/* * aes128.c * * Created: 27.11.2017 13:33:29 * Author: Matthias */ #include <aes128.h> /* the expanded keySize */ #define EXPANDED_KEY_SIZE 176 //int expandedKeySize; /* the expanded key */ //unsigned char expandedKey[EXPANDED_KEY_SIZE]; /* the cipher key */ //unsigned char key[16]; /* the cipher key size */ enum keySize{ SIZE_16 = 16, SIZE_24 = 24, SIZE_32 = 32 }; //enum keySize size; unsigned char sbox[256] = { //0 1 2 3 4 5 6 7 8 9 A B C D E F 0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76, //0 0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0, //1 0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15, //2 0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75, //3 0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84, //4 0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf, //5 0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8, //6 0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2, //7 0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73, //8 0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb, //9 0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79, //A 0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08, //B 0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a, //C 0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e, //D 0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf, //E 0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16 }; //F unsigned char rsbox[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 }; unsigned char 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}; void aes_init() { //UINT uitemp = 0; /* the expanded keySize */ //expandedKeySize = EXPANDED_KEY_SIZE; /* the cipher key */ //for (uitemp = 0; uitemp < 16; ++uitemp) //key[uitemp] = 0x00; /* the cipher key size */ //size = SIZE_16; } unsigned char getSBoxValue(unsigned char num) { return sbox[num]; } unsigned char getSBoxInvert(unsigned char num) { return rsbox[num]; } //Key generation /* Rijndael's key schedule rotate operation * rotate the word eight bits to the left * * rotate(1d2c3a4f) = 2c3a4f1d * * word is an char array of size 4 (32 bit) */ void rotate(unsigned char *word) { unsigned char c; int i; c = word[0]; for (i = 0; i < 3; i++) word[i] = word[i+1]; word[3] = c; } unsigned char getRconValue(unsigned char num) { return Rcon[num]; } void core(unsigned char *word, int iteration) { int i; /* rotate the 32-bit word 8 bits to the left */ rotate(word); /* apply S-Box substitution on all 4 parts of the 32-bit word */ for (i = 0; i < 4; ++i) { word[i] = getSBoxValue(word[i]); } /* XOR the output of the rcon operation with i to the first part (leftmost) only */ word[0] = word[0]^getRconValue(((unsigned char) iteration)); } /* Rijndael's key expansion * expands an 128,192,256 key into an 176,208,240 bytes key * * expandedKey is a pointer to an char array of large enough size * key is a pointer to a non-expanded key */ void expandKey(unsigned char *expandedKey, unsigned char *key, enum keySize size, /*size_t*/ unsigned int expandedKeySize) { /* current expanded keySize, in bytes */ int currentSize = 0; int rconIteration = 1; int i; unsigned char t[4] = {0,0,0,0}; // temporary 4-byte variable /* set the 16,24,32 bytes of the expanded key to the input key */ for (i = 0; i < size; i++) expandedKey[i] = key[i]; currentSize += size; while (currentSize < expandedKeySize) { /* assign the previous 4 bytes to the temporary value t */ for (i = 0; i < 4; i++) { t[i] = expandedKey[(currentSize - 4) + i]; } /* every 16,24,32 bytes we apply the core schedule to t * and increment rconIteration afterwards */ if(currentSize % size == 0) { core(t, rconIteration++); } /* For 256-bit keys, we add an extra sbox to the calculation */ if(size == SIZE_32 && ((currentSize % size) == 16)) { for(i = 0; i < 4; i++) t[i] = getSBoxValue(t[i]); } /* We XOR t with the four-byte block 16,24,32 bytes before the new expanded key. * This becomes the next four bytes in the expanded key. */ for(i = 0; i < 4; i++) { expandedKey[currentSize] = expandedKey[currentSize - size] ^ t[i]; currentSize++; } } } //Encrypt void subBytes(unsigned char *state) { int i; /* substitute all the values from the state with the value in the SBox * using the state value as index for the SBox */ for (i = 0; i < 16; i++) state[i] = getSBoxValue(state[i]); } void shiftRow(unsigned char *state, unsigned char nbr) { int i, j; unsigned char tmp; /* each iteration shifts the row to the left by 1 */ for (i = 0; i < nbr; i++) { tmp = state[0]; for (j = 0; j < 3; j++) state[j] = state[j+1]; state[3] = tmp; } } void shiftRows(unsigned char *state) { int i; /* iterate over the 4 rows and call shiftRow() with that row */ for (i = 0; i < 4; i++) shiftRow(state+i*4, i); } void addRoundKey(unsigned char *state, unsigned char *roundKey) { int i; for (i = 0; i < 16; i++) state[i] = state[i] ^ roundKey[i] ; } unsigned char galois_multiplication(unsigned char a, unsigned char b) { unsigned char p = 0; unsigned char counter; unsigned char hi_bit_set; for(counter = 0; counter < 8; counter++) { if((b & 1) == 1) p ^= a; hi_bit_set = (a & 0x80); a <<= 1; if(hi_bit_set == 0x80) a ^= 0x1b; b >>= 1; } return p; } void mixColumn(unsigned char *column) { unsigned char cpy[4]; int i; for(i = 0; i < 4; i++) { cpy[i] = column[i]; } column[0] = galois_multiplication(cpy[0],2) ^ galois_multiplication(cpy[3],1) ^ galois_multiplication(cpy[2],1) ^ galois_multiplication(cpy[1],3); column[1] = galois_multiplication(cpy[1],2) ^ galois_multiplication(cpy[0],1) ^ galois_multiplication(cpy[3],1) ^ galois_multiplication(cpy[2],3); column[2] = galois_multiplication(cpy[2],2) ^ galois_multiplication(cpy[1],1) ^ galois_multiplication(cpy[0],1) ^ galois_multiplication(cpy[3],3); column[3] = galois_multiplication(cpy[3],2) ^ galois_multiplication(cpy[2],1) ^ galois_multiplication(cpy[1],1) ^ galois_multiplication(cpy[0],3); } void mixColumns(unsigned char *state) { int i, j; unsigned char column[4]; /* iterate over the 4 columns */ for (i = 0; i < 4; i++) { /* construct one column by iterating over the 4 rows */ for (j = 0; j < 4; j++) { column[j] = state[(j*4)+i]; } /* apply the mixColumn on one column */ mixColumn(column); /* put the values back into the state */ for (j = 0; j < 4; j++) { state[(j*4)+i] = column[j]; } } } void aes_round(unsigned char *state, unsigned char *roundKey) { subBytes(state); shiftRows(state); mixColumns(state); addRoundKey(state, roundKey); } void createRoundKey(unsigned char *expandedKey, unsigned char *roundKey) { int i,j; /* iterate over the columns */ for (i = 0; i < 4; i++) { /* iterate over the rows */ for (j = 0; j < 4; j++) roundKey[(i+(j*4))] = expandedKey[(i*4)+j]; } } void aes_main(unsigned char *state, unsigned char *expandedKey, int nbrRounds) { int i = 0; unsigned char roundKey[16]; createRoundKey(expandedKey, roundKey); addRoundKey(state, roundKey); for (i = 1; i < nbrRounds; i++) { createRoundKey(expandedKey + 16*i, roundKey); aes_round(state, roundKey); } createRoundKey(expandedKey + 16*nbrRounds, roundKey); subBytes(state); shiftRows(state); addRoundKey(state, roundKey); } char aes_encrypt(unsigned char *input, unsigned char *output, unsigned char *key /*, enum keySize size*/) { enum keySize size = SIZE_16; /* the expanded keySize */ int expandedKeySize; /* the number of rounds */ int nbrRounds = 10; //NOTE: modded /* the expanded key */ //NOTE: modded: unsigned char *expandedKey = 0x00; //unsigned char expandedKey[(16*(nbrRounds+1))]; unsigned char expandedKey[176]; /* the 128 bit block to encode */ unsigned char block[16]; int i,j; /* set the number of rounds */ /*switch (size) { case SIZE_16: nbrRounds = 10; break; case SIZE_24: nbrRounds = 12; break; case SIZE_32: nbrRounds = 14; break; default: return 1; //UNKNOWN_KEYSIZE; break; }*/ //NOTE: modded expandedKeySize = (16*(nbrRounds+1)); /*if ((expandedKey = malloc(expandedKeySize * sizeof(char))) == NULL) { return MEMORY_ALLOCATION_PROBLEM; }*/ /* Set the block values, for the block: * a0,0 a0,1 a0,2 a0,3 * a1,0 a1,1 a1,2 a1,3 * a2,0 a2,1 a2,2 a2,3 * a3,0 a3,1 a3,2 a3,3 * the mapping order is a0,0 a1,0 a2,0 a3,0 a0,1 a1,1 ... a2,3 a3,3 */ /* iterate over the columns */ for (i = 0; i < 4; i++) { /* iterate over the rows */ for (j = 0; j < 4; j++) block[(i+(j*4))] = input[(i*4)+j]; } /* expand the key into an 176, 208, 240 bytes key */ expandKey(expandedKey, key, size, expandedKeySize); /* encrypt the block using the expandedKey */ aes_main(block, expandedKey, nbrRounds); /* unmap the block again into the output */ for (i = 0; i < 4; i++) { /* iterate over the rows */ for (j = 0; j < 4; j++) output[(i*4)+j] = block[(i+(j*4))]; } return 0; } //Decrypt void invSubBytes(unsigned char *state) { int i; /* substitute all the values from the state with the value in the SBox * using the state value as index for the SBox */ for (i = 0; i < 16; i++) state[i] = getSBoxInvert(state[i]); } void invShiftRow(unsigned char *state, unsigned char nbr) { int i, j; unsigned char tmp; /* each iteration shifts the row to the right by 1 */ for (i = 0; i < nbr; i++) { tmp = state[3]; for (j = 3; j > 0; j--) state[j] = state[j-1]; state[0] = tmp; } } void invShiftRows(unsigned char *state) { int i; /* iterate over the 4 rows and call invShiftRow() with that row */ for (i = 0; i < 4; i++) invShiftRow(state+i*4, i); } void invMixColumn(unsigned char *column) { unsigned char cpy[4]; int i; for(i = 0; i < 4; i++) { cpy[i] = column[i]; } column[0] = galois_multiplication(cpy[0],14) ^ galois_multiplication(cpy[3],9) ^ galois_multiplication(cpy[2],13) ^ galois_multiplication(cpy[1],11); column[1] = galois_multiplication(cpy[1],14) ^ galois_multiplication(cpy[0],9) ^ galois_multiplication(cpy[3],13) ^ galois_multiplication(cpy[2],11); column[2] = galois_multiplication(cpy[2],14) ^ galois_multiplication(cpy[1],9) ^ galois_multiplication(cpy[0],13) ^ galois_multiplication(cpy[3],11); column[3] = galois_multiplication(cpy[3],14) ^ galois_multiplication(cpy[2],9) ^ galois_multiplication(cpy[1],13) ^ galois_multiplication(cpy[0],11); } void invMixColumns(unsigned char *state) { int i, j; unsigned char column[4]; /* iterate over the 4 columns */ for (i = 0; i < 4; i++) { /* construct one column by iterating over the 4 rows */ for (j = 0; j < 4; j++) { column[j] = state[(j*4)+i]; } /* apply the invMixColumn on one column */ invMixColumn(column); /* put the values back into the state */ for (j = 0; j < 4; j++) { state[(j*4)+i] = column[j]; } } } void aes_invRound(unsigned char *state, unsigned char *roundKey) { invShiftRows(state); invSubBytes(state); addRoundKey(state, roundKey); invMixColumns(state); } void aes_invMain(unsigned char *state, unsigned char *expandedKey, int nbrRounds) { int i = 0; unsigned char roundKey[16]; createRoundKey(expandedKey + 16*nbrRounds, roundKey); addRoundKey(state, roundKey); for (i = nbrRounds-1; i > 0; i--) { createRoundKey(expandedKey + 16*i, roundKey); aes_invRound(state, roundKey); } createRoundKey(expandedKey, roundKey); invShiftRows(state); invSubBytes(state); addRoundKey(state, roundKey); } char aes_decrypt(unsigned char *input, unsigned char *output, unsigned char *key /*ยด, enum keySize size*/) { enum keySize size = SIZE_16; /* the expanded keySize */ int expandedKeySize; /* the number of rounds */ int nbrRounds; /* the expanded key */ unsigned char *expandedKey = 0x00; /* the 128 bit block to decode */ unsigned char block[16]; int i,j; /* set the number of rounds */ switch (size) { case SIZE_16: nbrRounds = 10; break; case SIZE_24: nbrRounds = 12; break; case SIZE_32: nbrRounds = 14; break; default: return 1; //UNKNOWN_KEYSIZE; break; } expandedKeySize = (16*(nbrRounds+1)); /*if ((expandedKey = malloc(expandedKeySize * sizeof(char))) == NULL) { return MEMORY_ALLOCATION_PROBLEM; }*/ /* Set the block values, for the block: * a0,0 a0,1 a0,2 a0,3 * a1,0 a1,1 a1,2 a1,3 * a2,0 a2,1 a2,2 a2,3 * a3,0 a3,1 a3,2 a3,3 * the mapping order is a0,0 a1,0 a2,0 a3,0 a0,1 a1,1 ... a2,3 a3,3 */ /* iterate over the columns */ for (i = 0; i < 4; i++) { /* iterate over the rows */ for (j = 0; j < 4; j++) block[(i+(j*4))] = input[(i*4)+j]; } /* expand the key into an 176, 208, 240 bytes key */ expandKey(expandedKey, key, size, expandedKeySize); /* decrypt the block using the expandedKey */ aes_invMain(block, expandedKey, nbrRounds); /* unmap the block again into the output */ for (i = 0; i < 4; i++) { /* iterate over the rows */ for (j = 0; j < 4; j++) output[(i*4)+j] = block[(i+(j*4))]; } return 0; }