Using secure proxies with Google Chrome

Maybe try importing that certificate into your system's certificate store and trust it. Chrome uses the OS to validate the security certificate.

I think it is very understandable that Chrome gives you an error instead a warning when the proxy's certificate is invalid because the proxy feature is probably implemented as a transparent add-on to its networking components. Requiring an additional UI to confirm the certificate of the proxy does not seem to be a useful feature.

The following steps will do the trick:

1. Generate the key and the certificate:

   openssl genrsa -out key.pem 1024
   openssl req -new -key key.pem -subj "/CN=localhost" -out req.pem
   openssl x509 -req -days 30 -in req.pem -signkey key.pem -out cert.pem
   

   Note that the only mandatory field is CN (CommonName) and must be the same domain of the one of the proxy.

2. Add the certificate to the system database using certutil (from package libnss3-tools in Debian):

   certutil -d "sql:$HOME/.pki/nssdb" -A -n dummy -i cert.pem -t C
   

   dummy is just a nickname and can be anything, but make sure to provide the -t C option.