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// Copyright 2019 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/execution/arm64/simulator-arm64.h"
#if defined(USE_SIMULATOR)
namespace v8 {
namespace internal {
// Randomly generated example key for simulating only.
const Simulator::PACKey Simulator::kPACKeyIA = {0xc31718727de20f71,
0xab9fd4e14b2fec51, 0};
namespace {
uint64_t GetNibble(uint64_t in_data, int position) {
return (in_data >> position) & 0xf;
}
uint64_t PACCellShuffle(uint64_t in_data) {
static int in_positions[16] = {52, 24, 44, 0, 28, 48, 4, 40,
32, 12, 56, 20, 8, 36, 16, 60};
uint64_t out_data = 0;
for (int i = 0; i < 16; ++i) {
out_data |= GetNibble(in_data, in_positions[i]) << (4 * i);
}
return out_data;
}
uint64_t PACCellInvShuffle(uint64_t in_data) {
static int in_positions[16] = {12, 24, 48, 36, 56, 44, 4, 16,
32, 52, 28, 8, 20, 0, 40, 60};
uint64_t out_data = 0;
for (int i = 0; i < 16; ++i) {
out_data |= GetNibble(in_data, in_positions[i]) << (4 * i);
}
return out_data;
}
uint64_t RotCell(uint64_t in_cell, int amount) {
DCHECK((amount >= 1) && (amount <= 3));
in_cell &= 0xf;
uint8_t temp = in_cell << 4 | in_cell;
return static_cast<uint64_t>((temp >> (4 - amount)) & 0xf);
}
uint64_t PACMult(uint64_t s_input) {
uint8_t t0;
uint8_t t1;
uint8_t t2;
uint8_t t3;
uint64_t s_output = 0;
for (int i = 0; i < 4; ++i) {
uint8_t s12 = (s_input >> (4 * (i + 12))) & 0xf;
uint8_t s8 = (s_input >> (4 * (i + 8))) & 0xf;
uint8_t s4 = (s_input >> (4 * (i + 4))) & 0xf;
uint8_t s0 = (s_input >> (4 * (i + 0))) & 0xf;
t0 = RotCell(s8, 1) ^ RotCell(s4, 2) ^ RotCell(s0, 1);
t1 = RotCell(s12, 1) ^ RotCell(s4, 1) ^ RotCell(s0, 2);
t2 = RotCell(s12, 2) ^ RotCell(s8, 1) ^ RotCell(s0, 1);
t3 = RotCell(s12, 1) ^ RotCell(s8, 2) ^ RotCell(s4, 1);
s_output |= static_cast<uint64_t>(t3) << (4 * (i + 0));
s_output |= static_cast<uint64_t>(t2) << (4 * (i + 4));
s_output |= static_cast<uint64_t>(t1) << (4 * (i + 8));
s_output |= static_cast<uint64_t>(t0) << (4 * (i + 12));
}
return s_output;
}
uint64_t PACSub(uint64_t t_input) {
uint64_t t_output = 0;
uint8_t substitutions[16] = {0xb, 0x6, 0x8, 0xf, 0xc, 0x0, 0x9, 0xe,
0x3, 0x7, 0x4, 0x5, 0xd, 0x2, 0x1, 0xa};
for (int i = 0; i < 16; ++i) {
unsigned index = ((t_input >> (4 * i)) & 0xf);
t_output |= static_cast<uint64_t>(substitutions[index]) << (4 * i);
}
return t_output;
}
uint64_t PACInvSub(uint64_t t_input) {
uint64_t t_output = 0;
uint8_t substitutions[16] = {0x5, 0xe, 0xd, 0x8, 0xa, 0xb, 0x1, 0x9,
0x2, 0x6, 0xf, 0x0, 0x4, 0xc, 0x7, 0x3};
for (int i = 0; i < 16; ++i) {
unsigned index = ((t_input >> (4 * i)) & 0xf);
t_output |= static_cast<uint64_t>(substitutions[index]) << (4 * i);
}
return t_output;
}
uint64_t TweakCellInvRot(uint64_t in_cell) {
uint64_t out_cell = 0;
out_cell |= (in_cell & 0x7) << 1;
out_cell |= (in_cell & 0x1) ^ ((in_cell >> 3) & 0x1);
return out_cell;
}
uint64_t TweakInvShuffle(uint64_t in_data) {
uint64_t out_data = 0;
out_data |= TweakCellInvRot(in_data >> 48) << 0;
out_data |= ((in_data >> 52) & 0xf) << 4;
out_data |= ((in_data >> 20) & 0xff) << 8;
out_data |= ((in_data >> 0) & 0xff) << 16;
out_data |= TweakCellInvRot(in_data >> 8) << 24;
out_data |= ((in_data >> 12) & 0xf) << 28;
out_data |= TweakCellInvRot(in_data >> 28) << 32;
out_data |= TweakCellInvRot(in_data >> 60) << 36;
out_data |= TweakCellInvRot(in_data >> 56) << 40;
out_data |= TweakCellInvRot(in_data >> 16) << 44;
out_data |= ((in_data >> 32) & 0xfff) << 48;
out_data |= TweakCellInvRot(in_data >> 44) << 60;
return out_data;
}
uint64_t TweakCellRot(uint64_t in_cell) {
uint64_t out_cell = 0;
out_cell |= ((in_cell & 0x1) ^ ((in_cell >> 1) & 0x1)) << 3;
out_cell |= (in_cell >> 0x1) & 0x7;
return out_cell;
}
uint64_t TweakShuffle(uint64_t in_data) {
uint64_t out_data = 0;
out_data |= ((in_data >> 16) & 0xff) << 0;
out_data |= TweakCellRot(in_data >> 24) << 8;
out_data |= ((in_data >> 28) & 0xf) << 12;
out_data |= TweakCellRot(in_data >> 44) << 16;
out_data |= ((in_data >> 8) & 0xff) << 20;
out_data |= TweakCellRot(in_data >> 32) << 28;
out_data |= ((in_data >> 48) & 0xfff) << 32;
out_data |= TweakCellRot(in_data >> 60) << 44;
out_data |= TweakCellRot(in_data >> 0) << 48;
out_data |= ((in_data >> 4) & 0xf) << 52;
out_data |= TweakCellRot(in_data >> 40) << 56;
out_data |= TweakCellRot(in_data >> 36) << 60;
return out_data;
}
} // namespace
// For a description of QARMA see:
// The QARMA Block Cipher Family, Roberto Avanzi, Qualcomm Product Security
// Initiative.
// The pseudocode is available in ARM DDI 0487D.b, J1-6946.
uint64_t Simulator::ComputePAC(uint64_t data, uint64_t context, PACKey key) {
uint64_t key0 = key.high;
uint64_t key1 = key.low;
const uint64_t RC[5] = {0x0000000000000000, 0x13198a2e03707344,
0xa4093822299f31d0, 0x082efa98ec4e6c89,
0x452821e638d01377};
const uint64_t Alpha = 0xc0ac29B7c97c50dd;
uint64_t modk0 = ((key0 & 0x1) << 63) | ((key0 >> 2) << 1) |
((key0 >> 63) ^ ((key0 >> 1) & 0x1));
uint64_t running_mod = context;
uint64_t working_val = data ^ key0;
uint64_t round_key;
for (int i = 0; i < 5; ++i) {
round_key = key1 ^ running_mod;
working_val ^= round_key;
working_val ^= RC[i];
if (i > 0) {
working_val = PACCellShuffle(working_val);
working_val = PACMult(working_val);
}
working_val = PACSub(working_val);
running_mod = TweakShuffle(running_mod);
}
round_key = modk0 ^ running_mod;
working_val ^= round_key;
working_val = PACCellShuffle(working_val);
working_val = PACMult(working_val);
working_val = PACSub(working_val);
working_val = PACCellShuffle(working_val);
working_val = PACMult(working_val);
working_val ^= key1;
working_val = PACCellInvShuffle(working_val);
working_val = PACInvSub(working_val);
working_val = PACMult(working_val);
working_val = PACCellInvShuffle(working_val);
working_val ^= key0;
working_val ^= running_mod;
for (int i = 0; i < 5; ++i) {
working_val = PACInvSub(working_val);
if (i < 4) {
working_val = PACMult(working_val);
working_val = PACCellInvShuffle(working_val);
}
running_mod = TweakInvShuffle(running_mod);
round_key = key1 ^ running_mod;
working_val ^= RC[4 - i];
working_val ^= round_key;
working_val ^= Alpha;
}
return working_val ^ modk0;
}
// The TTBR is selected by bit 63 or 55 depending on TBI for pointers without
// codes, but is always 55 once a PAC code is added to a pointer. For this
// reason, it must be calculated at the call site.
uint64_t Simulator::CalculatePACMask(uint64_t ptr, PointerType type, int ttbr) {
int bottom_pac_bit = GetBottomPACBit(ptr, ttbr);
int top_pac_bit = GetTopPACBit(ptr, type);
return unsigned_bitextract_64(top_pac_bit, bottom_pac_bit,
0xffffffffffffffff & ~kTTBRMask)
<< bottom_pac_bit;
}
uint64_t Simulator::AuthPAC(uint64_t ptr, uint64_t context, PACKey key,
PointerType type) {
DCHECK((key.number == 0) || (key.number == 1));
uint64_t pac_mask = CalculatePACMask(ptr, type, (ptr >> 55) & 1);
uint64_t original_ptr =
((ptr & kTTBRMask) == 0) ? (ptr & ~pac_mask) : (ptr | pac_mask);
uint64_t pac = ComputePAC(original_ptr, context, key);
uint64_t error_code = 1 << key.number;
if ((pac & pac_mask) == (ptr & pac_mask)) {
return original_ptr;
} else {
int error_lsb = GetTopPACBit(ptr, type) - 2;
uint64_t error_mask = UINT64_C(0x3) << error_lsb;
return (original_ptr & ~error_mask) | (error_code << error_lsb);
}
}
uint64_t Simulator::AddPAC(uint64_t ptr, uint64_t context, PACKey key,
PointerType type) {
int top_pac_bit = GetTopPACBit(ptr, type);
DCHECK(HasTBI(ptr, type));
int ttbr = (ptr >> 55) & 1;
uint64_t pac_mask = CalculatePACMask(ptr, type, ttbr);
uint64_t ext_ptr = (ttbr == 0) ? (ptr & ~pac_mask) : (ptr | pac_mask);
uint64_t pac = ComputePAC(ext_ptr, context, key);
// If the pointer isn't all zeroes or all ones in the PAC bitfield, corrupt
// the resulting code.
if (((ptr & (pac_mask | kTTBRMask)) != 0x0) &&
((~ptr & (pac_mask | kTTBRMask)) != 0x0)) {
pac ^= UINT64_C(1) << (top_pac_bit - 1);
}
uint64_t ttbr_shifted = static_cast<uint64_t>(ttbr) << 55;
return (pac & pac_mask) | ttbr_shifted | (ptr & ~pac_mask);
}
uint64_t Simulator::StripPAC(uint64_t ptr, PointerType type) {
uint64_t pac_mask = CalculatePACMask(ptr, type, (ptr >> 55) & 1);
return ((ptr & kTTBRMask) == 0) ? (ptr & ~pac_mask) : (ptr | pac_mask);
}
} // namespace internal
} // namespace v8
#endif // USE_SIMULATOR