Svanill (cli)

A command line tool to encrypt/decrypt your sensitive data.

The resulting data has the same format of Svanill (web), so you can pass data from one tool to the other.

To sync the encrypted data with an external server you can use svanill-vault-cli.

How to run

# encrypt (you will be prompted for the password)
svanill -i INPUT_FILE -o OUTPUT_FILE enc

# decrypt (you will be prompted for the password)
svanill -i INPUT_FILE -o OUTPUT_FILE dec

# you can omit input/output file, and use stdin/stdout instead

If you want to decrypt/open-in-editor/encrypt there is a tool that leverages svanill-cli, svanill-edit

svanill-edit FILENAME

Beware, to display plaintext in your editor of choice svanill-edit will keep a temporary file around, which is removed when the process terminates.

How to run the tests

cargo test

Goals

• have the means to manage secrets
• must be open source
• it must be a standalone program
• it must be portable (Linux, Windows (at least WSL), macOS, ...)
• it must be able to work in a sandboxed environment - no network, no filesystem, no ipc...
• the source code must be easily auditable
• any optional outgoing network requests must send data encrypted client-side

Non goals

• write the smallest possible file sacrificing documentation or readability
• give the ability to upload to more than one external service at once

Use cases

• You are using Svanill (web) too and you want to access your secrets using the command line
• You want to easily edit a file with secrets
• You want to share something privately, passing the password on a different channel

Encryption

Content is secured by a symmetric encryption algorithm, using AES-GCM.

The primitives comes from ring.

The key is derived using PBKDF2-HMAC-SHA-256, 100.000 iterations (default).

The size of the iv/nonce is 96 bit, randomly generated before any encryption.

The salt is 128 bit long, randomly generated before any encryption.

Random data is obtained from ring::rand::SystemRandom (its PRNG is suitable for cryptographic purposes).

Everything but the key is prepended to the ciphertext and thus public.

The data must be secure at rest, so the strength of the key is what matters most. You should use the longest passphrase you are confident to remember (assuming just english letters and digits, it should be at least 14 characters long - around 72 bit of entropy).

You can get informations about the produced output at Svanill (web) documentation.

To protect against a purposefully crafted high iteration number, which would starve the cpu, Svanill won't attempt to decrypt if that number is higher than what we use to encrypt.

Nothing from decryption is reused for future encryption, to prevent downgrade attacks or blatant compromissions (like reusing the iv).

Why not...

Most choices depend on the constraints of Svanill (web) documentation.

License

Svanill, an easily auditable tool to encrypt/decrypt your sensitive data. Copyright (C) 2017 Riccardo Attilio Galli

This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more details.

You should have received a copy of the GNU Affero General Public License along with this program. If not, see http://www.gnu.org/licenses/.