Replace `as _` casts with safer alternatives on Windows

4 files changed, 21 insertions, 13 deletions

diff --git a/installer-downloader/src/winapi_impl/ui.rs b/installer-downloader/src/winapi_impl/ui.rs
index bb6a3398d0..8d6fe7dcc4 100644
--- a/installer-downloader/src/winapi_impl/ui.rs
+++ b/installer-downloader/src/winapi_impl/ui.rs
@@ -412,7 +412,7 @@ fn handle_link_messages(
         if msg == WM_CTLCOLORSTATIC && Some(p) == link_hwnd {
             // SAFETY: `w` is a valid device context for WM_CTLCOLORSTATIC
             unsafe {
-                SetBkMode(w as HDC, TRANSPARENT as _);
+                SetBkMode(w as HDC, TRANSPARENT as i32);
                 SetTextColor(w as HDC, rgb(LINK_COLOR));
             }
             // Out of bounds background
diff --git a/mullvad-paths/src/windows.rs b/mullvad-paths/src/windows.rs
index dd46e1af3e..48ca700522 100644
--- a/mullvad-paths/src/windows.rs
+++ b/mullvad-paths/src/windows.rs
@@ -1,6 +1,7 @@
 use crate::{Error, Result, UserPermissions};
 use once_cell::sync::OnceCell;
 use std::{
+    ffi::c_void,
     io, mem,
     os::windows::io::{AsHandle, AsRawHandle, BorrowedHandle, FromRawHandle, OwnedHandle},
     path::{Path, PathBuf},
@@ -161,7 +162,7 @@ fn set_security_permissions(path: &Path, user_permissions: UserPermissions) -> R
         CreateWellKnownSid(
             WinBuiltinAdministratorsSid,
             ptr::null_mut(),
-            admin_psid.as_mut_ptr() as _,
+            admin_psid.as_mut_ptr().cast::<c_void>(),
             &raw mut admin_psid_len,
         )
     } == 0
@@ -195,7 +196,7 @@ fn set_security_permissions(path: &Path, user_permissions: UserPermissions) -> R
         CreateWellKnownSid(
             WinAuthenticatedUserSid,
             ptr::null_mut(),
-            au_psid.as_mut_ptr() as _,
+            au_psid.as_mut_ptr().cast::<c_void>(),
             &raw mut au_psid_len,
         )
     } == 0
@@ -211,7 +212,7 @@ fn set_security_permissions(path: &Path, user_permissions: UserPermissions) -> R
         MultipleTrusteeOperation: NO_MULTIPLE_TRUSTEE,
         TrusteeForm: TRUSTEE_IS_SID,
         TrusteeType: TRUSTEE_IS_GROUP,
-        ptstrName: au_psid.as_mut_ptr() as *mut _,
+        ptstrName: au_psid.as_mut_ptr().cast(),
     };
 
     let authenticated_users_ea = EXPLICIT_ACCESS_W {
@@ -250,8 +251,8 @@ fn set_security_permissions(path: &Path, user_permissions: UserPermissions) -> R
             wide_path.as_ptr(),
             SE_FILE_OBJECT,
             security_information,
-            admin_psid.as_mut_ptr() as *mut _,
-            admin_psid.as_mut_ptr() as *mut _,
+            admin_psid.as_mut_ptr().cast(),
+            admin_psid.as_mut_ptr().cast(),
             new_dacl,
             ptr::null(),
         )
@@ -530,7 +531,7 @@ fn is_local_system_user_token(token: &impl AsRawHandle) -> io::Result<bool> {
             GetTokenInformation(
                 token.as_raw_handle(),
                 TokenUser,
-                token_info.as_mut_ptr() as _,
+                token_info.as_mut_ptr().cast::<c_void>(),
                 u32::try_from(token_info.len()).expect("len must fit in u32"),
                 &raw mut returned_info_len,
             )
@@ -564,7 +565,7 @@ fn is_local_system_user_token(token: &impl AsRawHandle) -> io::Result<bool> {
         CreateWellKnownSid(
             WinLocalSystemSid,
             std::ptr::null_mut(),
-            local_system_sid.as_mut_ptr() as _,
+            local_system_sid.as_mut_ptr().cast::<c_void>(),
             &raw mut local_system_size,
         )
     } == 0
@@ -575,5 +576,10 @@ fn is_local_system_user_token(token: &impl AsRawHandle) -> io::Result<bool> {
     }
 
     // SAFETY: Both arguments point to valid security identifiers
-    Ok(unsafe { EqualSid(token_user.User.Sid, local_system_sid.as_ptr() as _) } != 0)
+    Ok(unsafe {
+        EqualSid(
+            token_user.User.Sid,
+            local_system_sid.as_mut_ptr().cast::<c_void>(),
+        )
+    } != 0)
 }
diff --git a/talpid-windows/src/fs.rs b/talpid-windows/src/fs.rs
index 7e8e968bcc..240d2eae02 100644
--- a/talpid-windows/src/fs.rs
+++ b/talpid-windows/src/fs.rs
@@ -1,3 +1,4 @@
+use std::ffi::c_void;
 use std::io;
 use std::os::windows::io::AsRawHandle;
 use std::ptr;
@@ -35,9 +36,10 @@ pub fn is_admin_owned<T: AsRawHandle>(handle: T) -> io::Result<bool> {
     }
 
     // SAFETY: `owner` is valid since `security_descriptor` still is, and the well-known type is a valid argument
-    let is_system_owned = unsafe { IsWellKnownSid(owner as _, WinLocalSystemSid) != 0 };
+    let is_system_owned = unsafe { IsWellKnownSid(owner.cast::<c_void>(), WinLocalSystemSid) != 0 };
     // SAFETY: `owner` is valid since `security_descriptor` still is, and the well-known type is a valid argument
-    let is_admin_owned = unsafe { IsWellKnownSid(owner as _, WinBuiltinAdministratorsSid) != 0 };
+    let is_admin_owned =
+        unsafe { IsWellKnownSid(owner.cast::<c_void>(), WinBuiltinAdministratorsSid) != 0 };
 
     // SAFETY: Since we no longer need the descriptor (or owner), it may be freed
     unsafe { LocalFree(security_descriptor.cast()) };
diff --git a/windows-installer/src/windows.rs b/windows-installer/src/windows.rs
index ab7c8738b4..229c1894ae 100644
--- a/windows-installer/src/windows.rs
+++ b/windows-installer/src/windows.rs
@@ -58,7 +58,7 @@ fn write_file_to_temp(data: &[u8]) -> anyhow::Result<TempPath> {
 
 /// Return a slice of data for the given resource
 fn find_binary_data(architecture: Architecture) -> anyhow::Result<&'static [u8]> {
-    let resource_id = match architecture {
+    let resource_id: usize = match architecture {
         Architecture::X64 => resource::IDB_X64EXE,
         Architecture::Arm64 => resource::IDB_ARM64EXE,
     };
@@ -68,7 +68,7 @@ fn find_binary_data(architecture: Architecture) -> anyhow::Result<&'static [u8]>
         // which is not available in windows-sys, as it is a macro.
         // `resource_id` is guaranteed by the build script to refer to an actual resource.
         // See https://learn.microsoft.com/en-us/windows/win32/api/libloaderapi/nf-libloaderapi-findresourcew
-        NonZero::new(unsafe { FindResourceW(0, resource_id as _, w!("BINARY")) })
+        NonZero::new(unsafe { FindResourceW(0, resource_id as *const u16, w!("BINARY")) })
     else {
         bail!("Failed to find resource: {}", io::Error::last_os_error());
     };