Rust Cryptographic Primitives
=============================
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This repository contains a collection of cryptographic primitives implemented in Rust. The goal is to provide a comprehensive set of cryptographic primitives that are easy to use and hard to misuse. 

This crate was done as a personal project to learn Rust and cryptography, implementing some of the algorithms I learned in the "Secure and Dependable Systems" course at my university. The code is open source and I am happy to receive contributions and feedback. Feel free to open an issue or a pull request on [this repository](https://github.com/razvanperial/cryptographic_primitives).

If this crate is useful to you, please consider giving it a star on [GitHub](https://github.com/razvanperial/cryptographic_primitives) :)

## Features

The crate currently provides the following cryptographic primitives, with an encryption and decryption function for each:

- Rail Fence Cipher
- Route Cipher
- Feistel Network
- Substitution-Permutation Network (SPN)
- Advanced Encryption Standard (AES)

The `helpers` module provides the following helper functions for cryptographic algorithms:

- `rotl8`
- `initialize_aes_sbox`
- `permute`
- `feistel_round_function`
- `kdf`
- `gmix_column`
- `gmix_column_inv`
- `xor_bytes`

The `constants` module provides some useful constants for cryptographic algorithms, such as:
- a sample `S-Box`
- a sample `P-Box`
- `MIX_COLUMNS_LOOKUP_2`, `MIX_COLUMNS_LOOKUP_3`, `MIX_COLUMNS_LOOKUP_9`, `MIX_COLUMNS_LOOKUP_11`, `MIX_COLUMNS_LOOKUP_13`, `MIX_COLUMNS_LOOKUP_14` lookup tables for the AES MixColumns operation

The `block_cipher` module provides the following block cipher modes of operation, with an encryption and decryption function for each:
- Electronic Codebook (ECB) mode
- Cipher Block Chaining (CBC) mode
- Counter (CTR) mode
- Output Feedback (OFB) mode

For any suggestions or requests, feel free to open an issue on [this repository](https://github.com/razvanperial/cryptographic_primitives).

## Usage

Add this to your `Cargo.toml`:

```toml
[dependencies]
cryptographic_primitives = "0.2.0"
```
You can also use `cargo` to add the dependency to your `Cargo.toml`:

```sh
cargo add cryptographic_primitives
```

Then, simply import the crate and use the cryptographic primitives:

```rust
use cryptographic_primitives::*;
```

## Example

Here is an example of using the `aes_128_encrypt` and `aes_128_decrypt` functions to encrypt and decrypt a plaintext using the Electronic Codebook (ECB) mode of operation:

```rust
use cryptographic_primitives::{aes_128_decrypt, aes_128_encrypt};
use cryptographic_primitives::block_ciphers::{ecb_encrypt, ecb_decrypt};

let plaintext = b"Hello, World!";
let key = 0x2b7e151628aed2a6abf7158809cf4f3c;

let encrypted = ecb_encrypt(plaintext, key, aes_128_encrypt).unwrap();
let decrypted = ecb_decrypt(&encrypted, key, aes_128_decrypt).unwrap();

assert_eq!(decrypted, plaintext);
```

## License

This project is licensed under the [MIT license](https://github.com/razvanperial/cryptographic_primitives/blob/master/LICENSE).