cleaned up buffer pruning code

Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "chacha20"
 description = "chacha20_poly1305 encryption tool"
-version = "1.1.1"
+version = "1.1.2"
 authors = ["Avril <flanchan@cumallover.me>"]
 edition = "2018"
 license = "gpl-3.0-or-later"

src/ext.rs

@@ -57,7 +57,7 @@ pub trait HexStringSliceIterExt
 }
 
 impl<S> HexStringSliceIterExt for S
-    where S: AsRef<[u8]>
+where S: AsRef<[u8]>
 {
     fn hex(&self) -> HexStringSliceIter<'_>
     {
@@ -120,3 +120,25 @@ impl<I: Iterator<Item = u8> + Clone> fmt::Display for HexStringIter<I>
 	($first, $( $rest ),+).0
     }
 }
+
+#[cfg(feature="explicit_clear")]
+#[inline(never)]
+pub fn explicit_prune(buffer : &mut[u8]) {
+    use std::ffi::c_void;
+    unsafe {
+	std::ptr::write_bytes(buffer.as_mut_ptr() as * mut c_void, 0, buffer.len());
+	#[cfg(nightly)]
+	if cfg!(target_arch = "x86_64") || cfg!(target_arch = "x86") {
+            asm!("clflush [{}]", in(reg)buffer.as_mut_ptr());
+	} else {
+            asm!("")
+	}
+	#[cfg(not(nightly))] {
+	    extern "C" {
+		fn explicit_bzero(_: *mut c_void, _:usize);
+	    }
+	    explicit_bzero(buffer.as_mut_ptr() as *mut c_void, buffer.len());
+	    
+	}
+    }
+}

src/stream.rs

@@ -97,35 +97,11 @@ where W: Write
     /// Clear the internal buffer while keeping it allocated for further use.
     ///
     /// This does not affect operations at all, all it does is 0 out the left-over temporary buffer from the last operation(s).
-    #[cfg_attr(all(nightly, feature="explicit_clear"), inline(never))] // We don't want this asm! being inlined and preventing other optimisations on caller functions.
     pub fn prune(&mut self)
     {
 	#[cfg(feature="explicit_clear")]
 	{
-	    use std::ffi::c_void;
-
-	    #[cfg(nightly)] 
-	    #[inline(never)] unsafe fn explicit_bzero(p: *mut c_void, s: usize)
-	    {
-		std::ptr::write_bytes(p, 0, s);
-
-		asm!("");
-	    }
-	    #[cfg(not(nightly))] 
-	    extern "C" {
-		fn explicit_bzero(_: *mut c_void, _:usize);
-	    }
-	    unsafe {
-		explicit_bzero(self.buffer.as_mut_ptr() as *mut c_void, self.buffer.len());
-
-		#[cfg(nightly)] 
-		if cfg!(target_arch = "x86_64") || cfg!(target_arch = "x86"){
-		    asm!(
-			"clflush [{}]",
-			in(reg) self.buffer.as_mut_ptr()
-		    );
-		}
-	    }
+	    explicit_prune(&mut self.buffer[..]);
 	    return;
 	}
 	#[cfg(not(feature="explicit_clear"))]