Embedded systems coursework 2.
Fork of Crypto_light by
cipher/AES.cpp
- Committer:
- feb11
- Date:
- 2013-09-14
- Revision:
- 7:2dbbdfb08123
- Parent:
- AES.cpp@ 2:473bac39ae7c
- Child:
- 8:a090264e9b2d
File content as of revision 7:2dbbdfb08123:
#include "AES.h" #include <string.h> #include <stdio.h> #include <stdlib.h> static const uint8_t sbox[] = { 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_s[] = { 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 uint32_t rcon[10]= { 0x01000000, 0x02000000, 0x04000000, 0x08000000, 0x10000000, 0x20000000, 0x40000000, 0x80000000, 0x1B000000, 0x36000000 }; AES::AES(const AES_TYPE t, uint8_t *key): state() { switch(t) { case AES_128: nr = 10; nk = 4; break; case AES_192: nr = 12; nk = 6; break; case AES_256: nr = 14; nk = 8; break; } keyExpansion(key); } void AES::keyExpansion(uint8_t *key) { uint32_t temp; int i = 0; while(i < nk) { w[i] = (key[4*i] << 24) + (key[4*i+1] << 16) + (key[4*i+2] << 8) + key[4*i+3]; i++; } i = nk; while(i < 4*(nr+1)) { temp = w[i-1]; if(i % nk == 0) { temp = rotWord(temp); temp = subWord(temp); temp ^= rcon[i/nk-1]; } else if(nk > 6 && i % nk == 4) temp = subWord(temp); w[i] = w[i-nk] ^ temp; i++; } } uint32_t AES::rotWord(uint32_t w) { return (w << 8) + (w >> 24); } uint32_t AES::invRotWord(uint32_t w) { return (w >> 8) + (w << 24); } uint32_t AES::subWord(uint32_t w) { uint32_t out = 0; for(int i = 0; i < 4; ++i) { uint8_t temp = (w & 0xFF); out |= (sbox[temp] << (8*i)); w = (w >> 8); } return out; } void AES::subBytes() { for(int i = 0; i < 16; ++i) state[i] = sbox[state[i]]; } void AES::invSubBytes() { for(int i = 0; i < 16; ++i) state[i] = inv_s[state[i]]; } void AES::shiftRows() { for(int r = 0; r < 4; ++r) { uint32_t temp = (state[r] << 24) + (state[r+4] << 16) + (state[r+8] << 8) + state[r+12]; int i = r; while(i > 0) { temp = rotWord(temp); --i; } state[r] = temp >> 24; state[r+4] = temp >> 16; state[r+8] = temp >> 8; state[r+12] = temp; } } void AES::invShiftRows() { for(int r = 0; r < 4; ++r) { uint32_t temp = (state[r] << 24) + (state[r+4] << 16) + (state[r+8] << 8) + state[r+12]; int i = r; while(i > 0) { temp = invRotWord(temp); --i; } state[r] = temp >> 24; state[r+4] = temp >> 16; state[r+8] = temp >> 8; state[r+12] = temp; } } /* Multiply two numbers in the GF(2^8) finite field defined * by the polynomial x^8 + x^4 + x^3 + x + 1 */ uint8_t gmul(uint8_t a, uint8_t b) { uint8_t p = 0; uint8_t counter; uint8_t carry; for (counter = 0; counter < 8; counter++) { if (b & 1) p ^= a; carry = (a & 0x80); a <<= 1; if (carry) a ^= 0x001B; /* what x^8 is modulo x^8 + x^4 + x^3 + x^2 + 1 */ b >>= 1; } return p; } void AES::mul(uint8_t *r) { uint8_t tmp[4]; memcpy(tmp, r, 4); r[0] = gmul(tmp[0],2) ^ gmul(tmp[1],3) ^ tmp[2] ^ tmp[3]; r[1] = tmp[0] ^ gmul(tmp[1],2) ^ gmul(tmp[2],3) ^ tmp[3]; r[2] = tmp[0] ^ tmp[1] ^ gmul(tmp[2],2) ^ gmul(tmp[3],3); r[3] = gmul(tmp[0],3) ^ tmp[1] ^ tmp[2] ^ gmul(tmp[3],2); } void AES::invMul(uint8_t *r) { uint8_t tmp[4]; memcpy(tmp, r, 4); r[0] = gmul(tmp[0],0x0e) ^ gmul(tmp[1],0x0b) ^ gmul(tmp[2],0x0d) ^ gmul(tmp[3],9); r[1] = gmul(tmp[0],9) ^ gmul(tmp[1],0x0e) ^ gmul(tmp[2],0x0b) ^ gmul(tmp[3],0x0d); r[2] = gmul(tmp[0],0x0d) ^ gmul(tmp[1],9) ^ gmul(tmp[2],0x0e) ^ gmul(tmp[3],0x0b); r[3] = gmul(tmp[0],0x0b) ^ gmul(tmp[1],0x0d) ^ gmul(tmp[2],9) ^ gmul(tmp[3],0x0e); } void AES::mixColumns() { for(int c = 0; c < 4; ++c) mul(&state[4*c]); } void AES::invMixColumns() { for(int c = 0; c < 4; ++c) invMul(&state[4*c]); } void AES::addRoundKey(int round) { for(int c = 0; c < 4; ++c) { uint32_t temp = (state[4*c] << 24) + (state[4*c+1] << 16) + (state[4*c+2] << 8) + state[4*c+3]; temp ^= w[round*4+c]; state[4*c] = temp >> 24; state[4*c+1] = temp >> 16; state[4*c+2] = temp >> 8; state[4*c+3] = temp; } } void AES::decryptBlock(uint8_t *out, uint8_t *in) { memcpy(state,in,16); addRoundKey(nr); for(int round = nr-1; round > 0; --round) { invShiftRows(); invSubBytes(); addRoundKey(round); invMixColumns(); } invShiftRows(); invSubBytes(); addRoundKey(0); memcpy(out, state, 16); } void AES::encryptBlock(uint8_t *out, uint8_t *in) { memcpy(state,in,16); addRoundKey(0); for(int round = 1; round < nr; ++round) { subBytes(); shiftRows(); mixColumns(); addRoundKey(round); } subBytes(); shiftRows(); addRoundKey(nr); memcpy(out, state, 16); } void AES::encrypt(uint8_t *out, uint8_t *in, uint32_t length) { for(uint32_t i = 0; i < length; i+=16) encryptBlock(&out[i], &in[i]); } void AES::decrypt(uint8_t *out, uint8_t *in, uint32_t length) { for(uint32_t i = 0; i < length; i+=16) decryptBlock(&out[i], &in[i]); } uint32_t AES::getBlockSize() const { return 16; }