literate_crypto/
cipher.rs

1use docext::docext;
2
3mod block;
4mod onetimepad;
5
6pub use {
7    block::{
8        aes,
9        Aes128,
10        Aes192,
11        Aes256,
12        BlockCipher,
13        BlockDecrypt,
14        BlockEncrypt,
15        BlockMode,
16        BlockSizeTooSmall,
17        Cbc,
18        Ctr,
19        Ecb,
20        Padding,
21        Pkcs7,
22    },
23    onetimepad::OneTimePad,
24};
25
26/// A cipher encrypts and decrypts data of arbitrary length using a symmetric
27/// key.
28///
29/// The encrypted data is called ciphertext, and the unencrypted data is called
30/// plaintext. Ciphertext should be statistically indistinguishable from random
31/// data.
32///
33/// The following relation must hold between the encrypt and decrypt methods:
34/// $$
35/// decrypt(encrypt(p, k), k) = p \quad \forall p \in \mathbf{P}, k \in
36/// \mathbf{K}
37/// $$
38///
39/// where $\mathbf{P}$ is the set of all possible plaintexts (plaintext space)
40/// and $\mathbf{K}$ is the set of all possible keys (key space). Note that the
41/// key space usually has a fixed size, while the plaintext space is infinite.
42#[docext]
43pub trait Cipher:
44    CipherEncrypt<EncryptionKey = Self::Key> + CipherDecrypt<DecryptionKey = Self::Key>
45{
46    type Key;
47}
48
49/// The encryption half of a [cipher](Cipher).
50pub trait CipherEncrypt {
51    type EncryptionErr;
52    type EncryptionKey;
53
54    /// Encrypt the plaintext.
55    fn encrypt(
56        &self,
57        data: Vec<u8>,
58        key: Self::EncryptionKey,
59    ) -> Result<Vec<u8>, Self::EncryptionErr>;
60}
61
62/// The decryption half of a [cipher](Cipher).
63pub trait CipherDecrypt {
64    type DecryptionErr;
65    type DecryptionKey;
66
67    /// Decrypt the ciphertext. This operation can fail, for example, if the
68    /// ciphertext was not created by this cipher.
69    fn decrypt(
70        &self,
71        data: Vec<u8>,
72        key: Self::DecryptionKey,
73    ) -> Result<Vec<u8>, Self::DecryptionErr>;
74}
literate_crypto/cipher.rs

literate_crypto/
cipher.rs
