gRPC cert

This project shows how to perform mutual TLS authentication with certificates (using gRPC). Normally, the client authenticates the server by verifying the server's certificate (this is the typical scenario in HTTPS). But this example shows also how the server can also authenticate the client. This is an authentication mechanism that does not require username / password, only certificates.

Finally, both the client and server extract the common name from the certificate. The client uses the common name as the server address to connect to. The server uses the common name as the port to listen to. This also means that the client and the server never need to be given an additional address to connect or bind to (respectively), they only need the certificates.

This project combines the following sources:

• https://bbengfort.github.io/programmer/2017/03/03/secure-grpc.html
• https://jbrandhorst.com/post/grpc-auth/

Dependencies

Install the compiler for the Protocol Buffer version 3 (aka proto3). It should be available in your distribution's packages.

Install the compiler for the Go programming language. It should also be available in your distribution's packages.

Slackware packages:

• proto3: http://slackbuilds.org/repository/14.2/misc/protobuf3
• Go: http://slackbuilds.org/repository/14.2/development/google-go-lang

Run the server and client

Run the server with automatically generated certificates:

make run-server

In a different terminal, run the client with automatically generated certificates:

make run-client