aes-gcm: Remove htable_new! macro.

Minimize the scope of `unsafe` in `HTable` construction.

Author: briansmith

src/aead/gcm/clmul.rs

@@ -18,7 +18,10 @@
     target_arch = "x86_64"
 ))]
 
-use super::{ffi::{BLOCK_LEN, KeyValue}, HTable, UpdateBlock, Xi};
+use super::{
+    ffi::{KeyValue, BLOCK_LEN},
+    HTable, UpdateBlock, Xi,
+};
 use crate::cpu;
 #[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
 use {super::UpdateBlocks, crate::polyfill::slice::AsChunks};
@@ -31,8 +34,11 @@ pub struct Key {
 impl Key {
     #[cfg(all(target_arch = "aarch64", target_endian = "little"))]
     pub(in super::super) fn new(value: KeyValue, _cpu: cpu::aarch64::PMull) -> Self {
+        prefixed_extern! {
+            fn gcm_init_clmul(HTable: *mut HTable, h: &KeyValue);
+        }
         Self {
-            h_table: unsafe { htable_new!(gcm_init_clmul, value) },
+            h_table: HTable::new(|table| unsafe { gcm_init_clmul(table, &value) }),
         }
     }
 
@@ -41,8 +47,11 @@ impl Key {
         value: KeyValue,
         _cpu: (cpu::intel::ClMul, cpu::intel::Ssse3),
     ) -> Self {
+        prefixed_extern! {
+            fn gcm_init_clmul(HTable: *mut HTable, h: &KeyValue);
+        }
         Self {
-            h_table: unsafe { htable_new!(gcm_init_clmul, value) },
+            h_table: HTable::new(|htable| unsafe { gcm_init_clmul(htable, &value) }),
         }
     }
 
@@ -52,8 +61,11 @@ impl Key {
         value: KeyValue,
         _cpu: (cpu::intel::ClMul, cpu::intel::Ssse3),
     ) -> Self {
+        prefixed_extern! {
+            fn gcm_init_clmul(HTable: *mut HTable, h: &KeyValue);
+        }
         Self {
-            h_table: unsafe { htable_new!(gcm_init_clmul, value) },
+            h_table: HTable::new(|table| unsafe { gcm_init_clmul(table, &value) }),
         }
     }
 

src/aead/gcm/clmulavxmovbe.rs

@@ -28,8 +28,11 @@ impl Key {
         value: KeyValue,
         _required_cpu_features: (intel::ClMul, intel::Avx, intel::Movbe),
     ) -> Self {
+        prefixed_extern! {
+            fn gcm_init_avx(HTable: *mut HTable, h: &KeyValue);
+        }
         Self {
-            h_table: unsafe { htable_new!(gcm_init_avx, value) },
+            h_table: HTable::new(|table| unsafe { gcm_init_avx(table, &value) }),
         }
     }
 

src/aead/gcm/ffi.rs

@@ -21,22 +21,6 @@ pub(in super::super) const BLOCK_LEN: usize = 16;
 pub(in super::super) type Block = [u8; BLOCK_LEN];
 pub(super) const ZERO_BLOCK: Block = [0u8; BLOCK_LEN];
 
-#[cfg(any(
-    all(target_arch = "aarch64", target_endian = "little"),
-    all(target_arch = "arm", target_endian = "little"),
-    target_arch = "x86",
-    target_arch = "x86_64"
-))]
-macro_rules! htable_new {
-    ( $name:ident, $value:expr $(,)? ) => {{
-        use crate::aead::gcm::ffi::HTable;
-        prefixed_extern! {
-            fn $name(HTable: &mut HTable, h: &[u64; 2]);
-        }
-        HTable::new($name, $value)
-    }};
-}
-
 /// SAFETY:
 ///  * The function `$name` must meet the contract of the `f` paramweter of
 ///    `ghash()`.
@@ -61,6 +45,7 @@ macro_rules! ghash {
     }};
 }
 
+#[repr(transparent)]
 pub(in super::super) struct KeyValue([u64; 2]);
 
 impl KeyValue {
@@ -84,14 +69,11 @@ impl KeyValue {
     target_arch = "x86_64"
 ))]
 impl HTable {
-    pub(super) unsafe fn new(
-        init: unsafe extern "C" fn(HTable: &mut HTable, &[u64; 2]),
-        value: KeyValue,
-    ) -> Self {
+    pub(super) fn new(init: impl FnOnce(&mut HTable)) -> Self {
         let mut r = Self {
             Htable: [U128 { hi: 0, lo: 0 }; HTABLE_LEN],
         };
-        unsafe { init(&mut r, &value.0) };
+        init(&mut r);
         r
     }
 

src/aead/gcm/neon.rs

@@ -28,15 +28,21 @@ pub struct Key {
 impl Key {
     #[cfg(all(target_arch = "aarch64", target_endian = "little"))]
     pub(in super::super) fn new(value: KeyValue, _cpu: cpu::aarch64::Neon) -> Self {
+        prefixed_extern! {
+            fn gcm_init_neon(HTable: *mut HTable, h: &KeyValue);
+        }
         Self {
-            h_table: unsafe { htable_new!(gcm_init_neon, value) },
+            h_table: HTable::new(|table| unsafe { gcm_init_neon(table, &value) }),
         }
     }
 
     #[cfg(all(target_arch = "arm", target_endian = "little"))]
     pub(in super::super) fn new(value: KeyValue, _cpu: cpu::arm::Neon) -> Self {
+        prefixed_extern! {
+            fn gcm_init_neon(HTable: *mut HTable, h: &KeyValue);
+        }
         Self {
-            h_table: unsafe { htable_new!(gcm_init_neon, value) },
+            h_table: HTable::new(|table| unsafe { gcm_init_neon(table, &value) }),
         }
     }
 }

src/aead/gcm/vclmulavx2.rs

@@ -28,8 +28,11 @@ pub struct Key {
 
 impl Key {
     pub(in super::super) fn new(value: KeyValue, _cpu: (Avx2, VAesClmul)) -> Self {
+        prefixed_extern! {
+            fn gcm_init_vpclmulqdq_avx2(HTable: *mut HTable, h: &KeyValue);
+        }
         Self {
-            h_table: unsafe { htable_new!(gcm_init_vpclmulqdq_avx2, value) },
+            h_table: HTable::new(|table| unsafe { gcm_init_vpclmulqdq_avx2(table, &value) }),
         }
     }