ncrypt_me/
decrypt.rs

1use super::{
2   EncryptedInfo, credentials::Credentials, encrypt::*, error::Error,
3   extract_encrypted_info_and_data,
4};
5use chacha20poly1305::aead::{Aead, Payload, generic_array::GenericArray};
6use secure_types::SecureBytes;
7use zeroize::Zeroize;
8
9/// Decrypts the data using the provided credentials
10///
11/// ### Arguments
12///
13/// - `data` - The data to decrypt
14/// - `credentials` - The credentials to use for decryption
15pub fn decrypt_data(data: Vec<u8>, credentials: Credentials) -> Result<SecureBytes, Error> {
16   let (_, encrypted_data) = extract_encrypted_info_and_data(&data)?;
17
18   let info = EncryptedInfo::from_encrypted_data(&data)?;
19
20   let decrypted_data = decrypt(credentials, info, encrypted_data)?;
21   let secure_data =
22      SecureBytes::from_vec(decrypted_data).map_err(|e| Error::Custom(e.to_string()))?;
23
24   Ok(secure_data)
25}
26
27/// Decrypts the data using the provided credentials
28///
29/// This is the same as `decrypt_data` but returns an unsecure [Vec<u8>]
30///
31/// Use this if the data you want to decrypt is too large to fit in a [SecureBytes]
32///
33/// ### Arguments
34///
35/// - `data` - The data to decrypt
36/// - `credentials` - The credentials to use for decryption
37pub fn decrypt_data_unsecured(data: Vec<u8>, credentials: Credentials) -> Result<Vec<u8>, Error> {
38   let (_, encrypted_data) = extract_encrypted_info_and_data(&data)?;
39
40   let info = EncryptedInfo::from_encrypted_data(&data)?;
41
42   let decrypted_data = decrypt(credentials, info, encrypted_data)?;
43   Ok(decrypted_data)
44}
45
46fn decrypt(credentials: Credentials, info: EncryptedInfo, data: Vec<u8>) -> Result<Vec<u8>, Error> {
47   credentials.is_valid()?;
48
49   let argon2 = &info.argon2;
50   let username = &credentials.username;
51   let password = &credentials.password;
52
53   let mut aad = username
54      .unlock_str(|username_str| argon2.hash_password(&username_str, info.username_salt.clone()))
55      .map_err(|e| Error::Custom(e.to_string()))?;
56
57   let password_hash = password
58      .unlock_str(|password_str| argon2.hash_password(&password_str, info.password_salt.clone()))
59      .map_err(|e| Error::Custom(e.to_string()))?;
60
61   let nonce = GenericArray::from_slice(&info.cipher_nonce);
62
63   let payload = Payload {
64      msg: data.as_ref(),
65      aad: &aad,
66   };
67
68   let cipher = xchacha20_poly_1305(password_hash);
69   let decrypted_data_res = cipher.decrypt(nonce, payload);
70   aad.zeroize();
71
72   let decrypted_data = match decrypted_data_res {
73      Ok(data) => data,
74      Err(e) => {
75         return Err(Error::DecryptionFailed(e.to_string()));
76      }
77   };
78
79   Ok(decrypted_data)
80}
ncrypt_me/decrypt.rs

ncrypt_me/
decrypt.rs
