rusty_crypt

A simple and secure Rust library providing an easy-to-use interface for AES-256-GCM authenticated encryption.

rusty_crypt provides high-level utilities to easily integrate modern symmetric encryption into Rust applications.

Features

• 🔐 AES-256-GCM authenticated encryption
• 🔑 Secure AES-256 key generation
• 🎲 Secure nonce generation
• 📦 Text encryption and decryption
• 📁 Binary data encryption and decryption
• ⚠️ Safe error handling with Result<T, CryptoError>
• 🚫 No panic-based cryptographic failures

---

Overview

rusty_crypt uses the AES-256-GCM algorithm.

AES-GCM provides:

• Confidentiality
  Data is encrypted and cannot be read without the key.

• Integrity
  Any modification of encrypted data is detected.

• Authentication
  Invalid keys or corrupted ciphertext are rejected during decryption.

AES-256 requires a:

32 bytes key (256 bits)

AES-GCM uses a:

12 bytes nonce (96 bits)

A unique nonce must be generated for every encryption operation.

---

Quick Start

Encrypt and decrypt text

use base64::{engine::general_purpose, Engine};

use rusty_crypt::{
    AesGeneratedKey,
    AesGcmEncrypt,
    AesGcmDecrypt,
    AesGcmGeneratedNonce,
};


fn main() -> Result<(), Box<dyn std::error::Error>> {

    let key = AesGeneratedKey.generate_key()?;

    let key_base64 = general_purpose::STANDARD.encode(key);


    let nonce_generator = AesGcmGeneratedNonce;


    let encryptor = AesGcmEncrypt::new(
        &nonce_generator
    );


    let decryptor = AesGcmDecrypt;


    let message = "Hello rusty_crypt!";


    let encrypted = encryptor.encrypt(
        message,
        &key_base64
    )?;


    println!(
        "Encrypted: {}",
        encrypted
    );


    let decrypted = decryptor.decrypt(
        &encrypted,
        &key_base64
    )?;


    println!(
        "Decrypted: {}",
        decrypted
    );


    Ok(())
}

---

Encrypt binary data

rusty_crypt can encrypt any binary data:

• Files
• Images
• Documents
• Network payloads
• Serialized data

Example:

use rusty_crypt::{
    AesGeneratedKey,
    AesGcmEncrypt,
    AesGcmDecrypt,
    AesGcmGeneratedNonce,
};


fn main() -> Result<(), Box<dyn std::error::Error>> {

    let key = AesGeneratedKey.generate_key()?;


    let nonce_generator = AesGcmGeneratedNonce;


    let encryptor = AesGcmEncrypt::new(
        &nonce_generator
    );


    let decryptor = AesGcmDecrypt;


    let data = b"Secret binary data";


    let (ciphertext, nonce) =
        encryptor.encrypt_bytes(
            data,
            &key
        )?;


    let mut encrypted_data = Vec::new();


    encrypted_data.extend_from_slice(
        &nonce
    );


    encrypted_data.extend_from_slice(
        &ciphertext
    );


    let decrypted =
        decryptor.decrypt_bytes(
            &encrypted_data,
            &key
        )?;


    assert_eq!(
        data,
        decrypted.as_slice()
    );


    Ok(())
}

---

Key generation

Generate a secure AES-256 key:

use rusty_crypt::AesGeneratedKey;


fn main() -> Result<(), Box<dyn std::error::Error>> {

    let key = AesGeneratedKey.generate_key()?;


    println!(
        "Key size: {} bytes",
        key.len()
    );


    Ok(())
}

Output:

Key size: 32 bytes

---

Nonce generation

Generate a secure AES-GCM nonce:

use rusty_crypt::AesGcmGeneratedNonce;


fn main() -> Result<(), Box<dyn std::error::Error>> {

    let nonce_generator = AesGcmGeneratedNonce;


    let nonce =
        nonce_generator.generate_nonce()?;


    println!(
        "Nonce size: {} bytes",
        nonce.len()
    );


    Ok(())
}

Output:

Nonce size: 12 bytes

---

Error handling

All cryptographic operations return:

Result<T, CryptoError>

The library does not panic when an encryption or decryption error occurs.

Available errors:

• Invalid Base64
• Invalid AES key size
• Invalid nonce size
• Invalid ciphertext format
• Encryption failure
• Decryption failure
• Invalid UTF-8 data
• Random generation failure

Example:

use rusty_crypt::AesGcmDecrypt;


fn main() {

    let decryptor = AesGcmDecrypt;


    match decryptor.decrypt(
        "invalid_data",
        "invalid_key"
    ) {

        Ok(value) => {
            println!(
                "Decrypted: {}",
                value
            );
        }


        Err(error) => {
            println!(
                "Crypto error: {}",
                error
            );
        }
    }
}

---

Security recommendations

For secure applications:

• Never reuse an AES-GCM nonce with the same key.
• Never expose encryption keys.
• Store keys securely.
• Do not hardcode keys inside your source code.
• Use a secure key management system for production.

rusty_crypt provides low-level cryptographic primitives.

---

Documentation

Full API documentation:

https://docs.rs/rusty_crypt

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License

MIT License