From d03fe358e73ef8c11665a6351d697aecdb27f56d Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Manuel=20V=C3=B6gele?= Date: Wed, 15 May 2019 09:26:42 +0200 Subject: [PATCH] Implement decryption --- aes.cpp | 104 +++++++++++++++++++++++++++++++++++++++++++++++++++++-- aes.hpp | 12 ++++++- main.cpp | 16 +++++---- 3 files changed, 122 insertions(+), 10 deletions(-) diff --git a/aes.cpp b/aes.cpp index d7e327b..d349582 100644 --- a/aes.cpp +++ b/aes.cpp @@ -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, 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, 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, @@ -84,6 +84,24 @@ void AES::encrypt_ecb(uint8_t data[16], const uint8_t key[16]) 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]) { 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 void AES::shift_rows(uint8_t data[16]) @@ -125,6 +152,25 @@ void AES::shift_rows(uint8_t data[16]) 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 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); } +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]) { PROFILER_RECORD; @@ -195,6 +255,44 @@ uint8_t AES::gf_mult2(uint8_t value) uint8_t AES::gf_mult3(uint8_t value) { PROFILER_RECORD; - uint8_t result = gf_mult2(value); - return result ^ value; + return gf_mult2(value) ^ 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; } diff --git a/aes.hpp b/aes.hpp index b6040ec..bada25d 100644 --- a/aes.hpp +++ b/aes.hpp @@ -7,21 +7,31 @@ class AES { private: 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 irreducible_polynomial; public: AES(); 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 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 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 r_sub_bytes(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 uint8_t gf_mult2(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); }; diff --git a/main.cpp b/main.cpp index 155c43f..10086d0 100644 --- a/main.cpp +++ b/main.cpp @@ -12,17 +12,21 @@ using namespace std; using namespace std::chrono; 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}; - 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] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0}; + 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); - 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++) { - 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; profiler.clear(); }