Merge branch 'release/0.9.3'

CONTRIBUTING.md

@@ -0,0 +1,28 @@
+# Contributing to curve25519-dalek
+
+If you have questions or comments, please feel free to email the
+authors. 
+
+For feature requests, suggestions, and bug reports, please open an issue on
+[our Github](https://github.com/isislovecruft/curve25519-dalek).  (Or, send us
+an email if you're opposed to using Github for whatever reason.)
+
+Patches are welcomed as pull requests on
+[our Github](https://github.com/isislovecruft/curve25519-dalek), as well as by
+email (preferably sent to all of the authors listed in `Cargo.toml`).
+
+All issues on curve25519-dalek are mentored, if you want help with a bug just
+ask @isislovecruft or @hdevalence.
+
+Some issues are easier than others. The `easy` label can be used to find the
+easy issues. If you want to work on an issue, please leave a comment so that we
+can assign it to you!
+
+# Code of Conduct
+
+We follow the [Rust Code of Conduct](http://www.rust-lang.org/conduct.html),
+with the following additional clauses:
+
+* We respect the rights to privacy and anonymity for contributors and people in
+  the community.  If someone wishes to contribute under a pseudonym different to
+  their primary identity, that wish is to be respected by all contributors.

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "curve25519-dalek"
-version = "0.9.2"
+version = "0.9.3"
 authors = ["Isis Lovecruft <isis@patternsinthevoid.net>",
            "Henry de Valence <hdevalence@hdevalence.ca>"]
 readme = "README.md"

README.md

@@ -1,5 +1,5 @@
 
-# curve25519-dalek  [![](https://img.shields.io/crates/v/curve25519-dalek.svg)](https://crates.io/curve25519-dalek) [![](https://docs.rs/curve25519-dalek/badge.svg)](https://docs.rs/curve25519-dalek) [![](https://travis-ci.org/isislovecruft/curve25519-dalek.svg?branch=master)](https://travis-ci.org/isislovecruft/curve25519-dalek)
+# curve25519-dalek  [![](https://img.shields.io/crates/v/curve25519-dalek.svg)](https://crates.io/crates/curve25519-dalek) [![](https://docs.rs/curve25519-dalek/badge.svg)](https://docs.rs/curve25519-dalek) [![](https://travis-ci.org/isislovecruft/curve25519-dalek.svg?branch=master)](https://travis-ci.org/isislovecruft/curve25519-dalek)
 
 **A low-level cryptographic library for point, group, field, and scalar
 operations on a curve isomorphic to the twisted Edwards curve defined by -x²+y²

src/field.rs

@@ -202,12 +202,18 @@ impl<'a, 'b> Mul<&'b FieldElement> for &'a FieldElement {
         let a: &[u64; 5] = &self.0;
         let b: &[u64; 5] = &_rhs.0;
 
+        // 64-bit precomputations
+        let b1_19 = b[1] * 19;
+        let b2_19 = b[2] * 19;
+        let b3_19 = b[3] * 19;
+        let b4_19 = b[4] * 19;
+
         // Multiply to get 128-bit coefficients of output
-        let     c0: u128 = m(a[0],b[0]) + ( m(a[4],b[1]) +   m(a[3],b[2]) +   m(a[2],b[3]) +   m(a[1],b[4]) )*19;
-        let mut c1: u128 = m(a[1],b[0]) +   m(a[0],b[1]) + ( m(a[4],b[2]) +   m(a[3],b[3]) +   m(a[2],b[4]) )*19;
-        let mut c2: u128 = m(a[2],b[0]) +   m(a[1],b[1]) +   m(a[0],b[2]) + ( m(a[4],b[3]) +   m(a[3],b[4]) )*19;
-        let mut c3: u128 = m(a[3],b[0]) +   m(a[2],b[1]) +   m(a[1],b[2]) +   m(a[0],b[3]) + ( m(a[4],b[4]) )*19;
-        let mut c4: u128 = m(a[4],b[0]) +   m(a[3],b[1]) +   m(a[2],b[2]) +   m(a[1],b[3]) +   m(a[0],b[4]);
+        let     c0: u128 = m(a[0],b[0]) + m(a[4],b1_19) + m(a[3],b2_19) + m(a[2],b3_19) + m(a[1],b4_19);
+        let mut c1: u128 = m(a[1],b[0]) + m(a[0],b[1])  + m(a[4],b2_19) + m(a[3],b3_19) + m(a[2],b4_19);
+        let mut c2: u128 = m(a[2],b[0]) + m(a[1],b[1])  + m(a[0],b[2])  + m(a[4],b3_19) + m(a[3],b4_19);
+        let mut c3: u128 = m(a[3],b[0]) + m(a[2],b[1])  + m(a[1],b[2])  + m(a[0],b[3])  + m(a[4],b4_19);
+        let mut c4: u128 = m(a[4],b[0]) + m(a[3],b[1])  + m(a[2],b[2])  + m(a[1],b[3])  + m(a[0],b[4]);
 
         // Now c[i] < 2^2b * (1+i + (4-i)*19) < 2^(2b + lg(1+4*19)) < 2^(2b + 6.27)
         // where b is the bitlength of the input limbs.