Add inherent {get,set}_block_pos methods

Author: dhardy

chacha20/src/lib.rs

@@ -265,6 +265,16 @@ impl<R: Rounds, V: Variant> ChaChaCore<R, V> {
             _pd: PhantomData,
         }
     }
+
+    #[inline(always)]
+    fn get_block_pos(&self) -> V::Counter {
+        V::get_block_pos(&self.state[12..])
+    }
+
+    #[inline(always)]
+    fn set_block_pos(&mut self, pos: V::Counter) {
+        V::set_block_pos(&mut self.state[12..], pos);
+    }
 }
 
 #[cfg(feature = "cipher")]
@@ -273,12 +283,12 @@ impl<R: Rounds, V: Variant> StreamCipherSeekCore for ChaChaCore<R, V> {
 
     #[inline(always)]
     fn get_block_pos(&self) -> Self::Counter {
-        V::get_block_pos(&self.state[12..])
+        self.get_block_pos()
     }
 
     #[inline(always)]
     fn set_block_pos(&mut self, pos: Self::Counter) {
-        V::set_block_pos(&mut self.state[12..], pos);
+        self.set_block_pos(pos)
     }
 }
 

chacha20/src/rng.rs

@@ -385,8 +385,7 @@ macro_rules! impl_chacha_rng {
             #[inline]
             #[allow(unused)]
             pub fn get_block_pos(&self) -> u64 {
-                let counter =
-                    self.core.core.state[12] as u64 | ((self.core.core.state[13] as u64) << 32);
+                let counter = self.core.get_block_pos();
                 if self.core.word_offset() != 0 {
                     counter - BUF_BLOCKS as u64 + self.core.word_offset() as u64 / 16
                 } else {