feat: hashes

Author: olehmisar

Nargo.toml

@@ -4,3 +4,4 @@ type = "lib"
 authors = ["Oleh Misarosh <olehmisar@gmail.com>"]
 
 [dependencies]
+sha256 = { tag = "v0.1.0", git = "https://github.com/noir-lang/sha256" }

README.md

@@ -7,7 +7,7 @@ Nodash is a utility library for [Noir](https://github.com/noir-lang/noir) langua
 Put this into your Nargo.toml.
 
 ```toml
-nodash = { git = "https://github.com/olehmisar/nodash/", tag = "v0.39.4" }
+nodash = { git = "https://github.com/olehmisar/nodash/", tag = "v0.39.5" }
 ```
 
 ## Docs
@@ -46,6 +46,53 @@ use nodash::div_ceil;
 assert(div_ceil(10 as u64, 3) == 4);
 ```
 
+### Hashes
+
+Hash functions can either accept a `[T; N]` or a `BoundedVec<T, N>` (if technically possible).
+
+#### `poseidon2`
+
+```rs
+use nodash::poseidon2;
+
+// hashes the whole array
+let hash = poseidon2([10, 20]);
+// hashes elements up to the length (in this case, 2)
+let hash = poseidon2(BoundedVec::from_parts([10, 20, 0], 2));
+```
+
+#### `pedersen`
+
+```rs
+use nodash::pedersen;
+
+let hash = pedersen([10, 20]);
+```
+
+#### `sha256`
+
+sha256 is expensive to compute in Noir, so use [poseidon2](#poseidon2) where possible.
+
+```rs
+use nodash::sha256;
+
+let hash = sha256([10, 20]);
+// or
+let hash = sha256(BoundedVec::from_parts([10, 20, 0], 2));
+```
+
+#### `keccak256`
+
+keccak256 is expensive to compute in Noir, so use [poseidon2](#poseidon2) where possible.
+
+```rs
+use nodash::keccak256;
+
+let hash = keccak256([10, 20]);
+// or
+let hash = keccak256(BoundedVec::from_parts([10, 20, 0], 2));
+```
+
 ### `solidity::encode_with_selector`
 
 Equivalent to `abi.encodeWithSelector` in Solidity.

src/hash.nr

@@ -0,0 +1,86 @@
+pub fn poseidon2<let N: u32>(input: impl ArrayOrBoundedVec<Field, N>) -> Field {
+    let input = input.as_bounded_vec();
+    std::hash::poseidon2::Poseidon2::hash(input.storage(), input.len())
+}
+
+// TODO: is it possible for pedersen to accept BoundedVec?
+pub fn pedersen<let N: u32>(input: [Field; N]) -> Field {
+    std::hash::pedersen_hash(input)
+}
+
+pub fn sha256<let N: u32>(input: impl ArrayOrBoundedVec<u8, N>) -> [u8; 32] {
+    let input = input.as_bounded_vec();
+    dep::sha256::sha256_var(input.storage(), input.len() as u64)
+}
+
+pub fn keccak256<let N: u32>(input: impl ArrayOrBoundedVec<u8, N>) -> [u8; 32] {
+    let input = input.as_bounded_vec();
+    std::hash::keccak256(input.storage(), input.len())
+}
+
+/// Needed because of https://github.com/noir-lang/noir/issues/7054
+trait ArrayOrBoundedVec<T, let N: u32> {
+    fn as_bounded_vec(self) -> BoundedVec<T, N>;
+}
+
+impl<T, let N: u32> ArrayOrBoundedVec<T, N> for [T; N] {
+    fn as_bounded_vec(self) -> BoundedVec<T, N> {
+        BoundedVec::from(self)
+    }
+}
+
+impl<T, let N: u32> ArrayOrBoundedVec<T, N> for BoundedVec<T, N> {
+    fn as_bounded_vec(self) -> BoundedVec<T, N> {
+        self
+    }
+}
+
+mod tests {
+    use crate::hash::{keccak256, pedersen, poseidon2, sha256};
+
+    global FIELD_INPUT_ARR: [Field; 2] = [1, 2];
+    global FIELD_INPUT_VEC: BoundedVec<Field, 2> = BoundedVec::from(FIELD_INPUT_ARR);
+    global FIELD_INPUT_VEC_LONGER: BoundedVec<Field, 3> = BoundedVec::from(FIELD_INPUT_ARR);
+
+    global U8_INPUT_ARR: [u8; 2] = [1, 2];
+    global U8_INPUT_VEC: BoundedVec<u8, 2> = BoundedVec::from(U8_INPUT_ARR);
+    global U8_INPUT_VEC_LONGER: BoundedVec<u8, 3> = BoundedVec::from(U8_INPUT_ARR);
+
+    #[test]
+    fn test_equivalence() {
+        assert(
+            (poseidon2(FIELD_INPUT_ARR) == poseidon2(FIELD_INPUT_VEC)),
+            // TODO: is this a bug? https://discord.com/channels/1113924620781883405/1333383938198212659
+            // & (poseidon2(FIELD_INPUT_ARR) == poseidon2(FIELD_INPUT_VEC_LONGER)),
+        );
+        assert(
+            (sha256(U8_INPUT_VEC) == sha256(U8_INPUT_ARR))
+                & (sha256(U8_INPUT_VEC_LONGER) == sha256(U8_INPUT_ARR)),
+        );
+        assert(
+            (keccak256(U8_INPUT_VEC) == keccak256(U8_INPUT_ARR))
+                & (keccak256(U8_INPUT_VEC_LONGER) == keccak256(U8_INPUT_ARR)),
+        );
+    }
+
+    #[test]
+    fn test_against_std() {
+        assert(
+            poseidon2(FIELD_INPUT_ARR)
+                == std::hash::poseidon2::Poseidon2::hash(FIELD_INPUT_ARR, FIELD_INPUT_ARR.len()),
+        );
+        assert(
+            poseidon2(FIELD_INPUT_VEC_LONGER)
+                == std::hash::poseidon2::Poseidon2::hash(
+                    FIELD_INPUT_VEC_LONGER.storage(),
+                    FIELD_INPUT_VEC_LONGER.len(),
+                ),
+        );
+        assert(pedersen(FIELD_INPUT_ARR) == std::hash::pedersen_hash(FIELD_INPUT_ARR));
+        assert(
+            sha256(U8_INPUT_ARR)
+                == dep::sha256::sha256_var(U8_INPUT_ARR, U8_INPUT_ARR.len() as u64),
+        );
+        assert(keccak256(U8_INPUT_ARR) == std::hash::keccak256(U8_INPUT_ARR, U8_INPUT_ARR.len()));
+    }
+}

src/lib.nr

@@ -1,10 +1,12 @@
+mod hash;
 mod math;
 mod solidity;
 mod string;
 mod tables;
 mod array;
 
 pub use array::pack_bytes;
+pub use hash::{keccak256, pedersen, poseidon2, sha256};
 pub use math::{clamp, div_ceil, sqrt::sqrt};
 pub use string::{field_to_hex, ord, str_to_u64, to_hex_string_bytes};