auth

README

Auth

A service for all your authn and authz needs.

Background

A list of articles we have found useful to make this service:

• https://cheatsheetseries.owasp.org/cheatsheets/Microservices_security.html
• https://auth0.com/docs/secure/tokens/token-best-practices

Server

The server is composed of the below operations.

Generate Password

The service allows you to generate a secure password. The system uses:

• https://github.com/sethvargo/go-password
• https://pkg.go.dev/golang.org/x/crypto/bcrypt

The user can specify a length. The default is 32 and above.

We take recommendations from NIST Password Guidelines.

Generate Key

The service allows you to generate a secure public and private keys.

RSA

The service will create a key pair using 4096 bits. This is the default or when you pass the kind rsa.

Ed25519

The service will generate a key pair of Ed25519. This is achieved by passing the ed25519 kind.

Generate Access Token

Access tokens are generated with RSA key pair as created by the key service. The user can specify a length. The default is 32 and above.

Once this is generated it is configured as follows:

key:
  rsa:
    public: base64-public-key
    private: base64-private-key

[key.rsa]
public = "base64-public-key"
private = "base64-private-key"

These keys should be stored and retrieved from an application configuration system.

The service needs administrators to create these access tokens. This is configured as follows:

server:
  v1:
    admins:
      - id: su-1234
        hash: bcrypt-password

[[server.v1.admins]]
id = "su-1234"
hash = "bcrypt-password"

Each admin has an id and a hash. The password and hash are generated by the password service. The user then sends id:password as Basic Authentication. This will give you an encrypted access token. This token is a password that is encrypted with the public key. So you could always generate your own token if needed.

The password and token should be stored and retrieved from an application configuration system. The hash is safe to just leave as is, not need to securely store it.

Issuer

This is used to add the issuer to service tokens. This is configured as follows:

server:
  v1:
    issuer: https://auth.falkowski.io

[server.v1]
issuer = "https://auth.falkowski.io"

Get Public Key

The service allows you to get the public key by kind. The supported kinds are the same as generating a key.

Generate Service Tokens

Service tokens are generated using Ed25519 key pair. Once this is generated it is configured as follows:

key:
  ed25519:
    public: base64-public-key
    private: base64-private-key

[key.ed25519]
public = "base64-public-key"
private = "base64-private-key"

The system generates service tokens from the access tokens. This is configured as follows:

server:
  v1:
    services:
      - id: service-name
        hash: bcrypt-password
        duration: 24h

[[server.v1.services]]
id = "service-name"
hash = "bcrypt-password"
duration = "24h"

Each service has an id, hash and duration. The access token is generated by the access token service. The user then sends the access token as Bearer Authentication. This will give you an encrypted service token with subject, audience and issuer that is valid for the duration.

JWT

The system will by default generate JWT tokens, or if we specify kind to be jwt.

Paseto

The system will generate a paseto token if the kind that is passed in is paseto.

Validate Service Tokens

The systems allows the validation of service tokens. The token is passed as Bearer Authentication along with a kind, audience and action.

Casbin

Casbin is used to authorize the token. Currently it is configured using ACL, using the following:

casbin:
  model: |
    [request_definition]
    r = sub, obj, act

    [policy_definition]
    p = sub, obj, act

    [policy_effect]
    e = some(where (p.eft == allow))

    [matchers]
    m = r.sub == p.sub && r.obj == p.obj && r.act == p.act
  policy: |
    p, subject, audience, action

[casbin]
model = """
[request_definition]
r = sub, obj, act

[policy_definition]
p = sub, obj, act

[policy_effect]
e = some(where (p.eft == allow))

[matchers]
m = r.sub == p.sub && r.obj == p.obj && r.act == p.act
"""
policy = """
p, subject, audience, action
"""

Policy

Here is an explanation of the different terms:

• Subject: This is the current service that gets the token to send to the service.
• Audience: Is the destination service you will be sending the token to.
• Action: Is the action/method of the service you are trying to authorize against.

Check out How it works?

Client

The client can be used in other projects. This is configured as follows:

client:
  v1:
    host: server_host
    timeout: 1s
    admin: base64(username:password)
    access: token generated by server

[client.v1]
host = "server_host"
timeout = "1s"
admin = "base64(username:password)"
access = "token generated by server"

Development

If you would like to contribute, here is how you can get started.

Structure

The project follows the structure in golang-standards/project-layout.

Dependencies

Please make sure that you have the following installed:

• Ruby
• Golang

Style

This project favours the Uber Go Style Guide

Setup

The get yourself setup, please run the following:

make setup

Binaries

To make sure everything compiles for the app, please run the following:

make build-test

Specs

To run all the specs, please run the following:

make specs

Features

To run all the features, please run the following:

make features

Changes

To see what has changed, please have a look at CHANGELOG.md