Merge pull request #829 from zcash/sinsemilla-primitive

Move Sinsemilla primitive impl into `sinsemilla` crate

halo2_gadgets/Cargo.toml

@@ -31,6 +31,7 @@ lazy_static = "1"
 pasta_curves = "0.5"
 proptest = { version = "1.0.0", optional = true }
 rand = "0.8"
+sinsemilla = "0.1"
 subtle = "2.3"
 uint = "0.9.2" # MSRV 1.56.1
 
@@ -40,6 +41,7 @@ plotters = { version = "0.3.0", default-features = false, optional = true }
 [dev-dependencies]
 criterion = "0.3"
 proptest = "1.0.0"
+sinsemilla = { version = "0.1", features = ["test-dependencies"] }
 
 [target.'cfg(unix)'.dev-dependencies]
 inferno = ">=0.11, <0.11.5" # MSRV 1.59
@@ -56,7 +58,10 @@ test-dev-graph = [
     "plotters/bitmap_encoder",
     "plotters/ttf",
 ]
-test-dependencies = ["proptest"]
+test-dependencies = [
+    "proptest",
+    "sinsemilla/test-dependencies",
+]
 
 # In-development features
 # See https://zcash.github.io/halo2/dev/features.html

halo2_gadgets/src/sinsemilla.rs

@@ -16,7 +16,8 @@ use std::fmt::Debug;
 pub mod chip;
 pub mod merkle;
 mod message;
-pub mod primitives;
+
+pub use ::sinsemilla as primitives;
 
 /// The set of circuit instructions required to use the [`Sinsemilla`](https://zcash.github.io/halo2/design/gadgets/sinsemilla.html) gadget.
 /// This trait is bounded on two constant parameters: `K`, the number of bits

halo2_gadgets/src/sinsemilla/chip/hash_to_point.rs

@@ -147,7 +147,11 @@ where
                         .collect();
 
                     let hasher_S = pallas::Point::hash_to_curve(S_PERSONALIZATION);
-                    let S = |chunk: &[bool]| hasher_S(&lebs2ip_k(chunk).to_le_bytes());
+                    let S = |chunk: &[bool]| {
+                        hasher_S(
+                            &lebs2ip_k(chunk.try_into().expect("correct length")).to_le_bytes(),
+                        )
+                    };
 
                     // We can use complete addition here because it differs from
                     // incomplete addition with negligible probability.
@@ -249,6 +253,7 @@ where
         let words: Value<Vec<u32>> = bitstring.map(|bitstring| {
             bitstring
                 .chunks_exact(sinsemilla::K)
+                .map(|chunk| chunk.try_into().expect("correct length"))
                 .map(lebs2ip_k)
                 .collect()
         });

halo2_gadgets/src/sinsemilla/merkle.rs

@@ -322,7 +322,6 @@ pub mod tests {
                                     (sibling, &node)
                                 };
 
-                                use crate::sinsemilla::primitives as sinsemilla;
                                 let merkle_crh =
                                     sinsemilla::HashDomain::from_Q(TestHashDomain.Q().into());