/* ============================================================================================================ * 2012036901 - 윤진한 주 의 사 항 1. 주석으로 표현된 구현 블록 0에서 12번까지 구현하여 128비트 AES 암호화 알고리즘을 구현해야 함 2. AES128(...) 함수의 호출과 리턴이 여러번 반복되더라도 메모리 누수가 생기지 않게 함 3. AddRoundKey 함수를 구현할 때에도 파라미터 rKey는 사전에 선언된 지역 배열을 가리키도록 해야 함 (정확한 구현을 위해서는 포인터 개념의 이해가 필요함) 4. 배열의 인덱스 계산시 아래에 정의된 KEY_SIZE, ROUNDKEY_SIZE, BLOCK_SIZE를 이용해야 함 (상수 그대로 사용하면 안됨. 예로, 4, 16는 안되고 KEY_SIZE/4, BLOCK_SIZE로 사용해야 함) * ============================================================================================================ */ #include #include #include "AES128.h" #define KEY_SIZE 16 #define ROUNDKEY_SIZE 176 #define BLOCK_SIZE 16 /*********************************************** { 구현 0 시작 } ********************************************/ static const uint8_t ori_sbox[256] = { 0x63, 0x7C, 0x77, 0x7B, 0xF2, 0x6B, 0x6F, 0xC5, 0x30, 0x01, 0x67, 0x2B, 0xFE, 0xD7, 0xAB, 0x76, 0xCA, 0x82, 0xC9, 0x7D, 0xFA, 0x59, 0x47, 0xF0, 0xAD, 0xD4, 0xA2, 0xAF, 0x9C, 0xA4, 0x72, 0xC0, 0xB7, 0xFD, 0x93, 0x26, 0x36, 0x3F, 0xF7, 0xCC, 0x34, 0xA5, 0xE5, 0xF1, 0x71, 0xD8, 0x31, 0x15, 0x04, 0xC7, 0x23, 0xC3, 0x18, 0x96, 0x05, 0x9A, 0x07, 0x12, 0x80, 0xE2, 0xEB, 0x27, 0xB2, 0x75, 0x09, 0x83, 0x2C, 0x1A, 0x1B, 0x6E, 0x5A, 0xA0, 0x52, 0x3B, 0xD6, 0xB3, 0x29, 0xE3, 0x2F, 0x84, 0x53, 0xD1, 0x00, 0xED, 0x20, 0xFC, 0xB1, 0x5B, 0x6A, 0xCB, 0xBE, 0x39, 0x4A, 0x4C, 0x58, 0xCF, 0xD0, 0xEF, 0xAA, 0xFB, 0x43, 0x4D, 0x33, 0x85, 0x45, 0xF9, 0x02, 0x7F, 0x50, 0x3C, 0x9F, 0xA8, 0x51, 0xA3, 0x40, 0x8F, 0x92, 0x9D, 0x38, 0xF5, 0xBC, 0xB6, 0xDA, 0x21, 0x10, 0xFF, 0xF3, 0xD2, 0xCD, 0x0C, 0x13, 0xEC, 0x5F, 0x97, 0x44, 0x17, 0xC4, 0xA7, 0x7E, 0x3D, 0x64, 0x5D, 0x19, 0x73, 0x60, 0x81, 0x4F, 0xDC, 0x22, 0x2A, 0x90, 0x88, 0x46, 0xEE, 0xB8, 0x14, 0xDE, 0x5E, 0x0B, 0xDB, 0xE0, 0x32, 0x3A, 0x0A, 0x49, 0x06, 0x24, 0x5C, 0xC2, 0xD3, 0xAC, 0x62, 0x91, 0x95, 0xE4, 0x79, 0xE7, 0xC8, 0x37, 0x6D, 0x8D, 0xD5, 0x4E, 0xA9, 0x6C, 0x56, 0xF4, 0xEA, 0x65, 0x7A, 0xAE, 0x08, 0xBA, 0x78, 0x25, 0x2E, 0x1C, 0xA6, 0xB4, 0xC6, 0xE8, 0xDD, 0x74, 0x1F, 0x4B, 0xBD, 0x8B, 0x8A, 0x70, 0x3E, 0xB5, 0x66, 0x48, 0x03, 0xF6, 0x0E, 0x61, 0x35, 0x57, 0xB9, 0x86, 0xC1, 0x1D, 0x9E, 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 }; static const uint8_t inv_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, 0x08, 0x2E, 0xA1, 0x66, 0x28, 0xD9, 0x24, 0xB2, 0x76, 0x5B, 0xA2, 0x49, 0x6D, 0x8B, 0xD1, 0x25, 0x72, 0xF8, 0xF6, 0x64, 0x86, 0x68, 0x98, 0x16, 0xD4, 0xA4, 0x5C, 0xCC, 0x5D, 0x65, 0xB6, 0x92, 0x6C, 0x70, 0x48, 0x50, 0xFD, 0xED, 0xB9, 0xDA, 0x5E, 0x15, 0x46, 0x57, 0xA7, 0x8D, 0x9D, 0x84, 0x90, 0xD8, 0xAB, 0x00, 0x8C, 0xBC, 0xD3, 0x0A, 0xF7, 0xE4, 0x58, 0x05, 0xB8, 0xB3, 0x45, 0x06, 0xD0, 0x2C, 0x1E, 0x8F, 0xCA, 0x3F, 0x0F, 0x02, 0xC1, 0xAF, 0xBD, 0x03, 0x01, 0x13, 0x8A, 0x6B, 0x3A, 0x91, 0x11, 0x41, 0x4F, 0x67, 0xDC, 0xEA, 0x97, 0xF2, 0xCF, 0xCE, 0xF0, 0xB4, 0xE6, 0x73, 0x96, 0xAC, 0x74, 0x22, 0xE7, 0xAD, 0x35, 0x85, 0xE2, 0xF9, 0x37, 0xE8, 0x1C, 0x75, 0xDF, 0x6E, 0x47, 0xF1, 0x1A, 0x71, 0x1D, 0x29, 0xC5, 0x89, 0x6F, 0xB7, 0x62, 0x0E, 0xAA, 0x18, 0xBE, 0x1B, 0xFC, 0x56, 0x3E, 0x4B, 0xC6, 0xD2, 0x79, 0x20, 0x9A, 0xDB, 0xC0, 0xFE, 0x78, 0xCD, 0x5A, 0xF4, 0x1F, 0xDD, 0xA8, 0x33, 0x88, 0x07, 0xC7, 0x31, 0xB1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xEC, 0x5F, 0x60, 0x51, 0x7F, 0xA9, 0x19, 0xB5, 0x4A, 0x0D, 0x2D, 0xE5, 0x7A, 0x9F, 0x93, 0xC9, 0x9C, 0xEF, 0xA0, 0xE0, 0x3B, 0x4D, 0xAE, 0x2A, 0xF5, 0xB0, 0xC8, 0xEB, 0xBB, 0x3C, 0x83, 0x53, 0x99, 0x61, 0x17, 0x2B, 0x04, 0x7E, 0xBA, 0x77, 0xD6, 0x26, 0xE1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0C, 0x7D }; static const uint8_t rcon[256] = { 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d }; static const uint8_t matrix[16] = { 0x02, 0x03, 0x01, 0x01, 0x01, 0x02, 0x03, 0x01, 0x01, 0x01, 0x02, 0x03, 0x03, 0x01, 0x01, 0x02 }; static const uint8_t inv_matrix[16] = { 0x0E, 0x0B, 0x0D, 0x09, 0x09, 0x0E, 0x0B, 0x0D, 0x0D, 0x09, 0x0E, 0x0B, 0x0B, 0x0D, 0x09, 0x0E }; // Additional Fuction - Galois field mutiplication. BYTE GF_Mutiplication(uint8_t num,BYTE data){ int i; BYTE tmp = 0; BYTE mask = 0x01; for (i = 0;i < num;i ++){ if (num & mask){ tmp ^= data; } if (data & 0x80){ data = (data << 1) ^ 0x1b; } else { data <<= 1; } mask <<= 1; } return tmp; }// Galois field mutiplication function. /*********************************************** { 구현 0 종료 } ********************************************/ /* <키스케줄링 함수> * * key 키스케줄링을 수행할 16바이트 키 * roundKey 키스케줄링의 결과인 176바이트 라운드키가 담길 공간 */ void expandKey(BYTE *key, BYTE *roundKey){ /*********************************************** { 구현 1 시작 } ********************************************/ int i,j,k,roundKey_filled = 0; BYTE tmp,gkey[4],tmp_key[4][4]; for (i = 0;i < KEY_SIZE/4;i ++){ for (j = 0;j < KEY_SIZE/4;j ++){ tmp_key[i][j] = *(key + i*4 + j); *(roundKey + (roundKey_filled++)) = tmp_key[i][j]; } }// The first round key is the original key itself. for (i = 1;i < ROUNDKEY_SIZE/KEY_SIZE;i ++){ for (j = 0;j < KEY_SIZE/4 ;j ++){ gkey[j] = tmp_key[3][j]; } tmp = gkey[0]; for (j = 0;j < KEY_SIZE/4 - 1 ;j ++){ gkey[j] = gkey[j + 1]; } gkey[KEY_SIZE/4 - 1] = tmp; // Shift left 1 bit. for (j = 0;j < KEY_SIZE/4 ;j ++){ gkey[j] = ori_sbox[ gkey[j] ]; }// Sub ori_sbox. gkey[0] ^= rcon[i]; // XOR with rcon matrix. for (j = 0;j < KEY_SIZE/4 ;j ++){ tmp_key[0][j] ^= gkey[j]; }// XOR gkey. for (j = 1;j < KEY_SIZE/4 ;j ++){ for (k = 0;k < KEY_SIZE/4 ;k ++){ tmp_key[j][k] ^= tmp_key[j-1][k]; } }// Make round key. for (j = 0;j < KEY_SIZE/4 ;j ++){ for (k = 0;k < KEY_SIZE/4 ;k ++){ *(roundKey + (roundKey_filled++)) = tmp_key[j][k]; } }// Insert calculated key into RoundKey. } /*********************************************** { 구현 1 종료 } ********************************************/ } /* * * block SubBytes 수행할 16바이트 블록. 수행 결과는 해당 배열에 바로 반영 * mode SubBytes 수행 모드 */ BYTE* subBytes(BYTE *block, int mode){ /* 필요하다 생각하면 추가 선언 */ int i; switch(mode){ case ENC: /*********************************************** { 구현 2 시작 } ********************************************/ for (i = 0;i < BLOCK_SIZE;i ++){ *(block + i) = ori_sbox[ *(block + i) ]; }// SubByte ori_sbox. /*********************************************** { 구현 2 종료 } ********************************************/ break; case DEC: /*********************************************** { 구현 3 시작 } ********************************************/ for (i = 0;i < BLOCK_SIZE;i ++){ *(block + i) = inv_sbox[ *(block + i) ]; }// SubByte inv_sbox. /*********************************************** { 구현 3 종료 } ********************************************/ break; default: fprintf(stderr, "Invalid mode!\n"); exit(1); } return block; } /* * * block ShiftRows 수행할 16바이트 블록. 수행 결과는 해당 배열에 바로 반영 * mode ShiftRows 수행 모드 */ BYTE* shiftRows(BYTE *block, int mode){ /* 필요하다 생각하면 추가 선언 */ int i,j,rep; BYTE tmp; switch(mode){ case ENC: /*********************************************** { 구현 4 시작 } ********************************************/ for (i = 1; i < BLOCK_SIZE/4;i ++){ for (rep = i;rep >= 1;rep --){ tmp = *(block + i); for (j = i; j < (i + BLOCK_SIZE - BLOCK_SIZE/4) ;j += 4){ *(block + j) = *(block + j + BLOCK_SIZE/4); } *(block + i + BLOCK_SIZE - BLOCK_SIZE/4) = tmp; } } // 1 left Shift 2nd Col, 2 left Shift 3rd Col, 3 left Shift 4th Col. /*********************************************** { 구현 4 종료 } ********************************************/ break; case DEC: /*********************************************** { 구현 5 시작 } ********************************************/ for (i = 1; i < BLOCK_SIZE/4;i ++){ for (rep = i;rep >= 1;rep --){ tmp = *(block + i + BLOCK_SIZE - BLOCK_SIZE/4); for (j = i + BLOCK_SIZE - BLOCK_SIZE/4; j >= i ;j -= 4){ *(block + j) = *(block + j - BLOCK_SIZE/4); } *(block + i) = tmp; } } // 1 right Shift 2nd Col, 2 right Shift 3rd Col, 3 right Shift 4th Col. /*********************************************** { 구현 5 종료 } ********************************************/ break; default: fprintf(stderr, "Invalid mode!\n"); exit(1); } return block; } /* * * block MixColumns을 수행할 16바이트 블록. 수행 결과는 해당 배열에 바로 반영 * mode MixColumns의 수행 모드 */ BYTE* mixColumns(BYTE *block, int mode){ /* 필요하다 생각하면 추가 선언 */ int i,j,k; BYTE tmp[16] = {0,}; BYTE tmp2[4][4]; for (i=0;i<4;i++){ for (j=0;j<4;j++){ tmp2[i][j] = *(block+i*4+j); } } for (i=0;i<4;i++){ for (j=0;j<4;j++){ *(block+i*4+j) = tmp2[j][i]; } } switch(mode){ case ENC: /*********************************************** { 구현 6 시작 } ********************************************/ for (i = 0;i < BLOCK_SIZE/4 ;i ++){ for (j = 0;j < BLOCK_SIZE/4 ;j ++){ for (k = 0;k < BLOCK_SIZE/4 ;k ++){ tmp[ i*4 +j ] ^= GF_Mutiplication(matrix[ i*4 + k ],*(block + k*4 + j)); } } }// Galois field mutiplication data with matirx. /*********************************************** { 구현 6 종료 } ********************************************/ break; case DEC: /*********************************************** { 구현 7 시작 } ********************************************/ for (i = 0;i < BLOCK_SIZE/4 ;i ++){ for (j = 0;j < BLOCK_SIZE/4 ;j ++){ for (k = 0;k < BLOCK_SIZE/4 ;k ++){ tmp[ i*4 +j ] ^= GF_Mutiplication(inv_matrix[ i*4 + k],*(block + k*4 + j)); } } }// Galois field mutiplication data with inv_matirx. /*********************************************** { 구현 7 종료 } ********************************************/ break; default: fprintf(stderr, "Invalid mode!\n"); exit(1); } for (i=0;i<4;i++){ for (j=0;j<4;j++){ tmp2[i][j] = tmp[i*4+j]; } } for (i = 0;i * * block AddRoundKey를 수행할 16바이트 블록. 수행 결과는 해당 배열에 반영 * rKey AddRoundKey를 수행할 16바이트 라운드키 */ BYTE* addRoundKey(BYTE *block, BYTE *rKey){ /*********************************************** { 구현 8 시작 } ********************************************/ int i,j; for (i = 0 ; i < BLOCK_SIZE/4 ; i++){ for (j = i ; j < BLOCK_SIZE ; j+=4){ *(block + j) ^= *(rKey + j); } }// XOR Calculate origin block data with RoundKey. /*********************************************** { 구현 8 종료 } ********************************************/ return block; } /* <128비트 AES 암호화 함수> * * plain 바이트 배열로 구성된 평문 (16바이트 고정) * key 128비트 암호키 (16바이트) * * @ret 암호화된 암호문 */ BYTE* encrypt(BYTE *plain, BYTE *key){ BYTE roundKey[ROUNDKEY_SIZE]; /*********************************************** { 구현 9 시작 } ********************************************/ int round; for (round = 0; round <= 10; round ++){ if (round == 0){ // initial round of encryption. expandKey(key,roundKey); addRoundKey(plain,roundKey); } else if (round == 10){ // final round of encryption. subBytes(plain,ENC); shiftRows(plain,ENC); addRoundKey(plain,roundKey + round*KEY_SIZE); } else { // 9 main rounds of encryption. subBytes(plain,ENC); shiftRows(plain,ENC); mixColumns(plain,ENC); addRoundKey(plain,roundKey + round*KEY_SIZE); } } return plain; /*********************************************** { 구현 9 종료 } ********************************************/ } /* <128비트 AES 복호화 함수> * * cipher 바이트 배열로 구성된 평문 (16바이트 고정) * key 128비트 암호키 (16바이트) * * @ret 복호화된 평문 */ BYTE* decrypt(BYTE *cipher, BYTE *key){ BYTE roundKey[ROUNDKEY_SIZE]; /*********************************************** { 구현 10 시작 } ********************************************/ int round; for (round = 10; round >=0; round --){ if (round == 0){ // final round of encryption. shiftRows(cipher,DEC); subBytes(cipher,DEC); addRoundKey(cipher,roundKey); } else if (round == 10){ // initial round of encryption. expandKey(key,roundKey); addRoundKey(cipher,roundKey + round*KEY_SIZE); } else { // 9 main rounds of encryption. shiftRows(cipher,DEC); subBytes(cipher,DEC); addRoundKey(cipher,roundKey + round*KEY_SIZE); mixColumns(cipher,DEC); } } return cipher; /*********************************************** { 구현 10 종료 } ********************************************/ } /* <128비트 AES 암복호화 함수> * * mode가 ENC일 경우 평문을 암호화하고, DEC일 경우 암호문을 복호화하는 함수 * * [ENC 모드] * plain 평문 바이트 배열 * cipher 결과(암호문)이 담길 바이트 배열. 호출하는 사용자가 사전에 메모리를 할당하여 파라미터로 넘김 * key 128비트 암호키 (16바이트) * * [DEC 모드] * plain 결과(평문)가 담길 바이트 배열. 호출하는 사용자가 사전에 메모리를 할당하여 파라미터로 넘김 * cipher 암호문 바이트 배열 * key 128비트 암호키 (16바이트) */ void AES128(BYTE *plain, BYTE *cipher, BYTE *key, int mode){ BYTE *tmp; if(mode == ENC){ tmp = encrypt(plain, key); /*********************************************** { 구현 11 시작 } ********************************************/ for (int i = 0; i < BLOCK_SIZE ; i ++){ *(cipher + i) = *(tmp + i); }// copy tmp blocks to ciper blocks. /*********************************************** { 구현 11 종료 } ********************************************/ }else if(mode == DEC){ tmp = decrypt(cipher, key); /*********************************************** { 구현 12 시작 } ********************************************/ for (int i = 0; i < BLOCK_SIZE ; i ++){ *(plain + i) = *(tmp + i); }// copy tmp blocks to plain blocks. /*********************************************** { 구현 12 종료 } ********************************************/ }else{ fprintf(stderr, "Invalid mode!\n"); exit(1); } }