ssb-recps-guard

Guards against accidentally publishing messages publicly (i.e. unencrypted)

Works by hooking the publish method, so must be installed as the LAST plugin

Example usage

const Stack = require('secret-stack')
const caps = require('ssb-caps')


const stack = Stack({ caps })
  .use(require('ssb-d2'))
  .use(require('ssb-recps-guard'))  // << must be last

const config = {
  // see ssb-config for other needed config
  recpsGuard: {
    allowedTypes: ['contact', 'pub']
  }
}
const sever = stack(config)

auto-blocked:

const unallowedMsg = {
  content: { type: 'profile' }
}

server.db.create(unallowedMsg, (err, msg) => {
  console.log(err)
  // => Error: recps-guard - no accidental public messages allowed!
})

config-allowed:

const allowedMsg = {
  content: { type: 'contact' }
}
// this type was allowed in our config (see above)

server.db.create(allowedType, (err, msg) => {
  console.log(msg.value.content)
  // => { type: 'contact' }
})

explictly public:

const explicitPublicMsg = {
  content: { type: 'profile' },
  allowPublic: true
}

server.db.create(explicitPublicMsg, (err, msg) => {
  console.log(msg.value.content)
  // => { type: 'profile' }
})

private:

const privateMsg = {
  content: {
    type: 'profile'
    recps: ['@ye+QM09iPcDJD6YvQYjoQc7sLF/IFhmNbEqgdzQo3lQ=.ed25519']
  }
}

server.db.create(privateMsg, (err, msg) => {
  console.log(msg.value.content)
  // => VayTFa.....yZ3Wqsg==.box

  // NOTE: this is private, so allowed through an content is encrypted
  // (in this example by ssb-private1, assuming that was installed)
})

NOTE that if you are using classic ssb-db, the API behaves the same:

const explicitPublicMsgDB1 = {
  content: { type: 'profile' },
  allowPublic: true
}

server.db.create(explicitPublicMsgDN!, (err, msg) => {
  console.log(msg.value.content)
  // => { type: 'profile' }
})

Installation

Because ssb-recps-guard hooks the publish method you must install it as the LAST plugin If you don't other plugins may also hook the publish and modify messages which may break guarentees this plugin tries to offer

(actually we will now throw if anyone else tries to hook publish after this plugin!)

Config

You can configure ssb-recps-guard behaviour through the config you pass in when starting secret-stack:

{
  recpsGuard: {
    allowedTypes: [String]
  }
}

where allowedTypes is an Array of message types which are allowed to be published publicly.

Explicit bypass

Messages which would normally be blocked by the guard bypass the guard by changing what's passed to the publish method to be of form { content, allowPublic: true }

The content is what will be passed to the normal publish function.

Design: this is deliberately verbose to avoid accidental publishing. It also has the benefit that if ssb-guard-recps isn't installed this publish will error because publish will expect the type to be in a different place.

API

You can check if ssb-recps-guard is installed in your server by looking to see if server.recpsGuard is present.

server.recpsGuard.allowedTypes => [String]

Returns a (sorted) Array of the types of messages which are allowed to be published publicly.