refactor: 将 DTLS 本地依赖迁移到 libs 目录

libs/dtls/src/curve/mod.rs

@@ -0,0 +1,17 @@
+pub mod named_curve;
+
+// https://www.iana.org/assignments/tls-parameters/tls-parameters.xhtml#tls-parameters-10
+#[derive(Copy, Clone, PartialEq, Eq, Debug)]
+pub enum EllipticCurveType {
+    NamedCurve = 0x03,
+    Unsupported,
+}
+
+impl From<u8> for EllipticCurveType {
+    fn from(val: u8) -> Self {
+        match val {
+            0x03 => EllipticCurveType::NamedCurve,
+            _ => EllipticCurveType::Unsupported,
+        }
+    }
+}