github.com/StackExchange/blackbox/v2@v2.0.1-0.20220331193400-d84e904973ab/README.md

BlackBox [![CircleCI](https://circleci.com/gh/StackExchange/blackbox.svg?style=shield)](https://circleci.com/gh/StackExchange/workflows/blackbox) [![Build Status](https://github.com/StackExchange/blackbox/workflows/build/badge.svg)](https://github.com/StackExchange/blackbox/actions?query=workflow%3Abuild+branch%3Amaster)
========

Safely store secrets in a VCS repo (i.e. Git, Mercurial, Subversion or Perforce). These commands make it easy for you to Gnu Privacy Guard (GPG) encrypt specific files in a repo so they are "encrypted at rest" in your repository. However, the scripts make it easy to decrypt them when you need to view or edit them, and decrypt them for use in production. Originally written for Puppet, BlackBox now works with any Git or Mercurial repository.

A slide presentation about an older release [is on SlideShare](http://www.slideshare.net/TomLimoncelli/the-blackbox-project-sfae).

Join our mailing list: [https://groups.google.com/d/forum/blackbox-project](https://groups.google.com/d/forum/blackbox-project)

Table of Contents
=================

- [BlackBox](#blackbox)
- [Table of Contents](#table-of-contents)
- [Overview](#overview)
- [Why is this important?](#why-is-this-important)
- [Installation Instructions](#installation-instructions)
- [Commands](#commands)
- [Compatibility](#compatibility)
- [How is the encryption done?](#how-is-the-encryption-done)
- [What does this look like to the typical user?](#what-does-this-look-like-to-the-typical-user)
- Configuration Management
  - [How to use the secrets with Ansible?](#how-to-use-the-secrets-with-ansible)
  - [How to use the secrets with Puppet?](#how-to-use-the-secrets-with-puppet)
    - [Entire files](#entire-files)
    - [Small strings](#small-strings)
- File Management
  - [How to enroll a new file into the system?](#how-to-enroll-a-new-file-into-the-system)
  - [How to remove a file from the system?](#how-to-remove-a-file-from-the-system)
- User Management
  - [How to indoctrinate a new user into the system?](#how-to-indoctrinate-a-new-user-into-the-system)
  - [How to remove a user from the system?](#how-to-remove-a-user-from-the-system)
- Repo Management
  - [Enabling BlackBox For a Repo](#enabling-blackbox-for-a-repo)
- [Set up automated users or “role accounts”](#set-up-automated-users-or-role-accounts)
- [Replacing expired keys](#replacing-expired-keys)
- [Some common errors](#some-common-errors)
- [Using BlackBox on Windows](#using-blackbox-on-windows)
- [Using BlackBox without a repo](#using-blackbox-without-a-repo)
- [Some Subversion gotchas](#some-subversion-gotchas)
- [Using Blackbox when gpg2 is installed next to gpg](#using-blackbox-when-gpg2-is-installed-next-to-gpg)
- [How to submit bugs or ask questions?](#how-to-submit-bugs-or-ask-questions)
- [Developer Info](#developer-info)
- [Alternatives](#alternatives)
- [License](#license)

Overview
========

Suppose you have a VCS repository (i.e. a Git or Mercurial repo) and certain files contain secrets such as passwords or SSL private keys. Often people just store such files "and hope that nobody finds them in the repo". That's not safe.

With BlackBox, those files are stored encrypted using GPG. Access to the VCS repo without also having the right GPG keys makes it worthless to have the files. As long as you keep your GPG keys safe, you don't have to worry about storing your VCS repo on an untrusted server. Heck, even if you trust your server, now you don't have to trust the people that do backups of that server, or the people that handle the backup tapes!

Rather than one GPG passphrase for all the files, each person with access has their own GPG keys in the system. Any file can be decrypted by anyone with their GPG key. This way, if one person leaves the company, you don't have to communicate a new password to everyone with access. Simply disable the one key that should no longer have access. The process for doing this is as easy as running 2 commands (1 to disable their key, 1 to re-encrypt all files.)

Automated processes often need access to all the decrypted files. This is easy too. For example, suppose Git is being used for Puppet files. The master needs access to the decrypted version of all the files. Simply set up a GPG key for the Puppet master (or the role account that pushes new files to the Puppet master) and have that user run `blackbox_postdeploy` after any files are updated.

Getting started
---------------

1. If you don't have a GPG key, set it up using instructions such as:
[Set up GPG key](https://help.github.com/articles/generating-a-new-gpg-key/). \
Now you are ready to go.

1. `cd` into a Git, Mercurial, Subversion or Perforce repository and run `blackbox_initialize`.

1. If a file is to be encrypted, run `blackbox_register_new_file` and you are done.

1. Add and remove keys with `blackbox_addadmin` and `blackbox_removeadmin`.

1. To view and/or edit a file, run `blackbox_edit`;
this will decrypt the file and open with whatever is specified by
your $EDITOR environment variable. \
When you close the editor the
file will automatically be encrypted again and the temporary plaintext
file will be shredded. \
If you need to leave the file decrypted while
you update you can use the`blackbox_edit_start` to decrypt the file
and `blackbox_edit_end` when you want to "put it back in the box."

Why is this important?
======================

OBVIOUSLY we don't want secret things like SSL private keys and passwords to be leaked.

NOT SO OBVIOUSLY when we store "secrets" in a VCS repo like Git or Mercurial, suddenly we are less able to share our code with other people. Communication between subteams of an organization is hurt. You can't collaborate as well. Either you find yourself emailing individual files around (yuck!), making a special repo with just the files needed by your collaborators (yuck!!), or just deciding that collaboration isn't worth all that effort (yuck!!!).

The ability to be open and transparent about our code, with the exception of a few specific files, is key to the kind of collaboration that DevOps and modern IT practitioners need to do.

Installation Instructions
=========================

- *The hard way (manual)*: Copy all the files in "bin" to your "bin".
- *The hard way (automatic)*: `make copy-install` will copy the bin files into $PREFIX/bin, default is /usr/local (uninstall with `make copy-uninstall`).
- *The symlinks way*: `make symlinks-install` will make symlinks of the bin files into $PREFIX/bin, default is /usr/local (uninstall with `make copy-uninstall`) (useful when doing development)
- *The MacPorts Way*: `sudo port install vcs_blackbox`
- *The Homebrew Way*: `brew install blackbox`
- *The RPM way*: Check out the repo and make an RPM via `make packages-rpm`; now you can distribute the RPM via local methods. (Requires [fpm](https://github.com/jordansissel/fpm).)
- *The Debian/Ubuntu way*: Check out the repo and make a DEB via `make packages-deb`; now you can distribute the DEB via local methods. (Requires [fpm](https://github.com/jordansissel/fpm).)
- *The Antigen Way*: Add `antigen bundle StackExchange/blackbox` to your .zshrc
- *The Zgenom Way*: Add `zgenom load StackExchange/blackbox` to your .zshrc where you're loading your other plugins.
- *The Nix Way*: `nix-shell -p blackbox`
- *The Pkgsrc Way*: `pkgin in scm-blackbox`

Commands
========

| Name:                               | Description:                                                            |
|-------------------------------------|-------------------------------------------------------------------------|
| `blackbox_edit <file>`              | Decrypt, run $EDITOR, re-encrypt a file                                 |
| `blackbox_edit_start <file>`        | Decrypt a file so it can be updated                                     |
| `blackbox_edit_end <file>`          | Encrypt a file after blackbox_edit_start was used                       |
| `blackbox_cat <file>`               | Decrypt and view the contents of a file                                 |
| `blackbox_view <file>`              | Like blackbox_cat but pipes to `less` or $PAGER                         |
| `blackbox_diff`                     | Diff decrypted files against their original crypted version             |
| `blackbox_initialize`               | Enable blackbox for a GIT or HG repo                                    |
| `blackbox_register_new_file <file>` | Encrypt a file for the first time                                       |
| `blackbox_deregister_file <file>`   | Remove a file from blackbox                                             |
| `blackbox_list_files`               | List the files maintained by blackbox                                   |
| `blackbox_list_admins`              | List admins currently authorized for blackbox                           |
| `blackbox_decrypt_file <file>`      | Decrypt a file                                                          |
| `blackbox_decrypt_all_files`        | Decrypt all managed files (INTERACTIVE)                                 |
| `blackbox_postdeploy`               | Decrypt all managed files (batch)                                       |
| `blackbox_addadmin <gpg-key>`       | Add someone to the list of people that can encrypt/decrypt secrets      |
| `blackbox_removeadmin <gpg-key>`    | Remove someone from the list of people that can encrypt/decrypt secrets |
| `blackbox_shred_all_files`          | Safely delete any decrypted files                                       |
| `blackbox_update_all_files`         | Decrypt then re-encrypt all files. Useful after keys are changed        |
| `blackbox_whatsnew <file>`          | show what has changed in the last commit for a given file               |

Compatibility
=============

BlackBox automatically determines which VCS you are using and does the right thing. It has a plug-in architecture to make it easy to extend to work with other systems. It has been tested to work with many operating systems.

- Version Control systems
  - `git` -- The Git
  - `hg` -- Mercurial
  - `svn` -- SubVersion (Thanks, Ben Drasin!)
  - `p4` -- Perforce
  - none -- The files can be decrypted outside of a repo if the `.blackbox` directory is intact
- Operating system
  - CentOS / RedHat
  - MacOS X
  - Cygwin (Thanks, Ben Drasin!) **See Note Below**
  - MinGW (git bash on windows) **See Note Below**
  - NetBSD
  - SmartOS

To add or fix support for a VCS system, look for code at the end of `bin/_blackbox_common.sh`

To add or fix support for a new operating system, look for the case statements in `bin/_blackbox_common.sh` and `bin/_stack_lib.sh` and maybe `tools/confidence_test.sh`

Using BlackBox on Windows
=========================

BlackBox can be used with Cygwin or MinGW.

### Protect the line endings

BlackBox assumes that `blackbox-admins.txt` and `blackbox-files.txt` will have
LF line endings. Windows users should be careful to configure Git or other systems
to not convert or "fix" those files.

If you use Git, add the following lines to your `.gitattributes` file:

    **/blackbox-admins.txt text eol=lf
    **/blackbox-files.txt text eol=lf

The latest version of `blackbox_initialize` will create a `.gitattributes` file in the `$BLACKBOXDATA`
directory (usually `.blackbox`) for you.

### Cygwin

Cygwin support requires the following packages:

Normal operation:

- gnupg
- git or mercurial or subversion or perforce (as appropriate)

Development (if you will be adding code and want to run the confidence test)

- procps
- make
- git (the confidence test currently only tests git)

### MinGW

MinGW (comes with Git for Windows) support requires the following:

Normal operation:

- [Git for Windows](https://git-scm.com/) (not tested with Mercurial)
  - Git Bash MINTTY returns a MinGW console.  So when you install make sure you pick `MINTTY` instead of windows console.  You'll be executing blackbox from the Git Bash prompt.
  - You need at least version 2.8.1 of Git for Windows.
- [GnuWin32](https://sourceforge.net/projects/getgnuwin32/files/) - needed for various tools not least of which is mktemp which is used by blackbox
  - after downloading the install just provides you with some batch files.  Because of prior issues at sourceforge and to make sure you get the latest version of each package the batch files handle the brunt of the work of getting the correct packages and installing them for you.
  - from a **windows command prompt** run `download.bat`  once it has completed run `install.bat` then add the path for those tools to your PATH (ex: `PATH=%PATH%;c:\GnuWin32\bin`)

Development:

- unknown (if you develop Blackbox under MinGW, please let us know if any additional packages are required to run `make test`)

How is the encryption done?
===========================

GPG has many different ways to encrypt a file. BlackBox uses the mode that lets you specify a list of keys that can decrypt the message.

If you have 5 people ("admins") that should be able to access the secrets, each creates a GPG key and adds their public key to the keychain. The GPG command used to encrypt the file lists all 5 key names, and therefore any 1 key can decrypt the file.

To remove someone's access, remove that admin's key name (i.e. email address) from the list of admins and re-encrypt all the files. They can still read the .gpg file (assuming they have access to the repository) but they can't decrypt it any more.

*What if they kept a copy of the old repo before you removed access?* Yes, they can decrypt old versions of the file. This is why when an admin leaves the team, you should change all your passwords, SSL certs, and so on. You should have been doing that before BlackBox, right?

*Why don't you use symmetric keys?* In other words, why mess with all this GPG key stuff and instead why don't we just encrypt all the files with a single passphrase. Yes, GPG supports that, but then we are managing a shared password, which is fraught with problems. If someone "leaves the team" we would have to communicate to everyone a new password. Now we just have to remove their key. This scales better.

*How do automated processes decrypt without asking for a password?* GPG requires a passphrase on a private key. However, it permits the creation of subkeys that have no passphrase. For automated processes, create a subkey that is only stored on the machine that needs to decrypt the files. For example, at Stack Exchange, when our Continuous Integration (CI) system pushes a code change to our Puppet masters, they run `blackbox_postdeploy` to decrypt all the files. The user that runs this code has a subkey that doesn't require a passphrase. Since we have many masters, each has its own key. And, yes, this means our Puppet Masters have to be very secure. However, they were already secure because, like, dude... if you can break into someone's puppet master you own their network.

*If you use Puppet, why didn't you just use hiera-eyaml?* There are 4 reasons:

1. This works with any Git or Mercurial repo, even if you aren't using Puppet.
2. hiera-eyaml decrypts "on demand" which means your Puppet Master now uses a lot of CPU to decrypt keys every time it is contacted. It slows down your master, which, in my case, is already slow enough.
3. This works with binary files, without having to ASCIIify them and paste them into a YAML file. Have you tried to do this with a cert that is 10K long and changes every few weeks? Ick.
4. hiera-eyaml didn't exist when I wrote this.

What does this look like to the typical user?
=============================================

- If you need to, start the GPG Agent: `eval $(gpg-agent --daemon)`
- Decrypt the file so it is editable: `blackbox_edit_start FILENAME`
- (You will need to enter your GPG passphrase.)
- Edit FILENAME as you desire: `vim FILENAME`
- Re-encrypt the file: `blackbox_edit_end FILENAME`
- Commit the changes. `git commit -a` or `hg commit`

Wait... it can be even easier than that! Run `blackbox_edit FILENAME`, and it'll decrypt the file in a temp file and call `$EDITOR` on it, re-encrypting again after the editor is closed.

How to use the secrets with Ansible?
===================================

Ansible Vault provides functionality for encrypting both entire files and strings stored within files; however,
keeping track of the password(s) required for decryption is not handled by this module.

Instead one must specify a password file when running the playbook.

Ansible example for password file: `my_secret_password.txt.gpg`

```
ansible-playbook --vault-password-file my_secret_password.txt site.yml
```

Alternatively, one can specify this in the `ANSIBLE_VAULT_PASSWORD_FILE` environment variable.

How to use the secrets with Puppet?
===================================

### Entire files:

Entire files, such as SSL certs and private keys, are treated just like regular files. You decrypt them any time you push a new release to the puppet master.

Puppet example for an encrypted file: `secret_file.key.gpg`

```
file { '/etc/my_little_secret.key':
    ensure  => 'file',
    owner   => 'root',
    group   => 'puppet',
    mode    => '0760',
    source  => "puppet:///modules/${module_name}/secret_file.key",
}
```

### Small strings:

Small strings, such as passwords and API keys, are stored in a hiera yaml file, which you encrypt with `blackbox_register_new_file`. For example, we use a file called `blackbox.yaml`. You can access them using the hiera() function.

*Setup:* Configure `hiera.yaml` by adding "blackbox" to the search hierarchy:

```
:hierarchy:
  - ...
  - blackbox
  - ...
```

In blackbox.yaml specify:

```
---
module::test_password: "my secret password"
```

In your Puppet Code, access the password as you would any hiera data:

```
$the_password = hiera('module::test_password', 'fail')

file {'/tmp/debug-blackbox.txt':
    content => $the_password,
    owner   => 'root',
    group   => 'root',
    mode    => '0600',
}
```

The variable `$the_password` will contain "my secret password" and can be used anywhere strings are used.

How to enroll a new file into the system?
=========================================

- If you need to, start the GPG Agent: `eval $(gpg-agent --daemon)`
- Add the file to the system:

```
blackbox_register_new_file path/to/file.name.key
```

Multiple file names can be specified on the command line:

Example 1: Register 2 files:

```
blackbox_register_new_file file1.txt file2.txt
```

Example 2: Register all the files in `$DIR`:

```
find $DIR -type f -not -name '*.gpg' -print0 | xargs -0 blackbox_register_new_file
```

How to remove a file from the system?
=====================================

This happens quite rarely, but we've got it covered:

```
blackbox_deregister_file path/to/file.name.key
```

How to indoctrinate a new user into the system?
===============================================

FYI: Your repo may use `keyrings/live` instead of `.blackbox`. See "Where is the configuration stored?"

`.blackbox/blackbox-admins.txt` is a file that lists which users are able to decrypt files. (More pedantically, it is a list of the GnuPG key names that the file is encrypted for.)

To join the list of people that can edit the file requires three steps; You create a GPG key and add it to the key ring. Then, someone that already has access adds you to the system. Lastly, you should test your access.

### Step 1: NEW USER creates a GPG key pair on a secure machine and adds to public keychain.

If you don't already have a GPG key, here's how to generate one:

```
gpg --gen-key
```

WARNING: New versions of GPG generate keys which are not understood by
old versions of GPG.  If you generate a key with a new version of GPG,
this will cause problems for users of older versions of GPG.
Therefore it is recommended that you either assure that everyone using
Blackbox have the exact same version of GPG, or generate GPG keys
using a version of GPG as old as the oldest version of GPG used by
everyone using Blackbox.

Pick defaults for encryption settings, 0 expiration. Pick a VERY GOOD passphrase. Store a backup of the private key someplace secure. For example, keep the backup copy on a USB drive that is locked in safe.  Or, at least put it on a secure machine with little or no internet access, full-disk-encryption, etc. Your employer probably has rules about how to store such things.

FYI: If generating the key is slow, this is usually because the system
isn't generating enough entropy.  Tip: Open another window on that
machine and run this command: `ls -R /`

Now that you have a GPG key, add yourself as an admin:

```
blackbox_addadmin KEYNAME
```

...where "KEYNAME" is the email address listed in the gpg key you created previously. For example:

```
blackbox_addadmin tal@example.com
```

When the command completes successfully, instructions on how to commit these changes will be output. Run the command as given to commit the changes. It will look like this:

```
git commit -m'NEW ADMIN: tal@example.com' .blackbox/pubring.gpg .blackbox/trustdb.gpg .blackbox/blackbox-admins.txt
```

Then push it to the repo:

```
git push

or

ht push

(or whatever is appropriate)
```

NOTE: Creating a Role Account? If you are adding the pubring.gpg of a role account, you can specify the directory where the pubring.gpg file can be found as a 2nd parameter: `blackbox_addadmin puppetmaster@puppet-master-1.example.com /path/to/the/dir`

### Step 2: EXISTING ADMIN adds new user to the system.

Ask someone that already has access to re-encrypt the data files. This gives you access. They simply decrypt and re-encrypt the data without making any changes.

Pre-check: Verify the new keys look good.

```
git pull    # Or whatever is required for your system
gpg --homedir=.blackbox --list-keys
```

For example, examine the key name (email address) to make sure it conforms to corporate standards.

Import the keychain into your personal keychain and reencrypt:

```
gpg --import .blackbox/pubring.gpg
blackbox_update_all_files
```

Push the re-encrypted files:

```
git commit -a
git push

or

hg commit
hg push
```

### Step 3: NEW USER tests.

Make sure you can decrypt a file. (Suggestion: Keep a dummy file in VCS just for new people to practice on.)

How to remove a user from the system?
=====================================

Simply run `blackbox_removeadmin` with their keyname then re-encrypt:

Example:

```
blackbox_removeadmin olduser@example.com
blackbox_update_all_files
```

When the command completes, you will be given a reminder to check in the change and push it.

Note that their keys will still be in the key ring, but they will go unused. If you'd like to clean up the keyring, use the normal GPG commands and check in the file.

FYI: Your repo may use `keyrings/live` instead of `.blackbox`. See "Where is the configuration stored?"

```
gpg --homedir=.blackbox --list-keys
gpg --homedir=.blackbox --delete-key olduser@example.com
git commit -m'Cleaned olduser@example.com from keyring'  .blackbox/*
```

FYI: Your repo may use `keyrings/live` instead of `.blackbox`. See "Where is the configuration stored?"

The key ring only has public keys. There are no secret keys to delete.

Remember that this person did have access to all the secrets at one time. They could have made a copy. Therefore, to be completely secure, you should change all passwords, generate new SSL keys, and so on just like when anyone that had privileged access leaves an organization.

Where is the configuration stored? .blackbox vs. keyrings/live
==============================================================

Blackbox stores its configuration data in the `.blackbox` subdirectory.  Older
repos use `keyrings/live`.  For backwards compatibility either will work.

All documentation refers to `.blackbox`.

You can convert an old repo by simply renaming the directory:

```
mv keyrings/live .blackbox
rmdir keyrings
```

There is no technical reason to convert old repos except that it is less
confusing to users.

This change was made in commit 60e782a0, release v1.20180615.

The details:

- First Blackbox checks `$BLACKBOXDATA`. If this environment variable is set, this is the directory that will be used. If it lists a directory that does not exist, Blackbox will print an error and exit.
- If `$BLACKBOXDATA` is not set: (which is the typical use case)
  - Blackbox will first try `keyrings/live` and use it if it exists.
  - Otherwise the default `.blackbox` will be used.  If `.blackbox` does not exist, Blackbox will print an error and exit.


Enabling BlackBox For a Repo
============================

Overview:

To add "blackbox" to a git or mercurial repo, you'll need to do the following:

1. Run the initialize script. This adds a few files to your repo in a directory called ".blackbox".
2. For the first user, create a GPG key and add it to the key ring.
3. Encrypt the files you want to be "secret".
4. For any automated user (one that must be able to decrypt without a passphrase), create a GPG key and create a subkey with an empty passphrase.

FYI: Your repo may use `keyrings/live` instead of `.blackbox`. See "Where is the configuration stored?"

### Run the initialize script.

You'll want to include blackbox's "bin" directory in your PATH:

```
export PATH=$PATH:/the/path/to/blackbox/bin
blackbox_initialize
```

If you're using antigen, adding `antigen bundle StackExchange/blackbox` to your .zshrc will download this repository and add it to your $PATH.

### For the first user, create a GPG key and add it to the key ring.

Follow the instructions for "[How to indoctrinate a new user into the system?](#how-to-indoctrinate-a-new-user-into-the-system)". Only do Step 1.

Once that is done, is a good idea to test the system by making sure a file can be added to the system (see "How to enroll a new file into the system?"), and a different user can decrypt the file.

Make a new file and register it:

```
rm -f foo.txt.gpg foo.txt
echo This is a test. >foo.txt
blackbox_register_new_file foo.txt
```

Decrypt it:

```
blackbox_edit_start foo.txt.gpg
cat foo.txt
echo This is the new file contents. >foo.txt
```

Re-encrypt it:

```
blackbox_edit_end foo.txt.gpg
ls -l foo.txt*
```

You should only see `foo.txt.gpg` as `foo.txt` should be gone.

The next step is to commit `foo.txt.gpg` and make sure another user can check out, view, and change the contents of the file. That is left as an exercise for the reader. If you are feel like taking a risk, don't commit `foo.txt.gpg` and delete it instead.

Set up automated users or "role accounts"
=========================================

i.e. This is how a Puppet Master can have access to the unencrypted data.

FYI: Your repo may use `keyrings/live` instead of `.blackbox`. See "Where is the configuration stored?"

An automated user (a "role account") is one that that must be able to decrypt without a passphrase. In general you'll want to do this for the user that pulls the files from the repo to the master. This may be automated with Jenkins CI or other CI system.

GPG keys have to have a passphrase. However, passphrases are optional on subkeys. Therefore, we will create a key with a passphrase then create a subkey without a passphrase. Since the subkey is very powerful, it should be created on a very secure machine.

There's another catch. The role account probably can't check files into Git/Mercurial. It probably only has read-only access to the repo. That's a good security policy. This means that the role account can't be used to upload the subkey public bits into the repo.

Therefore, we will create the key/subkey on a secure machine as yourself. From there we can commit the public portions into the repo. Also from this account we will export the parts that the role account needs, copy them to where the role account can access them, and import them as the role account.

ProTip: If asked to generate entropy, consider running this on the same machine in another window: `sudo dd if=/dev/sda of=/dev/null`

For the rest of this doc, you'll need to make the following substitutions:

- ROLEUSER: svc_deployacct or whatever your role account's name is.
- NEWMASTER: the machine this role account exists on.
- SECUREHOST: The machine you use to create the keys.

NOTE: This should be more automated/scripted. Patches welcome.

On SECUREHOST, create the puppet master's keys:

```
$ mkdir /tmp/NEWMASTER
$ cd /tmp/NEWMASTER
$ gpg --homedir . --gen-key
Your selection?
   (1) RSA and RSA (default)
What keysize do you want? (2048) DEFAULT
Key is valid for? (0) DEFAULT

# Real name: Puppet CI Deploy Account
# Email address: svc_deployacct@hostname.domain.name
```

NOTE: Rather than a real email address, use the username@FQDN of the host the key will be used on. If you use this role account on many machines, each should have its own key. By using the FQDN of the host, you will be able to know which key is which. In this doc, we'll refer to username@FQDN as $KEYNAME

Save the passphrase somewhere safe!

Create a sub-key that has no password:

```
$ gpg --homedir . --edit-key svc_deployacct
gpg> addkey
(enter passphrase)
  Please select what kind of key you want:
   (3) DSA (sign only)
   (4) RSA (sign only)
   (5) Elgamal (encrypt only)
   (6) RSA (encrypt only)
Your selection? 6
What keysize do you want? (2048)
Key is valid for? (0)
Command> key 2
(the new subkey has a "*" next to it)
Command> passwd
(enter the main key's passphrase)
(enter an empty passphrase for the subkey... confirm you want to do this)
Command> save
```

Now securely export this directory to NEWMASTER:

```
gpg --homedir . --export -a svc_sadeploy >/tmp/NEWMASTER/pubkey.txt
tar cvf /tmp/keys.tar .
rsync -avP /tmp/keys.tar NEWMASTER:/tmp/.
```

On NEWMASTER, receive the new GnuPG config:

```
sudo -u svc_deployacct bash
mkdir -m 0700 -p ~/.gnupg
cd ~/.gnupg && tar xpvf /tmp/keys.tar
```

<!---
Back on SECUREHOST, import the pubkey into the repository.

```
$ cd .blackbox
$ gpg --homedir . --import /tmp/NEWMASTER/pubkey.txt
```
-->

Back on SECUREHOST, add the new email address to .blackbox/blackbox-admins.txt:

```
cd /path/to/the/repo
blackbox_addadmin $KEYNAME /tmp/NEWMASTER
```

Verify that secring.gpg is a zero-length file. If it isn't, you have somehow added a private key to the keyring. Start over.

```
cd .blackbox
ls -l secring.gpg
```

Commit the recent changes:

```
cd .blackbox
git commit -m"Adding key for KEYNAME" pubring.gpg trustdb.gpg blackbox-admins.txt
```

Regenerate all encrypted files with the new key:

```
blackbox_update_all_files
git status
git commit -m"updated encryption" -a
git push
```

On NEWMASTER, import the keys and decrypt the files:

```
sudo -u svc_sadeploy bash   # Become the role account.
gpg --import /etc/puppet/.blackbox/pubring.gpg
export PATH=$PATH:/path/to/blackbox/bin
blackbox_postdeploy
sudo -u puppet cat /etc/puppet/hieradata/blackbox.yaml # or any encrypted file.
```

ProTip: If you get "gpg: decryption failed: No secret key" then you forgot to re-encrypt blackbox.yaml with the new key.

On SECUREHOST, securely delete your files:

```
cd /tmp/NEWMASTER
# On machines with the "shred" command:
shred -u /tmp/keys.tar
find . -type f -print0 | xargs -0 shred -u
# All else:
rm -rf /tmp/NEWMASTER
```

Also shred any other temporary files you may have made.

Replacing expired keys
======================

If someone's key has already expired, blackbox will stop
encrypting.  You see this error:

```
$ blackbox_edit_end modified_file.txt
--> Error: can't re-encrypt because a key has expired.
```

FYI: Your repo may use `keyrings/live` instead of `.blackbox`. See "Where is the configuration stored?"

You can also detect keys that are about to expire by issuing this command and manually reviewing the "expired:" dates:

    gpg --homedir=.blackbox  --list-keys

or... list UIDs that will expire within 1 month from today: (Warning: this also lists keys without an expiration date)

    gpg --homedir=.blackbox --list-keys  --with-colons --fixed-list-mode  | grep ^uid | awk -F: '$6 < '$(( $(date +%s) + 2592000))

Here's how to replace the key:

- Step 1. Administrator removes expired user:

Warning: This process will erase any unencrypted files that you were in the process of editing. Copy them elsewhere and restore the changes when done.

```
blackbox_removeadmin expired_user@example.com
# This next command overwrites any changed unencrypted files. See warning above.
blackbox_update_all_files
git commit -m "Re-encrypt all files"
gpg --homedir=.blackbox --delete-key expired_user@example.com
git commit -m 'Cleaned expired_user@example.com from keyring'  .blackbox/*
git push
```

- Step 2. Expired user adds an updated key:

```
git pull
blackbox_addadmin updated_user@example.com
git commit -m'NEW ADMIN: updated_user@example.com .blackbox/pubring.gpg .blackbox/trustdb.gpg .blackbox/blackbox-admins.txt
git push
```

- Step 3. Administrator re-encrypts all files with the updated key of the expired user:

```
git pull
gpg --import .blackbox/pubring.gpg
blackbox_update_all_files
git commit -m "Re-encrypt all files"
git push
```

- Step 4: Clean up:

Any files that were temporarily copied in the first step so as to not be overwritten can now be copied back and re-encrypted with the `blackbox_edit_end` command.

(Thanks to @chishaku for finding a solution to this problem!)

### Configure git to show diffs in encrypted files

It's possible to tell Git to decrypt versions of the file before running them through `git diff` or `git log`. To achieve this do:

- Add the following to `.gitattributes` at the top of the git repository:

```
*.gpg diff=blackbox
```

- Add the following to `.git/config`:

```
[diff "blackbox"]
    textconv = gpg --use-agent -q --batch --decrypt
````

And now commands like `git log -p file.gpg` will show a nice log of the changes in the encrypted file.

Some common errors
==================

`gpg: filename: skipped: No public key` -- Usually this means there is an item in `.blackbox/blackbox-admins.txt` that is not the name of the key. Either something invalid was inserted (like a filename instead of a username) or a user has left the organization and their key was removed from the keychain, but their name wasn't removed from the blackbox-admins.txt file.

`gpg: decryption failed: No secret key` -- Usually means you forgot to re-encrypt the file with the new key.

`Error: can't re-encrypt because a key has expired.` -- A user's key has expired and can't be used to encrypt any more. Follow the [Replace expired keys](#replace-expired-keys) tip.

FYI: Your repo may use `keyrings/live` instead of `.blackbox`. See "Where is the configuration stored?"

Using Blackbox without a repo
=============================

If the files are copied out of a repo they can still be decrypted and edited. Obviously edits, changes to keys, and such will be lost if they are made outside the repo. Also note that commands are most likely to only work if run from the base directory (i.e. the parent to the .blackbox directory).

The following commands have been tested outside a repo:

- `blackbox_postdeploy`
- `blackbox_edit_start`
- `blackbox_edit_end`

Some Subversion gotchas
=======================

The current implementation will store the blackbox in `/keyrings` at the root of the entire repo.  This will create an issue between environments that have different roots (i.e. checking out `/` on development vs `/releases/foo` in production). To get around this, you can `export BLACKBOX_REPOBASE=/path/to/repo` and set a specific base for your repo.

This was originally written for git and supports a two-phase commit, in which `commit` is a local commit and "push" sends the change upstream to the version control server when something is registered or deregistered with the system.  The current implementation will immediately `commit` a file (to the upstream subversion server) when you execute a `blackbox_*` command.

Using Blackbox when gpg2 is installed next to gpg
=================================================

In some situations, team members or automated roles need to install gpg
2.x alongside the system gpg version 1.x to catch up with the team's gpg
version. On Ubuntu 16, you can ```apt-get install gnupg2``` which
installs the binary gpg2. If you want to use this gpg2 binary, run every
blackbox command with GPG=gpg2.

For example:

```
GPG=gpg2 blackbox_postdeploy
```

How to submit bugs or ask questions?
====================================

We welcome questions, bug reports and feedback!

The best place to start is to join the [blackbox-project mailing list](https://groups.google.com/d/forum/blackbox-project) and ask there.

Bugs are tracked here in Github. Please feel free to [report bugs](https://github.com/StackExchange/blackbox/issues) yourself.

Developer Info
==============

Code submissions are gladly welcomed! The code is fairly easy to read.

Get the code:

```
git clone git@github.com:StackExchange/blackbox.git
```

Test your changes:

```
make confidence
```

This runs through a number of system tests. It creates a repo, encrypts files, decrypts files, and so on. You can run these tests to verify that the changes you made didn't break anything. You can also use these tests to verify that the system works with a new operating system.

Please submit tests with code changes:

The best way to change BlackBox is via Test Driven Development. First add a test to `tools/confidence.sh`. This test should fail, and demonstrate the need for the change you are about to make. Then fix the bug or add the feature you want. When you are done, `make confidence` should pass all tests. The PR you submit should include your code as well as the new test. This way the confidence tests accumulate as the system grows as we know future changes don't break old features.

Note: The tests currently assume "git" and have been tested only on CentOS, Mac OS X, and Cygwin. Patches welcome!

Alternatives
============

Here are other open source packages that do something similar to BlackBox. If you like them better than BlackBox, please use them.

- [git-crypt](https://www.agwa.name/projects/git-crypt/)
- [Pass](http://www.zx2c4.com/projects/password-store/)
- [Transcrypt](https://github.com/elasticdog/transcrypt)
- [Keyringer](https://keyringer.pw/)
- [git-secret](https://github.com/sobolevn/git-secret)

git-crypt has the best git integration. Once set up it is nearly transparent to the users. However it only works with git.


License
=======

This content is released under the MIT License.
See the [LICENSE.txt](LICENSE.txt) file.