feat(verkle): implement CRS

verkle/Cargo.toml

@@ -6,3 +6,14 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+ark-ec = "0.4.2"
+ark-ed-on-bls12-381-bandersnatch = "0.4.0"
+ark-ff = "0.4.2"
+ark-serialize = "0.4.2"
+banderwagon = { git = "https://github.com/crate-crypto/rust-verkle.git", rev = "7688f0aedfb147d3d391abfe8495e46c46d72ce0" }
+derive_more = "0.99.17"
+once_cell = "1.19.0"
+sha2 = "0.10.8"
+
+[dev-dependencies]
+hex = "0.4.3"

verkle/src/crs.rs

@@ -0,0 +1,88 @@
+use banderwagon::Element;
+use derive_more::{AsRef, Deref, Index};
+use once_cell::sync::Lazy;
+use sha2::{Digest, Sha256};
+
+const BASIS_LENGTH: usize = 256;
+
+const PEDERSEN_SEED: &[u8] = b"eth_verkle_oct_2021";
+
+pub static CRS: Lazy<Basis> = Lazy::new(Basis::new);
+
+#[derive(AsRef, Deref, Index)]
+pub struct Basis([Element; BASIS_LENGTH]);
+
+impl Basis {
+    fn new() -> Self {
+        let mut generated_elements = 0;
+        let mut elements = [Element::zero(); BASIS_LENGTH];
+
+        for i in 0u64.. {
+            if generated_elements == elements.len() {
+                break;
+            }
+
+            let mut hasher = Sha256::new();
+            hasher.update(PEDERSEN_SEED);
+            hasher.update(i.to_be_bytes());
+
+            if let Some(p) = banderwagon::try_reduce_to_element(&hasher.finalize()) {
+                elements[generated_elements] = p;
+                generated_elements += 1;
+            }
+        }
+
+        Self(elements)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use ark_serialize::Valid;
+    use banderwagon::CanonicalSerialize;
+
+    use super::*;
+
+    // Taken from:
+    // https://github.com/crate-crypto/go-ipa/blob/b1e8a79f509c5dd26b44d64c5f4aff67d7e69ed0/ipa/ipa_test.go#L210
+
+    const FIRST_POINT: &str = "01587ad1336675eb912550ec2a28eb8923b824b490dd2ba82e48f14590a298a0";
+    const LAST_POINT: &str = "3de2be346b539395b0c0de56a5ccca54a317f1b5c80107b0802af9a62276a4d8";
+    const ALL_POINTS_SHA: &str = "1fcaea10bf24f750200e06fa473c76ff0468007291fa548e2d99f09ba9256fdb";
+
+    #[test]
+    fn first_point() {
+        let mut bytes = vec![];
+        CRS[0].serialize_compressed(&mut bytes).unwrap();
+        assert_eq!(hex::encode(bytes), FIRST_POINT);
+    }
+
+    #[test]
+    fn last_point() {
+        let mut bytes = vec![];
+        CRS[255].serialize_compressed(&mut bytes).unwrap();
+        assert_eq!(hex::encode(bytes), LAST_POINT);
+    }
+
+    #[test]
+    fn all_points_hash() {
+        let mut hasher = Sha256::new();
+        for p in CRS.iter() {
+            let mut bytes = vec![];
+            p.serialize_compressed(&mut bytes).unwrap();
+            hasher.update(bytes);
+        }
+
+        assert_eq!(hex::encode(hasher.finalize()), ALL_POINTS_SHA);
+    }
+
+    #[test]
+    fn valid() {
+        for (i, p) in CRS.iter().enumerate() {
+            assert!(
+                p.check().is_ok(),
+                "point {p:?} at index {i} should be valid"
+            );
+        }
+    }
+}

verkle/src/lib.rs

@@ -1 +1 @@
-pub struct Verkle {}
+pub mod crs;