1 files changed, 127 insertions, 0 deletions
diff --git a/third_party/rust/neqo-crypto/src/secrets.rs b/third_party/rust/neqo-crypto/src/secrets.rs
new file mode 100644
index 0000000000..7e2739cfa5
--- /dev/null
+++ b/third_party/rust/neqo-crypto/src/secrets.rs
@@ -0,0 +1,127 @@
+// 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 crate::agentio::as_c_void;
+use crate::constants::Epoch;
+use crate::err::Res;
+use crate::p11::{PK11SymKey, PK11_ReferenceSymKey, SymKey};
+use crate::ssl::{PRFileDesc, SSLSecretCallback, SSLSecretDirection};
+
+use neqo_common::qdebug;
+use std::os::raw::c_void;
+use std::pin::Pin;
+
+experimental_api!(SSL_SecretCallback(
+    fd: *mut PRFileDesc,
+    cb: SSLSecretCallback,
+    arg: *mut c_void,
+));
+
+#[derive(Clone, Copy, Debug)]
+pub enum SecretDirection {
+    Read,
+    Write,
+}
+
+impl From<SSLSecretDirection::Type> for SecretDirection {
+    #[must_use]
+    fn from(dir: SSLSecretDirection::Type) -> Self {
+        match dir {
+            SSLSecretDirection::ssl_secret_read => Self::Read,
+            SSLSecretDirection::ssl_secret_write => Self::Write,
+            _ => unreachable!(),
+        }
+    }
+}
+
+#[derive(Debug, Default)]
+#[allow(clippy::module_name_repetitions)]
+pub struct DirectionalSecrets {
+    // We only need to maintain 3 secrets for the epochs used during the handshake.
+    secrets: [Option<SymKey>; 3],
+}
+
+impl DirectionalSecrets {
+    fn put(&mut self, epoch: Epoch, key: SymKey) {
+        assert!(epoch > 0);
+        let i = (epoch - 1) as usize;
+        assert!(i < self.secrets.len());
+        // assert!(self.secrets[i].is_none());
+        self.secrets[i] = Some(key);
+    }
+
+    pub fn take(&mut self, epoch: Epoch) -> Option<SymKey> {
+        assert!(epoch > 0);
+        let i = (epoch - 1) as usize;
+        assert!(i < self.secrets.len());
+        self.secrets[i].take()
+    }
+}
+
+#[derive(Debug, Default)]
+pub struct Secrets {
+    r: DirectionalSecrets,
+    w: DirectionalSecrets,
+}
+
+impl Secrets {
+    #[allow(clippy::unused_self)]
+    unsafe extern "C" fn secret_available(
+        _fd: *mut PRFileDesc,
+        epoch: u16,
+        dir: SSLSecretDirection::Type,
+        secret: *mut PK11SymKey,
+        arg: *mut c_void,
+    ) {
+        let secrets = arg.cast::<Self>().as_mut().unwrap();
+        secrets.put_raw(epoch, dir, secret);
+    }
+
+    fn put_raw(&mut self, epoch: Epoch, dir: SSLSecretDirection::Type, key_ptr: *mut PK11SymKey) {
+        let key_ptr = unsafe { PK11_ReferenceSymKey(key_ptr) };
+        let key = SymKey::from_ptr(key_ptr).expect("NSS shouldn't be passing out NULL secrets");
+        self.put(SecretDirection::from(dir), epoch, key);
+    }
+
+    fn put(&mut self, dir: SecretDirection, epoch: Epoch, key: SymKey) {
+        qdebug!("{:?} secret available for {:?}: {:?}", dir, epoch, key);
+        let keys = match dir {
+            SecretDirection::Read => &mut self.r,
+            SecretDirection::Write => &mut self.w,
+        };
+        keys.put(epoch, key);
+    }
+}
+
+#[derive(Debug)]
+pub struct SecretHolder {
+    secrets: Pin<Box<Secrets>>,
+}
+
+impl SecretHolder {
+    /// This registers with NSS.  The lifetime of this object needs to match the lifetime
+    /// of the connection, or bad things might happen.
+    pub fn register(&mut self, fd: *mut PRFileDesc) -> Res<()> {
+        let p = as_c_void(&mut self.secrets);
+        unsafe { SSL_SecretCallback(fd, Some(Secrets::secret_available), p) }
+    }
+
+    pub fn take_read(&mut self, epoch: Epoch) -> Option<SymKey> {
+        self.secrets.r.take(epoch)
+    }
+
+    pub fn take_write(&mut self, epoch: Epoch) -> Option<SymKey> {
+        self.secrets.w.take(epoch)
+    }
+}
+
+impl Default for SecretHolder {
+    fn default() -> Self {
+        Self {
+            secrets: Box::pin(Secrets::default()),
+        }
+    }
+}