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Implement decryption

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This commit is contained in:
Manuel Vögele
2019-05-15 09:26:42 +02:00
parent 702c37656f
commit d03fe358e7
3 changed files with 122 additions and 10 deletions
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104
aes.cpp
View File

@@ -25,7 +25,7 @@ const uint8_t AES::sbox[256] = {
0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf, 0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf,
0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16 }; 0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16 };
const uint8_t AES::rsbox[256] = { const uint8_t AES::r_sbox[256] = {
0x52, 0x09, 0x6a, 0xd5, 0x30, 0x36, 0xa5, 0x38, 0xbf, 0x40, 0xa3, 0x9e, 0x81, 0xf3, 0xd7, 0xfb, 0x52, 0x09, 0x6a, 0xd5, 0x30, 0x36, 0xa5, 0x38, 0xbf, 0x40, 0xa3, 0x9e, 0x81, 0xf3, 0xd7, 0xfb,
0x7c, 0xe3, 0x39, 0x82, 0x9b, 0x2f, 0xff, 0x87, 0x34, 0x8e, 0x43, 0x44, 0xc4, 0xde, 0xe9, 0xcb, 0x7c, 0xe3, 0x39, 0x82, 0x9b, 0x2f, 0xff, 0x87, 0x34, 0x8e, 0x43, 0x44, 0xc4, 0xde, 0xe9, 0xcb,
0x54, 0x7b, 0x94, 0x32, 0xa6, 0xc2, 0x23, 0x3d, 0xee, 0x4c, 0x95, 0x0b, 0x42, 0xfa, 0xc3, 0x4e, 0x54, 0x7b, 0x94, 0x32, 0xa6, 0xc2, 0x23, 0x3d, 0xee, 0x4c, 0x95, 0x0b, 0x42, 0xfa, 0xc3, 0x4e,
@@ -84,6 +84,24 @@ void AES::encrypt_ecb(uint8_t data[16], const uint8_t key[16])
add_round_key(data, round_keys[10]); add_round_key(data, round_keys[10]);
} }
void AES::decrypt_ecb(uint8_t data[16], const uint8_t key[16])
{
PROFILER_RECORD;
uint8_t round_keys[11][16];
construct_round_keys(key, round_keys);
add_round_key(data, round_keys[10]);
r_shift_rows(data);
r_sub_bytes(data);
for (int r = 9;r > 0;r--)
{
add_round_key(data, round_keys[r]);
r_mix_columns(data);
r_shift_rows(data);
r_sub_bytes(data);
}
add_round_key(data, round_keys[0]);
}
void AES::add_round_key(uint8_t data_[16], const uint8_t key_[16]) void AES::add_round_key(uint8_t data_[16], const uint8_t key_[16])
{ {
PROFILER_RECORD; PROFILER_RECORD;
@@ -104,6 +122,15 @@ void AES::sub_bytes(uint8_t data[16])
} }
} }
void AES::r_sub_bytes(uint8_t data[16])
{
PROFILER_RECORD;
for (int i = 0;i < 16;i++)
{
data[i] = r_sbox[data[i]];
}
}
#define SWAP(x, y, tmp) tmp = x; x = y; y = tmp #define SWAP(x, y, tmp) tmp = x; x = y; y = tmp
void AES::shift_rows(uint8_t data[16]) void AES::shift_rows(uint8_t data[16])
@@ -125,6 +152,25 @@ void AES::shift_rows(uint8_t data[16])
data[3] = tmp; data[3] = tmp;
} }
void AES::r_shift_rows(uint8_t data[16])
{
PROFILER_RECORD;
uint8_t tmp = data[13];
data[13] = data[9];
data[9] = data[5];
data[5] = data[1];
data[1] = tmp;
SWAP(data[2], data[10], tmp);
SWAP(data[6], data[14], tmp);
tmp = data[3];
data[3] = data[7];
data[7] = data[11];
data[11] = data[15];
data[15] = tmp;
}
#undef SWAP #undef SWAP
void AES::mix_columns(uint8_t data[16]) void AES::mix_columns(uint8_t data[16])
@@ -141,6 +187,20 @@ void AES::mix_columns(uint8_t data[16])
memcpy(data, data_new, 16); memcpy(data, data_new, 16);
} }
void AES::r_mix_columns(uint8_t data[16])
{
PROFILER_RECORD;
uint8_t data_new[16];
for (int i = 0;i < 4;i++)
{
data_new[i * 4 + 0] = gf_multE(data[i * 4 + 0]) ^ gf_multB(data[i * 4 + 1]) ^ gf_multD(data[i * 4 + 2]) ^ gf_mult9(data[i * 4 + 3]);
data_new[i * 4 + 1] = gf_mult9(data[i * 4 + 0]) ^ gf_multE(data[i * 4 + 1]) ^ gf_multB(data[i * 4 + 2]) ^ gf_multD(data[i * 4 + 3]);
data_new[i * 4 + 2] = gf_multD(data[i * 4 + 0]) ^ gf_mult9(data[i * 4 + 1]) ^ gf_multE(data[i * 4 + 2]) ^ gf_multB(data[i * 4 + 3]);
data_new[i * 4 + 3] = gf_multB(data[i * 4 + 0]) ^ gf_multD(data[i * 4 + 1]) ^ gf_mult9(data[i * 4 + 2]) ^ gf_multE(data[i * 4 + 3]);
}
mempcpy(data, data_new, 16);
}
void AES::construct_round_keys(const uint8_t initial_key_[16], uint8_t round_keys_[11][16]) void AES::construct_round_keys(const uint8_t initial_key_[16], uint8_t round_keys_[11][16])
{ {
PROFILER_RECORD; PROFILER_RECORD;
@@ -195,6 +255,44 @@ uint8_t AES::gf_mult2(uint8_t value)
uint8_t AES::gf_mult3(uint8_t value) uint8_t AES::gf_mult3(uint8_t value)
{ {
PROFILER_RECORD; PROFILER_RECORD;
uint8_t result = gf_mult2(value); return gf_mult2(value) ^ value;
return result ^ value; }
uint8_t AES::gf_mult4(uint8_t value)
{
PROFILER_RECORD;
return gf_mult2(gf_mult2(value));
}
uint8_t AES::gf_mult8(uint8_t value)
{
PROFILER_RECORD;
return gf_mult2(gf_mult4(value));
}
uint8_t AES::gf_mult9(uint8_t value)
{
PROFILER_RECORD;
return gf_mult8(value) ^ value;
}
uint8_t AES::gf_multB(uint8_t value)
{
PROFILER_RECORD;
return gf_mult8(value) ^ gf_mult3(value);
}
uint8_t AES::gf_multD(uint8_t value)
{
PROFILER_RECORD;
uint8_t gf4 = gf_mult4(value);
return gf_mult2(gf4) ^ gf4 ^ value;
}
uint8_t AES::gf_multE(uint8_t value)
{
PROFILER_RECORD;
uint8_t gf2 = gf_mult2(value);
uint8_t gf4 = gf_mult2(gf2);
return gf_mult2(gf4) ^ gf4 ^ gf2;
} }

12
aes.hpp
View File

@@ -7,21 +7,31 @@ class AES
{ {
private: private:
static const uint8_t sbox[256]; static const uint8_t sbox[256];
static const uint8_t rsbox[256]; static const uint8_t r_sbox[256];
static const uint8_t rc[10]; static const uint8_t rc[10];
static const uint8_t irreducible_polynomial; static const uint8_t irreducible_polynomial;
public: public:
AES(); AES();
static void encrypt_ecb(uint8_t data[16], const uint8_t key[16]); static void encrypt_ecb(uint8_t data[16], const uint8_t key[16]);
static void decrypt_ecb(uint8_t data[16], const uint8_t key[16]);
static void construct_round_keys(const uint8_t initial_key_[16], uint8_t round_keys_[11][16]); static void construct_round_keys(const uint8_t initial_key_[16], uint8_t round_keys_[11][16]);
static uint32_t roundkey_g(uint32_t last_roundkey, uint8_t round); static uint32_t roundkey_g(uint32_t last_roundkey, uint8_t round);
static void add_round_key(uint8_t data[16], const uint8_t key[16]); static void add_round_key(uint8_t data[16], const uint8_t key[16]);
static void shift_rows(uint8_t data[16]); static void shift_rows(uint8_t data[16]);
static void r_shift_rows(uint8_t data[16]);
static void sub_bytes(uint8_t data[16]); static void sub_bytes(uint8_t data[16]);
static void r_sub_bytes(uint8_t data[16]);
static void mix_columns(uint8_t data[16]); static void mix_columns(uint8_t data[16]);
static void r_mix_columns(uint8_t data[16]);
static void print_data(uint8_t data[16]); static void print_data(uint8_t data[16]);
static uint8_t gf_mult2(uint8_t value); static uint8_t gf_mult2(uint8_t value);
static uint8_t gf_mult3(uint8_t value); static uint8_t gf_mult3(uint8_t value);
static uint8_t gf_mult4(uint8_t value);
static uint8_t gf_mult8(uint8_t value);
static uint8_t gf_mult9(uint8_t value);
static uint8_t gf_multB(uint8_t value);
static uint8_t gf_multD(uint8_t value);
static uint8_t gf_multE(uint8_t value);
static uint8_t gf_reduce(uint8_t value); static uint8_t gf_reduce(uint8_t value);
}; };

16
main.cpp
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@@ -12,17 +12,21 @@ using namespace std;
using namespace std::chrono; using namespace std::chrono;
int main(int argc, char **argv) { int main(int argc, char **argv) {
uint8_t data[16] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}; //uint8_t data[16] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
const uint8_t key[16] = {0xA0,0x7C,0x3D,0x99,0xFA,0x00,0x02,0x46,0x97,0x33,0x73,0x50,0x31,0x7C,0xD3,0xDC}; uint8_t data[16] = {0xA0,0x7C,0x3D,0x99,0xFA,0x00,0x02,0x46,0x97,0x33,0x73,0x50,0x31,0x7C,0xD3,0xDC};
//const uint8_t key[16] = {0xA0,0x7C,0x3D,0x99,0xFA,0x00,0x02,0x46,0x97,0x33,0x73,0x50,0x31,0x7C,0xD3,0xDC};
uint8_t key[16] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
ifstream input("/dev/urandom", ios::binary); ifstream input("/dev/urandom", ios::binary);
for (int i = 0;i < 5000;i++) for (int i = 0;i < 100000;i++)
{ {
input.read((char*) data, 16); input.read((char*) key, 16);
AES::encrypt_ecb(data, key);
for (int d = 0;d < 16;d++) for (int d = 0;d < 16;d++)
{ {
cout << dec << (int) data[d] << ","; cout << dec << (int) key[d] << ",";
} }
AES::encrypt_ecb(data, key); profiler.clear();
AES::decrypt_ecb(data, key);
cout << profiler.calls["gf_reduce"] << endl; cout << profiler.calls["gf_reduce"] << endl;
profiler.clear(); profiler.clear();
} }