add x448 support

Author: stevefan1999-personal

Cargo.lock

@@ -24,6 +24,7 @@ aes = { version = "0.8.4", default-features = false, optional = true }
 aes-gcm = { version = "0.10.3", default-features = false, optional = true }
 ccm = { version = "0.5.0", default-features = false, optional = true }
 chacha20poly1305 = { version = "0.10.1", default-features = false, optional = true }
+crrl = { version = "0.9.0", default-features = false, optional = true }
 crypto-common = { version = "0.1.6", default-features = false }
 der = { version = "0.7.9", default-features = false, optional = true }
 digest = { version = "0.10.7", default-features = false }
@@ -124,12 +125,13 @@ eddsa-ed25519 = ["eddsa", "ed25519"]
 eddsa-full = ["eddsa-ed25519"]
 
 kx = ["rand", "elliptic-curve"]
+kx-x448 = ["kx", "x448"]
 kx-x25519 = ["kx", "dep:x25519-dalek"]
 kx-nist = ["sec1"]
 kx-p256 = ["kx", "p256", "kx-nist", "p256/ecdh"]
 kx-p384 = ["kx", "p384", "kx-nist", "p384/ecdh"]
 kx-p521 = ["kx", "p521", "kx-nist", "p521/ecdh"]
-kx-full = ["kx-x25519", "kx-p256", "kx-p384", "kx-p521"]
+kx-full = ["kx-x448", "kx-x25519", "kx-p256", "kx-p384", "kx-p521"]
 
 rsa = ["dep:rsa", "rsa/sha2", "pkcs1"]
 rsa-pkcs1 = ["rsa", "pkcs1"]
@@ -222,4 +224,5 @@ chacha20poly1305 = ["dep:chacha20poly1305"]
 elliptic-curve = ["dep:elliptic-curve"]
 gcm = []
 rand = ["dep:rand_core", "signature?/rand_core"]
-signature = ["dep:signature"]
+signature = ["dep:signature"]
+x448 = ["dep:crrl", "crrl/x448"]

Cargo.toml

@@ -1,6 +1,8 @@
 use rustls::crypto::SupportedKxGroup;
 
 pub const ALL_KX_GROUPS: &[&dyn SupportedKxGroup] = &[
+    #[cfg(feature = "kx-x448")]
+    &x448::X448,
     #[cfg(feature = "kx-x25519")]
     &x25519::X25519,
     #[cfg(feature = "kx-p256")]
@@ -16,3 +18,6 @@ pub mod nist;
 
 #[cfg(feature = "kx-x25519")]
 pub mod x25519;
+
+#[cfg(feature = "kx-x448")]
+pub mod x448;

src/kx.rs

@@ -0,0 +1,48 @@
+#[cfg(feature = "alloc")]
+use alloc::boxed::Box;
+
+use crrl::x448::{x448, x448_base};
+use crypto::{SharedSecret, SupportedKxGroup};
+use rand_core::RngCore;
+use rustls::crypto::{self, ActiveKeyExchange};
+
+#[derive(Debug)]
+pub struct X448;
+
+impl crypto::SupportedKxGroup for X448 {
+    fn name(&self) -> rustls::NamedGroup {
+        rustls::NamedGroup::X448
+    }
+
+    fn start(&self) -> Result<Box<dyn ActiveKeyExchange>, rustls::Error> {
+        let priv_key = {
+            let mut bytes = [0u8; 56];
+            rand_core::OsRng.fill_bytes(&mut bytes);
+            bytes
+        };
+        let pub_key = x448_base(&priv_key);
+        Ok(Box::new(X448KeyExchange { priv_key, pub_key }))
+    }
+}
+
+pub struct X448KeyExchange {
+    priv_key: [u8; 56],
+    pub_key: [u8; 56],
+}
+
+impl ActiveKeyExchange for X448KeyExchange {
+    fn complete(self: Box<X448KeyExchange>, peer: &[u8]) -> Result<SharedSecret, rustls::Error> {
+        let peer_public: [u8; 56] = peer
+            .try_into()
+            .map_err(|_| rustls::Error::from(rustls::PeerMisbehaved::InvalidKeyShare))?;
+        Ok(x448(&peer_public, &self.priv_key).as_ref().into())
+    }
+
+    fn pub_key(&self) -> &[u8] {
+        self.pub_key.as_slice()
+    }
+
+    fn group(&self) -> rustls::NamedGroup {
+        X448.name()
+    }
+}

src/kx/x448.rs

@@ -128,7 +128,6 @@ mod test {
         vs_openssl_as_client(group_list, OpenSslCipherSuites::default());
     }
     #[test]
-    #[should_panic] // no support
     fn vs_openssl_as_client_group_x448() {
         let mut group_list = OpenSslGroupsList::all_false();
         group_list.X448 = true;