salty/README.md

![logo](https://raw.githubusercontent.com/carlos8f/salty-gui/master/public/salt-shaker-inverse.png) salty
=====

Alternative public key encryption

## Description

Salty is a [nodejs](https://nodejs.org/)-powered CLI-based alternative to PGP/GPG using [NaCl](https://en.wikipedia.org/wiki/NaCl_(software)) instead of RSA/DSA.

Commits and tags in this repo are signed with GPG key [5FBB 2F98 3862 1AFF](https://keybase.io/carlos8f).

### Upcoming GUI

A GUI is being developed as a node HTTP server you can host locally or remotely to access your wallet. Follow its development [here](https://github.com/carlos8f/salty-gui).

### Features

- NO [3rd parties](https://peerio.com/pricing.html), NO [p2p network](https://en.wikipedia.org/wiki/PRISM_(surveillance_program)), NO [browser js](https://www.nccgroup.trust/us/about-us/newsroom-and-events/blog/2011/august/javascript-cryptography-considered-harmful/), NO [exotic/compiled deps](https://www.openssl.org/news/vulnerabilities.html), no [Comodo SSL](https://www.reddit.com/r/programming/comments/4pj89t/support_lets_encrypt_get_cloudflare_cdn_et_al_to/), and NO [shady corporations](https://github.com/VirgilSecurity). PERIOD.
- general purpose CLI, lightweight library attached
- audited, bundled dependencies - no install scripts or backdoors
- supports anonymous-sender or signed/verified messaging
- sharable pubkey string that can fit in a single tweet
- does NOT use your ssh keys, pgp keys, or anything RSA
- encrypt public key is always ephemeral - does NOT leak metadata
- sender identity is deniable, unless they explicitly commit to sign the message
- file length hidden with padding
- public signing/verifying with detached signatures
- binary or "ascii armor" PEM output
- import/export your wallet folder - PEM encoded and secretboxed with Scrypt KDF
- (new in 3.1) can use anonymous private [Github gists](https://gist.github.com/) to remotely store salty messages
- (new in 3.1) full tar/gz support for encrypting/decrypting directories (supports symmetric or asymmetric cipher)
- MIT-licensed

## Install (Mac OSX)

```
$ brew tap carlos8f/tap
$ brew install salty
```

## Other UNIX-based platforms:

Install first: [nodejs](https://nodejs.org/)

```
$ wget https://github.com/carlos8f/salty/archive/v4.0.0.tar.gz
$ shasum -a 256 v4.0.0.tar.gz
98d9b9a5bb6e11e1292a8153a4c8b0741bb53cefce826783297aa7df55c2f903  v4.0.0.tar.gz
$ tar -xf v4.0.0.tar.gz
$ sudo ln -sf `pwd`/salty-4.0.0/bin/salty /usr/local/bin/salty
```

## Useful links

- [S8F Console: How to use Salty](https://s8f.org/1465282150/) - Basic demonstration of the Salty CLI
- [Salty: PGP Evolved](https://s8f.org/1465262642/) - How Salty improves on the PGP model

## Format

Byte counts are in `()` parenthesis.

### Salty wallet

Designed to allow both decryption and signing.

```
  decryption      signing
-------------- + -----------
decryptSk (32)   signSk (64)
```

Example (wallets are stored as encrypted PEM on disk)

```
-----BEGIN SALTY WALLET-----
Proc-Type: 4,ENCRYPTED
DEK-Info: NACL-SCRYPT,IP3NRMw15AGYyU56xwYPVJFa4Xx0aock

OjCNhUvjNml3bebBVsIBpTBdvWSRkUG6vVZkdpzFZf9Ak/Bh0ghaXsEhuAiElEMy
2ghCEF5oQVO3dAWdflcvuVH3CSXlPlBfXWr6Y0EEOST3jYwaRS8Qfa2786YNBYCm
NBm4au6wbuVp8dL41jhLeQ==
-----END SALTY WALLET-----
```

### Salty pubkey

Designed to be sharable, human-readable, and unique.

```
              public keys                           optional meta
----------------------------------------- [space] --------  --------
  base58(encryptPk (32) + verifyPk (32))          "{name}"  <{email}>

```

Example:

```
2ZuU37oJ1erD85AzVohXq6Y74GHv2hjNYB9fu3P5o9rsGSvRo19HK2wTL4MLma3N6gVFqXN81VTqQ6apBhc5Kezq "Carlos" <carlos@s8f.org>
```

### Salty file

Designed to allow anonymous or signed messages, and verify message integrity.

```
required meta    ciphertext  
-------------- + ----------
ephemeral (80)    plaintext
```

### Ephemeral

Designed to hide the message and header inside an anonymously encrypted/authenticated payload.

```
    random         random      message length (encrypted, 24 bytes)
-------------- + ---------- + ---------------------------------------
encryptPk (32)   nonce (24)       totalSize (8 bytes, big endian)
```

### Plaintext

Appends a header to the message for verification, and pads the plaintext with null bytes.

```
--------- + ------- + -------------------
 message     header      null bytes (?)
```

### Header

Always contains a sha256 HMAC to authenticate the message, and optionally contains a signature from the sender.

```
hash: hex( sha256_hmac( shared_secret ) of message )
[from-salty-id]: base58(encryptPk (32) + verifyPk (32))
[to-salty-id]: base58(encryptPk (32) + verifyPk (32))
[signature]: base58( detached sig of previous headers )
```

Example:

```
hash:          3a5a42ad3cadea1ac4abd5169a7a1c2b2017404e00b9f08c5dee6c205f7a197a
from-salty-id: 2ZuU37oJ1erD85AzVohXq6Y74GHv2hjNYB9fu3P5o9rsGSvRo19HK2wTL4MLma3N6gVFqXN81VTqQ6apBhc5Kezq
to-salty-id:   self
signature:     5V1c1P5a8dqDVMPhwqnDF39ZrHpaw7jhetEgHyPUkjM8tYvugPzDJ3xyhD9WdJQ4AjwYkN2XdWhnTB3GTRMJuAEd
```

### Signature

Always contains the signer's public keys, a sha256 HMAC to authenticate the file, keyed with a 32-byte random nonce, and a signature.

```
from-salty-id: base58(encryptPk (32) + verifyPk (32))
hash-algorithm: algorithm
hash: hex( algorithm( file ) )
signature: base58( detached sig of previous headers )
```

Example:

```
from-salty-id: 2ZuU37oJ1erD85AzVohXq6Y74GHv2hjNYB9fu3P5o9rsGSvRo19HK2wTL4MLma3N6gVFqXN81VTqQ6apBhc5Kezq
hash-algorithm: sha256
hash: 19e406822f9eac2c19f0a0d59c1ab1f554e354fadbc1836f9e10858ce227ed2c
signature: 49VPoEqf3iNrpaWCjEejfe2vqT8ZHHkb68U6JRzxCEqWSoVoe7AjPEN2c3XYXgCuW7P3htsWbXZdF6LAsoyXoE3v
```

## Usage

```
  Usage: salty [options] [command]


  Commands:

    init [options]                                initialize or update a wallet
    id|pubkey                                     output your shareable pubkey string
    import|i <pubkey|url|file>                    import a pubkey
    ls|l                                          list imported keys
    rm <pubkey|email>                             remove pubkey
    encrypt|e [options] [infile|indir] [outfile]  encrypt a file
    decrypt|d [options] <infile|gist> [outfile]   decrypt and verify a file
    sign|s [options] <infile> [outfile]           create a signature
    verify|v [options] <insig> [infile]           verify a signature
    save [indir] [outfile]                        save an encrypted backup of your wallet
    restore [infile] [outdir]                     restore your wallet from a backup
    encode [infile]                               output base58-encoded data to STDOUT
    decode [infile]                               output base58-decoded data to STDOUT
    *

  Options:

    -h, --help          output usage information
    -V, --version       output the version number
    -w, --wallet <dir>  wallet location (default: ~/.salty)
    -F, --force         do it anyway
```

### salty encrypt

```
  Usage: encrypt|e [options] [infile|indir] [outfile]

  encrypt a file

  Options:

    -h, --help                 output usage information
    -t, --to <email>           email address to encrypt for. (must be imported first. default: self)
    -m, --message              compose a message instead of using [infile] (implies -a)
    -s, --sign                 sign the message to reveal/prove our identity
    -H, --header <key: value>  add a custom header (repeatable)
    -a, --armor                output ASCII armor to STDOUT
    -g, --gist                 upload encrypted result as a gist
    -F, --force                ignore warnings and do it
    -D, --delete               delete the original file after encryption
```

### salty decrypt

```
  Usage: decrypt|d [options] <infile|gist> [outfile]

  decrypt and verify a file

  Options:

    -h, --help    output usage information
    -s, --sig     require a signature
    -a, --armor   expect ASCII armor, output to STDOUT
    -g, --gist    download the encrypted input from a gist
    -F, --force   ignore warnings and do it
    -D, --delete  delete the salty file after verification

```

### salty sign

```
  Usage: sign|s [options] <infile> [outfile]

  create a signature

  Options:

    -h, --help                 output usage information
    -H, --header <key: value>  add a custom header (repeatable)
    -h, --hash <alg>           hash algorithm (default: sha256)
    -a, --armor                output ASCII armor to STDOUT
    -F, --force                ignore warnings and do it
```

### salty verify

```
 Usage: verify|v [options] <insig> [infile]

  verify a signature

  Options:

    -h, --help   output usage information
    -a, --armor  expect ASCII armor, output to STDOUT
```

## Log

### release 4.0

- now you can regenerate your decryption key with `salty init --regen`
- switch to base58-encoding for everything but hashes
- hashes are now hex-encoded
- `\r\n` newlines in header/PEM changed to `\n`
- Custom header support for encryption or signing
- import now dedupes on verifyPk/email
- key removal by pubkey/email now supported
- "attached" signatures now available with ASCII armor flag
- signatures can be verified without previous setup (wallet creation)
- signatures support arbitrary hash algorithms
- added `--no-translate` flag to output raw header

### release v3.1.0

- Added anonymous gist support
- Added tar/gz support for encrypting directories

- - -

### License: MIT

- Copyright (C) 2016 Carlos Rodriguez (http://s8f.org/)
- Copyright (C) 2016 Terra Eclipse, Inc. (http://www.terraeclipse.com/)

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the &quot;Software&quot;), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is furnished
to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED &quot;AS IS&quot;, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.