--- a/src/libpam/handle.rs	Sun Jun 08 04:21:58 2025 -0400
+++ b/src/libpam/handle.rs	Tue Jun 10 01:09:30 2025 -0400
@@ -1,110 +1,66 @@
 use super::conversation::LibPamConversation;
-use crate::constants::{ErrorCode, InvalidEnum, Result};
+use crate::constants::{ErrorCode, Result};
 use crate::conv::Message;
-use crate::handle::{PamApplicationOnly, PamModuleOnly, PamShared};
-use crate::libpam::memory;
-use crate::libpam::memory::Immovable;
-use crate::Conversation;
-use num_derive::FromPrimitive;
-use num_traits::FromPrimitive;
+use crate::handle::PamShared;
+pub use crate::libpam::pam_ffi::LibPamHandle;
+use crate::libpam::{memory, pam_ffi};
+use crate::{Conversation, PamHandleModule};
+use num_enum::{IntoPrimitive, TryFromPrimitive};
+use std::cell::Cell;
 use std::ffi::{c_char, c_int};
 use std::ops::{Deref, DerefMut};
-use std::result::Result as StdResult;
-use std::{mem, ptr};
-
-/// An owned PAM handle.
-#[repr(transparent)]
-pub struct OwnedLibPamHandle(*mut LibPamHandle);
-
-/// An opaque structure that a PAM handle points to.
-#[repr(C)]
-pub struct LibPamHandle {
-    _data: (),
-    _marker: Immovable,
-}
-
-impl LibPamHandle {
-    /// Gets a C string item.
-    ///
-    /// # Safety
-    ///
-    /// You better be requesting an item which is a C string.
-    unsafe fn get_cstr_item(&mut self, item_type: ItemType) -> Result<Option<&str>> {
-        let mut output = ptr::null();
-        let ret = unsafe { super::pam_get_item(self, item_type as c_int, &mut output) };
-        ErrorCode::result_from(ret)?;
-        memory::wrap_string(output.cast())
-    }
+use std::ptr;
 
-    /// Sets a C string item.
-    ///
-    /// # Safety
-    ///
-    /// You better be setting an item which is a C string.
-    unsafe fn set_cstr_item(&mut self, item_type: ItemType, data: Option<&str>) -> Result<()> {
-        let data_str = memory::option_cstr(data)?;
-        let ret = unsafe {
-            super::pam_set_item(
-                self,
-                item_type as c_int,
-                memory::prompt_ptr(data_str.as_ref()).cast(),
-            )
-        };
-        ErrorCode::result_from(ret)
-    }
+struct HandleWrap(*mut LibPamHandle);
 
-    /// Gets the `PAM_CONV` item from the handle.
-    fn conversation_item(&mut self) -> Result<&mut LibPamConversation<'_>> {
-        let output: *mut LibPamConversation = ptr::null_mut();
-        let result = unsafe {
-            super::pam_get_item(
-                self,
-                ItemType::Conversation.into(),
-                &mut output.cast_const().cast(),
-            )
-        };
-        ErrorCode::result_from(result)?;
-        // SAFETY: We got this result from PAM, and we're checking if it's null.
-        unsafe { output.as_mut() }.ok_or(ErrorCode::ConversationError)
-    }
-}
-
-impl PamApplicationOnly for OwnedLibPamHandle {
-    fn close(self, status: Result<()>) -> Result<()> {
-        let ret = unsafe { super::pam_end(self.0, ErrorCode::result_to_c(status)) };
-        // Forget rather than dropping, since dropping also calls pam_end.
-        mem::forget(self);
-        ErrorCode::result_from(ret)
-    }
-}
-
-impl Deref for OwnedLibPamHandle {
+impl Deref for HandleWrap {
     type Target = LibPamHandle;
     fn deref(&self) -> &Self::Target {
         unsafe { &*self.0 }
     }
 }
 
-impl DerefMut for OwnedLibPamHandle {
+impl DerefMut for HandleWrap {
     fn deref_mut(&mut self) -> &mut Self::Target {
         unsafe { &mut *self.0 }
     }
 }
 
+/// An owned PAM handle.
+pub struct OwnedLibPamHandle {
+    handle: HandleWrap,
+    last_return: Cell<Result<()>>,
+}
+
+// TODO: pam_authenticate - app
+//       pam_setcred - app
+//       pam_acct_mgmt - app
+//       pam_chauthtok - app
+//       pam_open_session - app
+//       pam_close_session - app
+//       pam_putenv - shared
+//       pam_getenv - shared
+//       pam_getenvlist - shared
+
 impl Drop for OwnedLibPamHandle {
-    /// Ends the PAM session with a zero error code.
-    /// You probably want to call [`close`](Self::close) instead of
-    /// letting this drop by itself.
+    /// Closes the PAM session on an owned PAM handle.
+    ///
+    /// See the [`pam_end` manual page][man] for more information.
+    ///
+    /// [man]: https://www.man7.org/linux/man-pages/man3/pam_end.3.html
     fn drop(&mut self) {
         unsafe {
-            super::pam_end(self.0, 0);
+            pam_ffi::pam_end(
+                self.handle.0,
+                ErrorCode::result_to_c(self.last_return.get()),
+            );
         }
     }
 }
 
 macro_rules! cstr_item {
     (get = $getter:ident, item = $item_type:path) => {
-        fn $getter(&mut self) -> Result<Option<&str>> {
+        fn $getter(&self) -> Result<Option<&str>> {
             unsafe { self.get_cstr_item($item_type) }
         }
     };
@@ -119,8 +75,9 @@
     fn get_user(&mut self, prompt: Option<&str>) -> Result<&str> {
         let prompt = memory::option_cstr(prompt)?;
         let mut output: *const c_char = ptr::null();
-        let ret =
-            unsafe { super::pam_get_user(self, &mut output, memory::prompt_ptr(prompt.as_ref())) };
+        let ret = unsafe {
+            pam_ffi::pam_get_user(self, &mut output, memory::prompt_ptr(prompt.as_ref()))
+        };
         ErrorCode::result_from(ret)?;
         unsafe { memory::wrap_string(output) }
             .transpose()
@@ -156,13 +113,13 @@
     }
 }
 
-impl PamModuleOnly for LibPamHandle {
+impl PamHandleModule for LibPamHandle {
     fn get_authtok(&mut self, prompt: Option<&str>) -> Result<&str> {
         let prompt = memory::option_cstr(prompt)?;
         let mut output: *const c_char = ptr::null_mut();
         // SAFETY: We're calling this with known-good values.
         let res = unsafe {
-            super::pam_get_authtok(
+            pam_ffi::pam_get_authtok(
                 self,
                 ItemType::AuthTok.into(),
                 &mut output,
@@ -190,9 +147,95 @@
     }
 }
 
+impl LibPamHandle {
+    /// Gets a C string item.
+    ///
+    /// # Safety
+    ///
+    /// You better be requesting an item which is a C string.
+    unsafe fn get_cstr_item(&self, item_type: ItemType) -> Result<Option<&str>> {
+        let mut output = ptr::null();
+        let ret = unsafe { pam_ffi::pam_get_item(self, item_type as c_int, &mut output) };
+        ErrorCode::result_from(ret)?;
+        memory::wrap_string(output.cast())
+    }
+
+    /// Sets a C string item.
+    ///
+    /// # Safety
+    ///
+    /// You better be setting an item which is a C string.
+    unsafe fn set_cstr_item(&mut self, item_type: ItemType, data: Option<&str>) -> Result<()> {
+        let data_str = memory::option_cstr(data)?;
+        let ret = unsafe {
+            pam_ffi::pam_set_item(
+                self,
+                item_type as c_int,
+                memory::prompt_ptr(data_str.as_ref()).cast(),
+            )
+        };
+        ErrorCode::result_from(ret)
+    }
+
+    /// Gets the `PAM_CONV` item from the handle.
+    fn conversation_item(&mut self) -> Result<&mut LibPamConversation<'_>> {
+        let output: *mut LibPamConversation = ptr::null_mut();
+        let result = unsafe {
+            pam_ffi::pam_get_item(
+                self,
+                ItemType::Conversation.into(),
+                &mut output.cast_const().cast(),
+            )
+        };
+        ErrorCode::result_from(result)?;
+        // SAFETY: We got this result from PAM, and we're checking if it's null.
+        unsafe { output.as_mut() }.ok_or(ErrorCode::ConversationError)
+    }
+}
+
+macro_rules! delegate {
+    (fn $meth:ident(&self $(, $param:ident: $typ:ty)*) -> Result<$ret:ty>) => {
+        fn $meth(&self $(, $param: $typ)*) -> Result<$ret> {
+            let result = self.handle.$meth($($param),*);
+            self.last_return.set(split(&result));
+            result
+        }
+    };
+    (fn $meth:ident(&mut self $(, $param:ident: $typ:ty)*) -> Result<$ret:ty>) => {
+        fn $meth(&mut self $(, $param: $typ)*) -> Result<$ret> {
+            let result = self.handle.$meth($($param),*);
+            self.last_return.set(split(&result));
+            result
+        }
+    };
+    (get = $get:ident$(, set = $set:ident)?) => {
+        delegate!(fn $get(&self) -> Result<Option<&str>>);
+        $(delegate!(set = $set);)?
+    };
+    (set = $set:ident) => {
+        delegate!(fn $set(&mut self, value: Option<&str>) -> Result<()>);
+    };
+}
+
+fn split<T>(result: &Result<T>) -> Result<()> {
+    result.as_ref().map(drop).map_err(|&e| e)
+}
+
+impl PamShared for OwnedLibPamHandle {
+    delegate!(fn get_user(&mut self, prompt: Option<&str>) -> Result<&str>);
+    delegate!(get = user_item, set = set_user_item);
+    delegate!(get = service, set = set_service);
+    delegate!(get = user_prompt, set = set_user_prompt);
+    delegate!(get = tty_name, set = set_tty_name);
+    delegate!(get = remote_user, set = set_remote_user);
+    delegate!(get = remote_host, set = set_remote_host);
+    delegate!(set = set_authtok_item);
+    delegate!(set = set_old_authtok_item);
+}
+
 /// Identifies what is being gotten or set with `pam_get_item`
 /// or `pam_set_item`.
-#[derive(FromPrimitive)]
+#[derive(TryFromPrimitive, IntoPrimitive)]
 #[repr(i32)]
 #[non_exhaustive] // because C could give us anything!
 pub enum ItemType {
@@ -223,16 +266,3 @@
     /// The type of `pam_get_authtok`.
     AuthTokType = 13,
 }
-
-impl TryFrom<c_int> for ItemType {
-    type Error = InvalidEnum<Self>;
-    fn try_from(value: c_int) -> StdResult<Self, Self::Error> {
-        Self::from_i32(value).ok_or(value.into())
-    }
-}
-
-impl From<ItemType> for c_int {
-    fn from(val: ItemType) -> Self {
-        val as Self
-    }
-}