encrypt/decrypt

ghstack-source-id: c7cca30
Pull Request resolved: #83

Author: pbelevich

test/test_csprng.py

@@ -354,5 +354,51 @@ def test_const_generator(self):
                     second = torch.empty(self.size, dtype=dtype, device=device).random_(generator=const_gen)
                     self.assertTrue((first - second).max().abs() == 0)
 
+    def test_encrypt_decrypt(self):
+        key_size_bytes = 16
+        block_size_bytes = 16
+
+        def sizeof(dtype):
+            if dtype == torch.bool:
+                return 1
+            elif dtype.is_floating_point:
+                return torch.finfo(dtype).bits // 8
+            else:
+                return torch.iinfo(dtype).bits // 8
+
+        for device in self.all_devices:
+            for key_dtype in self.all_dtypes:
+                key_size = key_size_bytes // sizeof(key_dtype)
+                key = torch.empty(key_size, dtype=key_dtype, device=device).random_()
+                for initial_dtype in self.all_dtypes:
+                    for encrypted_dtype in self.all_dtypes:
+                        for decrypted_dtype in self.all_dtypes:
+                            for initial_size in [0, 4, 8, 15, 16, 23, 42]:
+                                for mode in ["ecb", "ctr"]:
+                                    encrypted_size = (initial_size * sizeof(initial_dtype) + block_size_bytes - 1) // block_size_bytes * block_size_bytes // sizeof(encrypted_dtype)
+                                    decrypted_size = (encrypted_size * sizeof(encrypted_dtype) + block_size_bytes - 1) // block_size_bytes * block_size_bytes // sizeof(decrypted_dtype)
+
+                                    initial = torch.empty(initial_size, dtype=initial_dtype, device=device).random_()
+                                    encrypted = torch.empty(encrypted_size, dtype=encrypted_dtype, device=device).random_()
+                                    decrypted = torch.empty(decrypted_size, dtype=decrypted_dtype, device=device).random_()
+
+                                    initial_np = initial.cpu().numpy().view(np.int8)
+                                    decrypted_np = decrypted.cpu().numpy().view(np.int8)
+                                    padding_size_bytes = initial_size * sizeof(initial_dtype) - decrypted_size * sizeof(decrypted_dtype)
+                                    if padding_size_bytes != 0:
+                                        decrypted_np = decrypted_np[:padding_size_bytes]
+
+                                    csprng.encrypt(initial, encrypted, key, "aes128", mode)
+
+                                    if initial_size > 8:
+                                        self.assertFalse(np.array_equal(initial_np, decrypted_np))
+
+                                    csprng.decrypt(encrypted, decrypted, key, "aes128", mode)
+                                    decrypted_np = decrypted.cpu().numpy().view(np.int8)
+                                    if padding_size_bytes != 0:
+                                        decrypted_np = decrypted_np[:padding_size_bytes]
+
+                                    self.assertTrue(np.array_equal(initial_np, decrypted_np))
+
 if __name__ == '__main__':
     unittest.main()

torchcsprng/csrc/aes.h

@@ -63,15 +63,7 @@ namespace aes {
     #define Nr 10       // The number of rounds in AES Cipher.
 #endif
 
-#if !defined(__CUDACC__) && !defined(__HIPCC__)
-struct ulonglong2 // TODO: should have something like `__builtin_align__(16)`
-{
-  unsigned long long int x, y;
-};
-#endif
-
-typedef ulonglong2 block_t;
-constexpr size_t block_t_size = sizeof(block_t);
+constexpr size_t block_t_size = 16;
 
 typedef uint8_t state_t[4][4];
 
@@ -97,13 +89,33 @@ TORCH_CSPRNG_CONSTANT const uint8_t sbox[256] = {
   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 };
 
+TORCH_CSPRNG_CONSTANT const uint8_t 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 };
+
 // The round constant word array, Rcon[i], contains the values given by 
 // x to the power (i-1) being powers of x (x is denoted as {02}) in the field GF(2^8)
 TORCH_CSPRNG_CONSTANT const uint8_t Rcon[11] = {
   0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36 };
 
 #define getSBoxValue(num) (sbox[(num)])
 
+#define getSBoxInvert(num) (rsbox[(num)])
+
 // This function produces Nb(Nr+1) round keys. The round keys are used in each round to decrypt the states. 
 TORCH_CSPRNG_HOST_DEVICE void KeyExpansion(uint8_t* RoundKey, const uint8_t* Key){
   unsigned int i, j, k;
@@ -257,6 +269,78 @@ TORCH_CSPRNG_HOST_DEVICE void MixColumns(state_t* state)
   }
 }
 
+TORCH_CSPRNG_HOST_DEVICE uint8_t Multiply(uint8_t x, uint8_t y)
+{
+  return (((y & 1) * x) ^
+          ((y>>1 & 1) * xtime(x)) ^
+          ((y>>2 & 1) * xtime(xtime(x))) ^
+          ((y>>3 & 1) * xtime(xtime(xtime(x)))) ^
+          ((y>>4 & 1) * xtime(xtime(xtime(xtime(x)))))); /* this last call to xtime() can be omitted */
+}
+
+// MixColumns function mixes the columns of the state matrix.
+// The method used to multiply may be difficult to understand for the inexperienced.
+// Please use the references to gain more information.
+TORCH_CSPRNG_HOST_DEVICE void InvMixColumns(state_t* state)
+{
+  int i;
+  uint8_t a, b, c, d;
+  for (i = 0; i < 4; ++i)
+  {
+    a = (*state)[i][0];
+    b = (*state)[i][1];
+    c = (*state)[i][2];
+    d = (*state)[i][3];
+
+    (*state)[i][0] = Multiply(a, 0x0e) ^ Multiply(b, 0x0b) ^ Multiply(c, 0x0d) ^ Multiply(d, 0x09);
+    (*state)[i][1] = Multiply(a, 0x09) ^ Multiply(b, 0x0e) ^ Multiply(c, 0x0b) ^ Multiply(d, 0x0d);
+    (*state)[i][2] = Multiply(a, 0x0d) ^ Multiply(b, 0x09) ^ Multiply(c, 0x0e) ^ Multiply(d, 0x0b);
+    (*state)[i][3] = Multiply(a, 0x0b) ^ Multiply(b, 0x0d) ^ Multiply(c, 0x09) ^ Multiply(d, 0x0e);
+  }
+}
+
+// The SubBytes Function Substitutes the values in the
+// state matrix with values in an S-box.
+TORCH_CSPRNG_HOST_DEVICE void InvSubBytes(state_t* state)
+{
+  uint8_t i, j;
+  for (i = 0; i < 4; ++i)
+  {
+    for (j = 0; j < 4; ++j)
+    {
+      (*state)[j][i] = getSBoxInvert((*state)[j][i]);
+    }
+  }
+}
+
+TORCH_CSPRNG_HOST_DEVICE void InvShiftRows(state_t* state)
+{
+  uint8_t temp;
+
+  // Rotate first row 1 columns to right
+  temp = (*state)[3][1];
+  (*state)[3][1] = (*state)[2][1];
+  (*state)[2][1] = (*state)[1][1];
+  (*state)[1][1] = (*state)[0][1];
+  (*state)[0][1] = temp;
+
+  // Rotate second row 2 columns to right
+  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 right
+  temp = (*state)[0][3];
+  (*state)[0][3] = (*state)[1][3];
+  (*state)[1][3] = (*state)[2][3];
+  (*state)[2][3] = (*state)[3][3];
+  (*state)[3][3] = temp;
+}
+
 TORCH_CSPRNG_HOST_DEVICE void encrypt(uint8_t* state, const uint8_t* key) {
   uint8_t RoundKey[176];
   KeyExpansion(RoundKey, key); 
@@ -284,4 +368,29 @@ TORCH_CSPRNG_HOST_DEVICE void encrypt(uint8_t* state, const uint8_t* key) {
   AddRoundKey(Nr, (state_t*)state, RoundKey);
 }
 
+TORCH_CSPRNG_HOST_DEVICE void decrypt(uint8_t* state, const uint8_t* key) {
+  uint8_t RoundKey[176];
+  KeyExpansion(RoundKey, key);
+
+  uint8_t round = 0;
+
+  // Add the First round key to the state before starting the rounds.
+  AddRoundKey(Nr, (state_t*)state, RoundKey);
+
+  // There will be Nr rounds.
+  // The first Nr-1 rounds are identical.
+  // These Nr rounds are executed in the loop below.
+  // Last one without InvMixColumn()
+  for (round = (Nr - 1); ; --round)
+  {
+    InvShiftRows((state_t*)state);
+    InvSubBytes((state_t*)state);
+    AddRoundKey(round, (state_t*)state, RoundKey);
+    if (round == 0) {
+      break;
+    }
+    InvMixColumns((state_t*)state);
+  }
+}
+
 }}}