Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 246 insertions, 0 deletions

diff --git a/third_party/rust/nss-gk-api/src/util.rs b/third_party/rust/nss-gk-api/src/util.rs
new file mode 100644
index 0000000000..f06542eb45
--- /dev/null
+++ b/third_party/rust/nss-gk-api/src/util.rs
@@ -0,0 +1,246 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::convert::TryFrom;
+use std::marker::PhantomData;
+use std::mem;
+use std::os::raw::c_uint;
+use std::ptr::null_mut;
+
+use crate::prtypes::*;
+use crate::nss_prelude::*;
+
+/// Implement a smart pointer for NSS objects.
+///
+/// Most of the time the pointer is like a `Box`, but there are exceptions (e.g.
+/// PK11SymKey is internally reference counted so its pointer is like an `Arc`.)
+///
+/// Named "scoped" because that is what NSS calls its `unique_ptr` typedefs.
+macro_rules! scoped_ptr {
+    ($name:ident, $target:ty, $dtor:path) => {
+        pub struct $name {
+            ptr: *mut $target,
+        }
+
+        impl $name {
+            /// Create a new instance of `$name` from a pointer.
+            ///
+            /// # Errors
+            /// When passed a null pointer generates an error.
+            pub unsafe fn from_ptr(raw: *mut $target) -> Result<Self, $crate::err::Error> {
+                let ptr = $crate::err::into_result(raw)?;
+                Ok(Self { ptr })
+            }
+        }
+
+        impl $crate::err::IntoResult for *mut $target {
+            type Ok = $name;
+
+            unsafe fn into_result(self) -> Result<Self::Ok, $crate::err::Error> {
+                $name::from_ptr(self)
+            }
+        }
+
+        impl std::ops::Deref for $name {
+            type Target = *mut $target;
+            #[must_use]
+            fn deref(&self) -> &*mut $target {
+                &self.ptr
+            }
+        }
+
+        // Original implements DerefMut, but is that really a good idea?
+
+        impl Drop for $name {
+            fn drop(&mut self) {
+                unsafe { $dtor(self.ptr) };
+            }
+        }
+    }
+}
+
+macro_rules! impl_clone {
+    ($name:ty, $nss_fn:path) => {
+        impl Clone for $name {
+            #[must_use]
+            fn clone(&self) -> Self {
+                let ptr = unsafe { $nss_fn(self.ptr) };
+                assert!(!ptr.is_null());
+                Self { ptr }
+            }
+        }
+    }
+}
+
+impl SECItem {
+    /// Return contents as a slice.
+    ///
+    /// Unsafe due to calling from_raw_parts, or if 'a outlives &self. This
+    /// unsafety is encapsulated by the `as_slice` method of `SECItemBorrowed`
+    /// and `SECItemMut`.
+    ///
+    /// Note that safe code can construct a SECItem pointing to anything. The
+    /// same is not true of the safe wrappers `SECItemMut` and `SECItemBorrowed`
+    /// because their inner SECItem is private.
+    pub unsafe fn as_slice<'a>(&self) -> &'a [u8] {
+        // Sanity check the type, as some types don't count bytes in `Item::len`.
+        assert_eq!(self.type_, SECItemType::siBuffer);
+        // Note: `from_raw_parts` requires non-null `data` even for zero-length
+        // slices.
+        if self.len != 0 {
+            std::slice::from_raw_parts(self.data, usize::try_from(self.len).unwrap())
+        } else {
+            &[]
+        }
+    }
+}
+
+/// An owned SECItem.
+///
+/// The SECItem structure is allocated by Rust. The buffer referenced by the
+/// SECItem is allocated by NSS. `SECITEM_FreeItem` will be called to free the
+/// buffer when the SECItemMut is dropped.
+///
+/// This is used with NSS functions that return a variable amount of data.
+#[repr(transparent)]
+pub struct SECItemMut {
+    inner: SECItem,
+}
+
+impl<'a> Drop for SECItemMut {
+    #[allow(unused_must_use)]
+    fn drop(&mut self) {
+        // FreeItem unconditionally frees the buffer referenced by the SECItem.
+        // If the second argument is true, it also frees the SECItem itself,
+        // which we don't want to do, because rust owns that memory.
+        unsafe { SECITEM_FreeItem(&mut self.inner, PRBool::from(false)) };
+    }
+}
+
+impl AsRef<SECItem> for SECItemMut {
+    fn as_ref(&self) -> &SECItem {
+        &self.inner
+    }
+}
+
+impl AsMut<SECItem> for SECItemMut {
+    fn as_mut(&mut self) -> &mut SECItem {
+        &mut self.inner
+    }
+}
+
+impl SECItemMut {
+    /// Return contents as a slice.
+    pub fn as_slice(&self) -> &[u8] {
+        unsafe { self.inner.as_slice() }
+    }
+
+    /// Make an empty `SECItemMut` for passing as a mutable `*SECItem` argument.
+    pub fn make_empty() -> SECItemMut {
+        SECItemMut {
+            inner: SECItem {
+                type_: SECItemType::siBuffer,
+                data: null_mut(),
+                len: 0,
+            }
+        }
+    }
+}
+
+/// A borrowed SECItem.
+///
+/// The SECItem structure is allocated by Rust. The buffer referenced by the
+/// SECItem may be allocated either by Rust or NSS. The SECItem does not own the
+/// buffer and will not free it when dropped.
+///
+/// This is usually used to pass a reference to some borrowed rust memory to
+/// NSS. It is occasionally used to accept non-owned output data from NSS.
+#[repr(transparent)]
+pub struct SECItemBorrowed<'a> {
+    inner: SECItem,
+    phantom_data: PhantomData<&'a u8>,
+}
+
+impl<'a> AsRef<SECItem> for SECItemBorrowed<'a> {
+    fn as_ref(&self) -> &SECItem {
+        &self.inner
+    }
+}
+
+impl<'a> AsMut<SECItem> for SECItemBorrowed<'a> {
+    /// Get a mutable reference to the underlying SECItem struct.
+    ///
+    /// Note that even if the SECItem struct is mutable, the buffer it
+    /// references may not be. Take care not to pass the mutable
+    /// SECItem to NSS routines that will violate mutability rules.
+    //
+    // TODO: Should we make the danger more obvious, by using a non-trait method
+    // with "unsafe" in the name, or an unsafe method?
+    fn as_mut(&mut self) -> &mut SECItem {
+        &mut self.inner
+    }
+}
+
+impl<'a> SECItemBorrowed<'a> {
+    /// Return contents as a slice.
+    pub fn as_slice(&self) -> &'a [u8] {
+        unsafe { self.inner.as_slice() }
+    }
+
+    /// Create an empty `SECItemBorrowed`.
+    ///
+    /// This can be used (1) to pass an empty item as an argument, and (2) as an
+    /// output parameter when NSS returns a pointer to NSS-owned memory that
+    /// should not be freed when the SECItem is dropped.  If the memory should
+    /// be freed when the SECItem is dropped, use SECItemMut.
+    ///
+    /// It is safe to let the caller specify any lifetime here because no
+    /// borrowing is actually taking place. However, if the pointer in the
+    /// returned item is modified, care must be taken that the specified
+    /// lifetime accurately reflects the data referenced by the pointer.
+    pub fn make_empty() -> SECItemBorrowed<'a> {
+        SECItemBorrowed {
+            inner: SECItem {
+                type_: SECItemType::siBuffer,
+                data: null_mut(),
+                len: 0,
+            },
+            phantom_data: PhantomData,
+        }
+    }
+
+    /// Create a `SECItemBorrowed` wrapping a slice.
+    ///
+    /// Creating this object is technically safe, but using it is extremely dangerous.
+    /// Minimally, it can only be passed as a `const SECItem*` argument to functions,
+    /// or those that treat their argument as `const`.
+    pub fn wrap(buf: &'a [u8]) -> SECItemBorrowed<'a> {
+        SECItemBorrowed {
+            inner: SECItem {
+                type_: SECItemType::siBuffer,
+                data: buf.as_ptr() as *mut u8,
+                len: c_uint::try_from(buf.len()).unwrap(),
+            },
+            phantom_data: PhantomData,
+        }
+    }
+
+    /// Create a `SECItemBorrowed` wrapping a struct.
+    ///
+    /// Creating this object is technically safe, but using it is extremely dangerous.
+    /// Minimally, it can only be passed as a `const SECItem*` argument to functions,
+    /// or those that treat their argument as `const`.
+    pub fn wrap_struct<T>(v: &'a T) -> SECItemBorrowed<'a> {
+        SECItemBorrowed {
+            inner: SECItem {
+                type_: SECItemType::siBuffer,
+                data: (v as *const T as *mut T).cast(),
+                len: c_uint::try_from(mem::size_of::<T>()).unwrap(),
+            },
+            phantom_data: PhantomData,
+        }
+    }
+}