1 //! Low-level "hazmat" AES functions: AES-NI support.
2 //!
3 //! Note: this isn't actually used in the `Aes128`/`Aes192`/`Aes256`
4 //! implementations in this crate, but instead provides raw AES-NI accelerated
5 //! access to the AES round function gated under the `hazmat` crate feature.
6
7 use super::{
8 arch::*,
9 utils::{load8, store8},
10 };
11 use crate::{Block, ParBlocks};
12
13 /// AES cipher (encrypt) round function.
14 #[allow(clippy::cast_ptr_alignment)]
15 #[target_feature(enable = "aes")]
cipher_round(block: &mut Block, round_key: &Block)16 pub(crate) unsafe fn cipher_round(block: &mut Block, round_key: &Block) {
17 // Safety: `loadu` and `storeu` support unaligned access
18 let b = _mm_loadu_si128(block.as_ptr() as *const __m128i);
19 let k = _mm_loadu_si128(round_key.as_ptr() as *const __m128i);
20 let out = _mm_aesenc_si128(b, k);
21 _mm_storeu_si128(block.as_mut_ptr() as *mut __m128i, out);
22 }
23
24 /// AES cipher (encrypt) round function: parallel version.
25 #[allow(clippy::cast_ptr_alignment)]
26 #[target_feature(enable = "aes")]
cipher_round_par(blocks: &mut ParBlocks, round_keys: &ParBlocks)27 pub(crate) unsafe fn cipher_round_par(blocks: &mut ParBlocks, round_keys: &ParBlocks) {
28 let xmm_keys = load8(round_keys);
29 let mut xmm_blocks = load8(blocks);
30
31 for i in 0..8 {
32 xmm_blocks[i] = _mm_aesenc_si128(xmm_blocks[i], xmm_keys[i]);
33 }
34
35 store8(blocks, xmm_blocks);
36 }
37
38 /// AES cipher (encrypt) round function.
39 #[allow(clippy::cast_ptr_alignment)]
40 #[target_feature(enable = "aes")]
equiv_inv_cipher_round(block: &mut Block, round_key: &Block)41 pub(crate) unsafe fn equiv_inv_cipher_round(block: &mut Block, round_key: &Block) {
42 // Safety: `loadu` and `storeu` support unaligned access
43 let b = _mm_loadu_si128(block.as_ptr() as *const __m128i);
44 let k = _mm_loadu_si128(round_key.as_ptr() as *const __m128i);
45 let out = _mm_aesdec_si128(b, k);
46 _mm_storeu_si128(block.as_mut_ptr() as *mut __m128i, out);
47 }
48
49 /// AES cipher (encrypt) round function: parallel version.
50 #[allow(clippy::cast_ptr_alignment)]
51 #[target_feature(enable = "aes")]
equiv_inv_cipher_round_par(blocks: &mut ParBlocks, round_keys: &ParBlocks)52 pub(crate) unsafe fn equiv_inv_cipher_round_par(blocks: &mut ParBlocks, round_keys: &ParBlocks) {
53 let xmm_keys = load8(round_keys);
54 let mut xmm_blocks = load8(blocks);
55
56 for i in 0..8 {
57 xmm_blocks[i] = _mm_aesdec_si128(xmm_blocks[i], xmm_keys[i]);
58 }
59
60 store8(blocks, xmm_blocks);
61 }
62
63 /// AES mix columns function.
64 #[allow(clippy::cast_ptr_alignment)]
65 #[target_feature(enable = "aes")]
mix_columns(block: &mut Block)66 pub(crate) unsafe fn mix_columns(block: &mut Block) {
67 // Safety: `loadu` and `storeu` support unaligned access
68 let mut state = _mm_loadu_si128(block.as_ptr() as *const __m128i);
69
70 // Emulate mix columns by performing three inverse mix columns operations
71 state = _mm_aesimc_si128(state);
72 state = _mm_aesimc_si128(state);
73 state = _mm_aesimc_si128(state);
74
75 _mm_storeu_si128(block.as_mut_ptr() as *mut __m128i, state);
76 }
77
78 /// AES inverse mix columns function.
79 #[allow(clippy::cast_ptr_alignment)]
80 #[target_feature(enable = "aes")]
inv_mix_columns(block: &mut Block)81 pub(crate) unsafe fn inv_mix_columns(block: &mut Block) {
82 // Safety: `loadu` and `storeu` support unaligned access
83 let b = _mm_loadu_si128(block.as_ptr() as *const __m128i);
84 let out = _mm_aesimc_si128(b);
85 _mm_storeu_si128(block.as_mut_ptr() as *mut __m128i, out);
86 }
87