aes: Oxidize aes_nohw batch_get.

build.rs

@@ -872,7 +872,6 @@ fn prefix_all_symbols(pp: char, prefix_prefix: &str, prefix: &str) -> String {
         "aes_nohw_compact_block",
         "aes_nohw_uncompact_block",
         "aes_nohw_sub_bytes",
-        "aes_nohw_batch_get",
         "aes_nohw_batch_set",
         "aes_nohw_transpose",
         "aes_nohw_mix_columns",

crypto/fipsmodule/aes/aes_nohw.c

@@ -187,23 +187,6 @@ typedef struct {
 #endif
 }
 
-// aes_nohw_batch_get writes the |i|th block of |batch| to |out|. |batch| is in
-// compact form.
-/*static inline*/ void aes_nohw_batch_get(const AES_NOHW_BATCH *batch,
-                                      aes_word_t out[AES_NOHW_BLOCK_WORDS],
-                                      size_t i) {
-  dev_assert_secret(i < AES_NOHW_BATCH_SIZE);
-#if defined(OPENSSL_64_BIT)
-  out[0] = batch->w[i];
-  out[1] = batch->w[i + 4];
-#else
-  out[0] = batch->w[i];
-  out[1] = batch->w[i + 2];
-  out[2] = batch->w[i + 4];
-  out[3] = batch->w[i + 6];
-#endif
-}
-
 // aes_nohw_delta_swap returns |a| with bits |a & mask| and
 // |a & (mask << shift)| swapped. |mask| and |mask << shift| may not overlap.
 static inline aes_word_t aes_nohw_delta_swap(aes_word_t a, aes_word_t mask,
@@ -400,21 +383,6 @@ void aes_nohw_transpose(AES_NOHW_BATCH *batch) {
 #endif
 }
 
-// aes_nohw_to_batch writes the first |num_blocks| blocks in |batch| to |out|.
-// |num_blocks| must be at most |AES_NOHW_BATCH|.
-void aes_nohw_from_batch(uint8_t *out, size_t num_blocks,
-                                const AES_NOHW_BATCH *batch) {
-  AES_NOHW_BATCH copy = *batch;
-  aes_nohw_transpose(&copy);
-
-  debug_assert_nonsecret(num_blocks <= AES_NOHW_BATCH_SIZE);
-  for (size_t i = 0; i < num_blocks; i++) {
-    aes_word_t block[AES_NOHW_BLOCK_WORDS];
-    aes_nohw_batch_get(&copy, block, i);
-    aes_nohw_uncompact_block(out + 16 * i, block);
-  }
-}
-
 // AES round steps.
 
 void aes_nohw_sub_bytes(AES_NOHW_BATCH *batch) {

src/aead/aes/aes_nohw.rs

@@ -15,7 +15,7 @@
 
 use super::{Counter, KeyBytes, AES_KEY, BLOCK_LEN, MAX_ROUNDS};
 use crate::{
-    c, constant_time,
+    constant_time,
     polyfill::{self, usize_from_u32, ArraySplitMap as _},
 };
 use core::{array, mem::MaybeUninit, ops::RangeFrom};
@@ -90,16 +90,18 @@ impl Batch {
         unsafe { aes_nohw_batch_set(self, input, i) }
     }
 
+    // aes_nohw_batch_get writes the |i|th block of |batch| to |out|. |batch| is in
+    // compact form.
     fn get(&self, i: usize) -> [Word; BLOCK_WORDS] {
         assert!(i < self.w.len());
-        prefixed_extern! {
-            fn aes_nohw_batch_get(batch: &Batch, out: *mut [Word; BLOCK_WORDS], i: c::size_t);
-        }
-        let mut out = MaybeUninit::uninit();
-        unsafe {
-            aes_nohw_batch_get(self, out.as_mut_ptr(), i);
-            out.assume_init()
-        }
+        array::from_fn(|j| {
+            #[cfg(target_pointer_width = "64")]
+            const STRIDE: usize = 4;
+            #[cfg(target_pointer_width = "32")]
+            const STRIDE: usize = 2;
+
+            self.w[i + (j * STRIDE)]
+        })
     }
 
     fn sub_bytes(&mut self) {