defendor 0.0.6

A secure file encryption tool with AES-GCM and Argon2 for password hashing.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141

use argon2::{Algorithm, Argon2, Params, Version};
use secrecy::{ExposeSecret, SecretBox};
use zeroize::Zeroizing;

use crate::{
    KEY_LENGTH,
    error::{DefendorError, DefendorResult},
    key_manager::KeyManager,
    utils::{decrypt_data, encrypt_data, get_random_bytes},
};

// 32 bytes for salt
const SALT_LENGTH: usize = 32;

#[derive(Debug)]
pub struct PasswordConfig {
    pub salt: Vec<u8>,
    pub nonce: Vec<u8>,
    pub encrypted_key: Vec<u8>,
}

pub trait Password: KeyManager {
    type PasswordError: From<Self::KeyManagerError> + From<DefendorError>;
    fn get_password_config(
        &self,
    ) -> impl Future<Output = Result<PasswordConfig, Self::PasswordError>>;
    fn set_password_config(
        &mut self,
        config: PasswordConfig,
    ) -> impl Future<Output = Result<(), Self::PasswordError>>;
    fn delete_password_config(&mut self) -> impl Future<Output = Result<(), Self::PasswordError>>;
    /// 初始化密钥库
    fn init_password<Z>(
        &mut self,
        password: Z,
    ) -> impl Future<Output = Result<&mut Self, Self::PasswordError>>
    where
        Z: Into<Zeroizing<Vec<u8>>>,
    {
        async {
            let key = self.get_key().await?;
            let salt = get_random_bytes(SALT_LENGTH)?;
            let unlock_key = derive_key_by_password(&password.into(), &salt)?;
            let nonce = get_random_bytes(12)?;

            let encrypted_key = encrypt_data(key.expose_secret(), &unlock_key, &nonce)?;

            self.set_password_config(PasswordConfig {
                salt,
                nonce,
                encrypted_key,
            })
            .await?;

            Ok(self)
        }
    }

    /// 加载密钥库
    fn load_by_password<Z>(
        &mut self,
        password: Z,
    ) -> impl Future<Output = Result<&mut Self, Self::PasswordError>>
    where
        Z: Into<Zeroizing<Vec<u8>>>,
    {
        async {
            let password_config = self.get_password_config().await?;

            let unlock_key = derive_key_by_password(&password.into(), &password_config.salt)?;

            let key = decrypt_data(
                &password_config.encrypted_key,
                &unlock_key,
                &password_config.nonce,
            )?;

            self.set_key(SecretBox::new(Box::new(key))).await?;

            Ok(self)
        }
    }

    fn change_password<Z>(
        &mut self,
        old_password: Z,
        new_password: Z,
    ) -> impl Future<Output = Result<(), Self::PasswordError>>
    where
        Z: Into<Zeroizing<Vec<u8>>>,
    {
        async {
            let password_config = self.get_password_config().await?;
            let old_unlock_key =
                derive_key_by_password(&old_password.into(), &password_config.salt)?;
            let old_key = decrypt_data(
                &password_config.encrypted_key,
                &old_unlock_key,
                &password_config.nonce,
            )?;

            let key = self.get_key().await?;

            if key.expose_secret() != &old_key {
                return Err(DefendorError::PasswordError.into());
            }

            let salt = get_random_bytes(SALT_LENGTH)?;
            let unlock_key = derive_key_by_password(&new_password.into(), &salt)?;

            let nonce = get_random_bytes(12)?;
            let encrypted_key = encrypt_data(key.expose_secret(), &unlock_key, &nonce)?;

            self.set_password_config(PasswordConfig {
                salt,
                nonce,
                encrypted_key,
            })
            .await?;

            Ok(())
        }
    }
}

/// 密码和盐派生密钥，使用更高安全参数
fn derive_key_by_password(
    password: &Zeroizing<Vec<u8>>,
    salt: &[u8],
) -> DefendorResult<SecretBox<Vec<u8>>> {
    let argon2 = Argon2::new(
        Algorithm::Argon2id,
        Version::V0x13,
        Params::new(128 * 1024, 4, 4, None)?, // 128MB, 4线程, 4次迭代
    );
    let mut key = vec![0u8; KEY_LENGTH];

    argon2.hash_password_into(password, salt, &mut key)?;

    Ok(SecretBox::new(Box::new(key)))
}