aes internals: Make Rounds an enum.

Author: briansmith

src/aead/aes/ffi.rs

@@ -33,7 +33,7 @@ pub(in super::super) struct Counter(pub(super) [u8; BLOCK_LEN]);
 #[derive(Clone, Copy)]
 pub(super) struct AES_KEY {
     rd_key: RdKeys,
-    rounds: Rounds,
+    rounds: c_uint,
 }
 
 #[derive(Clone, Copy)]
@@ -43,18 +43,22 @@ union RdKeys {
     aes256: Aes256RoundKeys,
 }
 
-pub(super) type Aes128RoundKeys = [RdKey; AES_128_ROUNDS_PLUS_1];
-pub(super) type Aes256RoundKeys = [RdKey; AES_256_ROUNDS_PLUS_1];
+pub(super) type Aes128RoundKeys = [RdKey; Rounds::Aes128.into_usize() + 1];
+pub(super) type Aes256RoundKeys = [RdKey; Rounds::Aes256.into_usize() + 1];
 
 pub type RdKey = [u32; 4];
 
-pub type Rounds = c_uint;
-
-pub(super) const AES_128_ROUNDS_PLUS_1: usize = (AES_128_ROUNDS as usize) + 1;
-pub(super) const AES_256_ROUNDS_PLUS_1: usize = (AES_256_ROUNDS as usize) + 1;
+#[repr(u32)]
+pub enum Rounds {
+    Aes128 = 10,
+    Aes256 = 14,
+}
 
-pub const AES_128_ROUNDS: Rounds = 10;
-pub const AES_256_ROUNDS: Rounds = 14;
+impl Rounds {
+    const fn into_usize(self) -> usize {
+        self as usize
+    }
+}
 
 impl KeyBytes<'_> {
     pub(super) fn as_user_key_and_bits(&self) -> (*const u8, KeyBitLength) {

src/aead/aes/hw.rs

@@ -54,8 +54,8 @@ impl Key {
     #[cfg(all(target_arch = "aarch64", target_endian = "little"))]
     pub(in super::super) fn rd_keys_and_rounds(&self) -> (*const ffi::RdKey, ffi::Rounds) {
         match self {
-            Key::Aes128(rd_keys) => (rd_keys.as_ptr(), ffi::AES_128_ROUNDS),
-            Key::Aes256(rd_keys) => (rd_keys.as_ptr(), ffi::AES_256_ROUNDS),
+            Key::Aes128(rd_keys) => (rd_keys.as_ptr(), ffi::Rounds::Aes128),
+            Key::Aes256(rd_keys) => (rd_keys.as_ptr(), ffi::Rounds::Aes256),
         }
     }
 }

src/aead/aes/vp.rs

@@ -136,8 +136,8 @@ impl EncryptCtr32 for Key {
     fn ctr32_encrypt_within(&self, in_out: Overlapping<'_>, ctr: &mut Counter) {
         prefixed_extern_ctr32_encrypt_blocks_with_rd_keys! { vpaes_ctr32_encrypt_blocks }
         let (rd_keys, rounds) = match self {
-            Self::Aes128(rd_keys) => (rd_keys.as_ptr(), ffi::AES_128_ROUNDS),
-            Self::Aes256(rd_keys) => (rd_keys.as_ptr(), ffi::AES_256_ROUNDS),
+            Self::Aes128(rd_keys) => (rd_keys.as_ptr(), ffi::Rounds::Aes128),
+            Self::Aes256(rd_keys) => (rd_keys.as_ptr(), ffi::Rounds::Aes256),
         };
         unsafe {
             ffi::ctr32_encrypt_blocks(in_out, ctr, rd_keys, rounds, vpaes_ctr32_encrypt_blocks)