crypto/
aesni.rs

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
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

use aes::KeySize;
use aes::KeySize::{KeySize128, KeySize192, KeySize256};
use symmetriccipher::{BlockEncryptor, BlockDecryptor};
use util::supports_aesni;

#[derive(Copy)]
pub struct AesNiEncryptor {
    rounds: u8,
    round_keys: [u8; 240]
}

impl Clone for AesNiEncryptor { fn clone(&self) -> AesNiEncryptor { *self } }

#[derive(Copy)]
pub struct AesNiDecryptor {
    rounds: u8,
    round_keys: [u8; 240]
}

impl Clone for AesNiDecryptor { fn clone(&self) -> AesNiDecryptor { *self } }

/// The number of rounds as well as a function to setup an appropriately sized key.
type RoundSetupInfo = (u8, fn(&[u8], KeyType, &mut [u8]));

impl AesNiEncryptor {
    pub fn new(key_size: KeySize, key: &[u8]) -> AesNiEncryptor {
        if !supports_aesni() {
            panic!("AES-NI not supported on this architecture. If you are \
                using the MSVC toolchain, this is because the AES-NI method's \
                have not been ported, yet");
        }
        let (rounds, setup_function): RoundSetupInfo = match key_size {
            KeySize128 => (10, setup_working_key_aesni_128),
            KeySize192 => (12, setup_working_key_aesni_192),
            KeySize256 => (14, setup_working_key_aesni_256)
        };
        let mut e = AesNiEncryptor {
            rounds: rounds,
            round_keys: [0u8; 240]
        };
        setup_function(key, KeyType::Encryption, &mut e.round_keys[0..size(e.rounds)]);
        e
    }
}

impl AesNiDecryptor {
    pub fn new(key_size: KeySize, key: &[u8]) -> AesNiDecryptor {
        if !supports_aesni() {
            panic!("AES-NI not supported on this architecture. If you are \
                using the MSVC toolchain, this is because the AES-NI method's \
                have not been ported, yet");
        }
        let (rounds, setup_function): RoundSetupInfo = match key_size {
            KeySize128 => (10, setup_working_key_aesni_128),
            KeySize192 => (12, setup_working_key_aesni_192),
            KeySize256 => (14, setup_working_key_aesni_256)
        };
        let mut d = AesNiDecryptor {
            rounds: rounds,
            round_keys: [0u8; 240]
        };
        setup_function(key, KeyType::Decryption, &mut d.round_keys[0..size(d.rounds)]);
        d
    }

}

impl BlockEncryptor for AesNiEncryptor {
    fn block_size(&self) -> usize { 16 }
    fn encrypt_block(&self, input: &[u8], output: &mut [u8]) {
        encrypt_block_aesni(self.rounds, input, &self.round_keys[0..size(self.rounds)], output);
    }
}

impl BlockDecryptor for AesNiDecryptor {
    fn block_size(&self) -> usize { 16 }
    fn decrypt_block(&self, input: &[u8], output: &mut [u8]) {
        decrypt_block_aesni(self.rounds, input, &self.round_keys[0..size(self.rounds)], output);
    }
}

enum KeyType {
    Encryption,
    Decryption
}

#[inline(always)]
fn size(rounds: u8) -> usize { 16 * ((rounds as usize) + 1) }

extern {
    fn rust_crypto_aesni_aesimc(round_keys: *mut u8);
    fn rust_crypto_aesni_setup_working_key_128(key: *const u8, round_key: *mut u8);
    fn rust_crypto_aesni_setup_working_key_192(key: *const u8, round_key: *mut u8);
    fn rust_crypto_aesni_setup_working_key_256(key: *const u8, round_key: *mut u8);
    fn rust_crypto_aesni_encrypt_block(
            rounds: u8,
            input: *const u8,
            round_keys: *const u8,
            output: *mut u8);
    fn rust_crypto_aesni_decrypt_block(
            rounds: u8,
            input: *const u8,
            round_keys: *const u8,
            output: *mut u8);
}

fn setup_working_key_aesni_128(key: &[u8], key_type: KeyType, round_key: &mut [u8]) {
    unsafe {
        rust_crypto_aesni_setup_working_key_128(key.as_ptr(), round_key.as_mut_ptr());

        match key_type {
            KeyType::Decryption => {
                // range of rounds keys from #1 to #9; skip the first and last key
                for i in 1..10 {
                    rust_crypto_aesni_aesimc(round_key.get_unchecked_mut(16 * i));
                }
            }
            KeyType::Encryption => { /* nothing more to do */ }
        }
    }
}

fn setup_working_key_aesni_192(key: &[u8], key_type: KeyType, round_key: &mut [u8]) {
    unsafe {
        rust_crypto_aesni_setup_working_key_192(key.as_ptr(), round_key.as_mut_ptr());

        match key_type {
            KeyType::Decryption => {
                // range of rounds keys from #1 to #11; skip the first and last key
                for i in 1..12 {
                    rust_crypto_aesni_aesimc(round_key.get_unchecked_mut(16 * i));
                }
            }
            KeyType::Encryption => { /* nothing more to do */ }
        }
    }
}

fn setup_working_key_aesni_256(key: &[u8], key_type: KeyType, round_key: &mut [u8]) {
    unsafe {
        rust_crypto_aesni_setup_working_key_256(key.as_ptr(), round_key.as_mut_ptr());

        match key_type {
            KeyType::Decryption => {
                // range of rounds keys from #1 to #13; skip the first and last key
                for i in 1..14 {
                    rust_crypto_aesni_aesimc(round_key.get_unchecked_mut(16 * i));
                }
            }
            KeyType::Encryption => { /* nothing more to do */ }
        }
    }
}

fn encrypt_block_aesni(rounds: u8, input: &[u8], round_keys: &[u8], output: &mut [u8]) {
    unsafe {
        rust_crypto_aesni_encrypt_block(
                rounds,
                input.as_ptr(),
                round_keys.as_ptr(),
                output.as_mut_ptr());
    }
}

fn decrypt_block_aesni(rounds: u8, input: &[u8], round_keys: &[u8], output: &mut [u8]) {
    unsafe {
        rust_crypto_aesni_decrypt_block(
                rounds as u8,
                input.as_ptr(),
                round_keys.get_unchecked(round_keys.len() - 16),
                output.as_mut_ptr());
    }
}