1 files changed, 129 insertions, 0 deletions
diff --git a/third_party/rust/nss/src/util.rs b/third_party/rust/nss/src/util.rs
new file mode 100644
index 0000000000..39bf26c622
--- /dev/null
+++ b/third_party/rust/nss/src/util.rs
@@ -0,0 +1,129 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+use crate::error::*;
+use nss_sys::*;
+use std::{convert::TryFrom, ffi::CString, os::raw::c_char, sync::Once};
+
+// This is the NSS version that this crate is claiming to be compatible with.
+// We check it at runtime using `NSS_VersionCheck`.
+pub const COMPATIBLE_NSS_VERSION: &str = "3.26";
+
+static NSS_INIT: Once = Once::new();
+
+pub fn ensure_nss_initialized() {
+    NSS_INIT.call_once(|| {
+        let version_ptr = CString::new(COMPATIBLE_NSS_VERSION).unwrap();
+        if unsafe { NSS_VersionCheck(version_ptr.as_ptr()) == PR_FALSE } {
+            panic!("Incompatible NSS version!")
+        }
+        let empty = CString::default();
+        let flags = NSS_INIT_READONLY
+            | NSS_INIT_NOCERTDB
+            | NSS_INIT_NOMODDB
+            | NSS_INIT_FORCEOPEN
+            | NSS_INIT_OPTIMIZESPACE;
+        let context = unsafe {
+            NSS_InitContext(
+                empty.as_ptr(),
+                empty.as_ptr(),
+                empty.as_ptr(),
+                empty.as_ptr(),
+                std::ptr::null_mut(),
+                flags,
+            )
+        };
+        if context.is_null() {
+            let error = get_last_error();
+            panic!("Could not initialize NSS: {}", error);
+        }
+    })
+}
+
+pub fn map_nss_secstatus<F>(callback: F) -> Result<()>
+where
+    F: FnOnce() -> SECStatus,
+{
+    if callback() == SECStatus::SECSuccess {
+        return Ok(());
+    }
+    Err(get_last_error())
+}
+
+/// Retrieve and wrap the last NSS/NSPR error in the current thread.
+#[cold]
+pub fn get_last_error() -> Error {
+    let error_code = unsafe { PR_GetError() };
+    let error_text: String = usize::try_from(unsafe { PR_GetErrorTextLength() })
+        .map(|error_text_len| {
+            let mut out_str = vec![0u8; error_text_len + 1];
+            unsafe { PR_GetErrorText(out_str.as_mut_ptr() as *mut c_char) };
+            CString::new(&out_str[0..error_text_len])
+                .unwrap_or_else(|_| CString::default())
+                .to_str()
+                .unwrap_or_else(|_| "")
+                .to_owned()
+        })
+        .unwrap_or_else(|_| "".to_string());
+    ErrorKind::NSSError(error_code, error_text).into()
+}
+
+pub(crate) trait ScopedPtr
+where
+    Self: std::marker::Sized,
+{
+    type RawType;
+    unsafe fn from_ptr(ptr: *mut Self::RawType) -> Result<Self>;
+    fn as_ptr(&self) -> *const Self::RawType;
+    fn as_mut_ptr(&self) -> *mut Self::RawType;
+}
+
+// The macro defines a wrapper around pointers refering to types allocated by NSS,
+// calling their NSS destructor method when they go out of scope to avoid memory leaks.
+// The `as_ptr`/`as_mut_ptr` are provided to retrieve the raw pointers to pass to
+// NSS functions that consume them.
+#[macro_export]
+macro_rules! scoped_ptr {
+    ($scoped:ident, $target:ty, $dtor:path) => {
+        pub struct $scoped {
+            ptr: *mut $target,
+        }
+
+        impl crate::util::ScopedPtr for $scoped {
+            type RawType = $target;
+
+            #[allow(dead_code)]
+            unsafe fn from_ptr(ptr: *mut $target) -> crate::error::Result<$scoped> {
+                if !ptr.is_null() {
+                    Ok($scoped { ptr })
+                } else {
+                    Err(crate::error::ErrorKind::InternalError.into())
+                }
+            }
+
+            #[inline]
+            fn as_ptr(&self) -> *const $target {
+                self.ptr
+            }
+
+            #[inline]
+            fn as_mut_ptr(&self) -> *mut $target {
+                self.ptr
+            }
+        }
+
+        impl Drop for $scoped {
+            fn drop(&mut self) {
+                assert!(!self.ptr.is_null());
+                unsafe { $dtor(self.ptr) };
+            }
+        }
+    };
+}
+
+pub(crate) unsafe fn sec_item_as_slice(sec_item: &mut SECItem) -> Result<&mut [u8]> {
+    let sec_item_buf_len = usize::try_from(sec_item.len)?;
+    let buf = std::slice::from_raw_parts_mut(sec_item.data, sec_item_buf_len);
+    Ok(buf)
+}