/************************************************* * AES Source File * * (C) 1999-2007 The Botan Project * *************************************************/ #include #include namespace Botan { /************************************************* * AES Encryption * *************************************************/ void AES::enc(const byte in[], byte out[]) const { const u32bit* TE0 = TE; const u32bit* TE1 = TE + 256; const u32bit* TE2 = TE + 512; const u32bit* TE3 = TE + 768; u32bit T0, T1, T2, T3, B0, B1, B2, B3; B0 = TE0[in[ 0] ^ ME[ 0]] ^ TE1[in[ 5] ^ ME[ 5]] ^ TE2[in[10] ^ ME[10]] ^ TE3[in[15] ^ ME[15]] ^ EK[0]; B1 = TE0[in[ 4] ^ ME[ 4]] ^ TE1[in[ 9] ^ ME[ 9]] ^ TE2[in[14] ^ ME[14]] ^ TE3[in[ 3] ^ ME[ 3]] ^ EK[1]; B2 = TE0[in[ 8] ^ ME[ 8]] ^ TE1[in[13] ^ ME[13]] ^ TE2[in[ 2] ^ ME[ 2]] ^ TE3[in[ 7] ^ ME[ 7]] ^ EK[2]; B3 = TE0[in[12] ^ ME[12]] ^ TE1[in[ 1] ^ ME[ 1]] ^ TE2[in[ 6] ^ ME[ 6]] ^ TE3[in[11] ^ ME[11]] ^ EK[3]; for(u32bit j = 1; j != ROUNDS - 1; j += 2) { T0 = TE0[get_byte(0, B0)] ^ TE1[get_byte(1, B1)] ^ TE2[get_byte(2, B2)] ^ TE3[get_byte(3, B3)] ^ EK[4*j+0]; T1 = TE0[get_byte(0, B1)] ^ TE1[get_byte(1, B2)] ^ TE2[get_byte(2, B3)] ^ TE3[get_byte(3, B0)] ^ EK[4*j+1]; T2 = TE0[get_byte(0, B2)] ^ TE1[get_byte(1, B3)] ^ TE2[get_byte(2, B0)] ^ TE3[get_byte(3, B1)] ^ EK[4*j+2]; T3 = TE0[get_byte(0, B3)] ^ TE1[get_byte(1, B0)] ^ TE2[get_byte(2, B1)] ^ TE3[get_byte(3, B2)] ^ EK[4*j+3]; B0 = TE0[get_byte(0, T0)] ^ TE1[get_byte(1, T1)] ^ TE2[get_byte(2, T2)] ^ TE3[get_byte(3, T3)] ^ EK[4*j+4]; B1 = TE0[get_byte(0, T1)] ^ TE1[get_byte(1, T2)] ^ TE2[get_byte(2, T3)] ^ TE3[get_byte(3, T0)] ^ EK[4*j+5]; B2 = TE0[get_byte(0, T2)] ^ TE1[get_byte(1, T3)] ^ TE2[get_byte(2, T0)] ^ TE3[get_byte(3, T1)] ^ EK[4*j+6]; B3 = TE0[get_byte(0, T3)] ^ TE1[get_byte(1, T0)] ^ TE2[get_byte(2, T1)] ^ TE3[get_byte(3, T2)] ^ EK[4*j+7]; } out[ 0] = SE[get_byte(0, B0)] ^ ME[16]; out[ 1] = SE[get_byte(1, B1)] ^ ME[17]; out[ 2] = SE[get_byte(2, B2)] ^ ME[18]; out[ 3] = SE[get_byte(3, B3)] ^ ME[19]; out[ 4] = SE[get_byte(0, B1)] ^ ME[20]; out[ 5] = SE[get_byte(1, B2)] ^ ME[21]; out[ 6] = SE[get_byte(2, B3)] ^ ME[22]; out[ 7] = SE[get_byte(3, B0)] ^ ME[23]; out[ 8] = SE[get_byte(0, B2)] ^ ME[24]; out[ 9] = SE[get_byte(1, B3)] ^ ME[25]; out[10] = SE[get_byte(2, B0)] ^ ME[26]; out[11] = SE[get_byte(3, B1)] ^ ME[27]; out[12] = SE[get_byte(0, B3)] ^ ME[28]; out[13] = SE[get_byte(1, B0)] ^ ME[29]; out[14] = SE[get_byte(2, B1)] ^ ME[30]; out[15] = SE[get_byte(3, B2)] ^ ME[31]; } /************************************************* * AES Decryption * *************************************************/ void AES::dec(const byte in[], byte out[]) const { const u32bit* TD0 = TD; const u32bit* TD1 = TD + 256; const u32bit* TD2 = TD + 512; const u32bit* TD3 = TD + 768; u32bit T0, T1, T2, T3, B0, B1, B2, B3; B0 = TD0[in[ 0] ^ MD[ 0]] ^ TD1[in[13] ^ MD[13]] ^ TD2[in[10] ^ MD[10]] ^ TD3[in[ 7] ^ MD[ 7]] ^ DK[0]; B1 = TD0[in[ 4] ^ MD[ 4]] ^ TD1[in[ 1] ^ MD[ 1]] ^ TD2[in[14] ^ MD[14]] ^ TD3[in[11] ^ MD[11]] ^ DK[1]; B2 = TD0[in[ 8] ^ MD[ 8]] ^ TD1[in[ 5] ^ MD[ 5]] ^ TD2[in[ 2] ^ MD[ 2]] ^ TD3[in[15] ^ MD[15]] ^ DK[2]; B3 = TD0[in[12] ^ MD[12]] ^ TD1[in[ 9] ^ MD[ 9]] ^ TD2[in[ 6] ^ MD[ 6]] ^ TD3[in[ 3] ^ MD[ 3]] ^ DK[3]; for(u32bit j = 1; j != ROUNDS - 1; j += 2) { T0 = TD0[get_byte(0, B0)] ^ TD1[get_byte(1, B3)] ^ TD2[get_byte(2, B2)] ^ TD3[get_byte(3, B1)] ^ DK[4*j+0]; T1 = TD0[get_byte(0, B1)] ^ TD1[get_byte(1, B0)] ^ TD2[get_byte(2, B3)] ^ TD3[get_byte(3, B2)] ^ DK[4*j+1]; T2 = TD0[get_byte(0, B2)] ^ TD1[get_byte(1, B1)] ^ TD2[get_byte(2, B0)] ^ TD3[get_byte(3, B3)] ^ DK[4*j+2]; T3 = TD0[get_byte(0, B3)] ^ TD1[get_byte(1, B2)] ^ TD2[get_byte(2, B1)] ^ TD3[get_byte(3, B0)] ^ DK[4*j+3]; B0 = TD0[get_byte(0, T0)] ^ TD1[get_byte(1, T3)] ^ TD2[get_byte(2, T2)] ^ TD3[get_byte(3, T1)] ^ DK[4*j+4]; B1 = TD0[get_byte(0, T1)] ^ TD1[get_byte(1, T0)] ^ TD2[get_byte(2, T3)] ^ TD3[get_byte(3, T2)] ^ DK[4*j+5]; B2 = TD0[get_byte(0, T2)] ^ TD1[get_byte(1, T1)] ^ TD2[get_byte(2, T0)] ^ TD3[get_byte(3, T3)] ^ DK[4*j+6]; B3 = TD0[get_byte(0, T3)] ^ TD1[get_byte(1, T2)] ^ TD2[get_byte(2, T1)] ^ TD3[get_byte(3, T0)] ^ DK[4*j+7]; } out[ 0] = SD[get_byte(0, B0)] ^ MD[16]; out[ 1] = SD[get_byte(1, B3)] ^ MD[17]; out[ 2] = SD[get_byte(2, B2)] ^ MD[18]; out[ 3] = SD[get_byte(3, B1)] ^ MD[19]; out[ 4] = SD[get_byte(0, B1)] ^ MD[20]; out[ 5] = SD[get_byte(1, B0)] ^ MD[21]; out[ 6] = SD[get_byte(2, B3)] ^ MD[22]; out[ 7] = SD[get_byte(3, B2)] ^ MD[23]; out[ 8] = SD[get_byte(0, B2)] ^ MD[24]; out[ 9] = SD[get_byte(1, B1)] ^ MD[25]; out[10] = SD[get_byte(2, B0)] ^ MD[26]; out[11] = SD[get_byte(3, B3)] ^ MD[27]; out[12] = SD[get_byte(0, B3)] ^ MD[28]; out[13] = SD[get_byte(1, B2)] ^ MD[29]; out[14] = SD[get_byte(2, B1)] ^ MD[30]; out[15] = SD[get_byte(3, B0)] ^ MD[31]; } /************************************************* * AES Key Schedule * *************************************************/ void AES::key(const byte key[], u32bit length) { static const u32bit RC[10] = { 0x01000000, 0x02000000, 0x04000000, 0x08000000, 0x10000000, 0x20000000, 0x40000000, 0x80000000, 0x1B000000, 0x36000000 }; ROUNDS = (length / 4) + 6; SecureBuffer XEK, XDK; const u32bit X = length / 4; for(u32bit j = 0; j != X; ++j) XEK[j] = load_be(key, j); for(u32bit j = X; j < 4*(ROUNDS+1); j += X) { XEK[j] = XEK[j-X] ^ S(rotate_left(XEK[j-1], 8)) ^ RC[(j-X)/X]; for(u32bit k = 1; k != X; ++k) { if(X == 8 && k == 4) XEK[j+k] = XEK[j+k-X] ^ S(XEK[j+k-1]); else XEK[j+k] = XEK[j+k-X] ^ XEK[j+k-1]; } } for(u32bit j = 0; j != 4*(ROUNDS+1); j += 4) { XDK[j ] = XEK[4*ROUNDS-j ]; XDK[j+1] = XEK[4*ROUNDS-j+1]; XDK[j+2] = XEK[4*ROUNDS-j+2]; XDK[j+3] = XEK[4*ROUNDS-j+3]; } for(u32bit j = 4; j != length + 24; ++j) XDK[j] = TD[SE[get_byte(0, XDK[j])] + 0] ^ TD[SE[get_byte(1, XDK[j])] + 256] ^ TD[SE[get_byte(2, XDK[j])] + 512] ^ TD[SE[get_byte(3, XDK[j])] + 768]; for(u32bit j = 0; j != 4; ++j) for(u32bit k = 0; k != 4; ++k) { ME[4*j+k ] = get_byte(k, XEK[j]); ME[4*j+k+16] = get_byte(k, XEK[j+4*ROUNDS]); MD[4*j+k ] = get_byte(k, XDK[j]); MD[4*j+k+16] = get_byte(k, XEK[j]); } EK.copy(XEK + 4, length + 20); DK.copy(XDK + 4, length + 20); } /************************************************* * AES Byte Substitution * *************************************************/ u32bit AES::S(u32bit input) { return make_u32bit(SE[get_byte(0, input)], SE[get_byte(1, input)], SE[get_byte(2, input)], SE[get_byte(3, input)]); } /************************************************* * AES Constructor * *************************************************/ AES::AES(u32bit key_size) : BlockCipher(16, key_size) { if(key_size != 16 && key_size != 24 && key_size != 32) throw Invalid_Key_Length(name(), key_size); ROUNDS = (key_size / 4) + 6; } /************************************************* * Clear memory of sensitive data * *************************************************/ void AES::clear() throw() { EK.clear(); DK.clear(); ME.clear(); MD.clear(); } }