Preshared keys

src/key.rs

@@ -15,6 +15,10 @@ pub struct PubKey {
     data: [u8; 32],
 }
 
+pub struct PresharedKey {
+    data: [u8; 32],
+}
+
 impl Key for PrivKey {
     fn get_data(&self) -> [u8; 32] {
         self.data.to_owned()
@@ -27,6 +31,12 @@ impl Key for PubKey {
     }
 }
 
+impl Key for PresharedKey {
+    fn get_data(&self) -> [u8; 32] {
+        self.data.to_owned()
+    }
+}
+
 impl Display for dyn Key {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         write!(
@@ -54,6 +64,7 @@ impl Display for PrivKey {
         )
     }
 }
+
 impl Display for PubKey {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         write!(
@@ -68,10 +79,28 @@ impl Display for PubKey {
     }
 }
 
+impl Display for PresharedKey {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(
+            f,
+            "{}",
+            base64::engine::GeneralPurpose::new(
+                &base64::alphabet::STANDARD,
+                base64::engine::general_purpose::GeneralPurposeConfig::new()
+            )
+            .encode(self.get_data())
+        )
+    }
+}
+
 impl PrivKey {
     pub fn generate() -> Self {
         let mut buf: [u8; 32] = [0; 32];
         StdRng::from_entropy().fill_bytes(&mut buf);
+        //Curve25519 clamping
+        buf[0] &= 248;
+        buf[31] &= 127;
+        buf[31] |= 64;
         PrivKey { data: buf }
     }
 
@@ -83,6 +112,14 @@ impl PrivKey {
     }
 }
 
+impl PresharedKey {
+    pub fn generate() -> Self {
+        let mut buf: [u8; 32] = [0; 32];
+        StdRng::from_entropy().fill_bytes(&mut buf);
+        PresharedKey { data: buf }
+    }
+}
+
 impl From<[u8; 32]> for PrivKey {
     fn from(value: [u8; 32]) -> Self {
         PrivKey { data: value }
@@ -97,6 +134,20 @@ impl From<&[u8; 32]> for PrivKey {
     }
 }
 
+impl From<[u8; 32]> for PresharedKey {
+    fn from(value: [u8; 32]) -> Self {
+        PresharedKey { data: value }
+    }
+}
+
+impl From<&[u8; 32]> for PresharedKey {
+    fn from(value: &[u8; 32]) -> Self {
+        PresharedKey {
+            data: value.clone(),
+        }
+    }
+}
+
 pub fn generate_key_pair() -> (PrivKey, PubKey) {
     let privkey = PrivKey::generate();
     let pubkey = privkey.derive_pubkey();