docs: improve secrets documentation

This commit is contained in:
Johannes Kirschbauer
2024-04-26 10:44:14 +02:00
parent 3f8e1c85b6
commit 05f3da28f8
2 changed files with 459 additions and 4 deletions

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## Secrets (CLI Reference)
#### Adding Secrets (set)
```bash
clan secrets set mysecret
> Paste your secret:
```
!!! note
As you type your secret won't be displayed. Press Enter to save the secret.
#### List all Secrets (list)
```bash
clan secrets list
```
#### Assigning Access (set)
By default, secrets are encrypted for your key. To specify which users and machines can access a secret:
```bash
clan secrets set --machine <machine1> --machine <machine2> --user <user1> --user <user2> <secret_name>
```
#### Displaying Secrets (get)
```bash
clan secrets get mysecret
```
#### Rename
TODO
#### Remove
TODO
#### import-sops
TODO
### Users (Reference)
Learn how to manage users and allowing access to existing secrets.
#### list user
Lists all added users
```bash
clan secrets user list
```
``` {.console, title="Example output", .no-copy}
jon
sara
```
!!! Question "Who can execute this command?"
Everyone - completely public.
#### add user
add a user
```bash
clan secrets users add {username} {public-key}
```
!!! Note
Changes can be trusted by maintainer review in version control.
#### get user
get a user public key
```bash
clan secrets users get {username}
```
``` {.console, title="Example output", .no-copy}
age1zk8uzrte55wkg9lkqxu5x6twsj2ja4lehegks0cw4mkg6jv37d9qsjpt44
```
#### remove user
remove a user
```bash
clan secrets users remove {username}
```
!!! Note
Changes can be trusted by maintainer review in version control.
#### add-secret user
Grants the user (`username`) access to the secret (`secret_name`)
```bash
clan secrets users add-secret {username} {secret_name}
```
!!! Note
Requires the executor of the command to have access to the secret (`secret_name`).
#### remove-secret user
remove the user (`username`) from accessing the secret (`secret_name`)
!!! Danger "Make sure at least one person has access."
It might still be possible for the machine to access the secret. (See [machines](#machines))
We highly recommend to use version control such as `git` which allows you to rollback secrets in case anything gets messed up.
```bash
clan secrets users remove-secret {username} {secret_name}
```
!!! Question "Who can execute this command?"
Requires the executor of the command to have access to the secret (`secret_name`).
### Machines (Reference)
- [list](): list machines
- [add](): add a machine
- [get](): get a machine public key
- [remove](): remove a machine
- [add-secret](): allow a machine to access a secret
- [remove-secret](): remove a machine's access to a secret
#### List machine
New machines in Clan come with age keys stored in `./sops/machines/<machine_name>`. To list these machines:
```bash
clan secrets machines list
```
#### Add machine
For clan machines the machine key is generated automatically on demand if none exists.
```bash
clan secrets machines add <machine_name> <age_key>
```
If you already have a device key and want to add it manually, see: [How to obtain a remote key](#obtain-remote-keys-manually)
#### get machine
TODO
#### remove machine
TODO
#### add-secret machine
TODO
#### remove-secret machine
TODO
### Groups (Reference)
The Clan-CLI makes it easy to manage access by allowing you to create groups.
- [list](): list groups
- [add-user](): add a user to group
- [remove-user](): remove a user from group
- [add-machine](): add a machine to group
- [remove-machine](): remove a machine from group
- [add-secret](): allow a user to access a secret
- [remove-secret](): remove a group's access to a secret
#### List Groups
```bash
clan secrets groups list
```
#### add-user
Assign users to a new group, e.g., `admins`:
```bash
clan secrets groups add-user admins <username>
```
!!! info
The group is created if no such group existed before.
The user must exist in beforehand (See: [users](#users-reference))
```{.console, .no-copy}
.
├── flake.nix
. ...
└── sops
├── groups
│ └── admins
│ └── users
│ └── <username> -> ../../../users/<username>
```
#### remove-user
TODO
#### add-machine
TODO
#### remove-machine
TODO
#### add-secret
```bash
clan secrets groups add-secret <group_name> <secret_name>
```
#### remove-secret
TODO
### Key (Reference)
- [generate]() generate age key
- [show]() show age public key
- [update]() re-encrypt all secrets with current keys (useful when changing keys)
#### generate
TODO
#### show
TODO
#### update
TODO
## Further
Secrets in the repository follow this structure:
```{.console, .no-copy}
sops/
├── secrets/
│ └── <secret_name>/
│ ├── secret
│ └── users/
│ └── <your_username>/
```
The content of the secret is stored encrypted inside the `secret` file under `mysecret`.
By default, secrets are encrypted with your key to ensure readability.
### Obtain remote keys manually
To fetch a **SSH host key** from a preinstalled system:
```bash
ssh-keyscan <domain_name> | nix shell nixpkgs#ssh-to-age -c ssh-to-age
```
!!! Success
This command converts the SSH key into an age key on the fly. Since this is the format used by the clan secrets backend.
Once added the **SSH host key** enables seamless integration of existing machines with clan.
Then add the key by executing:
```bash
clan secrets machines add <machine_name> <age_key>
```
See also: [Machine reference](#machines-reference)
### NixOS integration
A NixOS machine will automatically import all secrets that are encrypted for the
current machine. At runtime it will use the host key to decrypt all secrets into
an in-memory, non-persistent filesystem using [sops-nix](https://github.com/Mic92/sops-nix).
In your nixos configuration you can get a path to secrets like this `config.sops.secrets.<name>.path`. For example:
```nix
{ config, ...}: {
sops.secrets.my-password.neededForUsers = true;
users.users.mic92 = {
isNormalUser = true;
passwordFile = config.sops.secrets.my-password.path;
};
}
```
See the [readme](https://github.com/Mic92/sops-nix) of sops-nix for more
examples.
### Migration: Importing existing sops-based keys / sops-nix
`clan secrets` stores each secret in a single file, whereas [sops](https://github.com/Mic92/sops-nix) commonly allows to put all secrets in a yaml or json document.
If you already happened to use sops-nix, you can migrate by using the `clan secrets import-sops` command by importing these files:
```bash
% clan secrets import-sops --prefix matchbox- --group admins --machine matchbox nixos/matchbox/secrets/secrets.yaml
```
This will create secrets for each secret found in `nixos/matchbox/secrets/secrets.yaml` in a `./sops` folder of your repository.
Each member of the group `admins` in this case will be able to decrypt the secrets with their respective key.
Since our clan secret module will auto-import secrets that are encrypted for a particular nixos machine,
you can now remove `sops.secrets.<secrets> = { };` unless you need to specify more options for the secret like owner/group of the secret file.

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@@ -6,7 +6,7 @@ Clan utilizes the [sops](https://github.com/getsops/sops) format and integrates
This documentation will guide you through managing secrets with the Clan CLI
## 1. Initializing Secrets
## Initializing Secrets (Quickstart)
### Create Your Master Keypair
@@ -28,11 +28,11 @@ Generated age private key at '/home/joerg/.config/sops/age/keys.txt' for your us
Also add your age public key to the repository with 'clan secrets users add YOUR_USER age1wkth7uhpkl555g40t8hjsysr20drq286netu8zptw50lmqz7j95sw2t3l7' (replace YOUR_USER with your actual username)
```
!!! warning
!!! warning
Make sure to keep a safe backup of the private key you've just created.
If it's lost, you won't be able to get to your secrets anymore because they all need the master key to be unlocked.
!!! note
!!! note
It's safe to add any secrets created by the clan CLI and placed in your repository to version control systems like `git`.
### Add Your Public Key
@@ -41,7 +41,7 @@ Also add your age public key to the repository with 'clan secrets users add YOUR
clan secrets users add <your_username> <your_public_key>
```
!!! note
!!! note
Choose the same username as on your Setup/Source Machine that you use to control the deployment with.
Once run this will create the following files:
@@ -53,6 +53,137 @@ sops/
└── key.json
```
---
> If you followed the quickstart tutorial all necessary secrets are initialized at this point.
- Continue with [deploying machines](./machines.md)
- Learn about the [basics concept](#concept) of clan secrets
---
## Concept
The secrets system conceptually knows two different entities:
- **Machine**: consumes secrets
- **User**: manages access to secrets
**A Users** Can add or revoke machines' access to secrets.
**A machine** Can decrypt secrets that where encrypted specifically for that machine.
!!! Danger
**Always make sure at least one _User_ has access to a secret**. Otherwise you could lock yourself out from accessing the secret.
### Inherited implications
By default clan uses [sops](https://github.com/getsops/sops) through [sops-nix](https://github.com/Mic92/sops-nix) for managing its secrets which inherits some implications that are important to understand:
- **Public/Private keys**: Entities are identified via their public keys. Each Entity can use their respective private key to decrypt a secret.
- **Public keys are stored**: All Public keys are stored inside the repository
- **Secrets are stored Encrypted**: secrets are stored inside the repository encrypted with the respective public keys
- **Secrets are deployed encrypted**: Fully encrypted secrets are deployed to machines at deployment time.
- **Secrets are decrypted by sops on-demand**: Each machine decrypts its secrets at runtime and stores them at an ephemeral location.
- **Machine key-pairs are auto-generated**: When a machine is created **no user-interaction is required** to setup public/private key-pairs.
- **secrets are re-encrypted**: In case machines, users or groups are modified secrets get re-encrypted on demand.
!!! Important
After revoking access to a secret you should also change the underlying secret. i.e. change the API key, or the password.
---
### Machine and user keys
The following diagrams illustrates how a user can provide a secret (i.e. a Password).
- By using the **Clan CLI** a user encrypts the password with both the **User public-key** and the **machine's public-key**
- The *Machine* can decrypt the password with its private-key on demand.
- The *User* is able to decrypt the password to make changes to it.
```plantuml
@startuml
!include C4_Container.puml
Person(user, "User", "Someone who manages secrets")
ContainerDb(secret, "Secret")
Container(machine, "Machine", "A Machine. i.e. Needs the Secret for a given Service." )
Rel_R(user, secret, "Encrypt", "", "Pubkeys: User, Machine")
Rel_L(secret, user, "Decrypt", "", "user privkey")
Rel_R(secret, machine, "Decrypt", "", "machine privkey" )
@enduml
```
### Groups
It is possible to create semantic groups to make access control more convenient.
#### User groups
Here we illustrate how machine groups work.
Common use cases:
- **Shared Management**: Access among multiple users. I.e. a subset of secrets/machines that have two admins
```plantuml
@startuml
!include C4_Container.puml
System_Boundary(c1, "Group") {
Person(user1, "User A", "has access")
Person(user2, "User B", "has access")
}
ContainerDb(secret, "Secret")
Container(machine, "Machine", "A Machine. i.e. Needs the Secret for a given Service." )
Rel_R(c1, secret, "Encrypt", "", "Pubkeys: User A, User B, Machine")
Rel_R(secret, machine, "Decrypt", "", "machine privkey" )
@enduml
```
<!-- TODO: See also [Groups Reference](#groups-reference) -->
---
#### Machine groups
Here we illustrate how machine groups work.
Common use cases:
- **Shared secrets**: Among multiple machines such as Wifi passwords
```plantuml
@startuml
!include C4_Container.puml
!include C4_Deployment.puml
Person(user, "User", "Someone who manages secrets")
ContainerDb(secret, "Secret")
System_Boundary(c1, "Group") {
Container(machine1, "Machine A", "Both machines need the same secret" )
Container(machine2, "Machine B", "Both machines need the same secret" )
}
Rel_R(user, secret, "Encrypt", "", "Pubkeys: machine A, machine B, User")
Rel(secret, c1, "Decrypt", "", "Both machine A or B can decrypt using their private key" )
@enduml
```
<!-- TODO: See also [Groups Reference](#groups-reference) -->
---
## 2. Adding Machine Keys
New machines in Clan come with age keys stored in `./sops/machines/<machine_name>`. To list these machines: