refactor: 将 DTLS 本地依赖迁移到 libs 目录

libs/dtls/src/extension/extension_supported_elliptic_curves.rs

@@ -0,0 +1,50 @@
+#[cfg(test)]
+mod extension_supported_elliptic_curves_test;
+
+use super::*;
+use crate::curve::named_curve::*;
+
+const EXTENSION_SUPPORTED_GROUPS_HEADER_SIZE: usize = 6;
+
+/// ## Specifications
+///
+/// * [RFC 8422 §5.1.1]
+///
+/// [RFC 8422 §5.1.1]: https://tools.ietf.org/html/rfc8422#section-5.1.1
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct ExtensionSupportedEllipticCurves {
+    pub elliptic_curves: Vec<NamedCurve>,
+}
+
+impl ExtensionSupportedEllipticCurves {
+    pub fn extension_value(&self) -> ExtensionValue {
+        ExtensionValue::SupportedEllipticCurves
+    }
+
+    pub fn size(&self) -> usize {
+        2 + 2 + self.elliptic_curves.len() * 2
+    }
+
+    pub fn marshal<W: Write>(&self, writer: &mut W) -> Result<()> {
+        writer.write_u16::<BigEndian>(2 + 2 * self.elliptic_curves.len() as u16)?;
+        writer.write_u16::<BigEndian>(2 * self.elliptic_curves.len() as u16)?;
+        for v in &self.elliptic_curves {
+            writer.write_u16::<BigEndian>(*v as u16)?;
+        }
+
+        Ok(writer.flush()?)
+    }
+
+    pub fn unmarshal<R: Read>(reader: &mut R) -> Result<Self> {
+        let _ = reader.read_u16::<BigEndian>()?;
+
+        let group_count = reader.read_u16::<BigEndian>()? as usize / 2;
+        let mut elliptic_curves = vec![];
+        for _ in 0..group_count {
+            let elliptic_curve = reader.read_u16::<BigEndian>()?.into();
+            elliptic_curves.push(elliptic_curve);
+        }
+
+        Ok(ExtensionSupportedEllipticCurves { elliptic_curves })
+    }
+}