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| 1 | +use rustc_middle::ty::layout::LayoutOf as _; |
| 2 | +use rustc_middle::ty::Ty; |
| 3 | +use rustc_span::Symbol; |
| 4 | +use rustc_target::spec::abi::Abi; |
| 5 | + |
| 6 | +use crate::*; |
| 7 | +use shims::foreign_items::EmulateForeignItemResult; |
| 8 | + |
| 9 | +impl<'mir, 'tcx: 'mir> EvalContextExt<'mir, 'tcx> for crate::MiriInterpCx<'mir, 'tcx> {} |
| 10 | +pub(super) trait EvalContextExt<'mir, 'tcx: 'mir>: |
| 11 | + crate::MiriInterpCxExt<'mir, 'tcx> |
| 12 | +{ |
| 13 | + fn emulate_x86_aesni_intrinsic( |
| 14 | + &mut self, |
| 15 | + link_name: Symbol, |
| 16 | + abi: Abi, |
| 17 | + args: &[OpTy<'tcx, Provenance>], |
| 18 | + dest: &PlaceTy<'tcx, Provenance>, |
| 19 | + ) -> InterpResult<'tcx, EmulateForeignItemResult> { |
| 20 | + let this = self.eval_context_mut(); |
| 21 | + // Prefix should have already been checked. |
| 22 | + let unprefixed_name = link_name.as_str().strip_prefix("llvm.x86.aesni.").unwrap(); |
| 23 | + |
| 24 | + match unprefixed_name { |
| 25 | + // Used to implement the _mm_aesdec_si128, _mm256_aesdec_epi128 |
| 26 | + // and _mm512_aesdec_epi128 functions. |
| 27 | + // Performs one round of an AES decryption on each 128-bit word of |
| 28 | + // `state` with the corresponding 128-bit key of `key`. |
| 29 | + // https://www.intel.com/content/www/us/en/docs/intrinsics-guide/index.html#text=_mm_aesdec_si128 |
| 30 | + "aesdec" | "aesdec.256" | "aesdec.512" => { |
| 31 | + let [state, key] = |
| 32 | + this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?; |
| 33 | + |
| 34 | + aes_round(this, state, key, dest, |state, key| { |
| 35 | + let key = aes::Block::from(key.to_le_bytes()); |
| 36 | + let mut state = aes::Block::from(state.to_le_bytes()); |
| 37 | + // `aes::hazmat::equiv_inv_cipher_round` documentation states that |
| 38 | + // it performs the same operation as the x86 aesdec instruction. |
| 39 | + aes::hazmat::equiv_inv_cipher_round(&mut state, &key); |
| 40 | + u128::from_le_bytes(state.into()) |
| 41 | + })?; |
| 42 | + } |
| 43 | + // Used to implement the _mm_aesdeclast_si128, _mm256_aesdeclast_epi128 |
| 44 | + // and _mm512_aesdeclast_epi128 functions. |
| 45 | + // Performs last round of an AES decryption on each 128-bit word of |
| 46 | + // `state` with the corresponding 128-bit key of `key`. |
| 47 | + // https://www.intel.com/content/www/us/en/docs/intrinsics-guide/index.html#text=_mm_aesdeclast_si128 |
| 48 | + "aesdeclast" | "aesdeclast.256" | "aesdeclast.512" => { |
| 49 | + let [state, key] = |
| 50 | + this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?; |
| 51 | + |
| 52 | + aes_round(this, state, key, dest, |state, key| { |
| 53 | + let mut state = aes::Block::from(state.to_le_bytes()); |
| 54 | + // `aes::hazmat::equiv_inv_cipher_round` does the following operations: |
| 55 | + // state = InvShiftRows(state) |
| 56 | + // state = InvSubBytes(state) |
| 57 | + // state = InvMixColumns(state) |
| 58 | + // state = state ^ key |
| 59 | + // But we need to skip the InvMixColumns. |
| 60 | + // First, use a zeroed key to skip the XOR. |
| 61 | + aes::hazmat::equiv_inv_cipher_round(&mut state, &aes::Block::from([0; 16])); |
| 62 | + // Then, undo the InvMixColumns with MixColumns. |
| 63 | + aes::hazmat::mix_columns(&mut state); |
| 64 | + // Finally, do the XOR. |
| 65 | + u128::from_le_bytes(state.into()) ^ key |
| 66 | + })?; |
| 67 | + } |
| 68 | + // Used to implement the _mm_aesenc_si128, _mm256_aesenc_epi128 |
| 69 | + // and _mm512_aesenc_epi128 functions. |
| 70 | + // Performs one round of an AES encryption on each 128-bit word of |
| 71 | + // `state` with the corresponding 128-bit key of `key`. |
| 72 | + // https://www.intel.com/content/www/us/en/docs/intrinsics-guide/index.html#text=_mm_aesenc_si128 |
| 73 | + "aesenc" | "aesenc.256" | "aesenc.512" => { |
| 74 | + let [state, key] = |
| 75 | + this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?; |
| 76 | + |
| 77 | + aes_round(this, state, key, dest, |state, key| { |
| 78 | + let key = aes::Block::from(key.to_le_bytes()); |
| 79 | + let mut state = aes::Block::from(state.to_le_bytes()); |
| 80 | + // `aes::hazmat::cipher_round` documentation states that |
| 81 | + // it performs the same operation as the x86 aesenc instruction. |
| 82 | + aes::hazmat::cipher_round(&mut state, &key); |
| 83 | + u128::from_le_bytes(state.into()) |
| 84 | + })?; |
| 85 | + } |
| 86 | + // Used to implement the _mm_aesenclast_si128, _mm256_aesenclast_epi128 |
| 87 | + // and _mm512_aesenclast_epi128 functions. |
| 88 | + // Performs last round of an AES encryption on each 128-bit word of |
| 89 | + // `state` with the corresponding 128-bit key of `key`. |
| 90 | + // https://www.intel.com/content/www/us/en/docs/intrinsics-guide/index.html#text=_mm_aesenclast_si128 |
| 91 | + "aesenclast" | "aesenclast.256" | "aesenclast.512" => { |
| 92 | + let [state, key] = |
| 93 | + this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?; |
| 94 | + |
| 95 | + aes_round(this, state, key, dest, |state, key| { |
| 96 | + let mut state = aes::Block::from(state.to_le_bytes()); |
| 97 | + // `aes::hazmat::cipher_round` does the following operations: |
| 98 | + // state = ShiftRows(state) |
| 99 | + // state = SubBytes(state) |
| 100 | + // state = MixColumns(state) |
| 101 | + // state = state ^ key |
| 102 | + // But we need to skip the MixColumns. |
| 103 | + // First, use a zeroed key to skip the XOR. |
| 104 | + aes::hazmat::cipher_round(&mut state, &aes::Block::from([0; 16])); |
| 105 | + // Then, undo the MixColumns with InvMixColumns. |
| 106 | + aes::hazmat::inv_mix_columns(&mut state); |
| 107 | + // Finally, do the XOR. |
| 108 | + u128::from_le_bytes(state.into()) ^ key |
| 109 | + })?; |
| 110 | + } |
| 111 | + // Used to implement the _mm_aesimc_si128 function. |
| 112 | + // Performs the AES InvMixColumns operation on `op` |
| 113 | + "aesimc" => { |
| 114 | + let [op] = this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?; |
| 115 | + |
| 116 | + // Transmute to `u128` |
| 117 | + let op = op.transmute(this.machine.layouts.u128, this)?; |
| 118 | + let dest = dest.transmute(this.machine.layouts.u128, this)?; |
| 119 | + |
| 120 | + let state = this.read_scalar(&op)?.to_u128()?; |
| 121 | + let mut state = aes::Block::from(state.to_le_bytes()); |
| 122 | + aes::hazmat::inv_mix_columns(&mut state); |
| 123 | + |
| 124 | + this.write_scalar(Scalar::from_u128(u128::from_le_bytes(state.into())), &dest)?; |
| 125 | + } |
| 126 | + // TODO: Implement the `llvm.x86.aesni.aeskeygenassist` when possible |
| 127 | + // with an external crate. |
| 128 | + _ => return Ok(EmulateForeignItemResult::NotSupported), |
| 129 | + } |
| 130 | + Ok(EmulateForeignItemResult::NeedsJumping) |
| 131 | + } |
| 132 | +} |
| 133 | + |
| 134 | +// Performs an AES round (given by `f`) on each 128-bit word of |
| 135 | +// `state` with the corresponding 128-bit key of `key`. |
| 136 | +fn aes_round<'tcx>( |
| 137 | + this: &mut crate::MiriInterpCx<'_, 'tcx>, |
| 138 | + state: &OpTy<'tcx, Provenance>, |
| 139 | + key: &OpTy<'tcx, Provenance>, |
| 140 | + dest: &PlaceTy<'tcx, Provenance>, |
| 141 | + f: impl Fn(u128, u128) -> u128, |
| 142 | +) -> InterpResult<'tcx, ()> { |
| 143 | + assert_eq!(dest.layout.size, state.layout.size); |
| 144 | + assert_eq!(dest.layout.size, key.layout.size); |
| 145 | + |
| 146 | + // Transmute arguments to arrays of `u128`. |
| 147 | + assert_eq!(dest.layout.size.bytes() % 16, 0); |
| 148 | + let len = dest.layout.size.bytes() / 16; |
| 149 | + |
| 150 | + let u128_array_layout = |
| 151 | + this.layout_of(Ty::new_array(this.tcx.tcx, this.tcx.types.u128, len))?; |
| 152 | + |
| 153 | + let state = state.transmute(u128_array_layout, this)?; |
| 154 | + let key = key.transmute(u128_array_layout, this)?; |
| 155 | + let dest = dest.transmute(u128_array_layout, this)?; |
| 156 | + |
| 157 | + for i in 0..len { |
| 158 | + let state = this.read_scalar(&this.project_index(&state, i)?)?.to_u128()?; |
| 159 | + let key = this.read_scalar(&this.project_index(&key, i)?)?.to_u128()?; |
| 160 | + let dest = this.project_index(&dest, i)?; |
| 161 | + |
| 162 | + let res = f(state, key); |
| 163 | + |
| 164 | + this.write_scalar(Scalar::from_u128(res), &dest)?; |
| 165 | + } |
| 166 | + |
| 167 | + Ok(()) |
| 168 | +} |
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