smart_locker/utils/
config.rs

1use aes_gcm::aead::consts::U12;
2use aes_gcm::aead::KeyInit;
3use aes_gcm::{Aes256Gcm, Key, Nonce};
4use flate2::write::GzEncoder;
5use flate2::Compression;
6
7pub const SIGNATURE: &[u8; 8] = b"SMARTLKR"; // Signature fixe pour identifier le format
8pub const FORMAT_VERSION: u8 = 1; // Version actuelle du format
9pub const NONCE_SIZE: usize = 12; // Taille du nonce (12 octets pour AES-GCM)
10pub const KEY_SIZE: usize = 32; // Taille de la clé symétrique (32 octets pour AES-256)
11
12/// Configuration structure for encryption settings.
13/// This structure defines the parameters used for AES-GCM encryption,
14/// including the signature, format version, nonce size, key size, and compression settings.
15pub struct EncryptionConfig {
16    /// Fixed signature to identify the format.
17    pub signature: &'static [u8; 8],
18    /// Current version of the format.
19    pub format_version: u8,
20    /// Size of the nonce (12 bytes for AES-GCM).
21    pub nonce_size: usize,
22    /// Size of the symmetric key (32 bytes for AES-256).
23    pub key_size: usize,
24    /// Compression level for Gzip.
25    pub compression: Compression,
26}
27
28impl Default for EncryptionConfig {
29    fn default() -> Self {
30        Self::new()
31    }
32}
33
34impl EncryptionConfig {
35    /// Creates a new instance of the encryption configuration with default values.
36    pub fn new() -> Self {
37        Self {
38            signature: SIGNATURE,
39            format_version: FORMAT_VERSION,
40            nonce_size: NONCE_SIZE,
41            key_size: KEY_SIZE,
42            compression: Compression::default(),
43        }
44    }
45
46    /// Initializes the AES-GCM cipher with the provided key.
47    ///
48    /// # Arguments
49    /// * `key_data` - A byte slice containing the encryption key.
50    ///
51    /// # Returns
52    /// * `Ok(Aes256Gcm)` - The initialized AES-GCM cipher.
53    /// * `Err(String)` - An error message if the key size is invalid.
54    pub fn init_cipher(&self, key_data: &[u8]) -> Result<Aes256Gcm, String> {
55        if key_data.len() != self.key_size {
56            return Err(format!(
57                "Invalid key size: expected {} bytes, got {} bytes",
58                self.key_size,
59                key_data.len()
60            ));
61        }
62        let key = Key::<Aes256Gcm>::from_slice(key_data);
63        Ok(Aes256Gcm::new(key))
64    }
65
66    /// Generates a random nonce for AES-GCM encryption.
67    ///
68    /// # Returns
69    /// * `Nonce<U12>` - A randomly generated nonce of 12 bytes.
70    pub fn generate_nonce(&self) -> Nonce<U12> {
71        let random_bytes = rand::random::<[u8; NONCE_SIZE]>();
72        *Nonce::<U12>::from_slice(&random_bytes)
73    }
74
75    /// Initializes a Gzip compressor with the specified compression level.
76    ///
77    /// # Returns
78    /// * `GzEncoder<Vec<u8>>` - A Gzip encoder for compressing data.
79    pub fn init_compressor(&self) -> GzEncoder<Vec<u8>> {
80        GzEncoder::new(Vec::new(), self.compression)
81    }
82}
smart_locker/utils/config.rs

smart_locker/utils/
config.rs
