[BUG]: `EntraMockResponsePlugin` crashes on startup: `Unable to resolve service for type X509Certificate2`

[hkachouti]

Description

Starting Dev Proxy with EntraMockResponsePlugin enabled fails immediately with a DI resolution error on all versions from v2.0.0 onwards (tested v2.0.0, v2.2.0, v2.3.0). The same configuration works correctly on v1.3.0.

Expected behaviour

Dev Proxy starts and intercepts requests to login.microsoftonline.com, returning mock token responses.

Actual behaviour

Immediate crash:

fail    An error occurred while running Dev Proxy
Exception Details: System.InvalidOperationException: Unable to resolve service for type
'System.Security.Cryptography.X509Certificates.X509Certificate2'
while attempting to activate 'DevProxy.Plugins.Mocking.EntraMockResponsePlugin'.
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.CreateArgumentCallSites(...)
   at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteFactory.CreateConstructorCallSite(...)
   ...

Steps to reproduce

1. Install Dev Proxy v2.3.0 (or any v2.x):

   winget install DevProxy.DevProxy --version 2.3.0 --force
   

2. Create devproxyrc.json:

   {
     "$schema": "https://raw.githubusercontent.com/dotnet/dev-proxy/main/schemas/v2.3.0/rc.schema.json",
     "plugins": [
       {
         "name": "EntraMockResponsePlugin",
         "enabled": true,
         "pluginPath": "~appFolder/plugins/DevProxy.Plugins.dll",
         "configSection": "entraMocks"
       }
     ],
     "urlsToWatch": [
       "https://login.microsoftonline.com/*"
     ],
     "entraMocks": {
       "mocksFile": "entra-mocks.json"
     }
   }

3. Create entra-mocks.json:

   {
     "$schema": "https://raw.githubusercontent.com/dotnet/dev-proxy/main/schemas/v2.3.0/mockresponseplugin.mocksfile.schema.json",
     "mocks": [
       {
         "request": {
           "url": "https://login.microsoftonline.com/*/oauth2/v2.0/token",
           "method": "POST"
         },
         "response": {
           "statusCode": 200,
           "body": {
             "token_type": "Bearer",
             "expires_in": 3600,
             "access_token": "mock-access-token"
           },
           "headers": [
             { "name": "Content-Type", "value": "application/json" }
           ]
         }
       }
     ]
   }

4. Run:

   devproxy --config-file devproxyrc.json
   

Dev Proxy Version

2.3.0

Operating system (environment)

Windows

Shell

PowerShell

Configuration file

{
"$schema": "https://raw.githubusercontent.com/dotnet/dev-proxy/main/schemas/v1.3.0/rc.schema.json",
"asSystemProxy": false,
"validateSchemas": false,
"port": 8001,
"apiPort": 9500,
"plugins": [
{
"name": "EntraMockResponsePlugin",
"enabled": true,
"pluginPath": "~appFolder/plugins/DevProxy.Plugins.dll",
"configSection": "entraMocksPlugin"
}
],
"urlsToWatch": [
"https://login.microsoftonline.com/*"
],
"entraMocksPlugin": {
"$schema": "https://raw.githubusercontent.com/dotnet/dev-proxy/main/schemas/v1.3.0/mockresponseplugin.schema.json",
"mocksFile": "entra-mocks.json"
},
"logLevel": "information",
"showSkipMessages": true,
"showTimestamps": true
}

Additional Info

No response

[waldekmastykarz]

Thanks for reporting and sorry you hit the snag. On it