rmfakecloud

rmfakecloud is fake of the cloud sync the remarkable tablet is using. If you want to sync/backup your files and have full control of the hosting/storage environment and don't trust Google.

Status

early prototype (sync and notifications work). no security and a lot of quick and dirty hacks.

Install

From sources

Install and build the project:

go get -u github.com/ddvk/rmfakecloud

run ~/go/bin/rmfakecloud

or clone an do: go run .

env variables

PORT to change the port number (default: 3000)
DATA_DIR to set data/files directory (default: data in current dir)

Prerequisites / Device Modifications

Without patching the binary

all needed artifacts are in device/ folder

Install a root CA on the device, you can use the device/gencert.sh script

generate a CA and host certificate for *.appspot.com
create the CA folder: mkdir -p /usr/local/share/ca-certificates
copy the CA.crt file to /usr/local/share/ca-certificates and run update-ca-certificates
modify the hosts file /etc/hosts
- so the options are:
  1. run a reverse https proxy on the rm tablet as a service, e.g. secure
    - stop xochitl systemctl stop xochitl
    - add to /etc/hosts
      127.0.0.1 service-manager-production-dot-remarkable-production.appspot.com 127.0.0.1 local.appspot.com 127.0.0.1 my.remarkable.com
    - set the address of your api host:port in the reverse proxy secure -cert proxy.bundle.crt -key proxy.key http://host_where_the_api_is_running:3000 or use the provided systemd unit file and put the config in proxycfg
    - run the host
    - run fixsync.sh on the device to mark all files as new (not to be deleted from the device)
    - start xochitl systemctl start xochitl
  2. run the fakeapi on port 443 with a certificate signed by the CA you installed and resolve
  - modify the hosts files to point to this host
  1. install only the CA certificate on the device
  - modify your DNS Server/router to resolve the aforementioned addesses to a https reverse proxy
  - install the hosts certificate on the proxy and route to the api e.g:
    - on a ubiquity router /etc/dnsmasq.d/rm.conf address=/my.remarkable.com/192.168.0.10 etc
    - on a synology there is an application portal which you can configure as a reverse proxy
  - CONS this will affect ALL devices, but you use the mobile apps and windows clients without modifications

Caveats/ WARNING

connecting to the api will delete all you files, unless you mark them as not synced synced:false prior to syncing

TODO

How the cloud sync works or (will I lose my files) requested by @torwag

(my interpretation and flawed observations)

Given a new unregistered device, all the files that are generated locally have a status synced:false

Registration:

the device sends a post request to: my.remarkable.com/token/json/2/device/new containing the random key (currently any key will be accepted) and gets a device token

with the device token it obtains expiring access tokens: my.remarkable.com/token/json/2/user/new

having a user access token:

sends a request to the services locator to get the urls of additional services: /service/json/1/(web|mail|notification|storage)(now always local.appspot.com) it gets a list of all documents

Gets the list of documents from the server: /document-storage/json/2/docs the order may be not correct at all:

deletes all documents not in the list and having synced: false
deletes all documents from the cloud that have deleted: true
applies renames, page changes
sends all new and marks them synced: true
sends all modified documents (having a greater Version number?)
it doesn't re-download any changed/newer documents

So if you just point the device to a new empty server, all documents will be deleted from the device. Going back will again, delete all documents and put what was on the server

Riebart / rmfakecloud