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-rw-r--r--src/cipher.c91
-rw-r--r--src/tweakey.c28
-rw-r--r--src/tweakey.h18
3 files changed, 60 insertions, 77 deletions
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 */
generated by cgit v1.2.3 (git 2.39.1) at 2025-12-06 22:08:54 +0000