wgctrl-rs(userspace): use curve25519-dalek directly instead of x25519-dalek

This removes our need to use a forked version that had an updated rand dependency

Cargo.lock

@@ -211,8 +211,9 @@ dependencies = [
 
 [[package]]
 name = "curve25519-dalek"
-version = "3.0.2"
-source = "git+https://github.com/mcginty/curve25519-dalek?branch=main#2028ad6ee8783af2f260efb0390680f639c22c7e"
+version = "4.0.0-pre.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4033478fbf70d6acf2655ac70da91ee65852d69daf7a67bf7a2f518fb47aafcf"
 dependencies = [
  "byteorder",
  "digest",
@@ -1101,18 +1102,6 @@ dependencies = [
  "unicode-xid",
 ]
 
-[[package]]
-name = "synstructure"
-version = "0.12.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "474aaa926faa1603c40b7885a9eaea29b444d1cb2850cb7c0e37bb1a4182f4fa"
-dependencies = [
- "proc-macro2",
- "quote",
- "syn",
- "unicode-xid",
-]
-
 [[package]]
 name = "tap"
 version = "1.0.1"
@@ -1374,12 +1363,12 @@ name = "wgctrl"
 version = "1.4.1"
 dependencies = [
  "base64",
+ "curve25519-dalek",
  "hex",
  "libc",
  "rand_core",
  "subtle",
  "wgctrl-sys",
- "x25519-dalek",
 ]
 
 [[package]]
@@ -1428,33 +1417,8 @@ version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "85e60b0d1b5f99db2556934e21937020776a5d31520bf169e851ac44e6420214"
 
-[[package]]
-name = "x25519-dalek"
-version = "1.1.0"
-source = "git+https://github.com/mcginty/x25519-dalek?branch=master#8edb77eda328f09f19f8ba9d33b114c5afafa457"
-dependencies = [
- "curve25519-dalek",
- "rand_core",
- "zeroize",
-]
-
 [[package]]
 name = "zeroize"
 version = "1.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "377db0846015f7ae377174787dd452e1c5f5a9050bc6f954911d01f116daa0cd"
-dependencies = [
- "zeroize_derive",
-]
-
-[[package]]
-name = "zeroize_derive"
-version = "1.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a2c1e130bebaeab2f23886bf9acbaca14b092408c452543c857f66399cd6dab1"
-dependencies = [
- "proc-macro2",
- "quote",
- "syn",
- "synstructure",
-]

wgctrl-rs/Cargo.toml

@@ -20,4 +20,4 @@ wgctrl-sys = { path = "../wgctrl-sys" }
 [target.'cfg(not(target_os = "linux"))'.dependencies]
 rand_core = "0.6"
 subtle = "2"
-x25519-dalek = { git = "https://github.com/mcginty/x25519-dalek", branch = "master" } # pending https://github.com/dalek-cryptography/x25519-dalek/pull/64
+curve25519-dalek = "4.0.0-pre.1"

wgctrl-rs/src/backends/userspace.rs

@@ -1,3 +1,5 @@
+use curve25519_dalek::scalar::Scalar;
+
 use crate::{Backend, Device, DeviceUpdate, InterfaceName, PeerConfig, PeerInfo, PeerStats};
 
 #[cfg(target_os = "linux")]
@@ -396,11 +398,16 @@ pub struct Key(pub [u8; 32]);
 impl Key {
     /// Generates and returns a new private key.
     pub fn generate_private() -> Self {
-        use rand_core::OsRng;
-        use x25519_dalek::StaticSecret;
+        use rand_core::{OsRng, RngCore};
 
-        let key = StaticSecret::new(OsRng);
-        Self(key.to_bytes())
+        let mut bytes = [0u8; 32];
+        OsRng.fill_bytes(&mut bytes);
+
+        // Apply key clamping.
+        bytes[0] &= 248;
+        bytes[31] &= 127;
+        bytes[31] |= 64;
+        Self(bytes)
     }
 
     /// Generates and returns a new preshared key.
@@ -414,13 +421,12 @@ impl Key {
 
     /// Generates a public key for this private key.
     pub fn generate_public(&self) -> Self {
-        use x25519_dalek::{PublicKey, StaticSecret};
+        use curve25519_dalek::constants::ED25519_BASEPOINT_TABLE;
 
-        let mut public_bytes = [0u8; 32];
-        let private_key = StaticSecret::from(self.0);
-        let public_key = PublicKey::from(&private_key);
-        public_bytes.copy_from_slice(public_key.as_bytes());
-        Self(public_bytes)
+        // https://github.com/dalek-cryptography/x25519-dalek/blob/1c39ff92e0dfc0b24aa02d694f26f3b9539322a5/src/x25519.rs#L150
+        let point = (&ED25519_BASEPOINT_TABLE * &Scalar::from_bits(self.0)).to_montgomery();
+
+        Self(point.to_bytes())
     }
 
     /// Generates an all-zero key.
@@ -466,3 +472,41 @@ impl Key {
         Ok(Self(sized_bytes))
     }
 }
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn test_pubkey_generation() {
+        let privkey = "SGb+ojrRNDuMePufwtIYhXzA//k6wF3R21tEBgKlzlM=";
+        let pubkey = "DD5yKRfzExcV5+kDnTroDgCU15latdMjiQ59j1hEuk8=";
+
+        let private = Key::from_base64(privkey).unwrap();
+        let public = Key::generate_public(&private);
+
+        assert_eq!(public.to_base64(), pubkey);
+    }
+
+    #[test]
+    fn test_rng_sanity_private() {
+        let first = Key::generate_private();
+        assert!(!first.is_zero());
+        for _ in 0..100_000 {
+            let key = Key::generate_private();
+            assert!(first != key);
+            assert!(!key.is_zero());
+        }
+    }
+
+    #[test]
+    fn test_rng_sanity_preshared() {
+        let first = Key::generate_preshared();
+        assert!(!first.is_zero());
+        for _ in 0..100_000 {
+            let key = Key::generate_preshared();
+            assert!(first != key);
+            assert!(!key.is_zero());
+        }
+    }
+}