Merge branch 'release-v0.7.15-sys-v0.8.0' into releaseopenssl-v0.8.0openssl-sys-v0.7.15

1 files changed, 58 insertions, 0 deletions

diff --git a/openssl/src/crypto/util.rs b/openssl/src/crypto/util.rs
new file mode 100644
index 00000000..be72aa59
--- /dev/null
+++ b/openssl/src/crypto/util.rs
@@ -0,0 +1,58 @@
+use libc::{c_int, c_char, c_void};
+
+use std::any::Any;
+use std::panic;
+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<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 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 [i8]) -> usize {
+    let result = panic::catch_unwind(|| {
+        // build a `i8` slice to pass to the user callback
+        let pass_slice = unsafe { slice::from_raw_parts_mut(buf, size as usize) };
+        let callback = unsafe { &mut *(cb_state as *mut CallbackState<F>) };
+
+        callback.cb.take().unwrap()(pass_slice)
+    });
+
+    if let Ok(len) = result {
+        return len as c_int;
+    } else {
+        return 0;
+    }
+}