequest()
    {
        try
        {
            using var client = new HttpClient();
            using var content = new MultipartFormDataContent();
            // Add the SOAP XML
            var soapXml = @"
                            
                                
                            ";
            var soapContent = new StringContent(soapXml, Encoding.UTF8, "text/xml");
            content.Add(soapContent, "file", "soap.xml");
            // Add any additional files (if needed)
            // var fileBytes = ... // Read your file content
            // var fileContent = new ByteArrayContent(fileBytes);
            // content.Add(fileContent, "file", "filename.ext");
            // Send the request
            var response = await client.PostAsync("https://example.com/your-soap-endpoint", content);
            if (response.IsSuccessStatusCode)
            {
                // Process the success response
                return Ok("SOAP request sent successfully!");
            }
            else
            {
                // Handle the error response
                return BadRequest("Error sending SOAP request.");
            }
        }
        catch (Exception ex)
        {
            // Handle exceptions
            return StatusCode(500, $"An error occurred: {ex.Message}");
        }
    }
}

Adjust the Code: Replace the placeholder SOAP XML and endpoint URL with your actual values. If you need to include additional files (e.g., attachments), add them as separate parts in the MultipartFormDataContent.

Remember to handle exceptions appropriately and adjust the code to match your specific SOAP service requirements. 🚀

For more examples and details, you can refer to the following resources:

Adjust the Code:

Replace the placeholder SOAP XML and endpoint URL with your actual values.

   If you need to include additional files (e.g., attachments), add them as separate parts in the `MultipartFormDataContent`.