Shitkey: Simple and Secure File Encryption

Shitkey is a command-line tool for securely encrypting and decrypting files using a password. It is written in Go and uses modern cryptographic primitives to ensure the confidentiality and integrity of your data.

Simple Interface: A straightforward command-line interface for encrypting and decrypting files.
Strong Cryptography: Shitkey uses AES-256 in GCM mode for encryption.
Password-Based Key Derivation: It uses scrypt to derive a strong cryptographic key from your password, making it resistant to brute-force attacks.
Salt and Nonce Generation: Each encryption operation uses a unique, cryptographically-secure random salt and nonce to protect against common attacks.
Cross-Platform: The tool is written in Go, which makes it easy to compile and run on various operating systems.

Installation

From Source

Clone the repository:

git clone https://github.com/nthnn/shitkey.git
cd shitkey

Build the executable:
```
go build -o shitkey
```
(Optional) Move the executable to your PATH:
```
sudo mv shitkey /usr/local/bin/
```

Debian/Ubuntu

You can build a .deb package using the provided build.sh script.

Clone the repository and navigate to the directory:

git clone https://github.com/nthnn/shitkey.git
cd shitkey

Run the build script:
```
./build.sh
```
Install the generated .deb package:
```
sudo dpkg -i shitkey_1.4_amd64.deb
```

Usage

Encrypt a file

To encrypt a file, use the encrypt command followed by the filename. The encrypted file will have a .sk extension.

shitkey encrypt mysecretfile.txt

Decrypt a file

To decrypt a file, use the decrypt command followed by the filename. The input file must have a .sk extension.

shitkey decrypt mysecretfile.txt.sk

View version

To display the version of Shitkey, use the version command.

shitkey version

How it works

Password Input: The user is prompted to enter a password, which is read securely without being echoed to the terminal.
Salt Generation: A cryptographically-secure random salt is generated for each encryption process. The salt has a size of 32 bytes.
Key Derivation: The scrypt algorithm is used to derive a strong encryption key from the user's password and the generated salt. The key size is 32 bytes.
Encryption: The derived key is used to create an AES-256 cipher block. An AEAD (Authenticated Encryption with Associated Data) scheme, GCM (Galois/Counter Mode), is used for encryption to ensure both confidentiality and integrity. A unique nonce (12 bytes in size) is also generated for the encryption process.
File Output: The encrypted data is written to a new file with the .sk extension. This new file contains the salt, the nonce, and the ciphertext in that specific order.

License

Shitkey is free software licensed under the GNU General Public License v3.0 or any later version. You should have received a copy of the GNU General Public License with this program. If not, see https://www.gnu.org/licenses/.