--- a/src/pam_ffi/memory.rs	Wed Jun 04 03:53:36 2025 -0400
+++ b/src/pam_ffi/memory.rs	Thu Jun 05 03:41:38 2025 -0400
@@ -8,7 +8,9 @@
 use std::{ptr, slice};
 
 /// Makes whatever it's in not [`Send`], [`Sync`], or [`Unpin`].
-pub type Immovable = PhantomData<(*mut u8, PhantomPinned)>;
+#[repr(C)]
+#[derive(Debug)]
+pub struct Immovable(pub PhantomData<(*mut u8, PhantomPinned)>);
 
 /// Safely converts a `&str` option to a `CString` option.
 pub fn option_cstr(prompt: Option<&str>) -> Result<Option<CString>> {
@@ -71,7 +73,7 @@
     }
     unsafe {
         let data_alloc = libc::calloc(data.len() + 1, 1);
-        libc::memcpy(data_alloc, data.as_ptr() as *const c_void, data.len());
+        libc::memcpy(data_alloc, data.as_ptr().cast(), data.len());
         Ok(data_alloc.cast())
     }
 }
@@ -85,7 +87,7 @@
 /// It's up to you to provide a valid C string.
 pub unsafe fn zero_c_string(cstr: *mut c_void) {
     if !cstr.is_null() {
-        libc::memset(cstr, 0, libc::strlen(cstr as *const c_char));
+        libc::memset(cstr, 0, libc::strlen(cstr.cast()));
     }
 }
 
@@ -113,17 +115,14 @@
             max: (u32::MAX - 5) as usize,
             actual: source.len(),
         })?;
+        // SAFETY: We're only allocating here.
         let data = unsafe {
-            let dest_buffer = libc::malloc(buffer_size as usize) as *mut CBinaryData;
+            let dest_buffer: *mut CBinaryData = libc::malloc(buffer_size as usize).cast();
             let data = &mut *dest_buffer;
             data.total_length = buffer_size.to_be_bytes();
             data.data_type = data_type;
             let dest = data.data.as_mut_ptr();
-            libc::memcpy(
-                dest as *mut c_void,
-                source.as_ptr() as *const c_void,
-                source.len(),
-            );
+            libc::memcpy(dest.cast(), source.as_ptr().cast(), source.len());
             dest_buffer
         };
         Ok(data)