If there is problems start a local development server in .net core version 6 web app using SSL. You can disable SSL in the launch profile. When I started a new website today in the local dev I got the error message “SEC_ERROR_INADEQUATE_KEY_USAGE”. I tried to copy the personal certificate in the certificate manager but that didn’t work. So I decided to disable SSL instead. This is how you can disable SSL in the local dev:
1. Right click on project name in solution explorer and select Properties.
2. Select Debug > General.
3. Click on link Open launch profile.
4. In the IIS Express section untick “Use SSL”.
5. Hit F5 to start website without SSL.


Convert SSL certificate to PFX using OpenSSL

If you want to create a password protected PFX file from certificate file and a private key you can use OpenSSL. Follow these steps to create a PFX file.

ssl certificate
  • 1. Download the SSL/TLS tookit from https://www.openssl.org.
  • 2. Run this command in a terminal window:
    “{PATH}\openssl.exe” pkcs12 -export -out “{PATH}\{filename-of-pfx}.pfx” -inkey “{PATH}{filename-of-key}.key” -in “{PATH}{filename-of-certificate}.crt” -certfile {PATH}{filename-of-ca-bundle}.crt
  • 3. Choose a password for the pfx file.
  • 4. Done, the pfx file is now created at specified path.

Error when reading from PFX certificate SSL/TLS

Establish a secure connection to a server. Authentication with certificate.

Error message
The request was aborted: Could not create SSL/TLS secure channel.

  1. Start Microsoft Management Console, either from control panel or by run command “mmc”.
  2. In MMC select File > Add/Remove Snap-In (Ctrl+M).

    mmc add remove snap in
  3. Select Certificates > Add > OK. In next window select Local Computer.

    mmc add certificate
  4. When Certificates is added select Certificates > Personal > Certificates.
  5. You can see all the installed certificates in the window to the right. In order to add a permission right-click on a certificate and select All Tasks > Manage Private Keys.

    mmc manage private keys
  6. Search for user IIS_IUSRS (IIS User) and then add the user. You can configure the permissions like full control, read etc.
    when the user is added.

    mmc add iis user