Refactor signing and verification to use ed25519-dalek

`perf` shows the server spends most of its time in signature generation. Benchmarking shows ed25519-dalek is about 40% faster than Ring generating signatures on x86_64. Replaced Verifier and Signer with ed25519-dalek for signature operations. Updated relevant imports and function calls.
int08h · Oct 11, 2024 · 52e5a04 · 52e5a04
1 parent dad0919
commit 52e5a04
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Showing 6 changed files with 46 additions and 45 deletions.
diff --git a/Cargo.toml b/Cargo.toml
@@ -35,6 +35,7 @@ yaml-rust = "0.4"
 zeroize = "1.8"
 data-encoding = "2.6"
 enum-iterator = "2.1"
+ed25519-dalek = "2.1"
 
 # Used by 'awskms' and 'gcpkms'
 futures = { version = "^0.3", optional = true }

diff --git a/src/bin/roughenough-client.rs b/src/bin/roughenough-client.rs
@@ -33,7 +33,7 @@ use ring::rand;
 use ring::rand::SecureRandom;
 use roughenough::key::LongTermKey;
 use roughenough::merkle::MerkleTree;
-use roughenough::sign::Verifier;
+use roughenough::sign::MsgVerifier;
 use roughenough::version::Version;
 use roughenough::{
     roughenough_version, Error, RtMessage, Tag, CERTIFICATE_CONTEXT, REQUEST_FRAMING_BYTES,
@@ -314,7 +314,7 @@ impl ResponseHandler {
     }
 
     fn validate_sig(&self, public_key: &[u8], sig: &[u8], data: &[u8]) -> bool {
-        let mut verifier = Verifier::new(public_key);
+        let mut verifier = MsgVerifier::new(public_key);
         verifier.update(data);
         verifier.verify(sig)
     }

diff --git a/src/key/longterm.rs b/src/key/longterm.rs
@@ -18,7 +18,7 @@
 
 use crate::key::OnlineKey;
 use crate::message::RtMessage;
-use crate::sign::Signer;
+use crate::sign::MsgSigner;
 use crate::tag::Tag;
 use crate::CERTIFICATE_CONTEXT;
 use ring::digest;
@@ -30,7 +30,7 @@ use std::fmt::Formatter;
 /// Represents the server's long-term identity.
 ///
 pub struct LongTermKey {
-    signer: Signer,
+    signer: MsgSigner,
     srv_value: Vec<u8>,
 }
 
@@ -43,8 +43,8 @@ impl LongTermKey {
     }
 
     pub fn new(seed: &[u8]) -> Self {
-        let signer = Signer::from_seed(seed);
-        let srv_value = LongTermKey::calc_srv_value(signer.public_key_bytes());
+        let signer = MsgSigner::from_seed(seed);
+        let srv_value = LongTermKey::calc_srv_value(&signer.public_key_bytes());
 
         LongTermKey {
             signer,
@@ -70,7 +70,7 @@ impl LongTermKey {
     }
 
     /// Return the public key for the provided seed
-    pub fn public_key(&self) -> &[u8] {
+    pub fn public_key(&self) -> Vec<u8> {
         self.signer.public_key_bytes()
     }
 

diff --git a/src/key/online.rs b/src/key/online.rs
@@ -19,7 +19,7 @@ use std::time::{SystemTime, UNIX_EPOCH};
 use byteorder::{LittleEndian, WriteBytesExt};
 
 use crate::message::RtMessage;
-use crate::sign::Signer;
+use crate::sign::MsgSigner;
 use crate::tag::Tag;
 use crate::version::Version;
 use crate::SIGNED_RESPONSE_CONTEXT;
@@ -28,7 +28,7 @@ use crate::SIGNED_RESPONSE_CONTEXT;
 /// Represents the delegated Roughtime ephemeral online key.
 ///
 pub struct OnlineKey {
-    signer: Signer,
+    signer: MsgSigner,
 }
 
 impl Default for OnlineKey {
@@ -40,7 +40,7 @@ impl Default for OnlineKey {
 impl OnlineKey {
     pub fn new() -> Self {
         OnlineKey {
-            signer: Signer::new(),
+            signer: MsgSigner::new(),
         }
     }
 
@@ -51,7 +51,7 @@ impl OnlineKey {
         let pub_key_bytes = self.signer.public_key_bytes();
 
         let mut dele_msg = RtMessage::with_capacity(3);
-        dele_msg.add_field(Tag::PUBK, pub_key_bytes).unwrap();
+        dele_msg.add_field(Tag::PUBK, &pub_key_bytes).unwrap();
         dele_msg.add_field(Tag::MINT, &zeros).unwrap();
         dele_msg.add_field(Tag::MAXT, &max).unwrap();
 

diff --git a/src/responder.rs b/src/responder.rs
@@ -25,13 +25,12 @@ use data_encoding::{Encoding, HEXLOWER_PERMISSIVE};
 use mio::net::UdpSocket;
 
 use crate::config::ServerConfig;
-use crate::error::Error::SendingResponseFailed;
 use crate::grease::Grease;
 use crate::key::{LongTermKey, OnlineKey};
 use crate::merkle::MerkleTree;
 use crate::stats::ServerStats;
 use crate::version::Version;
-use crate::{Error, RtMessage, Tag};
+use crate::{RtMessage, Tag};
 
 const HEX: Encoding = HEXLOWER_PERMISSIVE;
 
@@ -50,7 +49,7 @@ impl Responder {
     pub fn new(version: Version, config: &dyn ServerConfig, ltk: &mut LongTermKey) -> Responder {
         let online_key = OnlineKey::new();
         let cert_bytes = ltk.make_cert(&online_key).encode().expect("make_cert");
-        let long_term_public_key = HEX.encode(ltk.public_key());
+        let long_term_public_key = HEX.encode(&ltk.public_key());
         let requests = Vec::with_capacity(config.batch_size() as usize);
         let grease = Grease::new(config.fault_percentage());
         let thread_id = thread::current().name().unwrap().to_string();

diff --git a/src/sign.rs b/src/sign.rs
@@ -20,8 +20,8 @@ use std::fmt;
 use std::fmt::Formatter;
 
 use data_encoding::{Encoding, HEXLOWER_PERMISSIVE};
+use ed25519_dalek::{SigningKey, Signature, Verifier, Signer, VerifyingKey, SecretKey};
 use ring::rand::SecureRandom;
-use ring::signature::{self, Ed25519KeyPair, KeyPair};
 use ring::rand;
 
 const HEX: Encoding = HEXLOWER_PERMISSIVE;
@@ -30,58 +30,58 @@ const INITIAL_BUF_SIZE: usize = 1024;
 
 /// A multi-step (init-update-finish) interface for verifying an Ed25519 signature
 #[derive(Debug)]
-pub struct Verifier {
-    pubkey: Vec<u8>,
+pub struct MsgVerifier {
+    pubkey: VerifyingKey,
     buf: Vec<u8>,
 }
 
-impl Verifier {
+impl MsgVerifier {
     pub fn new(pubkey: &[u8]) -> Self {
-        Verifier {
-            pubkey: Vec::from(pubkey),
+        let pk: &[u8; 32] = pubkey.try_into().expect("valid pubkey");
+        MsgVerifier {
+            pubkey: VerifyingKey::from_bytes(pk).unwrap(),
             buf: Vec::with_capacity(INITIAL_BUF_SIZE),
         }
     }
 
     pub fn update(&mut self, data: &[u8]) {
-        self.buf.reserve(data.len());
         self.buf.extend_from_slice(data);
     }
 
-    pub fn verify(&self, expected_sig: &[u8]) -> bool {
-        let pk = signature::UnparsedPublicKey::new(&signature::ED25519, &self.pubkey);
-
-        match pk.verify(&self.buf, expected_sig) {
+    pub fn verify(&self, provided_sig: &[u8]) -> bool {
+        let sig = Signature::from_slice(provided_sig).expect("valid signature");
+        match self.pubkey.verify(&self.buf, &sig) {
             Ok(_) => true,
             _ => false,
         }
     }
 }
 
 /// A multi-step (init-update-finish) interface for creating an Ed25519 signature
-pub struct Signer {
-    key_pair: Ed25519KeyPair,
+pub struct MsgSigner {
+    signing_key: SigningKey,
     buf: Vec<u8>,
 }
 
-impl Default for Signer {
+impl Default for MsgSigner {
     fn default() -> Self {
         Self::new()
     }
 }
 
-impl Signer {
+impl MsgSigner {
     pub fn new() -> Self {
         let rng = rand::SystemRandom::new();
         let mut seed = [0u8; 32];
         rng.fill(&mut seed).unwrap();
 
-        Signer::from_seed(&seed)
+        MsgSigner::from_seed(&seed)
     }
 
     pub fn from_seed(seed: &[u8]) -> Self {
-        Signer {
-            key_pair: Ed25519KeyPair::from_seed_unchecked(seed).unwrap(),
+        let secret_key = SecretKey::try_from(seed).expect("invalid seed");
+        MsgSigner {
+            signing_key: SigningKey::from(secret_key),
             buf: Vec::with_capacity(INITIAL_BUF_SIZE),
         }
     }
@@ -92,29 +92,30 @@ impl Signer {
     }
 
     pub fn sign(&mut self) -> Vec<u8> {
-        let signature = self.key_pair.sign(&self.buf).as_ref().to_vec();
+        let signature = self.signing_key.sign(&self.buf).to_vec();
         self.buf.clear();
 
         signature
     }
 
-    pub fn public_key_bytes(&self) -> &[u8] {
-        self.key_pair.public_key().as_ref()
+    pub fn public_key_bytes(&self) -> Vec<u8> {
+        let binding = self.signing_key.verifying_key();
+        binding.as_bytes().to_vec()
     }
 }
 
-impl fmt::Display for Signer {
+impl fmt::Display for MsgSigner {
     fn fmt(&self, f: &mut Formatter) -> fmt::Result {
-        write!(f, "{}", HEX.encode(self.public_key_bytes()))
+        write!(f, "{}", HEX.encode(&self.public_key_bytes()))
     }
 }
 
-impl fmt::Debug for Signer {
+impl fmt::Debug for MsgSigner {
     fn fmt(&self, f: &mut Formatter) -> fmt::Result {
         write!(
             f,
             "Signer({}, {:?})",
-            HEX.encode(self.public_key_bytes()),
+            HEX.encode(&self.public_key_bytes()),
             self.buf
         )
     }
@@ -135,7 +136,7 @@ mod test {
             "e5564300c360ac729086e2cc806e828a84877f1eb8e5d974d873e065224901555fb8821590a33bacc61e39701cf9b46bd25bf5f0595bbe24655141438e7a100b".as_ref()
         ).unwrap();
 
-        let v = Verifier::new(&pubkey);
+        let v = MsgVerifier::new(&pubkey);
         let result = v.verify(&signature);
         assert_eq!(result, true);
     }
@@ -152,7 +153,7 @@ mod test {
             "124f6fc6b0d100842769e71bd530664d888df8507df6c56dedfdb509aeb93416e26b918d38aa06305df3095697c18b2aa832eaa52edc0ae49fbae5a85e150c07".as_ref()
         ).unwrap();
 
-        let mut v = Verifier::new(&pubkey);
+        let mut v = MsgVerifier::new(&pubkey);
         v.update(&message);
         let result = v.verify(&signature);
         assert_eq!(result, true);
@@ -167,7 +168,7 @@ mod test {
             "e5564300c360ac729086e2cc806e828a84877f1eb8e5d974d873e065224901555fb8821590a33bacc61e39701cf9b46bd25bf5f0595bbe24655141438e7a100b".as_ref()
         ).unwrap();
 
-        let mut s = Signer::from_seed(&seed);
+        let mut s = MsgSigner::from_seed(&seed);
         let sig = s.sign();
         assert_eq!(sig, expected_sig);
     }
@@ -183,7 +184,7 @@ mod test {
             "d9868d52c2bebce5f3fa5a79891970f309cb6591e3e1702a70276fa97c24b3a8e58606c38c9758529da50ee31b8219cba45271c689afa60b0ea26c99db19b00c".as_ref()
         ).unwrap();
 
-        let mut s = Signer::from_seed(&seed);
+        let mut s = MsgSigner::from_seed(&seed);
         s.update(&message);
         let sig = s.sign();
         assert_eq!(sig, expected_sig);
@@ -196,11 +197,11 @@ mod test {
 
         let message = "Hello world".as_bytes();
 
-        let mut signer = Signer::from_seed(&seed);
+        let mut signer = MsgSigner::from_seed(&seed);
         signer.update(&message);
         let signature = signer.sign();
 
-        let mut v = Verifier::new(signer.public_key_bytes());
+        let mut v = MsgVerifier::new(&signer.public_key_bytes());
         v.update(&message);
         let result = v.verify(&signature);