HTTPS error in ASP.NET Core app running on IISExpress - PR_CONNECT_RESET_ERROR

Question

When I try to run this app locally (when the SSL is enabled),

I always get this page that complains about Secure Connection:

https://localhost:44300/

Secure Connection Failed

An error occurred during a connection to localhost:44300. PR_CONNECT_RESET_ERROR

1. The page you are trying to view cannot be shown because the authenticity of the received data could not be verified.
2. Please contact the website owners to inform them of this problem.

What I've tried so far:

1. Add a self signed localhost certificate with this Power Shell command:

New-SelfSignedCertificate -DnsName "localhost" -CertStoreLocation "cert:\\LocalMachine\\My"

2. Run mmc.exe and export that certificate created by above Power Shell script from

[Console Root\\Certificates (Local Computer)\\Personal\\Certificates]

to

[Console Root\\Certificates (Local Computer)\\Trusted Root Certification Authorities\\Certificates .

This hasn't worked so far. If I run the app unchecking the Enable SSL , it works fine.

Please advise on a possible solution for SSL enabled environment.

Answer 1

Regenerating IIS Express localhost certificates worked for me:

1. Open Windows PowerShell ISE using Admin privileges.

2. Run this script:

Start-Transcript -Path "$($MyInvocation.MyCommand.Path).log"
try {
    Write-Host "Creating cert resources"
    $ekuOidCollection = [System.Security.Cryptography.OidCollection]::new();
    $ekuOidCollection.Add([System.Security.Cryptography.Oid]::new("1.3.6.1.5.5.7.3.1","Server Authentication")) | Out-Null
    $sanBuilder = [System.Security.Cryptography.X509Certificates.SubjectAlternativeNameBuilder]::new();
    $sanBuilder.AddDnsName("localhost") | Out-Null
    
    Write-Host "Creating cert extensions"
    $certificateExtensions = @(
        # Subject Alternative Name
        $sanBuilder.Build($true),        
        # ASP.NET Core OID
        [System.Security.Cryptography.X509Certificates.X509Extension]::new(
            "1.3.6.1.4.1.311.84.1.1",
            [System.Text.Encoding]::ASCII.GetBytes("IIS Express Development Certificate"),
            $false),
            # KeyUsage
            [System.Security.Cryptography.X509Certificates.X509KeyUsageExtension]::new(
                [System.Security.Cryptography.X509Certificates.X509KeyUsageFlags]::KeyEncipherment,
                $true),
                # Enhanced key usage
        [System.Security.Cryptography.X509Certificates.X509EnhancedKeyUsageExtension]::new(
            $ekuOidCollection,
            $true),
            # Basic constraints
            [System.Security.Cryptography.X509Certificates.X509BasicConstraintsExtension]::new($false,$false,0,$true)
        )
    Write-Host "Creating cert parameters"
    $parameters = @{
        Subject = "localhost";
        KeyAlgorithm = "RSA";
        KeyLength = 2048;
        CertStoreLocation = "Cert:\LocalMachine\My";
        KeyExportPolicy = "Exportable";
        NotBefore = Get-Date;
        NotAfter = (Get-Date).AddYears(1);
        HashAlgorithm = "SHA256";
        Extension = $certificateExtensions;
        SuppressOid = @("2.5.29.14");
        FriendlyName = "IIS Express Development Certificate"
    }
    Write-Host "Creating cert"
    $cert = New-SelfSignedCertificate @parameters

    $rootStore = New-Object System.Security.Cryptography.X509Certificates.X509Store -ArgumentList Root, LocalMachine
    $rootStore.Open("MaxAllowed")
    $rootStore.Add($cert)
    $rootStore.Close()
    
    Write-Host "Creating port bindings"
    # Add an Http.Sys binding for port 44300-44399
    $command = 'netsh'
    for ($i=44300; $i -le 44399; $i++) {
        $optionsDelete = @('http', 'delete', 'sslcert', "ipport=0.0.0.0:$i")
        $optionsAdd = @('http', 'add', 'sslcert', "ipport=0.0.0.0:$i", "certhash=$($cert.Thumbprint)", 'appid={214124cd-d05b-4309-9af9-9caa44b2b74a}')
        Write-Host "Running $command $optionsDelete"
        & $command $optionsDelete
        Write-Host "Running $command $optionsAdd"
        & $command $optionsAdd
    } 
}
catch {
    Write-Error $_.Exception.Message
}
finally {
    Stop-Transcript
}

It should work just fine now.

(The script is by @Shirhatti from this Github issue page: https://github.com/dotnet/aspnetcore/issues/26437 )