Merge branch 'implem-ti'

1 files changed, 215 insertions, 0 deletions

diff --git a/src/add_threshold/tweakey.c b/src/add_threshold/tweakey.c
new file mode 100644
index 0000000..e228a69
--- /dev/null
+++ b/src/add_threshold/tweakey.c
@@ -0,0 +1,215 @@
+/*
+Implementation of the Lilliput-AE tweakable block cipher.
+
+Authors, hereby denoted as "the implementer":
+    Alexandre Adomnicai,
+    Kévin Le Gouguec,
+    Léo Reynaud,
+    2019.
+
+For more information, feedback or questions, refer to our website:
+https://paclido.fr/lilliput-ae
+
+To the extent possible under law, the implementer has waived all copyright
+and related or neighboring rights to the source code in this file.
+http://creativecommons.org/publicdomain/zero/1.0/
+
+---
+
+This file provides a first-order threshold implementation of Lilliput-TBC's
+tweakey schedule, where the tweak and the key are split into two shares.
+*/
+
+#include <stdint.h>
+#include <string.h>
+
+#include "constants.h"
+#include "random.h"
+#include "tweakey.h"
+
+
+#define LANE_BITS  64
+#define LANE_BYTES (LANE_BITS/8)
+#define LANES_NB   (TWEAKEY_BYTES/LANE_BYTES)
+
+
+void tweakey_state_init(
+    uint8_t TK_X[TWEAKEY_BYTES],
+    uint8_t TK_Y[KEY_BYTES],
+    const uint8_t key[KEY_BYTES],
+    const uint8_t tweak[TWEAK_BYTES]
+)
+{
+    uint8_t SHARES_0[KEY_BYTES];
+    randombytes(sizeof(SHARES_0), SHARES_0);
+
+    memcpy(TK_Y, SHARES_0, KEY_BYTES);
+    memcpy(TK_X, tweak, TWEAK_BYTES);
+
+    for (size_t i=0; i<KEY_BYTES; i++){
+        TK_X[i+TWEAK_BYTES] = key[i] ^ SHARES_0[i];
+    }
+}
+
+
+void tweakey_state_extract(
+    const uint8_t TK_X[TWEAKEY_BYTES],
+    const uint8_t TK_Y[KEY_BYTES],
+    uint8_t round_constant,
+    uint8_t round_tweakey_X[ROUND_TWEAKEY_BYTES],
+    uint8_t round_tweakey_Y[ROUND_TWEAKEY_BYTES]
+)
+{
+    memset(round_tweakey_X, 0, ROUND_TWEAKEY_BYTES);
+    memset(round_tweakey_Y, 0, ROUND_TWEAKEY_BYTES);
+
+    for (size_t j=0; j<LANES_NB; j++)
+    {
+        const uint8_t *TKj_X = TK_X + j*LANE_BYTES;
+
+        for (size_t k=0; k<LANE_BYTES; k++)
+        {
+            round_tweakey_X[k] ^= TKj_X[k];
+        }
+    }
+
+
+    for (size_t j=0; j<(KEY_BYTES / LANE_BYTES); j++)
+    {
+        const uint8_t *TKj_Y = TK_Y + j*LANE_BYTES;
+
+        for (size_t k=0; k<LANE_BYTES; k++)
+        {
+            round_tweakey_Y[k] ^= TKj_Y[k];
+        }
+    }
+
+    round_tweakey_X[0] ^= round_constant;
+}
+
+
+static void _multiply_M(const uint8_t x[LANE_BYTES], uint8_t y[LANE_BYTES])
+{
+    y[7] = x[6];
+    y[6] = x[5];
+    y[5] = x[5]<<3 ^ x[4];
+    y[4] = x[4]>>3 ^ x[3];
+    y[3] = x[2];
+    y[2] = x[6]<<2 ^ x[1];
+    y[1] = x[0];
+    y[0] = x[7];
+}
+
+static void _multiply_M2(const uint8_t x[LANE_BYTES], uint8_t y[LANE_BYTES])
+{
+    uint8_t x_M_5 = x[5]<<3 ^ x[4];
+    uint8_t x_M_4 = x[4]>>3 ^ x[3];
+
+    y[7] = x[5];
+    y[6] = x_M_5;
+    y[5] = x_M_5<<3 ^ x_M_4;
+    y[4] = x_M_4>>3 ^ x[2];
+    y[3] = x[6]<<2  ^ x[1];
+    y[2] = x[5]<<2  ^ x[0];
+    y[1] = x[7];
+    y[0] = x[6];
+}
+
+static void _multiply_M3(const uint8_t x[LANE_BYTES], uint8_t y[LANE_BYTES])
+{
+    uint8_t x_M_5  = x[5]<<3  ^ x[4];
+    uint8_t x_M_4  = x[4]>>3  ^ x[3];
+    uint8_t x_M2_5 = x_M_5<<3 ^ x_M_4;
+    uint8_t x_M2_4 = x_M_4>>3 ^ x[2];
+
+    y[7] = x_M_5;
+    y[6] = x_M2_5;
+    y[5] = x_M2_5<<3 ^ x_M2_4;
+    y[4] = x_M2_4>>3 ^ x[6]<<2 ^ x[1];
+    y[3] = x[5]<<2   ^ x[0];
+    y[2] = x_M_5<<2  ^ x[7];
+    y[1] = x[6];
+    y[0] = x[5];
+}
+
+static void _multiply_MR(const uint8_t x[LANE_BYTES], uint8_t y[LANE_BYTES])
+{
+    y[0] = x[1];
+    y[1] = x[2];
+    y[2] = x[3]    ^ x[4]>>3;
+    y[3] = x[4];
+    y[4] = x[5]    ^ x[6]<<3;
+    y[5] = x[3]<<2 ^ x[6];
+    y[6] = x[7];
+    y[7] = x[0];
+}
+
+static void _multiply_MR2(const uint8_t x[LANE_BYTES], uint8_t y[LANE_BYTES])
+{
+    uint8_t x_MR_4 = x[5] ^ x[6]<<3;
+
+    y[0] = x[2];
+    y[1] = x[3]    ^ x[4]>>3;
+    y[2] = x[4]    ^ x_MR_4>>3;
+    y[3] = x_MR_4;
+    y[4] = x[3]<<2 ^ x[6]      ^ x[7]<<3;
+    y[5] = x[4]<<2 ^ x[7];
+    y[6] = x[0];
+    y[7] = x[1];
+}
+
+static void _multiply_MR3(const uint8_t x[LANE_BYTES], uint8_t y[LANE_BYTES])
+{
+    uint8_t x_MR_4  = x[5]    ^ x[6]<<3;
+    uint8_t x_MR2_4 = x[3]<<2 ^ x[6]    ^ x[7]<<3;
+
+    y[0] = x[3]      ^ x[4]>>3;
+    y[1] = x[4]      ^ x_MR_4>>3;
+    y[2] = x_MR_4    ^ x_MR2_4>>3;
+    y[3] = x_MR2_4;
+    y[4] = x[0]<<3   ^ x[4]<<2   ^ x[7];
+    y[5] = x_MR_4<<2 ^ x[0];
+    y[6] = x[1];
+    y[7] = x[2];
+}
+
+typedef void (*matrix_multiplication)(const uint8_t x[LANE_BYTES], uint8_t y[LANE_BYTES]);
+
+static const matrix_multiplication ALPHAS[6] = {
+    _multiply_M,
+    _multiply_M2,
+    _multiply_M3,
+    _multiply_MR,
+    _multiply_MR2,
+    _multiply_MR3
+};
+
+
+void tweakey_state_update(uint8_t TK_X[TWEAKEY_BYTES], uint8_t TK_Y[KEY_BYTES])
+{
+    /* Skip lane 0, as it is multiplied by the identity matrix. */
+
+    for (size_t j=1; j<(TWEAK_BYTES/LANE_BYTES); j++)
+    {
+        uint8_t *TKj_X = TK_X + j*LANE_BYTES;
+
+        uint8_t TKj_old_X[LANE_BYTES];
+        memcpy(TKj_old_X, TKj_X, LANE_BYTES);
+
+        ALPHAS[j-1](TKj_old_X, TKj_X);
+    }
+
+    for (size_t j=0; j<(KEY_BYTES/LANE_BYTES); j++)
+    {
+        uint8_t *TKj_X = TK_X + (j + (TWEAK_BYTES/LANE_BYTES))*LANE_BYTES;
+        uint8_t *TKj_Y = TK_Y + j*LANE_BYTES;
+
+        uint8_t TKj_X_old[LANE_BYTES];
+        uint8_t TKj_Y_old[LANE_BYTES];
+        memcpy(TKj_X_old, TKj_X, LANE_BYTES);
+        memcpy(TKj_Y_old, TKj_Y, LANE_BYTES);
+
+        ALPHAS[j-1 + (TWEAK_BYTES/LANE_BYTES)](TKj_X_old, TKj_X);
+        ALPHAS[j-1 + (TWEAK_BYTES/LANE_BYTES)](TKj_Y_old, TKj_Y);
+    }
+}