add test vectors & fix nits

crypto/src/hash/mod.rs

@@ -1,7 +1,7 @@
 use crate::{ElementHasher, HashFn};
 
 mod rpo;
-pub use rpo::Rpo as Hasher;
+pub use rpo::Rpo256 as Hasher;
 
 // TYPE ALIASES
 // ================================================================================================

crypto/src/hash/rpo/mds_freq.rs

@@ -156,7 +156,7 @@ fn block3(x: [i64; 3], y: [i64; 3]) -> [i64; 3] {
 
 #[cfg(test)]
 mod tests {
-    use super::super::Rpo;
+    use super::super::Rpo256;
     use crate::hash::rpo::MDS;
     use proptest::prelude::*;
     use winterfell::math::{fields::f64::BaseElement, FieldElement};
@@ -187,7 +187,7 @@ mod tests {
             v2 = v1.clone();
 
             apply_mds_naive(&mut v1);
-            Rpo::apply_mds(&mut v2);
+            Rpo256::apply_mds(&mut v2);
 
             prop_assert_eq!(v1, v2);
         }

crypto/src/hash/rpo/mod.rs

@@ -50,10 +50,10 @@ const INV_ALPHA: u64 = 10540996611094048183;
 // HASHER IMPLEMENTATION
 // ================================================================================================
 
-/// Implementation of [Hasher] trait for Rescue Prime Optimized (RPO) hash function with 256-bit output.
+/// Implementation of [Hasher] trait for Rescue Prime Optimized (Rpo256) hash function with 256-bit output.
 ///
 /// The hash function is implemented according to the Rescue Prime Optimized
-/// [specifications](https://github.org/aszepieniec/rpo/)
+/// [specifications](https://github.com/ASDiscreteMathematics/rpo)
 ///
 /// The parameters used to instantiate the function are:
 /// * Field: 64-bit prime field with modulus 2^64 - 2^32 + 1.
@@ -66,29 +66,29 @@ const INV_ALPHA: u64 = 10540996611094048183;
 /// and it can be serialized into 32 bytes (256 bits).
 ///
 /// ## Hash output consistency
-/// Functions [hash_elements()](Rpo::hash_elements), [merge()](Rpo::merge), and
-/// [merge_with_int()](Rpo::merge_with_int) are internally consistent. That is, computing
+/// Functions [hash_elements()](Rpo256::hash_elements), [merge()](Rpo256::merge), and
+/// [merge_with_int()](Rpo256::merge_with_int) are internally consistent. That is, computing
 /// a hash for the same set of elements using these functions will always produce the same
-/// result. For example, merging two digests using [merge()](Rpo::merge) will produce the
+/// result. For example, merging two digests using [merge()](Rpo256::merge) will produce the
 /// same result as hashing 8 elements which make up these digests using
-/// [hash_elements()](Rpo::hash_elements) function.
+/// [hash_elements()](Rpo256::hash_elements) function.
 ///
-/// However, [hash()](Rpo::hash) function is not consistent with functions mentioned above.
+/// However, [hash()](Rpo256::hash) function is not consistent with functions mentioned above.
 /// For example, if we take two field elements, serialize them to bytes and hash them using
-/// [hash()](Rpo::hash), the result will differ from the result obtained by hashing these
-/// elements directly using [hash_elements()](Rpo::hash_elements) function. The reason for
-/// this difference is that [hash()](Rpo::hash) function needs to be able to handle
+/// [hash()](Rpo256::hash), the result will differ from the result obtained by hashing these
+/// elements directly using [hash_elements()](Rpo256::hash_elements) function. The reason for
+/// this difference is that [hash()](Rpo256::hash) function needs to be able to handle
 /// arbitrary binary strings, which may or may not encode valid field elements - and thus,
 /// deserialization procedure used by this function is different from the procedure used to
 /// deserialize valid field elements.
 ///
 /// Thus, if the underlying data consists of valid field elements, it might make more sense
 /// to deserialize them into field elements and then hash them using
-/// [hash_elements()](Rpo::hash_elements) function rather then hashing the serialized bytes
-/// using [hash()](Rpo::hash) function.
-pub struct Rpo();
+/// [hash_elements()](Rpo256::hash_elements) function rather then hashing the serialized bytes
+/// using [hash()](Rpo256::hash) function.
+pub struct Rpo256();
 
-impl HashFn for Rpo {
+impl HashFn for Rpo256 {
     type Digest = RpoDigest256;
 
     fn hash(bytes: &[u8]) -> Self::Digest {
@@ -188,7 +188,7 @@ impl HashFn for Rpo {
     }
 }
 
-impl ElementHasher for Rpo {
+impl ElementHasher for Rpo256 {
     type BaseField = Felt;
 
     fn hash_elements<E: FieldElement<BaseField = Self::BaseField>>(elements: &[E]) -> Self::Digest {
@@ -237,7 +237,7 @@ impl ElementHasher for Rpo {
 // HASH FUNCTION IMPLEMENTATION
 // ================================================================================================
 
-impl Rpo {
+impl Rpo256 {
     // RESCUE PERMUTATION
     // --------------------------------------------------------------------------------------------
 
@@ -718,7 +718,7 @@ const INV_MDS: [[Felt; STATE_WIDTH]; STATE_WIDTH] = [
 // ================================================================================================
 
 /// Rescue round constants;
-/// computed as in section ?? from [specifications](https://github.org/aszepieniec/rpo/)
+/// computed as in [specifications](https://github.com/ASDiscreteMathematics/rpo)
 ///
 /// The constants are broken up into two arrays ARK1 and ARK2; ARK1 contains the constants for the
 /// first half of RPO round, and ARK2 contains constants for the second half of RPO round.

crypto/src/hash/rpo/tests.rs

@@ -1,5 +1,5 @@
 use super::{
-    ElementHasher, Felt, FieldElement, HashFn, Rpo, RpoDigest256, StarkField, ALPHA, INV_ALPHA,
+    ElementHasher, Felt, FieldElement, HashFn, Rpo256, RpoDigest256, StarkField, ALPHA, INV_ALPHA,
     INV_MDS, MDS, STATE_WIDTH, ZERO,
 };
 use core::convert::TryInto;
@@ -41,7 +41,7 @@ fn test_sbox() {
     expected.iter_mut().for_each(|v| *v = v.exp(ALPHA));
 
     let mut actual = state;
-    Rpo::apply_sbox(&mut actual);
+    Rpo256::apply_sbox(&mut actual);
 
     assert_eq!(expected, actual);
 }
@@ -54,7 +54,7 @@ fn test_inv_sbox() {
     expected.iter_mut().for_each(|v| *v = v.exp(INV_ALPHA));
 
     let mut actual = state;
-    Rpo::apply_inv_sbox(&mut actual);
+    Rpo256::apply_inv_sbox(&mut actual);
 
     assert_eq!(expected, actual);
 }
@@ -68,8 +68,8 @@ fn hash_elements_vs_merge() {
         RpoDigest256::new(elements[4..].try_into().unwrap()),
     ];
 
-    let m_result = Rpo::merge(&digests);
-    let h_result = Rpo::hash_elements(&elements);
+    let m_result = Rpo256::merge(&digests);
+    let h_result = Rpo256::hash_elements(&elements);
     assert_eq!(m_result, h_result);
 }
 
@@ -80,22 +80,22 @@ fn hash_elements_vs_merge_with_int() {
 
     // ----- value fits into a field element ------------------------------------------------------
     let val: Felt = Felt::new(rand_value());
-    let m_result = Rpo::merge_with_int(seed, val.as_int());
+    let m_result = Rpo256::merge_with_int(seed, val.as_int());
 
     let mut elements = seed.as_elements().to_vec();
     elements.push(val);
-    let h_result = Rpo::hash_elements(&elements);
+    let h_result = Rpo256::hash_elements(&elements);
 
     assert_eq!(m_result, h_result);
 
     // ----- value does not fit into a field element ----------------------------------------------
     let val = Felt::MODULUS + 2;
-    let m_result = Rpo::merge_with_int(seed, val);
+    let m_result = Rpo256::merge_with_int(seed, val);
 
     let mut elements = seed.as_elements().to_vec();
     elements.push(Felt::new(val));
     elements.push(Felt::new(1));
-    let h_result = Rpo::hash_elements(&elements);
+    let h_result = Rpo256::hash_elements(&elements);
 
     assert_eq!(m_result, h_result);
 }
@@ -103,23 +103,23 @@ fn hash_elements_vs_merge_with_int() {
 #[test]
 fn hash_padding() {
     // adding a zero bytes at the end of a byte string should result in a different hash
-    let r1 = Rpo::hash(&[1_u8, 2, 3]);
-    let r2 = Rpo::hash(&[1_u8, 2, 3, 0]);
+    let r1 = Rpo256::hash(&[1_u8, 2, 3]);
+    let r2 = Rpo256::hash(&[1_u8, 2, 3, 0]);
     assert_ne!(r1, r2);
 
     // same as above but with bigger inputs
-    let r1 = Rpo::hash(&[1_u8, 2, 3, 4, 5, 6]);
-    let r2 = Rpo::hash(&[1_u8, 2, 3, 4, 5, 6, 0]);
+    let r1 = Rpo256::hash(&[1_u8, 2, 3, 4, 5, 6]);
+    let r2 = Rpo256::hash(&[1_u8, 2, 3, 4, 5, 6, 0]);
     assert_ne!(r1, r2);
 
     // same as above but with input splitting over two elements
-    let r1 = Rpo::hash(&[1_u8, 2, 3, 4, 5, 6, 7]);
-    let r2 = Rpo::hash(&[1_u8, 2, 3, 4, 5, 6, 7, 0]);
+    let r1 = Rpo256::hash(&[1_u8, 2, 3, 4, 5, 6, 7]);
+    let r2 = Rpo256::hash(&[1_u8, 2, 3, 4, 5, 6, 7, 0]);
     assert_ne!(r1, r2);
 
     // same as above but with multiple zeros
-    let r1 = Rpo::hash(&[1_u8, 2, 3, 4, 5, 6, 7, 0, 0]);
-    let r2 = Rpo::hash(&[1_u8, 2, 3, 4, 5, 6, 7, 0, 0, 0, 0]);
+    let r1 = Rpo256::hash(&[1_u8, 2, 3, 4, 5, 6, 7, 0, 0]);
+    let r2 = Rpo256::hash(&[1_u8, 2, 3, 4, 5, 6, 7, 0, 0, 0, 0]);
     assert_ne!(r1, r2);
 }
 
@@ -128,8 +128,8 @@ fn hash_elements_padding() {
     let e1 = [Felt::new(rand_value()); 2];
     let e2 = [e1[0], e1[1], ZERO];
 
-    let r1 = Rpo::hash_elements(&e1);
-    let r2 = Rpo::hash_elements(&e2);
+    let r1 = Rpo256::hash_elements(&e1);
+    let r2 = Rpo256::hash_elements(&e2);
     assert_ne!(r1, r2);
 }
 
@@ -151,7 +151,155 @@ fn hash_elements() {
         RpoDigest256::new(elements[4..8].try_into().unwrap()),
     ];
 
-    let m_result = Rpo::merge(&digests);
-    let h_result = Rpo::hash_elements(&elements);
+    let m_result = Rpo256::merge(&digests);
+    let h_result = Rpo256::hash_elements(&elements);
     assert_eq!(m_result, h_result);
 }
+
+#[test]
+fn hash_test_vectors() {
+    let elements = [
+        Felt::new(0),
+        Felt::new(1),
+        Felt::new(2),
+        Felt::new(3),
+        Felt::new(4),
+        Felt::new(5),
+        Felt::new(6),
+        Felt::new(7),
+        Felt::new(8),
+        Felt::new(9),
+        Felt::new(10),
+        Felt::new(11),
+        Felt::new(12),
+        Felt::new(13),
+        Felt::new(14),
+        Felt::new(15),
+        Felt::new(16),
+        Felt::new(17),
+        Felt::new(18),
+    ];
+
+    for i in 0..elements.len() {
+        let expected = RpoDigest256::new(EXPECTED[i].try_into().unwrap());
+        let result = Rpo256::hash_elements(&elements[..(i + 1)]);
+        assert_eq!(result, expected);
+    }
+}
+
+const EXPECTED: [[Felt; 4]; 19] = [
+    [
+        Felt::new(1502364727743950833),
+        Felt::new(5880949717274681448),
+        Felt::new(162790463902224431),
+        Felt::new(6901340476773664264),
+    ],
+    [
+        Felt::new(7478710183745780580),
+        Felt::new(3308077307559720969),
+        Felt::new(3383561985796182409),
+        Felt::new(17205078494700259815),
+    ],
+    [
+        Felt::new(17439912364295172999),
+        Felt::new(17979156346142712171),
+        Felt::new(8280795511427637894),
+        Felt::new(9349844417834368814),
+    ],
+    [
+        Felt::new(5105868198472766874),
+        Felt::new(13090564195691924742),
+        Felt::new(1058904296915798891),
+        Felt::new(18379501748825152268),
+    ],
+    [
+        Felt::new(9133662113608941286),
+        Felt::new(12096627591905525991),
+        Felt::new(14963426595993304047),
+        Felt::new(13290205840019973377),
+    ],
+    [
+        Felt::new(3134262397541159485),
+        Felt::new(10106105871979362399),
+        Felt::new(138768814855329459),
+        Felt::new(15044809212457404677),
+    ],
+    [
+        Felt::new(162696376578462826),
+        Felt::new(4991300494838863586),
+        Felt::new(660346084748120605),
+        Felt::new(13179389528641752698),
+    ],
+    [
+        Felt::new(2242391899857912644),
+        Felt::new(12689382052053305418),
+        Felt::new(235236990017815546),
+        Felt::new(5046143039268215739),
+    ],
+    [
+        Felt::new(9585630502158073976),
+        Felt::new(1310051013427303477),
+        Felt::new(7491921222636097758),
+        Felt::new(9417501558995216762),
+    ],
+    [
+        Felt::new(1994394001720334744),
+        Felt::new(10866209900885216467),
+        Felt::new(13836092831163031683),
+        Felt::new(10814636682252756697),
+    ],
+    [
+        Felt::new(17486854790732826405),
+        Felt::new(17376549265955727562),
+        Felt::new(2371059831956435003),
+        Felt::new(17585704935858006533),
+    ],
+    [
+        Felt::new(11368277489137713825),
+        Felt::new(3906270146963049287),
+        Felt::new(10236262408213059745),
+        Felt::new(78552867005814007),
+    ],
+    [
+        Felt::new(17899847381280262181),
+        Felt::new(14717912805498651446),
+        Felt::new(10769146203951775298),
+        Felt::new(2774289833490417856),
+    ],
+    [
+        Felt::new(3794717687462954368),
+        Felt::new(4386865643074822822),
+        Felt::new(8854162840275334305),
+        Felt::new(7129983987107225269),
+    ],
+    [
+        Felt::new(7244773535611633983),
+        Felt::new(19359923075859320),
+        Felt::new(10898655967774994333),
+        Felt::new(9319339563065736480),
+    ],
+    [
+        Felt::new(4935426252518736883),
+        Felt::new(12584230452580950419),
+        Felt::new(8762518969632303998),
+        Felt::new(18159875708229758073),
+    ],
+    [
+        Felt::new(14871230873837295931),
+        Felt::new(11225255908868362971),
+        Felt::new(18100987641405432308),
+        Felt::new(1559244340089644233),
+    ],
+    [
+        Felt::new(8348203744950016968),
+        Felt::new(4041411241960726733),
+        Felt::new(17584743399305468057),
+        Felt::new(16836952610803537051),
+    ],
+    [
+        Felt::new(16139797453633030050),
+        Felt::new(1090233424040889412),
+        Felt::new(10770255347785669036),
+        Felt::new(16982398877290254028),
+    ],
+];

crypto/src/merkle/mod.rs

@@ -1,4 +1,4 @@
-use crate::{Felt, FieldElement, Word};
+use crate::{Felt, Word, ZERO};
 
 pub mod merkle_path_set;
 pub mod merkle_tree;
@@ -20,6 +20,7 @@ pub enum MerkleError {
 // HELPER FUNCTIONS
 // ================================================================================================
 
+#[cfg(test)]
 const fn int_to_node(value: u64) -> Word {
-    [Felt::new(value), Felt::ZERO, Felt::ZERO, Felt::ZERO]
+    [Felt::new(value), ZERO, ZERO, ZERO]
 }