1 files changed, 93 insertions, 0 deletions
diff --git a/vendor/openssl/src/util.rs b/vendor/openssl/src/util.rs
new file mode 100644
index 000000000..d852a4b9d
--- /dev/null
+++ b/vendor/openssl/src/util.rs
@@ -0,0 +1,93 @@
+use crate::error::ErrorStack;
+use foreign_types::{ForeignType, ForeignTypeRef};
+use libc::{c_char, c_int, c_void};
+use std::any::Any;
+use std::panic::{self, AssertUnwindSafe};
+use std::slice;
+
+/// Wraps a user-supplied callback and a slot for panics thrown inside the callback (while FFI
+/// frames are on the stack).
+///
+/// When dropped, checks if the callback has panicked, and resumes unwinding if so.
+pub struct CallbackState<F> {
+    /// The user callback. Taken out of the `Option` when called.
+    cb: Option<F>,
+    /// If the callback panics, we place the panic object here, to be re-thrown once OpenSSL
+    /// returns.
+    panic: Option<Box<dyn Any + Send + 'static>>,
+}
+
+impl<F> CallbackState<F> {
+    pub fn new(callback: F) -> Self {
+        CallbackState {
+            cb: Some(callback),
+            panic: None,
+        }
+    }
+}
+
+impl<F> Drop for CallbackState<F> {
+    fn drop(&mut self) {
+        if let Some(panic) = self.panic.take() {
+            panic::resume_unwind(panic);
+        }
+    }
+}
+
+/// Password callback function, passed to private key loading functions.
+///
+/// `cb_state` is expected to be a pointer to a `CallbackState`.
+pub unsafe extern "C" fn invoke_passwd_cb<F>(
+    buf: *mut c_char,
+    size: c_int,
+    _rwflag: c_int,
+    cb_state: *mut c_void,
+) -> c_int
+where
+    F: FnOnce(&mut [u8]) -> Result<usize, ErrorStack>,
+{
+    let callback = &mut *(cb_state as *mut CallbackState<F>);
+
+    let result = panic::catch_unwind(AssertUnwindSafe(|| {
+        let pass_slice = slice::from_raw_parts_mut(buf as *mut u8, size as usize);
+        callback.cb.take().unwrap()(pass_slice)
+    }));
+
+    match result {
+        Ok(Ok(len)) => len as c_int,
+        Ok(Err(_)) => {
+            // FIXME restore error stack
+            0
+        }
+        Err(err) => {
+            callback.panic = Some(err);
+            0
+        }
+    }
+}
+
+pub trait ForeignTypeExt: ForeignType {
+    unsafe fn from_ptr_opt(ptr: *mut Self::CType) -> Option<Self> {
+        if ptr.is_null() {
+            None
+        } else {
+            Some(Self::from_ptr(ptr))
+        }
+    }
+}
+impl<FT: ForeignType> ForeignTypeExt for FT {}
+
+pub trait ForeignTypeRefExt: ForeignTypeRef {
+    unsafe fn from_const_ptr<'a>(ptr: *const Self::CType) -> &'a Self {
+        Self::from_ptr(ptr as *mut Self::CType)
+    }
+
+    unsafe fn from_const_ptr_opt<'a>(ptr: *const Self::CType) -> Option<&'a Self> {
+        if ptr.is_null() {
+            None
+        } else {
+            Some(Self::from_const_ptr(ptr as *mut Self::CType))
+        }
+    }
+}
+impl<FT: ForeignTypeRef> ForeignTypeRefExt for FT {}