add get_curve (#226)

boring/src/ssl/mod.rs

@@ -696,6 +696,22 @@ impl SslCurve {
 
     #[cfg(feature = "pq-experimental")]
     pub const P256_KYBER768_DRAFT00: SslCurve = SslCurve(ffi::NID_P256Kyber768Draft00);
+
+    /// Returns the curve name
+    ///
+    /// This corresponds to [`SSL_get_curve_name`]
+    ///
+    /// [`SSL_get_curve_name`]: https://commondatastorage.googleapis.com/chromium-boringssl-docs/ssl.h.html#SSL_get_curve_name
+    pub fn name(&self) -> Option<&'static str> {
+        unsafe {
+            let ptr = ffi::SSL_get_curve_name(self.0 as u16);
+            if ptr.is_null() {
+                return None;
+            }
+
+            CStr::from_ptr(ptr).to_str().ok()
+        }
+    }
 }
 
 /// A compliance policy.
@@ -2745,6 +2761,19 @@ impl SslRef {
             .expect("invalid default server curves list");
     }
 
+    /// Returns the [`SslCurve`] used for this `SslRef`.
+    ///
+    /// This corresponds to [`SSL_get_curve_id`]
+    ///
+    /// [`SSL_get_curve_id`]: https://commondatastorage.googleapis.com/chromium-boringssl-docs/ssl.h.html#SSL_get_curve_id
+    pub fn curve(&self) -> Option<SslCurve> {
+        let curve_id = unsafe { ffi::SSL_get_curve_id(self.as_ptr()) };
+        if curve_id == 0 {
+            return None;
+        }
+        Some(SslCurve(curve_id.into()))
+    }
+
     /// Returns an `ErrorCode` value for the most recent operation on this `SslRef`.
     ///
     /// This corresponds to [`SSL_get_error`].

boring/src/ssl/test/mod.rs

@@ -920,6 +920,15 @@ fn server_set_default_curves_list() {
     ssl.server_set_default_curves_list();
 }
 
+#[test]
+fn get_curve() {
+    let server = Server::builder().build();
+    let client = server.client_with_root_ca();
+    let client_stream = client.connect();
+    let curve = client_stream.ssl().curve().expect("curve");
+    assert!(curve.name().is_some());
+}
+
 #[test]
 fn test_get_ciphers() {
     let ctx_builder = SslContext::builder(SslMethod::tls()).unwrap();