Extraction de fonctions communes à ΘCB3 et SCT-2

1 files changed, 69 insertions, 0 deletions

diff --git a/src/ae-common.h b/src/ae-common.h
new file mode 100644
index 0000000..6343f98
--- /dev/null
+++ b/src/ae-common.h
@@ -0,0 +1,69 @@
+#ifndef AE_COMMON_H
+#define AE_COMMON_H
+
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+
+#include "cipher.h"
+#include "parameters.h"
+
+
+static inline uint8_t upper_nibble(uint8_t i)
+{
+    return i >> 4;
+}
+
+static inline uint8_t lower_nibble(uint8_t i)
+{
+    return i & 0x0f;
+}
+
+static inline void encrypt(const uint8_t K[KEY_BYTES],
+                           const uint8_t T[TWEAK_BYTES],
+                           const uint8_t M[BLOCK_BYTES],
+                           uint8_t C[BLOCK_BYTES])
+{
+    lilliput_tbc_encrypt(K, T, M, C);
+}
+
+static inline void decrypt(const uint8_t K[KEY_BYTES],
+                           const uint8_t T[TWEAK_BYTES],
+                           const uint8_t C[BLOCK_BYTES],
+                           uint8_t M[BLOCK_BYTES])
+{
+    lilliput_tbc_decrypt(K, T, C, M);
+}
+
+static inline void xor_into(uint8_t dest[BLOCK_BYTES], const uint8_t src[BLOCK_BYTES])
+{
+    for (size_t i=0; i<BLOCK_BYTES; i++)
+        dest[i] ^= src[i];
+}
+
+static inline void xor_arrays(size_t len, uint8_t out[len], const uint8_t a[len], const uint8_t b[len])
+{
+    for (size_t i=0; i<len; i++)
+        out[i] = a[i] ^ b[i];
+}
+
+static inline void pad10(size_t X_len, const uint8_t X[X_len], uint8_t padded[BLOCK_BYTES])
+{
+    /* pad10*(X) = X || 1 || 0^{n-|X|-1} */
+
+    /* Assume that len<BLOCK_BYTES. */
+
+    size_t pad_len = BLOCK_BYTES-X_len;
+
+    memcpy(padded+pad_len, X, X_len);
+
+    padded[pad_len-1] = 0x80;
+
+    if (pad_len > 1)
+    {
+        memset(padded, 0, pad_len-1);
+    }
+}
+
+
+#endif /* AE_COMMON_H */