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
|
//! Implementation of AEAD using Windows CNG API.
use crate::{Error, Result};
use crate::crypto::aead::{Aead, CipherOp};
use crate::seal;
use crate::types::{AEADAlgorithm, SymmetricAlgorithm};
use eax::online::{EaxOnline, Encrypt, Decrypt};
use win_crypto_ng::symmetric::{BlockCipherKey, Aes};
use win_crypto_ng::symmetric::block_cipher::generic_array::{GenericArray, ArrayLength};
use win_crypto_ng::symmetric::block_cipher::generic_array::typenum::{U128, U192, U256};
trait GenericArrayExt {
const LEN: usize;
}
impl<T, N: ArrayLength<T>> GenericArrayExt for GenericArray<T, N> {
const LEN: usize = N::USIZE;
}
impl AEADAlgorithm {
pub(crate) fn context(
&self,
sym_algo: SymmetricAlgorithm,
key: &[u8],
nonce: &[u8],
op: CipherOp,
) -> Result<Box<dyn Aead>> {
let nonce = GenericArray::from_slice(nonce);
match self {
AEADAlgorithm::EAX => match sym_algo {
| SymmetricAlgorithm::AES128 => {
let key = GenericArray::from_slice(key);
Ok(match op {
CipherOp::Encrypt =>
Box::new(EaxOnline::<BlockCipherKey<Aes, U128>, Encrypt>::with_key_and_nonce(key, nonce)),
CipherOp::Decrypt =>
Box::new(EaxOnline::<BlockCipherKey<Aes, U128>, Decrypt>::with_key_and_nonce(key, nonce)),
})
}
SymmetricAlgorithm::AES192 => {
let key = GenericArray::from_slice(key);
Ok(match op {
CipherOp::Encrypt =>
Box::new(EaxOnline::<BlockCipherKey<Aes, U192>, Encrypt>::with_key_and_nonce(key, nonce)),
CipherOp::Decrypt =>
Box::new(EaxOnline::<BlockCipherKey<Aes, U192>, Decrypt>::with_key_and_nonce(key, nonce)),
})
}
SymmetricAlgorithm::AES256 => {
let key = GenericArray::from_slice(key);
Ok(match op {
CipherOp::Encrypt =>
Box::new(EaxOnline::<BlockCipherKey<Aes, U256>, Encrypt>::with_key_and_nonce(key, nonce)),
CipherOp::Decrypt =>
Box::new(EaxOnline::<BlockCipherKey<Aes, U256>, Decrypt>::with_key_and_nonce(key, nonce)),
})
}
_ => Err(Error::UnsupportedSymmetricAlgorithm(sym_algo).into()),
},
_ => Err(Error::UnsupportedAEADAlgorithm(self.clone()).into()),
}
}
}
macro_rules! impl_aead {
($($type: ty),*) => {
$(
impl Aead for EaxOnline<$type, Encrypt> {
fn update(&mut self, ad: &[u8]) { self.update_assoc(ad) }
fn digest_size(&self) -> usize { <eax::Tag as GenericArrayExt>::LEN }
fn digest(&mut self, digest: &mut [u8]) {
let tag = self.tag_clone();
digest[..tag.len()].copy_from_slice(&tag[..]);
}
fn encrypt(&mut self, dst: &mut [u8], src: &[u8]) {
let len = core::cmp::min(dst.len(), src.len());
dst[..len].copy_from_slice(&src[..len]);
EaxOnline::<$type, Encrypt>::encrypt(self, &mut dst[..len])
}
fn decrypt(&mut self, _dst: &mut [u8], _src: &[u8]) {
panic!("AEAD decryption called in the encryption context")
}
}
impl seal::Sealed for EaxOnline<$type, Encrypt> {}
)*
$(
impl Aead for EaxOnline<$type, Decrypt> {
fn update(&mut self, ad: &[u8]) { self.update_assoc(ad) }
fn digest_size(&self) -> usize { <eax::Tag as GenericArrayExt>::LEN }
fn digest(&mut self, digest: &mut [u8]) {
let tag = self.tag_clone();
digest[..tag.len()].copy_from_slice(&tag[..]);
}
fn encrypt(&mut self, _dst: &mut [u8], _src: &[u8]) {
panic!("AEAD encryption called in the decryption context")
}
fn decrypt(&mut self, dst: &mut [u8], src: &[u8]) {
let len = core::cmp::min(dst.len(), src.len());
dst[..len].copy_from_slice(&src[..len]);
self.decrypt_unauthenticated_hazmat(&mut dst[..len])
}
}
impl seal::Sealed for EaxOnline<$type, Decrypt> {}
)*
};
}
impl_aead!(BlockCipherKey<Aes, U128>, BlockCipherKey<Aes, U192>, BlockCipherKey<Aes, U256>);
|
