export more, benchmarks

.idea/diffie-hellman.iml

@@ -2,8 +2,10 @@
 <module type="EMPTY_MODULE" version="4">
   <component name="NewModuleRootManager">
     <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$/bench/src" isTestSource="false" />
       <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
       <sourceFolder url="file://$MODULE_DIR$/tests" isTestSource="true" />
+      <excludeFolder url="file://$MODULE_DIR$/bench/target" />
       <excludeFolder url="file://$MODULE_DIR$/target" />
     </content>
     <orderEntry type="inheritedJdk" />

bench/rust-toolchain.toml

@@ -0,0 +1,2 @@
+[toolchain]
+channel = "nightly"

bench/src/lib.rs

@@ -0,0 +1,64 @@
+#![feature(test)]
+extern crate test;
+
+mod benches {
+    use test::{black_box, Bencher};
+    use diffie_hellman::{clamp_u256, Public, Secret, CURVE_25519, U256};
+
+    #[bench]
+    fn diffie_hellman(b: &mut Bencher) {
+        let a = Secret::from(U256::from_u32(123456789));
+        let p = Public::from(&Secret::from(U256::from_u64(987654321)));
+
+        b.iter(|| {
+            black_box(a.diffie_hellman(&p));
+        })
+    }
+
+    #[bench]
+    fn public_key_derivation(b: &mut Bencher) {
+        let a = Secret::from(U256::from_u32(123456789));
+
+        b.iter(|| {
+            black_box(Public::from(&a))
+        })
+    }
+
+    #[bench]
+    fn montgomery_point_add(b: &mut Bencher) {
+        let p = CURVE_25519.point(U256::from_u32(123456789));
+        let q = p.double();
+
+        b.iter(|| {
+            black_box(p.add(q, p))
+        })
+    }
+
+    #[bench]
+    fn montgomery_point_double(b: &mut Bencher) {
+        let p = CURVE_25519.point(U256::from_u32(123456789));
+
+        b.iter(|| {
+            black_box(p.double())
+        })
+    }
+
+    #[bench]
+    fn montgomery_ladder(b: &mut Bencher) {
+        let p = CURVE_25519.point(U256::from_u32(123456789));
+
+        b.iter(|| {
+            black_box(p.ladder(clamp_u256(U256::from_u64(987654321))))
+        })
+    }
+
+    #[bench]
+    fn constant_time_montgomery_ladder(b: &mut Bencher) {
+        let p = CURVE_25519.point(U256::from_u32(123456789));
+
+        b.iter(|| {
+            black_box(p.ct_ladder(clamp_u256(U256::from_u64(987654321))))
+        })
+    }
+}
+

src/lib.rs

@@ -1,4 +1,4 @@
-use crypto_bigint::{ConstChoice, Encoding, NonZero, U256};
+pub use crypto_bigint::{ConstChoice, Encoding, NonZero, U256};
 use std::fmt::{Display, Formatter};
 use std::ops::{Div, Mul};
 
@@ -31,7 +31,7 @@ impl MontgomeryCurve {
     }
 }
 
-fn clamp_u256(x: U256) -> U256 {
+pub fn clamp_u256(x: U256) -> U256 {
     let mut bytes: [u8; 32] = x.to_le_bytes();
 
     // clamp value