Bind remove and get session callbacks

openssl/src/ssl/callbacks.rs

@@ -12,7 +12,8 @@ use dh::Dh;
 #[cfg(any(all(feature = "v101", ossl101), all(feature = "v102", ossl102)))]
 use ec::EcKey;
 use pkey::Params;
-use ssl::{get_callback_idx, get_ssl_callback_idx, SniError, SslAlert, SslRef, SslSession};
+use ssl::{get_callback_idx, get_ssl_callback_idx, SniError, SslAlert, SslContextRef, SslRef,
+          SslSession, SslSessionRef};
 #[cfg(any(all(feature = "v102", ossl102), all(feature = "v110", ossl110),
           all(feature = "v111", ossl111)))]
 use ssl::AlpnError;
@@ -295,3 +296,50 @@ where
     // the return code doesn't indicate error vs success, but whether or not we consumed the session
     1
 }
+
+pub unsafe extern "C" fn raw_remove_session<F>(
+    ctx: *mut ffi::SSL_CTX,
+    session: *mut ffi::SSL_SESSION,
+) where
+    F: Fn(&SslContextRef, &SslSessionRef) + 'static + Sync + Send,
+{
+    let callback = ffi::SSL_CTX_get_ex_data(ctx, get_callback_idx::<F>());
+    let callback = &*(callback as *mut F);
+
+    let ctx = SslContextRef::from_ptr(ctx);
+    let session = SslSessionRef::from_ptr(session);
+
+    callback(ctx, session)
+}
+
+#[cfg(any(ossl110, ossl111))]
+type DataPtr = *const c_uchar;
+#[cfg(not(any(ossl110, ossl111)))]
+type DataPtr = *mut c_uchar;
+
+pub unsafe extern "C" fn raw_get_session<F>(
+    ssl: *mut ffi::SSL,
+    data: DataPtr,
+    len: c_int,
+    copy: *mut c_int,
+) -> *mut ffi::SSL_SESSION
+where
+    F: Fn(&mut SslRef, &[u8]) -> Option<SslSession> + 'static + Sync + Send,
+{
+    let ctx = ffi::SSL_get_SSL_CTX(ssl as *const _);
+    let callback = ffi::SSL_CTX_get_ex_data(ctx, get_callback_idx::<F>());
+    let callback = &*(callback as *mut F);
+
+    let ssl = SslRef::from_ptr_mut(ssl);
+    let data = slice::from_raw_parts(data as *const u8, len as usize);
+
+    match callback(ssl, data) {
+        Some(session) => {
+            let p = session.as_ptr();
+            mem::forget(p);
+            *copy = 0;
+            p
+        }
+        None => ptr::null_mut(),
+    }
+}

openssl/src/ssl/mod.rs

@@ -1195,6 +1195,58 @@ impl SslContextBuilder {
         }
     }
 
+    /// Sets the callback which is called when sessions are removed from the context.
+    ///
+    /// Sessions can be removed because they have timed out or because they are considered faulty.
+    ///
+    /// This corresponds to [`SSL_CTX_sess_set_remove_cb`].
+    ///
+    /// [`SSL_CTX_sess_set_remove_cb`]: https://www.openssl.org/docs/manmaster/man3/SSL_CTX_sess_set_new_cb.html
+    pub fn set_remove_session_callback<F>(&mut self, callback: F)
+    where
+        F: Fn(&SslContextRef, &SslSessionRef) + 'static + Sync + Send,
+    {
+        unsafe {
+            let callback = Box::new(callback);
+            ffi::SSL_CTX_set_ex_data(
+                self.as_ptr(),
+                get_callback_idx::<F>(),
+                Box::into_raw(callback) as *mut _,
+            );
+            ffi::SSL_CTX_sess_set_remove_cb(
+                self.as_ptr(),
+                Some(callbacks::raw_remove_session::<F>),
+            );
+        }
+    }
+
+    /// Sets the callback which is called when a client proposed to resume a session but it was not
+    /// found in the internal cache.
+    ///
+    /// The callback is passed a reference to the session ID provided by the client. It should
+    /// return the session corresponding to that ID if available. This is only used for servers, not
+    /// clients.
+    ///
+    /// This corresponds to [`SSL_CTX_sess_set_get_cb`].
+    ///
+    /// # Safety
+    ///
+    /// The returned `SslSession` must not be associated with a different `SslContext`.
+    ///
+    /// [`SSL_CTX_sess_set_get_cb`]: https://www.openssl.org/docs/manmaster/man3/SSL_CTX_sess_set_new_cb.html
+    pub unsafe fn set_get_session_callback<F>(&mut self, callback: F)
+    where
+        F: Fn(&mut SslRef, &[u8]) -> Option<SslSession> + 'static + Sync + Send,
+    {
+        let callback = Box::new(callback);
+        ffi::SSL_CTX_set_ex_data(
+            self.as_ptr(),
+            get_callback_idx::<F>(),
+            Box::into_raw(callback) as *mut _,
+        );
+        ffi::SSL_CTX_sess_set_get_cb(self.as_ptr(), Some(callbacks::raw_get_session::<F>));
+    }
+
     /// Sets the session caching mode use for connections made with the context.
     ///
     /// Returns the previous session caching mode.