From 67a8e705a7858f7d26434d6ac471a7c88105e193 Mon Sep 17 00:00:00 2001
From: Pierre Krieger <pierre.krieger1708@gmail.com>
Date: Tue, 15 Jan 2019 17:14:58 +0100
Subject: [PATCH] Cache the secp256k1 object in secio (#856)

* Cache the secp256k1 object in secio

* Fix feature flag disabled
---
 protocols/secio/Cargo.toml       |  4 ++--
 protocols/secio/src/handshake.rs |  8 ++++----
 protocols/secio/src/lib.rs       | 10 ++++++++--
 3 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/protocols/secio/Cargo.toml b/protocols/secio/Cargo.toml
index 33b3f527..6ef8b0f8 100644
--- a/protocols/secio/Cargo.toml
+++ b/protocols/secio/Cargo.toml
@@ -22,7 +22,7 @@ aes-ctr = "0.1.0"
 aesni = { version = "0.4.1", features = ["nocheck"], optional = true }
 twofish = "0.1.0"
 ctr = "0.1"
-lazy_static = { version = "1.2.0", optional = true }
+lazy_static = "1.2.0"
 rw-stream-sink = { version = "0.1.0", path = "../../misc/rw-stream-sink" }
 tokio-io = "0.1.0"
 sha2 = "0.7.1"
@@ -39,7 +39,7 @@ stdweb = { version = "0.4", default-features = false }
 [features]
 default = ["rsa", "secp256k1"]
 rsa = ["ring/rsa_signing"]
-aes-all = ["aesni", "lazy_static"]
+aes-all = ["aesni"]
 
 [dev-dependencies]
 criterion = "0.2"
diff --git a/protocols/secio/src/handshake.rs b/protocols/secio/src/handshake.rs
index 2411781e..46ad1e2c 100644
--- a/protocols/secio/src/handshake.rs
+++ b/protocols/secio/src/handshake.rs
@@ -49,6 +49,8 @@ use tokio_io::{AsyncRead, AsyncWrite};
 #[cfg(all(feature = "ring", not(any(target_os = "emscripten", target_os = "unknown"))))]
 use untrusted::Input as UntrustedInput;
 use crate::{KeyAgreement, SecioConfig, SecioKeyPairInner};
+#[cfg(feature = "secp256k1")]
+use crate::SECP256K1;
 
 // This struct contains the whole context of a handshake, and is filled progressively
 // throughout the various parts of the handshake.
@@ -398,8 +400,7 @@ where
                             let data_to_sign = Sha256::digest(&data_to_sign);
                             let message = secp256k1::Message::from_slice(data_to_sign.as_ref())
                                 .expect("digest output length doesn't match secp256k1 input length");
-                            let secp256k1 = secp256k1::Secp256k1::signing_only();
-                            secp256k1
+                            SECP256K1
                                 .sign(&message, private)
                                 .serialize_der()
                         },
@@ -491,11 +492,10 @@ where
                     let data_to_verify = Sha256::digest(&data_to_verify);
                     let message = secp256k1::Message::from_slice(data_to_verify.as_ref())
                         .expect("digest output length doesn't match secp256k1 input length");
-                    let secp256k1 = secp256k1::Secp256k1::verification_only();
                     let signature = secp256k1::Signature::from_der(remote_exch.get_signature());
                     let remote_public_key = secp256k1::key::PublicKey::from_slice(remote_public_key);
                     if let (Ok(signature), Ok(remote_public_key)) = (signature, remote_public_key) {
-                        match secp256k1.verify(&message, &signature, &remote_public_key) {
+                        match SECP256K1.verify(&message, &signature, &remote_public_key) {
                             Ok(()) => (),
                             Err(_) => {
                                 debug!("failed to verify the remote's signature");
diff --git a/protocols/secio/src/lib.rs b/protocols/secio/src/lib.rs
index 8b2f5c8d..21ec9bc2 100644
--- a/protocols/secio/src/lib.rs
+++ b/protocols/secio/src/lib.rs
@@ -90,6 +90,7 @@ use bytes::BytesMut;
 use ed25519_dalek::Keypair as Ed25519KeyPair;
 use futures::stream::MapErr as StreamMapErr;
 use futures::{Future, Poll, Sink, StartSend, Stream};
+use lazy_static::lazy_static;
 use libp2p_core::{PeerId, PublicKey, upgrade::{UpgradeInfo, InboundUpgrade, OutboundUpgrade}};
 use log::debug;
 #[cfg(all(feature = "rsa", not(any(target_os = "emscripten", target_os = "unknown"))))]
@@ -115,6 +116,12 @@ pub use crate::algo_support::Digest;
 pub use crate::exchange::KeyAgreement;
 pub use crate::stream_cipher::Cipher;
 
+// Cached `Secp256k1` context, to avoid recreating it every time.
+#[cfg(feature = "secp256k1")]
+lazy_static! {
+    static ref SECP256K1: secp256k1::Secp256k1<secp256k1::All> = secp256k1::Secp256k1::new();
+}
+
 /// Implementation of the `ConnectionUpgrade` trait of `libp2p_core`. Automatically applies
 /// secio on any connection.
 #[derive(Clone)]
@@ -288,8 +295,7 @@ impl SecioKeyPair {
             }
             #[cfg(feature = "secp256k1")]
             SecioKeyPairInner::Secp256k1 { ref private } => {
-                let secp = secp256k1::Secp256k1::signing_only();
-                let pubkey = secp256k1::key::PublicKey::from_secret_key(&secp, private);
+                let pubkey = secp256k1::key::PublicKey::from_secret_key(&SECP256K1, private);
                 PublicKey::Secp256k1(pubkey.serialize().to_vec())
             }
         }