hishtory: Better Shell Hishtory

hishtory is a better shell history. It stores your shell history in context (what directory you ran the command it, whether it succeeded or failed, how long it took, etc). This is all stored in a local SQLite DB and e2e encrypted while synced to local SQLite DBs running on all your other computers. All of this is easily queryable via the hishtory CLI. This means from your laptop, you can easily find that complex bash pipeline you wrote on your server, and see the context in which you ran it.

hishtory is written in Go and uses AES-GCM for end-to-end encrypting your hishtory entries while syncing them. The binary is reproducibly built and SLSA Level 3 to make it easy to verify you're getting the code contained in this repository.

Getting Started

To install hishtory on your first machine:

curl https://hishtory.dev/install.py | python3 -

At this point, hishtory is already persisting your shell history. Give it a try with hishtory query and see below for more details on the advanced query features.

Then to install hishtory on your other computers, you need your secret key. Get this by running hishtory status. Once you have it, you follow similar steps to install hishtory on your other computers:

curl https://hishtory.dev/install.py | python3 -
hishtory init $YOUR_HISHTORY_SECRET

Now if you run hishtory query on first computer, you can automatically see the commands you've run on all your other computers!

Features

Querying

hishtory query is the main interface for searching through your shell history. See some below annotated queries:

Command	Explanation
hishtory query psql	Find all commands containing psql
hishtory query psql db.example.com	Find all commands containing psql and db.example.com
hishtory query docker hostname:my-server	Find all commands containing docker that were run on the computer with hostname my-server
hishtory query nano user:root	Find all commands containing nano that were run as root
hishtory query exit_code:127	Find all commands that exited with code 127
hishtory query service before:2022-02-01	Find all commands containing service run before February 1st 2022
hishtory query service after:2022-02-01	Find all commands containing service run after February 1st 2022

For true power users, you can query via SQL via sqlite3 ~/.hishtory/.hishtory.db.

In addition, hishtory export dumps all commands to stdout separated by a single line. This can be useful for certain advanced use cases.

Enable/Disable

If you want to temporarily turn on/off hishtory recording, you can do so via hishtory disable (to turn off recording) and hishtory enable (to turn on recording). You can check whether or not hishtory is enabled via hishtory status.

Updating

To update hishtory to the latest version, just run hishtory update to transparently download and apply the latest update.

Design

The hishtory CLI is written in Go. It hooks into the shell in order to track information about all commands that are run (specifically in bash this is done via trap DEBUG and overriding $PROMPT_COMMAND). It takes this data and saves it in a local SQLite DB managed via GORM. When the user runs hishtory query, a SQL query is run to find matching entries in the local SQLite DB.

Syncing Design

When hishtory is installed, it generates a random secret key. Computers that share a history share this secret key (which is manually copied by the user). It deterministically generates three additional secrets from the secret key:

1. UserId = HMAC(SecretKey, "user_id")
2. DeviceId = HMAC(SecretKey, "device_id")
3. EncryptionKey = HMAC(SecretKey, "encryption_key")

At installation time, hishtory registers itself with the backend which stores the tuple (UserId, DeviceId) which represents a one-to-many relationship between user and devices. In addition, it creates a DumpRequest specific that a new device was created and it needs a copy of the existing bash history.

When a command is run:

1. hishtory encrypts (via AES-GCM with EncryptionKey) the command (and all the metadata) and sends it to the backend along with the UserId to persist it for. The backend retrieves a list of all associated DeviceIds and stores a copy of the encrypted blob for each device associated with that user. Once a given device has read an encrypted blob, that entry can be deleted in order to save space (in essence this is a per-device queue, but implemented on top of postgres because this is small scale and I already am running a postgres instance).
2. hishtory checks for any pending DumpRequests, and if there are any sends a complete (encrypted) copy of the local SQLite DB to be shared with the requesting device.

When the user runs hishtory query, it retrieves all unread blobs from the backend, decrypts them, and adds them to the local SQLite DB.

Security

Hishtory is designed to ensure that the backend cannot read your shell history. This is achieved by:

1. Encrypting history entries with a secret key that the backend never sees
2. Using SLSA to support secure updates that guarantee that you're running the code contained in this repo

If you find any security issues in hishtory, please reach out to david@daviddworken.com.