Go Signature

This project is the result of learning Signatures for packing and signing messages that may be sent out to a -third-party-server- to validate the authenticity and trust of the content.

NOTE: This project does not send the data to any server, but both roles are assumed in this solution.

This project makes a CLI tool to make it easy to test the encoding, decoding and signing features.

Try it

Use it now with a Docker instance. It will open an interactive shell where you can start to play with some commands. Please refer to How to use the command CLI tool below, for more details.

docker pull jorelosorio/go-signature:latest

docker run -i -t jorelosorio/go-signature

How to use the command CLI tool

To create a new pair of private and public keys and export them as private_key.pem and public_key.pem

sign create-keys --export-path .

To encode a new message

sign encode-message --sender "Jorge Osorio" --payload "HOLA" --private-key-path ./private_key.pem

To encode a new message importing the payload from a file

sign encode-message --sender "Jorge Osorio" --payload-path ./payload.txt --private-key-path ./private_key.pem

To decode a new message

sign decode-message --public-key-path ./public_key.pem --base64-message {BASE64_ENCODED_CONTAINER_DATA}

If you want more details about a specific command usage use --help argument. For instance: sign encode-message --help . For general information run sign --help. There are also shortcuts for the commands in the help description.

Tools

• GoLang 1.17
• Docker
• Visual Studio Code Optional!

  It requires a Remote - Containers extension. for more information please refers to: https://code.visualstudio.com/docs/remote/containers#_getting-started

• Protocol Buffers 3.19.4

  For more about what Protocol Buffers is please refer to: https://developers.google.com/protocol-buffers/docs/overview

Data structure

A Message struct has the following attributes.

Sender (String)
Payload (Bytes)

A * Container struct has the following attributes.

Signature (Bytes)
Message (Message)

* Container is the main structure to be sent, because it contains the message to be transported and the signature associated with it, When validating the authenticity it shall be made with the message.

Development

This project contains a Dockerfile file with all required dependencies to run it using Visual Studio Code + Remote - Containers extension. However, if you want to make it run locally in your development machine, please follow the instructions below.

Install Go

Install it from https://go.dev/dl/

Protocol Buffers for Go

To install the Protocol Buffers compiler select the right OS and architecture from https://github.com/protocolbuffers/protobuf/releases/tag/v3.19.4 and follow the commands.

NOTE: Replace protoc-3.19.4-linux-x86_64.zip by your right configuration, For the purpose of this project, we are using a Linux machine inside a docker container. To get more information about other options and platforms please refer to https://github.com/protocolbuffers/protobuf/blob/master/src/README.md

wget https://github.com/protocolbuffers/protobuf/releases/download/v3.19.4/protoc-3.19.4-linux-x86_64.zip

unzip protoc-3.19.4-linux-x86_64.zip -d /usr/local

rm protoc-3.19.4-linux-x86_64.zip

Run the following command to install the Go protocol buffers plugin

go install google.golang.org/protobuf/cmd/protoc-gen-go@latest

NOTE: To get more information about Protocol Buffers in Go, please referes to: https://developers.google.com/protocol-buffers/docs/gotutorial and https://github.com/protocolbuffers/protobuf-go

Data generation

Only required if you add/remove new fields

protoc --go_out=. proto/*.proto

Build the command CLI tool

In the main workspace path run the following command to generate a build executable

go build -o bin/sign

If you are using windows the sign will become sign.exe instead.

Build Docker

To build the docker image use Dockerfile.deploy and the command

docker build -f Dockerfile.deploy -t jorelosorio/go-signature:latest .

To run the docker image as an interactive shell

docker run -i -t jorelosorio/go-signature

If everything goes well run:

sign --help