How to install the __mitmproxy__ certificate authority in Windows 7:
  1. Copy the ~/.mitmproxy/mitmproxy-ca-cert.p12 file to the target system.
  2. Double-click the certificate file. You should see a certificate import wizard:
  3. Click "Next" until you're prompted for the certificate store:
  4. Select "Place all certificates in the following store", and select "Trusted Root Certification Authorities":

  5. Click "Next" and "Finish".