Suppression des structures (tweakey|cipher)_state

Pas l'impression  que l'utilisation  de structures  dans les  codes de
référence soit très idiomatique.

4 files changed, 65 insertions, 82 deletions

diff --git a/crypto_aead/lilliputaei128v1/ref/test/test-tweakey.c b/crypto_aead/lilliputaei128v1/ref/test/test-tweakey.c
index a10981f..2b0bad5 100644
--- a/crypto_aead/lilliputaei128v1/ref/test/test-tweakey.c
+++ b/crypto_aead/lilliputaei128v1/ref/test/test-tweakey.c
@@ -90,16 +90,16 @@ int main()
 
     for (const vector *v=VECTORS; v<ARRAY_END(VECTORS); v++)
     {
-        tweakey_state tk;
-        tweakey_state_init(&tk, v->key, v->tweak);
+        uint8_t tk[TWEAKEY_BYTES];
+        tweakey_state_init(tk, v->key, v->tweak);
 
         uint8_t rtk[ROUND_TWEAKEY_BYTES];
-        tweakey_state_extract(&tk, rtk, 0);
+        tweakey_state_extract(tk, 0, rtk);
 
         for (uint8_t i=1; i<ROUNDS; i++)
         {
-            tweakey_state_update(&tk);
-            tweakey_state_extract(&tk, rtk, i);
+            tweakey_state_update(tk);
+            tweakey_state_extract(tk, i, rtk);
         }
 
         if (memcmp(rtk, v->last_rtk, sizeof(rtk)) != 0)
diff --git a/src/cipher.c b/src/cipher.c
index 7f1152a..4190359 100644
--- a/src/cipher.c
+++ b/src/cipher.c
@@ -26,18 +26,9 @@ const uint8_t PERMUTATIONS[2][BLOCK_BYTES] = {
 };
 
 
-struct cipher_state
+static void _state_init(uint8_t X[BLOCK_BYTES], const uint8_t message[BLOCK_BYTES])
 {
-    uint8_t X[BLOCK_BYTES];
-};
-
-
-typedef struct cipher_state cipher_state;
-
-
-static void _state_init(cipher_state *X, const uint8_t message[BLOCK_BYTES])
-{
-    memcpy(X->X, message, sizeof(X->X));
+    memcpy(X, message, BLOCK_BYTES);
 }
 
 
@@ -47,27 +38,27 @@ static void _compute_round_tweakeys(
     uint8_t RTK[ROUNDS][ROUND_TWEAKEY_BYTES]
 )
 {
-    tweakey_state TK;
-    tweakey_state_init(&TK, key, tweak);
-    tweakey_state_extract(&TK, RTK[0], 0);
+    uint8_t TK[TWEAKEY_BYTES];
+    tweakey_state_init(TK, key, tweak);
+    tweakey_state_extract(TK, 0, RTK[0]);
 
     for (uint8_t i=1; i<ROUNDS; i++)
     {
-        tweakey_state_update(&TK);
-        tweakey_state_extract(&TK, RTK[i], i);
+        tweakey_state_update(TK);
+        tweakey_state_extract(TK, i, RTK[i]);
     }
 }
 
 
-static void _nonlinear_layer(cipher_state *X, const uint8_t RTK[ROUND_TWEAKEY_BYTES])
+static void _nonlinear_layer(uint8_t X[BLOCK_BYTES], const uint8_t RTK[ROUND_TWEAKEY_BYTES])
 {
     uint8_t F[ROUND_TWEAKEY_BYTES];
-    for (size_t j=0; j<sizeof(F); j++)
+    for (size_t j=0; j<ROUND_TWEAKEY_BYTES; j++)
     {
-        F[j] = X->X[j] ^ RTK[j];
+        F[j] = X[j] ^ RTK[j];
     }
 
-    for (size_t j=0; j<sizeof(F); j++)
+    for (size_t j=0; j<ROUND_TWEAKEY_BYTES; j++)
     {
         F[j] = S[F[j]];
     }
@@ -75,29 +66,29 @@ static void _nonlinear_layer(cipher_state *X, const uint8_t RTK[ROUND_TWEAKEY_BY
     for (size_t j=0; j<8; j++)
     {
         size_t dest_j = 15-j;
-        X->X[dest_j] ^= F[j];
+        X[dest_j] ^= F[j];
     }
 }
 
-static void _linear_layer(cipher_state *X)
+static void _linear_layer(uint8_t X[BLOCK_BYTES])
 {
-    X->X[15] ^= X->X[1];
-    X->X[15] ^= X->X[2];
-    X->X[15] ^= X->X[3];
-    X->X[15] ^= X->X[4];
-    X->X[15] ^= X->X[5];
-    X->X[15] ^= X->X[6];
-    X->X[15] ^= X->X[7];
-
-    X->X[14] ^= X->X[7];
-    X->X[13] ^= X->X[7];
-    X->X[12] ^= X->X[7];
-    X->X[11] ^= X->X[7];
-    X->X[10] ^= X->X[7];
-    X->X[9]  ^= X->X[7];
+    X[15] ^= X[1];
+    X[15] ^= X[2];
+    X[15] ^= X[3];
+    X[15] ^= X[4];
+    X[15] ^= X[5];
+    X[15] ^= X[6];
+    X[15] ^= X[7];
+
+    X[14] ^= X[7];
+    X[13] ^= X[7];
+    X[12] ^= X[7];
+    X[11] ^= X[7];
+    X[10] ^= X[7];
+    X[9]  ^= X[7];
 }
 
-static void _permutation_layer(cipher_state *X, permutation p)
+static void _permutation_layer(uint8_t X[BLOCK_BYTES], permutation p)
 {
     if (p == PERMUTATION_NONE)
     {
@@ -105,17 +96,17 @@ static void _permutation_layer(cipher_state *X, permutation p)
     }
 
     uint8_t X_old[BLOCK_BYTES];
-    memcpy(X_old, X, sizeof(X_old));
+    memcpy(X_old, X, BLOCK_BYTES);
 
     const uint8_t *pi = PERMUTATIONS[p];
 
     for (size_t j=0; j<BLOCK_BYTES; j++)
     {
-        X->X[pi[j]] = X_old[j];
+        X[pi[j]] = X_old[j];
     }
 }
 
-static void _one_round_egfn(cipher_state *X, const uint8_t RTK[ROUND_TWEAKEY_BYTES], permutation p)
+static void _one_round_egfn(uint8_t X[BLOCK_BYTES], const uint8_t RTK[ROUND_TWEAKEY_BYTES], permutation p)
 {
     _nonlinear_layer(X, RTK);
     _linear_layer(X);
@@ -130,20 +121,20 @@ void lilliput_tbc_encrypt(
     uint8_t ciphertext[BLOCK_BYTES]
 )
 {
-    cipher_state X;
-    _state_init(&X, message);
+    uint8_t X[BLOCK_BYTES];
+    _state_init(X, message);
 
     uint8_t RTK[ROUNDS][ROUND_TWEAKEY_BYTES];
     _compute_round_tweakeys(key, tweak, RTK);
 
     for (uint8_t i=0; i<ROUNDS-1; i++)
     {
-        _one_round_egfn(&X, RTK[i], PERMUTATION_ENCRYPTION);
+        _one_round_egfn(X, RTK[i], PERMUTATION_ENCRYPTION);
     }
 
-    _one_round_egfn(&X, RTK[ROUNDS-1], PERMUTATION_NONE);
+    _one_round_egfn(X, RTK[ROUNDS-1], PERMUTATION_NONE);
 
-    memcpy(ciphertext, X.X, BLOCK_BYTES);
+    memcpy(ciphertext, X, BLOCK_BYTES);
 }
 
 void lilliput_tbc_decrypt(
@@ -153,18 +144,18 @@ void lilliput_tbc_decrypt(
     uint8_t message[BLOCK_BYTES]
 )
 {
-    cipher_state X;
-    _state_init(&X, ciphertext);
+    uint8_t X[BLOCK_BYTES];
+    _state_init(X, ciphertext);
 
     uint8_t RTK[ROUNDS][ROUND_TWEAKEY_BYTES];
     _compute_round_tweakeys(key, tweak, RTK);
 
     for (uint8_t i=0; i<ROUNDS-1; i++)
     {
-        _one_round_egfn(&X, RTK[ROUNDS-1-i], PERMUTATION_DECRYPTION);
+        _one_round_egfn(X, RTK[ROUNDS-1-i], PERMUTATION_DECRYPTION);
     }
 
-    _one_round_egfn(&X, RTK[0], PERMUTATION_NONE);
+    _one_round_egfn(X, RTK[0], PERMUTATION_NONE);
 
-    memcpy(message, X.X, BLOCK_BYTES);
+    memcpy(message, X, BLOCK_BYTES);
 }
diff --git a/src/tweakey.c b/src/tweakey.c
index 7c66ee9..761ec53 100644
--- a/src/tweakey.c
+++ b/src/tweakey.c
@@ -12,25 +12,25 @@
 
 
 void tweakey_state_init(
-    tweakey_state *TK,
+    uint8_t TK[TWEAKEY_BYTES],
     const uint8_t key[KEY_BYTES],
     const uint8_t tweak[TWEAK_BYTES]
 )
 {
-    memcpy(TK->TK,             tweak, TWEAK_BYTES);
-    memcpy(TK->TK+TWEAK_BYTES, key,   KEY_BYTES);
+    memcpy(TK,             tweak, TWEAK_BYTES);
+    memcpy(TK+TWEAK_BYTES, key,   KEY_BYTES);
 }
 
 
 void tweakey_state_extract(
-    const tweakey_state *TK,
-    uint8_t round_tweakey[ROUND_TWEAKEY_BYTES], /* output */
-    uint8_t i                                   /* round constant */
+    const uint8_t TK[TWEAKEY_BYTES],
+    uint8_t round_constant,
+    uint8_t round_tweakey[ROUND_TWEAKEY_BYTES]
 )
 {
     memset(round_tweakey, 0, ROUND_TWEAKEY_BYTES);
 
-    for (const uint8_t *lane=TK->TK; lane<TK->TK+TWEAKEY_BYTES; lane+=LANE_BYTES)
+    for (const uint8_t *lane=TK; lane<TK+TWEAKEY_BYTES; lane+=LANE_BYTES)
     {
         for (size_t j=0; j<LANE_BYTES; j++)
         {
@@ -38,25 +38,25 @@ void tweakey_state_extract(
         }
     }
 
-    round_tweakey[0] ^= i;
+    round_tweakey[0] ^= round_constant;
 }
 
 
-static void _permute_state(tweakey_state *TK)
+static void _permute_state(uint8_t TK[TWEAKEY_BYTES])
 {
     uint8_t TK_old[TWEAKEY_BYTES];
-    memcpy(TK_old, TK->TK, sizeof(TK_old));
+    memcpy(TK_old, TK, TWEAKEY_BYTES);
 
     for (size_t j=0; j<TWEAKEY_BYTES; j+=LANE_BYTES)
     {
         for (size_t k=0; k<LANE_BYTES; k++)
         {
-            TK->TK[j+h[k]] = TK_old[j+k];
+            TK[j+h[k]] = TK_old[j+k];
         }
     }
 }
 
-static void _multiply_state(tweakey_state *TK)
+static void _multiply_state(uint8_t TK[TWEAKEY_BYTES])
 {
     /* Lane 0 is multiplied by Id; lane 1 by P_0, lane 2 by P_1... */
 
@@ -67,12 +67,12 @@ static void _multiply_state(tweakey_state *TK)
         for (size_t k=0; k<LANE_BYTES; k++)
         {
             size_t offset = j*LANE_BYTES + k;
-            TK->TK[offset] = P_lane[TK->TK[offset]];
+            TK[offset] = P_lane[TK[offset]];
         }
     }
 }
 
-void tweakey_state_update(tweakey_state *TK)
+void tweakey_state_update(uint8_t TK[TWEAKEY_BYTES])
 {
     _permute_state(TK);
     _multiply_state(TK);
diff --git a/src/tweakey.h b/src/tweakey.h
index 0642724..5470bc8 100644
--- a/src/tweakey.h
+++ b/src/tweakey.h
@@ -6,26 +6,18 @@
 #include "parameters.h"
 
 
-struct tweakey_state
-{
-    uint8_t TK[TWEAKEY_BYTES];
-};
-
-typedef struct tweakey_state tweakey_state;
-
-
 void tweakey_state_init(
-    tweakey_state *TK,
+    uint8_t TK[TWEAKEY_BYTES],
     const uint8_t key[KEY_BYTES],
     const uint8_t tweak[TWEAK_BYTES]
 );
 
 void tweakey_state_extract(
-    const tweakey_state *TK,
-    uint8_t round_tweakey[ROUND_TWEAKEY_BYTES], /* output */
-    uint8_t i                                   /* round constant */
+    const uint8_t TK[TWEAKEY_BYTES],
+    uint8_t round_constant,
+    uint8_t round_tweakey[ROUND_TWEAKEY_BYTES] /* output */
 );
 
-void tweakey_state_update(tweakey_state *TK);
+void tweakey_state_update(uint8_t TK[TWEAKEY_BYTES]);
 
 #endif /* TWEAKEY_H */