trelent_hyok/held_data/encryption/
custom.rs

1//! Custom encryption strategy implementation.
2//!
3//! This module enables integration with any encryption algorithm by allowing
4//! users to provide their own encryption and decryption functions. It supports:
5//!
6//! - Custom encryption algorithms
7//! - Flexible metadata handling
8//! - Error handling
9//! - Thread-safe operations
10
11use crate::dek::DEK;
12use crate::error::encryption::EncryptionError;
13use crate::held_data::encryption::EncryptionStrategy;
14use async_trait::async_trait;
15use std::sync::Arc;
16
17/// A customizable encryption strategy that accepts user-defined functions.
18///
19/// This strategy allows integration with any encryption algorithm by accepting
20/// closures for encryption and decryption. Features include:
21///
22/// - Flexible algorithm choice
23/// - Custom metadata handling
24/// - Error handling
25/// - Thread-safe operations
26///
27/// # Security
28///
29/// When implementing custom operations, ensure:
30/// - Strong encryption algorithms
31/// - Proper key handling
32/// - Secure metadata management
33/// - Authentication where needed
34///
35/// # Example
36/// ```no_run
37/// use hyokashi::{CustomStrategy, EncryptionError, DEK};
38///
39/// // Define custom encryption/decryption functions
40/// let encrypt = |dek: DEK, data: Vec<u8>, metadata: Vec<u8>| {
41///     Box::pin(async move {
42///         // Implement secure encryption...
43///         Ok(data)
44///     })
45/// };
46///
47/// let decrypt = |dek: DEK, data: Vec<u8>, metadata: Vec<u8>| {
48///     Box::pin(async move {
49///         // Implement secure decryption...
50///         Ok(data)
51///     })
52/// };
53///
54/// // Create the custom strategy
55/// let strategy = CustomStrategy::new(encrypt, decrypt);
56///
57/// // Use the strategy
58///     let dek = DEK::new(vec![1, 2, 3]);
59///     let data = vec![4, 5, 6];
60///     let metadata = vec![7, 8, 9];
61///
62///     let encrypted = strategy.encrypt(dek.clone(), data.clone(), metadata.clone()).await?;
63///     let decrypted = strategy.decrypt(dek, encrypted, metadata).await?;
64///     assert_eq!(data, decrypted);
65///
66/// ```
67pub struct CustomStrategy<ED: Send> {
68    encrypt_fn: Arc<
69        dyn (Fn(
70            DEK,
71            Vec<u8>,
72            ED
73        ) -> futures::future::BoxFuture<'static, Result<Vec<u8>, EncryptionError>>) +
74        Send +
75        Sync
76    >,
77    decrypt_fn: Arc<
78        dyn (Fn(
79            DEK,
80            Vec<u8>,
81            ED
82        ) -> futures::future::BoxFuture<'static, Result<Vec<u8>, EncryptionError>>) +
83        Send +
84        Sync
85    >,
86}
87
88impl<ED: Send> CustomStrategy<ED> {
89    /// Creates a new custom strategy with provided encryption and decryption functions
90    ///
91    /// # Arguments
92    /// * `encrypt_fn` - Async function for encryption
93    /// * `decrypt_fn` - Async function for decryption
94    ///
95    /// # Returns
96    /// * `Self` - New instance of CustomStrategy
97    pub fn new<E, D>(encrypt_fn: E, decrypt_fn: D) -> Self
98    where
99        E: Fn(
100            DEK,
101                Vec<u8>,
102            ED
103        ) -> futures::future::BoxFuture<'static, Result<Vec<u8>, EncryptionError>> +
104        Send +
105        Sync +
106        'static,
107        D: Fn(
108            DEK,
109                Vec<u8>,
110            ED
111        ) -> futures::future::BoxFuture<'static, Result<Vec<u8>, EncryptionError>> +
112        Send +
113        Sync +
114        'static
115    {
116        CustomStrategy {
117            encrypt_fn: Arc::new(encrypt_fn),
118            decrypt_fn: Arc::new(decrypt_fn),
119        }
120    }
121}
122
123/// Container for custom encryption metadata
124#[derive(Debug, Clone)]
125pub struct CustomEncryptionData {
126    /// Custom metadata for encryption/decryption operations
127    pub metadata: Vec<u8>,
128}
129
130#[async_trait]
131impl<ED: Send> EncryptionStrategy for CustomStrategy<ED> {
132    type EncryptionData = ED;
133
134    /// Encrypts data using the custom encryption function
135    ///
136    /// # Arguments
137    /// * `dek` - Data Encryption Key
138    /// * `plaintext` - Data to encrypt
139    /// * `encryption_data` - Custom encryption metadata
140    ///
141    /// # Returns
142    /// * `Result<Vec<u8>, EncryptionError>` - Encrypted data or error
143    async fn encrypt(
144        &self,
145        dek: DEK,
146        plaintext: Vec<u8>,
147        encryption_data: Self::EncryptionData
148    ) -> Result<Vec<u8>, EncryptionError> {
149        (self.encrypt_fn)(dek, plaintext, encryption_data).await
150    }
151
152    /// Decrypts data using the custom decryption function
153    ///
154    /// # Arguments
155    /// * `dek` - Data Encryption Key
156    /// * `ciphertext` - Encrypted data
157    /// * `encryption_data` - Custom encryption metadata
158    ///
159    /// # Returns
160    /// * `Result<Vec<u8>, EncryptionError>` - Decrypted data or error
161    async fn decrypt(
162        &self,
163        dek: DEK,
164        ciphertext: Vec<u8>,
165        encryption_data: Self::EncryptionData
166    ) -> Result<Vec<u8>, EncryptionError> {
167        (self.decrypt_fn)(dek, ciphertext, encryption_data).await
168    }
169}
trelent_hyok/held_data/encryption/custom.rs

trelent_hyok/held_data/encryption/
custom.rs
