/* rijndael-alg-ref.c v2.0 August '99 * Reference ANSI C code * authors: Paulo Barreto * Vincent Rijmen, K.U.Leuven * * This code is placed in the public domain. */ #include "mvOs.h" #include "mvAesAlg.h" #include "mvAesBoxes.dat" MV_U8 mul1(MV_U8 aa, MV_U8 bb); void KeyAddition(MV_U8 a[4][MAXBC], MV_U8 rk[4][MAXBC], MV_U8 BC); void ShiftRow128Enc(MV_U8 a[4][MAXBC]); void ShiftRow128Dec(MV_U8 a[4][MAXBC]); void Substitution(MV_U8 a[4][MAXBC], MV_U8 box[256]); void MixColumn(MV_U8 a[4][MAXBC], MV_U8 rk[4][MAXBC]); void InvMixColumn(MV_U8 a[4][MAXBC]); #define mul(aa, bb) (mask[bb] & Alogtable[aa + Logtable[bb]]) MV_U8 mul1(MV_U8 aa, MV_U8 bb) { return mask[bb] & Alogtable[aa + Logtable[bb]]; } void KeyAddition(MV_U8 a[4][MAXBC], MV_U8 rk[4][MAXBC], MV_U8 BC) { /* Exor corresponding text input and round key input bytes */ ((MV_U32*)(&(a[0][0])))[0] ^= ((MV_U32*)(&(rk[0][0])))[0]; ((MV_U32*)(&(a[1][0])))[0] ^= ((MV_U32*)(&(rk[1][0])))[0]; ((MV_U32*)(&(a[2][0])))[0] ^= ((MV_U32*)(&(rk[2][0])))[0]; ((MV_U32*)(&(a[3][0])))[0] ^= ((MV_U32*)(&(rk[3][0])))[0]; } void ShiftRow128Enc(MV_U8 a[4][MAXBC]) { /* Row 0 remains unchanged * The other three rows are shifted a variable amount */ MV_U8 tmp[MAXBC]; tmp[0] = a[1][1]; tmp[1] = a[1][2]; tmp[2] = a[1][3]; tmp[3] = a[1][0]; ((MV_U32*)(&(a[1][0])))[0] = ((MV_U32*)(&(tmp[0])))[0]; /* a[1][0] = tmp[0]; a[1][1] = tmp[1]; a[1][2] = tmp[2]; a[1][3] = tmp[3]; */ tmp[0] = a[2][2]; tmp[1] = a[2][3]; tmp[2] = a[2][0]; tmp[3] = a[2][1]; ((MV_U32*)(&(a[2][0])))[0] = ((MV_U32*)(&(tmp[0])))[0]; /* a[2][0] = tmp[0]; a[2][1] = tmp[1]; a[2][2] = tmp[2]; a[2][3] = tmp[3]; */ tmp[0] = a[3][3]; tmp[1] = a[3][0]; tmp[2] = a[3][1]; tmp[3] = a[3][2]; ((MV_U32*)(&(a[3][0])))[0] = ((MV_U32*)(&(tmp[0])))[0]; /* a[3][0] = tmp[0]; a[3][1] = tmp[1]; a[3][2] = tmp[2]; a[3][3] = tmp[3]; */ } void ShiftRow128Dec(MV_U8 a[4][MAXBC]) { /* Row 0 remains unchanged * The other three rows are shifted a variable amount */ MV_U8 tmp[MAXBC]; tmp[0] = a[1][3]; tmp[1] = a[1][0]; tmp[2] = a[1][1]; tmp[3] = a[1][2]; ((MV_U32*)(&(a[1][0])))[0] = ((MV_U32*)(&(tmp[0])))[0]; /* a[1][0] = tmp[0]; a[1][1] = tmp[1]; a[1][2] = tmp[2]; a[1][3] = tmp[3]; */ tmp[0] = a[2][2]; tmp[1] = a[2][3]; tmp[2] = a[2][0]; tmp[3] = a[2][1]; ((MV_U32*)(&(a[2][0])))[0] = ((MV_U32*)(&(tmp[0])))[0]; /* a[2][0] = tmp[0]; a[2][1] = tmp[1]; a[2][2] = tmp[2]; a[2][3] = tmp[3]; */ tmp[0] = a[3][1]; tmp[1] = a[3][2]; tmp[2] = a[3][3]; tmp[3] = a[3][0]; ((MV_U32*)(&(a[3][0])))[0] = ((MV_U32*)(&(tmp[0])))[0]; /* a[3][0] = tmp[0]; a[3][1] = tmp[1]; a[3][2] = tmp[2]; a[3][3] = tmp[3]; */ } void Substitution(MV_U8 a[4][MAXBC], MV_U8 box[256]) { /* Replace every byte of the input by the byte at that place * in the nonlinear S-box */ int i, j; for(i = 0; i < 4; i++) for(j = 0; j < 4; j++) a[i][j] = box[a[i][j]] ; } void MixColumn(MV_U8 a[4][MAXBC], MV_U8 rk[4][MAXBC]) { /* Mix the four bytes of every column in a linear way */ MV_U8 b[4][MAXBC]; int i, j; for(j = 0; j < 4; j++){ b[0][j] = mul(25,a[0][j]) ^ mul(1,a[1][j]) ^ a[2][j] ^ a[3][j]; b[1][j] = mul(25,a[1][j]) ^ mul(1,a[2][j]) ^ a[3][j] ^ a[0][j]; b[2][j] = mul(25,a[2][j]) ^ mul(1,a[3][j]) ^ a[0][j] ^ a[1][j]; b[3][j] = mul(25,a[3][j]) ^ mul(1,a[0][j]) ^ a[1][j] ^ a[2][j]; } for(i = 0; i < 4; i++) /*for(j = 0; j < BC; j++) a[i][j] = b[i][j];*/ ((MV_U32*)(&(a[i][0])))[0] = ((MV_U32*)(&(b[i][0])))[0] ^ ((MV_U32*)(&(rk[i][0])))[0];; } void InvMixColumn(MV_U8 a[4][MAXBC]) { /* Mix the four bytes of every column in a linear way * This is the opposite operation of Mixcolumn */ MV_U8 b[4][MAXBC]; int i, j; for(j = 0; j < 4; j++){ b[0][j] = mul(223,a[0][j]) ^ mul(104,a[1][j]) ^ mul(238,a[2][j]) ^ mul(199,a[3][j]); b[1][j] = mul(223,a[1][j]) ^ mul(104,a[2][j]) ^ mul(238,a[3][j]) ^ mul(199,a[0][j]); b[2][j] = mul(223,a[2][j]) ^ mul(104,a[3][j]) ^ mul(238,a[0][j]) ^ mul(199,a[1][j]); b[3][j] = mul(223,a[3][j]) ^ mul(104,a[0][j]) ^ mul(238,a[1][j]) ^ mul(199,a[2][j]); } for(i = 0; i < 4; i++) /*for(j = 0; j < BC; j++) a[i][j] = b[i][j];*/ ((MV_U32*)(&(a[i][0])))[0] = ((MV_U32*)(&(b[i][0])))[0]; } int rijndaelKeySched (MV_U8 k[4][MAXKC], int keyBits, int blockBits, MV_U8 W[MAXROUNDS+1][4][MAXBC]) { /* Calculate the necessary round keys * The number of calculations depends on keyBits and blockBits */ int KC, BC, ROUNDS; int i, j, t, rconpointer = 0; MV_U8 tk[4][MAXKC]; switch (keyBits) { case 128: KC = 4; break; case 192: KC = 6; break; case 256: KC = 8; break; default : return (-1); } switch (blockBits) { case 128: BC = 4; break; case 192: BC = 6; break; case 256: BC = 8; break; default : return (-2); } switch (keyBits >= blockBits ? keyBits : blockBits) { case 128: ROUNDS = 10; break; case 192: ROUNDS = 12; break; case 256: ROUNDS = 14; break; default : return (-3); /* this cannot happen */ } for(j = 0; j < KC; j++) for(i = 0; i < 4; i++) tk[i][j] = k[i][j]; t = 0; /* copy values into round key array */ for(j = 0; (j < KC) && (t < (ROUNDS+1)*BC); j++, t++) for(i = 0; i < 4; i++) W[t / BC][i][t % BC] = tk[i][j]; while (t < (ROUNDS+1)*BC) { /* while not enough round key material calculated */ /* calculate new values */ for(i = 0; i < 4; i++) tk[i][0] ^= S[tk[(i+1)%4][KC-1]]; tk[0][0] ^= rcon[rconpointer++]; if (KC != 8) for(j = 1; j < KC; j++) for(i = 0; i < 4; i++) tk[i][j] ^= tk[i][j-1]; else { for(j = 1; j < KC/2; j++) for(i = 0; i < 4; i++) tk[i][j] ^= tk[i][j-1]; for(i = 0; i < 4; i++) tk[i][KC/2] ^= S[tk[i][KC/2 - 1]]; for(j = KC/2 + 1; j < KC; j++) for(i = 0; i < 4; i++) tk[i][j] ^= tk[i][j-1]; } /* copy values into round key array */ for(j = 0; (j < KC) && (t < (ROUNDS+1)*BC); j++, t++) for(i = 0; i < 4; i++) W[t / BC][i][t % BC] = tk[i][j]; } return 0; } int rijndaelEncrypt128(MV_U8 a[4][MAXBC], MV_U8 rk[MAXROUNDS+1][4][MAXBC], int rounds) { /* Encryption of one block. */ int r, BC, ROUNDS; BC = 4; ROUNDS = rounds; /* begin with a key addition */ KeyAddition(a,rk[0],BC); /* ROUNDS-1 ordinary rounds */ for(r = 1; r < ROUNDS; r++) { Substitution(a,S); ShiftRow128Enc(a); MixColumn(a, rk[r]); /*KeyAddition(a,rk[r],BC);*/ } /* Last round is special: there is no MixColumn */ Substitution(a,S); ShiftRow128Enc(a); KeyAddition(a,rk[ROUNDS],BC); return 0; } int rijndaelDecrypt128(MV_U8 a[4][MAXBC], MV_U8 rk[MAXROUNDS+1][4][MAXBC], int rounds) { int r, BC, ROUNDS; BC = 4; ROUNDS = rounds; /* To decrypt: apply the inverse operations of the encrypt routine, * in opposite order * * (KeyAddition is an involution: it 's equal to its inverse) * (the inverse of Substitution with table S is Substitution with the inverse table of S) * (the inverse of Shiftrow is Shiftrow over a suitable distance) */ /* First the special round: * without InvMixColumn * with extra KeyAddition */ KeyAddition(a,rk[ROUNDS],BC); ShiftRow128Dec(a); Substitution(a,Si); /* ROUNDS-1 ordinary rounds */ for(r = ROUNDS-1; r > 0; r--) { KeyAddition(a,rk[r],BC); InvMixColumn(a); ShiftRow128Dec(a); Substitution(a,Si); } /* End with the extra key addition */ KeyAddition(a,rk[0],BC); return 0; }