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Experimental AES replacement
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@chfast
chfast committed Mar 14, 2017
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277 changes: 277 additions & 0 deletions libdevcrypto/AES.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -31,6 +31,283 @@ using namespace dev;
using namespace dev::crypto;
using namespace CryptoPP;

// The number of columns comprising a state in AES. This is a constant in AES. Value=4
#define Nb 4
// The number of 32 bit words in a key.
#define Nk 4
// Key length in bytes [128 bit]
#define KEYLEN 16
// The number of rounds in AES Cipher.
#define Nr 10


/*****************************************************************************/
/* Private variables: */
/*****************************************************************************/
// state - array holding the intermediate results during decryption.
typedef uint8_t state_t[4][4];

// The array that stores the round keys.
static uint8_t RoundKey[176];

// The Key input to the AES Program
static const uint8_t* Key;

// The lookup-tables are marked const so they can be placed in read-only storage instead of RAM
// The numbers below can be computed dynamically trading ROM for RAM -
// This can be useful in (embedded) bootloader applications, where ROM is often limited.
static const uint8_t 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,
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 };

// The round constant word array, Rcon[i], contains the values given by
// x to th e power (i-1) being powers of x (x is denoted as {02}) in the field GF(2^8)
// Note that i starts at 1, not 0).
static const uint8_t Rcon[255] = {
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 };


static uint8_t getSBoxValue(uint8_t num)
{
return sbox[num];
}

// This function produces Nb(Nr+1) round keys. The round keys are used in each round to decrypt the states.
static void KeyExpansion(void)
{
uint32_t i, j, k;
uint8_t tempa[4]; // Used for the column/row operations

// The first round key is the key itself.
for(i = 0; i < Nk; ++i)
{
RoundKey[(i * 4) + 0] = Key[(i * 4) + 0];
RoundKey[(i * 4) + 1] = Key[(i * 4) + 1];
RoundKey[(i * 4) + 2] = Key[(i * 4) + 2];
RoundKey[(i * 4) + 3] = Key[(i * 4) + 3];
}

// All other round keys are found from the previous round keys.
for(; (i < (Nb * (Nr + 1))); ++i)
{
for(j = 0; j < 4; ++j)
{
tempa[j]=RoundKey[(i-1) * 4 + j];
}
if (i % Nk == 0)
{
// This function rotates the 4 bytes in a word to the left once.
// [a0,a1,a2,a3] becomes [a1,a2,a3,a0]

// Function RotWord()
{
k = tempa[0];
tempa[0] = tempa[1];
tempa[1] = tempa[2];
tempa[2] = tempa[3];
tempa[3] = k;
}

// SubWord() is a function that takes a four-byte input word and
// applies the S-box to each of the four bytes to produce an output word.

// Function Subword()
{
tempa[0] = getSBoxValue(tempa[0]);
tempa[1] = getSBoxValue(tempa[1]);
tempa[2] = getSBoxValue(tempa[2]);
tempa[3] = getSBoxValue(tempa[3]);
}

tempa[0] = tempa[0] ^ Rcon[i/Nk];
}
RoundKey[i * 4 + 0] = RoundKey[(i - Nk) * 4 + 0] ^ tempa[0];
RoundKey[i * 4 + 1] = RoundKey[(i - Nk) * 4 + 1] ^ tempa[1];
RoundKey[i * 4 + 2] = RoundKey[(i - Nk) * 4 + 2] ^ tempa[2];
RoundKey[i * 4 + 3] = RoundKey[(i - Nk) * 4 + 3] ^ tempa[3];
}
}

// This function adds the round key to state.
// The round key is added to the state by an XOR function.
static void AddRoundKey(state_t* state, uint8_t round)
{
uint8_t i,j;
for(i=0;i<4;++i)
{
for(j = 0; j < 4; ++j)
{
(*state)[i][j] ^= RoundKey[round * Nb * 4 + i * Nb + j];
}
}
}

// The SubBytes Function Substitutes the values in the
// state matrix with values in an S-box.
static void SubBytes(state_t* state)
{
uint8_t i, j;
for(i = 0; i < 4; ++i)
{
for(j = 0; j < 4; ++j)
{
(*state)[j][i] = getSBoxValue((*state)[j][i]);
}
}
}

// The ShiftRows() function shifts the rows in the state to the left.
// Each row is shifted with different offset.
// Offset = Row number. So the first row is not shifted.
static void ShiftRows(state_t* state)
{
uint8_t temp;

// Rotate first row 1 columns to left
temp = (*state)[0][1];
(*state)[0][1] = (*state)[1][1];
(*state)[1][1] = (*state)[2][1];
(*state)[2][1] = (*state)[3][1];
(*state)[3][1] = temp;

// Rotate second row 2 columns to left
temp = (*state)[0][2];
(*state)[0][2] = (*state)[2][2];
(*state)[2][2] = temp;

temp = (*state)[1][2];
(*state)[1][2] = (*state)[3][2];
(*state)[3][2] = temp;

// Rotate third row 3 columns to left
temp = (*state)[0][3];
(*state)[0][3] = (*state)[3][3];
(*state)[3][3] = (*state)[2][3];
(*state)[2][3] = (*state)[1][3];
(*state)[1][3] = temp;
}

static uint8_t xtime(uint8_t x)
{
return ((x<<1) ^ (((x>>7) & 1) * 0x1b));
}

// MixColumns function mixes the columns of the state matrix
static void MixColumns(state_t* state)
{
uint8_t i;
uint8_t Tmp,Tm,t;
for(i = 0; i < 4; ++i)
{
t = (*state)[i][0];
Tmp = (*state)[i][0] ^ (*state)[i][1] ^ (*state)[i][2] ^ (*state)[i][3] ;
Tm = (*state)[i][0] ^ (*state)[i][1] ; Tm = xtime(Tm); (*state)[i][0] ^= Tm ^ Tmp ;
Tm = (*state)[i][1] ^ (*state)[i][2] ; Tm = xtime(Tm); (*state)[i][1] ^= Tm ^ Tmp ;
Tm = (*state)[i][2] ^ (*state)[i][3] ; Tm = xtime(Tm); (*state)[i][2] ^= Tm ^ Tmp ;
Tm = (*state)[i][3] ^ t ; Tm = xtime(Tm); (*state)[i][3] ^= Tm ^ Tmp ;
}
}


// Cipher is the main function that encrypts the PlainText.
static void Cipher(state_t* state)
{
uint8_t round = 0;

// Add the First round key to the state before starting the rounds.
AddRoundKey(state, 0);

// There will be Nr rounds.
// The first Nr-1 rounds are identical.
// These Nr-1 rounds are executed in the loop below.
for(round = 1; round < Nr; ++round)
{
SubBytes(state);
ShiftRows(state);
MixColumns(state);
AddRoundKey(state, round);
}

// The last round is given below.
// The MixColumns function is not here in the last round.
SubBytes(state);
ShiftRows(state);
AddRoundKey(state, Nr);
}

static void BlockCopy(uint8_t* output, const uint8_t* input)
{
uint8_t i;
for (i=0;i<KEYLEN;++i)
{
output[i] = input[i];
}
}


void dev::AES128_CTR_process_buffer(uint8_t* output, const uint8_t* input, uint32_t length, const uint8_t* key, const uint8_t* iv)
{
state_t state;
uint32_t i = 0;
uint8_t ctr[KEYLEN];

BlockCopy(ctr, iv);
Key = key;
KeyExpansion();

while (i < length)
{
if ((i & 0x0000000F) == 0)
{
BlockCopy(&state[0][0], ctr);
Cipher(&state);

for (int j = KEYLEN - 1; j >= 0; --j)
{
++(ctr[j]);

if (ctr[j])
break;
}
}

output[i] = (input[i]) ^ (((uint8_t*)state)[i & 0x0000000F]);
++i;
}
}



bytes dev::aesDecrypt(bytesConstRef _ivCipher, std::string const& _password, unsigned _rounds, bytesConstRef _salt)
{
bytes pw = asBytes(_password);
Expand Down
2 changes: 2 additions & 0 deletions libdevcrypto/AES.h
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Original file line number Diff line number Diff line change
Expand Up @@ -29,6 +29,8 @@
namespace dev
{

void AES128_CTR_process_buffer(uint8_t* output, const uint8_t* input, uint32_t length, const uint8_t* key, const uint8_t* iv);

bytes aesDecrypt(bytesConstRef _cipher, std::string const& _password, unsigned _rounds = 2000, bytesConstRef _salt = bytesConstRef());

}
44 changes: 12 additions & 32 deletions libdevcrypto/Common.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -163,42 +163,22 @@ std::pair<bytes, h128> dev::encryptSymNoAuth(SecureFixedHash<16> const& _k, byte

bytes dev::encryptAES128CTR(bytesConstRef _k, h128 const& _iv, bytesConstRef _plain)
{
if (_k.size() != 16 && _k.size() != 24 && _k.size() != 32)
return bytes();
SecByteBlock key(_k.data(), _k.size());
try
{
CTR_Mode<AES>::Encryption e;
e.SetKeyWithIV(key, key.size(), _iv.data());
bytes ret(_plain.size());
e.ProcessData(ret.data(), _plain.data(), _plain.size());
return ret;
}
catch (CryptoPP::Exception& _e)
{
cerr << _e.what() << endl;
return bytes();
}
if (_k.size() != 16)
return {};

bytes ret(_plain.size());
AES128_CTR_process_buffer(ret.data(), _plain.data(), _plain.size(), _k.data(), _iv.data());
return ret;
}

bytesSec dev::decryptAES128CTR(bytesConstRef _k, h128 const& _iv, bytesConstRef _cipher)
{
if (_k.size() != 16 && _k.size() != 24 && _k.size() != 32)
return bytesSec();
SecByteBlock key(_k.data(), _k.size());
try
{
CTR_Mode<AES>::Decryption d;
d.SetKeyWithIV(key, key.size(), _iv.data());
bytesSec ret(_cipher.size());
d.ProcessData(ret.writable().data(), _cipher.data(), _cipher.size());
return ret;
}
catch (CryptoPP::Exception& _e)
{
cerr << _e.what() << endl;
return bytesSec();
}
if (_k.size() != 16)
return {};

bytesSec ret(_cipher.size());
AES128_CTR_process_buffer(ret.writable().data(), _cipher.data(), _cipher.size(), _k.data(), _iv.data());
return ret;
}

Public dev::recover(Signature const& _sig, h256 const& _message)
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