ladybird/Libraries/LibCrypto/Cipher/AES.cpp

404 lines
16 KiB
C++

/*
* Copyright (c) 2020, Ali Mohammad Pur <mpfard@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/StringBuilder.h>
#include <LibCrypto/Cipher/AES.h>
#include <LibCrypto/Cipher/AESTables.h>
namespace Crypto::Cipher {
template<typename T>
constexpr u32 get_key(T pt)
{
return ((u32)(pt)[0] << 24) ^ ((u32)(pt)[1] << 16) ^ ((u32)(pt)[2] << 8) ^ ((u32)(pt)[3]);
}
constexpr void swap_keys(u32* keys, size_t i, size_t j)
{
u32 temp = keys[i];
keys[i] = keys[j];
keys[j] = temp;
}
ByteString AESCipherBlock::to_byte_string() const
{
StringBuilder builder;
for (auto value : m_data)
builder.appendff("{:02x}", value);
return builder.to_byte_string();
}
ByteString AESCipherKey::to_byte_string() const
{
StringBuilder builder;
for (size_t i = 0; i < (rounds() + 1) * 4; ++i)
builder.appendff("{:02x}", m_rd_keys[i]);
return builder.to_byte_string();
}
void AESCipherKey::expand_encrypt_key(ReadonlyBytes user_key, size_t bits)
{
u32* round_key;
u32 temp;
size_t i { 0 };
VERIFY(!user_key.is_null());
VERIFY(is_valid_key_size(bits));
VERIFY(user_key.size() == bits / 8);
round_key = round_keys();
if (bits == 128) {
m_rounds = 10;
} else if (bits == 192) {
m_rounds = 12;
} else {
m_rounds = 14;
}
round_key[0] = get_key(user_key.data());
round_key[1] = get_key(user_key.data() + 4);
round_key[2] = get_key(user_key.data() + 8);
round_key[3] = get_key(user_key.data() + 12);
if (bits == 128) {
for (;;) {
temp = round_key[3];
// clang-format off
round_key[4] = round_key[0] ^
(AESTables::Encode2[(temp >> 16) & 0xff] & 0xff000000) ^
(AESTables::Encode3[(temp >> 8) & 0xff] & 0x00ff0000) ^
(AESTables::Encode0[(temp ) & 0xff] & 0x0000ff00) ^
(AESTables::Encode1[(temp >> 24) ] & 0x000000ff) ^ AESTables::RCON[i];
// clang-format on
round_key[5] = round_key[1] ^ round_key[4];
round_key[6] = round_key[2] ^ round_key[5];
round_key[7] = round_key[3] ^ round_key[6];
++i;
if (i == 10)
break;
round_key += 4;
}
return;
}
round_key[4] = get_key(user_key.data() + 16);
round_key[5] = get_key(user_key.data() + 20);
if (bits == 192) {
for (;;) {
temp = round_key[5];
// clang-format off
round_key[6] = round_key[0] ^
(AESTables::Encode2[(temp >> 16) & 0xff] & 0xff000000) ^
(AESTables::Encode3[(temp >> 8) & 0xff] & 0x00ff0000) ^
(AESTables::Encode0[(temp ) & 0xff] & 0x0000ff00) ^
(AESTables::Encode1[(temp >> 24) ] & 0x000000ff) ^ AESTables::RCON[i];
// clang-format on
round_key[7] = round_key[1] ^ round_key[6];
round_key[8] = round_key[2] ^ round_key[7];
round_key[9] = round_key[3] ^ round_key[8];
++i;
if (i == 8)
break;
round_key[10] = round_key[4] ^ round_key[9];
round_key[11] = round_key[5] ^ round_key[10];
round_key += 6;
}
return;
}
round_key[6] = get_key(user_key.data() + 24);
round_key[7] = get_key(user_key.data() + 28);
if (true) { // bits == 256
for (;;) {
temp = round_key[7];
// clang-format off
round_key[8] = round_key[0] ^
(AESTables::Encode2[(temp >> 16) & 0xff] & 0xff000000) ^
(AESTables::Encode3[(temp >> 8) & 0xff] & 0x00ff0000) ^
(AESTables::Encode0[(temp ) & 0xff] & 0x0000ff00) ^
(AESTables::Encode1[(temp >> 24) ] & 0x000000ff) ^ AESTables::RCON[i];
// clang-format on
round_key[9] = round_key[1] ^ round_key[8];
round_key[10] = round_key[2] ^ round_key[9];
round_key[11] = round_key[3] ^ round_key[10];
++i;
if (i == 7)
break;
temp = round_key[11];
// clang-format off
round_key[12] = round_key[4] ^
(AESTables::Encode2[(temp >> 24) ] & 0xff000000) ^
(AESTables::Encode3[(temp >> 16) & 0xff] & 0x00ff0000) ^
(AESTables::Encode0[(temp >> 8) & 0xff] & 0x0000ff00) ^
(AESTables::Encode1[(temp ) & 0xff] & 0x000000ff) ;
// clang-format on
round_key[13] = round_key[5] ^ round_key[12];
round_key[14] = round_key[6] ^ round_key[13];
round_key[15] = round_key[7] ^ round_key[14];
round_key += 8;
}
return;
}
}
void AESCipherKey::expand_decrypt_key(ReadonlyBytes user_key, size_t bits)
{
u32* round_key;
expand_encrypt_key(user_key, bits);
round_key = round_keys();
// reorder round keys
for (size_t i = 0, j = 4 * rounds(); i < j; i += 4, j -= 4) {
swap_keys(round_key, i, j);
swap_keys(round_key, i + 1, j + 1);
swap_keys(round_key, i + 2, j + 2);
swap_keys(round_key, i + 3, j + 3);
}
// apply inverse mix-column to middle rounds
for (size_t i = 1; i < rounds(); ++i) {
round_key += 4;
// clang-format off
round_key[0] =
AESTables::Decode0[AESTables::Encode1[(round_key[0] >> 24) ] & 0xff] ^
AESTables::Decode1[AESTables::Encode1[(round_key[0] >> 16) & 0xff] & 0xff] ^
AESTables::Decode2[AESTables::Encode1[(round_key[0] >> 8) & 0xff] & 0xff] ^
AESTables::Decode3[AESTables::Encode1[(round_key[0] ) & 0xff] & 0xff] ;
round_key[1] =
AESTables::Decode0[AESTables::Encode1[(round_key[1] >> 24) ] & 0xff] ^
AESTables::Decode1[AESTables::Encode1[(round_key[1] >> 16) & 0xff] & 0xff] ^
AESTables::Decode2[AESTables::Encode1[(round_key[1] >> 8) & 0xff] & 0xff] ^
AESTables::Decode3[AESTables::Encode1[(round_key[1] ) & 0xff] & 0xff] ;
round_key[2] =
AESTables::Decode0[AESTables::Encode1[(round_key[2] >> 24) ] & 0xff] ^
AESTables::Decode1[AESTables::Encode1[(round_key[2] >> 16) & 0xff] & 0xff] ^
AESTables::Decode2[AESTables::Encode1[(round_key[2] >> 8) & 0xff] & 0xff] ^
AESTables::Decode3[AESTables::Encode1[(round_key[2] ) & 0xff] & 0xff] ;
round_key[3] =
AESTables::Decode0[AESTables::Encode1[(round_key[3] >> 24) ] & 0xff] ^
AESTables::Decode1[AESTables::Encode1[(round_key[3] >> 16) & 0xff] & 0xff] ^
AESTables::Decode2[AESTables::Encode1[(round_key[3] >> 8) & 0xff] & 0xff] ^
AESTables::Decode3[AESTables::Encode1[(round_key[3] ) & 0xff] & 0xff] ;
// clang-format on
}
}
void AESCipher::encrypt_block(AESCipherBlock const& in, AESCipherBlock& out)
{
u32 s0, s1, s2, s3, t0, t1, t2, t3;
size_t r { 0 };
auto const& dec_key = key();
auto const* round_keys = dec_key.round_keys();
s0 = get_key(in.bytes().offset_pointer(0)) ^ round_keys[0];
s1 = get_key(in.bytes().offset_pointer(4)) ^ round_keys[1];
s2 = get_key(in.bytes().offset_pointer(8)) ^ round_keys[2];
s3 = get_key(in.bytes().offset_pointer(12)) ^ round_keys[3];
r = dec_key.rounds() >> 1;
// apply the first |r - 1| rounds
for (;;) {
// clang-format off
t0 = AESTables::Encode0[(s0 >> 24) ] ^
AESTables::Encode1[(s1 >> 16) & 0xff] ^
AESTables::Encode2[(s2 >> 8) & 0xff] ^
AESTables::Encode3[(s3 ) & 0xff] ^ round_keys[4];
t1 = AESTables::Encode0[(s1 >> 24) ] ^
AESTables::Encode1[(s2 >> 16) & 0xff] ^
AESTables::Encode2[(s3 >> 8) & 0xff] ^
AESTables::Encode3[(s0 ) & 0xff] ^ round_keys[5];
t2 = AESTables::Encode0[(s2 >> 24) ] ^
AESTables::Encode1[(s3 >> 16) & 0xff] ^
AESTables::Encode2[(s0 >> 8) & 0xff] ^
AESTables::Encode3[(s1 ) & 0xff] ^ round_keys[6];
t3 = AESTables::Encode0[(s3 >> 24) ] ^
AESTables::Encode1[(s0 >> 16) & 0xff] ^
AESTables::Encode2[(s1 >> 8) & 0xff] ^
AESTables::Encode3[(s2 ) & 0xff] ^ round_keys[7];
// clang-format on
round_keys += 8;
--r;
if (r == 0)
break;
// clang-format off
s0 = AESTables::Encode0[(t0 >> 24) ] ^
AESTables::Encode1[(t1 >> 16) & 0xff] ^
AESTables::Encode2[(t2 >> 8) & 0xff] ^
AESTables::Encode3[(t3 ) & 0xff] ^ round_keys[0];
s1 = AESTables::Encode0[(t1 >> 24) ] ^
AESTables::Encode1[(t2 >> 16) & 0xff] ^
AESTables::Encode2[(t3 >> 8) & 0xff] ^
AESTables::Encode3[(t0 ) & 0xff] ^ round_keys[1];
s2 = AESTables::Encode0[(t2 >> 24) ] ^
AESTables::Encode1[(t3 >> 16) & 0xff] ^
AESTables::Encode2[(t0 >> 8) & 0xff] ^
AESTables::Encode3[(t1 ) & 0xff] ^ round_keys[2];
s3 = AESTables::Encode0[(t3 >> 24) ] ^
AESTables::Encode1[(t0 >> 16) & 0xff] ^
AESTables::Encode2[(t1 >> 8) & 0xff] ^
AESTables::Encode3[(t2 ) & 0xff] ^ round_keys[3];
// clang-format on
}
// apply the last round and put the encrypted data into out
// clang-format off
s0 = (AESTables::Encode2[(t0 >> 24) ] & 0xff000000) ^
(AESTables::Encode3[(t1 >> 16) & 0xff] & 0x00ff0000) ^
(AESTables::Encode0[(t2 >> 8) & 0xff] & 0x0000ff00) ^
(AESTables::Encode1[(t3 ) & 0xff] & 0x000000ff) ^ round_keys[0];
out.put(0, s0);
s1 = (AESTables::Encode2[(t1 >> 24) ] & 0xff000000) ^
(AESTables::Encode3[(t2 >> 16) & 0xff] & 0x00ff0000) ^
(AESTables::Encode0[(t3 >> 8) & 0xff] & 0x0000ff00) ^
(AESTables::Encode1[(t0 ) & 0xff] & 0x000000ff) ^ round_keys[1];
out.put(4, s1);
s2 = (AESTables::Encode2[(t2 >> 24) ] & 0xff000000) ^
(AESTables::Encode3[(t3 >> 16) & 0xff] & 0x00ff0000) ^
(AESTables::Encode0[(t0 >> 8) & 0xff] & 0x0000ff00) ^
(AESTables::Encode1[(t1 ) & 0xff] & 0x000000ff) ^ round_keys[2];
out.put(8, s2);
s3 = (AESTables::Encode2[(t3 >> 24) ] & 0xff000000) ^
(AESTables::Encode3[(t0 >> 16) & 0xff] & 0x00ff0000) ^
(AESTables::Encode0[(t1 >> 8) & 0xff] & 0x0000ff00) ^
(AESTables::Encode1[(t2 ) & 0xff] & 0x000000ff) ^ round_keys[3];
out.put(12, s3);
// clang-format on
}
void AESCipher::decrypt_block(AESCipherBlock const& in, AESCipherBlock& out)
{
u32 s0, s1, s2, s3, t0, t1, t2, t3;
size_t r { 0 };
auto const& dec_key = key();
auto const* round_keys = dec_key.round_keys();
s0 = get_key(in.bytes().offset_pointer(0)) ^ round_keys[0];
s1 = get_key(in.bytes().offset_pointer(4)) ^ round_keys[1];
s2 = get_key(in.bytes().offset_pointer(8)) ^ round_keys[2];
s3 = get_key(in.bytes().offset_pointer(12)) ^ round_keys[3];
r = dec_key.rounds() >> 1;
// apply the first |r - 1| rounds
for (;;) {
// clang-format off
t0 = AESTables::Decode0[(s0 >> 24) ] ^
AESTables::Decode1[(s3 >> 16) & 0xff] ^
AESTables::Decode2[(s2 >> 8) & 0xff] ^
AESTables::Decode3[(s1 ) & 0xff] ^ round_keys[4];
t1 = AESTables::Decode0[(s1 >> 24) ] ^
AESTables::Decode1[(s0 >> 16) & 0xff] ^
AESTables::Decode2[(s3 >> 8) & 0xff] ^
AESTables::Decode3[(s2 ) & 0xff] ^ round_keys[5];
t2 = AESTables::Decode0[(s2 >> 24) ] ^
AESTables::Decode1[(s1 >> 16) & 0xff] ^
AESTables::Decode2[(s0 >> 8) & 0xff] ^
AESTables::Decode3[(s3 ) & 0xff] ^ round_keys[6];
t3 = AESTables::Decode0[(s3 >> 24) ] ^
AESTables::Decode1[(s2 >> 16) & 0xff] ^
AESTables::Decode2[(s1 >> 8) & 0xff] ^
AESTables::Decode3[(s0 ) & 0xff] ^ round_keys[7];
// clang-format on
round_keys += 8;
--r;
if (r == 0)
break;
// clang-format off
s0 = AESTables::Decode0[(t0 >> 24) ] ^
AESTables::Decode1[(t3 >> 16) & 0xff] ^
AESTables::Decode2[(t2 >> 8) & 0xff] ^
AESTables::Decode3[(t1 ) & 0xff] ^ round_keys[0];
s1 = AESTables::Decode0[(t1 >> 24) ] ^
AESTables::Decode1[(t0 >> 16) & 0xff] ^
AESTables::Decode2[(t3 >> 8) & 0xff] ^
AESTables::Decode3[(t2 ) & 0xff] ^ round_keys[1];
s2 = AESTables::Decode0[(t2 >> 24) ] ^
AESTables::Decode1[(t1 >> 16) & 0xff] ^
AESTables::Decode2[(t0 >> 8) & 0xff] ^
AESTables::Decode3[(t3 ) & 0xff] ^ round_keys[2];
s3 = AESTables::Decode0[(t3 >> 24) ] ^
AESTables::Decode1[(t2 >> 16) & 0xff] ^
AESTables::Decode2[(t1 >> 8) & 0xff] ^
AESTables::Decode3[(t0 ) & 0xff] ^ round_keys[3];
// clang-format on
}
// apply the last round and put the decrypted data into out
// clang-format off
s0 = ((u32)AESTables::Decode4[(t0 >> 24) ] << 24) ^
((u32)AESTables::Decode4[(t3 >> 16) & 0xff] << 16) ^
((u32)AESTables::Decode4[(t2 >> 8) & 0xff] << 8) ^
((u32)AESTables::Decode4[(t1 ) & 0xff] ) ^ round_keys[0];
out.put(0, s0);
s1 = ((u32)AESTables::Decode4[(t1 >> 24) ] << 24) ^
((u32)AESTables::Decode4[(t0 >> 16) & 0xff] << 16) ^
((u32)AESTables::Decode4[(t3 >> 8) & 0xff] << 8) ^
((u32)AESTables::Decode4[(t2 ) & 0xff] ) ^ round_keys[1];
out.put(4, s1);
s2 = ((u32)AESTables::Decode4[(t2 >> 24) ] << 24) ^
((u32)AESTables::Decode4[(t1 >> 16) & 0xff] << 16) ^
((u32)AESTables::Decode4[(t0 >> 8) & 0xff] << 8) ^
((u32)AESTables::Decode4[(t3 ) & 0xff] ) ^ round_keys[2];
out.put(8, s2);
s3 = ((u32)AESTables::Decode4[(t3 >> 24) ] << 24) ^
((u32)AESTables::Decode4[(t2 >> 16) & 0xff] << 16) ^
((u32)AESTables::Decode4[(t1 >> 8) & 0xff] << 8) ^
((u32)AESTables::Decode4[(t0 ) & 0xff] ) ^ round_keys[3];
out.put(12, s3);
// clang-format on
}
void AESCipherBlock::overwrite(ReadonlyBytes bytes)
{
auto data = bytes.data();
auto length = bytes.size();
VERIFY(length <= this->data_size());
this->bytes().overwrite(0, data, length);
if (length < this->data_size()) {
switch (padding_mode()) {
case PaddingMode::Null:
// fill with zeros
__builtin_memset(m_data + length, 0, this->data_size() - length);
break;
case PaddingMode::CMS:
// fill with the length of the padding bytes
__builtin_memset(m_data + length, this->data_size() - length, this->data_size() - length);
break;
case PaddingMode::RFC5246:
// fill with the length of the padding bytes minus one
__builtin_memset(m_data + length, this->data_size() - length - 1, this->data_size() - length);
break;
default:
// FIXME: We should handle the rest of the common padding modes
VERIFY_NOT_REACHED();
break;
}
}
}
}