feat(hints): Add BLAKE2S_FINALIZE hint variant

CHANGELOG.md

@@ -2,6 +2,35 @@
 
 #### Upcoming Changes
 
+* Add alternative hint code for hint on finalize_blake2s[#1072](https://github.com/lambdaclass/cairo-rs/pull/1072)
+
+    `BuiltinHintProcessor` now supports the following hint:
+
+     ```python
+    %{
+        # Add dummy pairs of input and output.
+        from starkware.cairo.common.cairo_blake2s.blake2s_utils import IV, blake2s_compress
+
+        _n_packed_instances = int(ids.N_PACKED_INSTANCES)
+        assert 0 <= _n_packed_instances < 20
+        _blake2s_input_chunk_size_felts = int(ids.BLAKE2S_INPUT_CHUNK_SIZE_FELTS)
+        assert 0 <= _blake2s_input_chunk_size_felts < 100
+
+        message = [0] * _blake2s_input_chunk_size_felts
+        modified_iv = [IV[0] ^ 0x01010020] + IV[1:]
+        output = blake2s_compress(
+            message=message,
+            h=modified_iv,
+            t0=0,
+            t1=0,
+            f0=0xffffffff,
+            f1=0,
+        )
+        padding = (message + modified_iv + [0, 0xffffffff] + output) * (_n_packed_instances - 1)
+        segments.write_arg(ids.blake2s_ptr_end, padding)
+        %}
+    ```
+
 * Implement hint for `starkware.cairo.common.cairo_keccak.keccak._copy_inputs` as described by whitelist `starknet/security/whitelists/cairo_keccak.json` [#1058](https://github.com/lambdaclass/cairo-rs/pull/1058)
 
 `BuiltinHintProcessor` now supports the following hint:
@@ -36,6 +65,7 @@
         y0 = pack(ids.point0.y, PRIME)
 
         value = new_x = (pow(slope, 2, SECP_P) - x0 - x1) % SECP_P
+    %}
     ```
 
 * Add missing hint on vrf.json lib [#1053](https://github.com/lambdaclass/cairo-rs/pull/1053):
@@ -59,7 +89,7 @@
 
      `BuiltinHintProcessor` now supports the following hints:
 
-    ```
+    ```python
     %{
        ids.a_lsb = ids.a & 1
        ids.b_lsb = ids.b & 1

cairo_programs/blake2s_finalize_v3.cairo

@@ -0,0 +1,69 @@
+%builtins range_check bitwise
+
+from starkware.cairo.common.alloc import alloc
+from starkware.cairo.common.registers import get_fp_and_pc
+from starkware.cairo.common.math import assert_nn_le, split_felt, unsigned_div_rem
+from starkware.cairo.common.cairo_blake2s.blake2s import blake2s
+from starkware.cairo.common.cairo_builtins import BitwiseBuiltin
+from starkware.cairo.common.cairo_blake2s.blake2s import INPUT_BLOCK_FELTS, INSTANCE_SIZE, _get_sigma, _finalize_blake2s_inner, N_PACKED_INSTANCES
+
+const BLAKE2S_INPUT_CHUNK_SIZE_FELTS = INPUT_BLOCK_FELTS;
+
+// Verifies that the results of blake2s() are valid.
+func finalize_blake2s{range_check_ptr, bitwise_ptr: BitwiseBuiltin*}(
+    blake2s_ptr_start: felt*, blake2s_ptr_end: felt*
+) {
+    alloc_locals;
+
+    let (__fp__, _) = get_fp_and_pc();
+
+    let (sigma) = _get_sigma();
+
+    tempvar n = (blake2s_ptr_end - blake2s_ptr_start) / INSTANCE_SIZE;
+    if (n == 0) {
+        return ();
+    }
+
+    %{
+        # Add dummy pairs of input and output.
+        from starkware.cairo.common.cairo_blake2s.blake2s_utils import IV, blake2s_compress
+
+        _n_packed_instances = int(ids.N_PACKED_INSTANCES)
+        assert 0 <= _n_packed_instances < 20
+        _blake2s_input_chunk_size_felts = int(ids.BLAKE2S_INPUT_CHUNK_SIZE_FELTS)
+        assert 0 <= _blake2s_input_chunk_size_felts < 100
+
+        message = [0] * _blake2s_input_chunk_size_felts
+        modified_iv = [IV[0] ^ 0x01010020] + IV[1:]
+        output = blake2s_compress(
+            message=message,
+            h=modified_iv,
+            t0=0,
+            t1=0,
+            f0=0xffffffff,
+            f1=0,
+        )
+        padding = (message + modified_iv + [0, 0xffffffff] + output) * (_n_packed_instances - 1)
+        segments.write_arg(ids.blake2s_ptr_end, padding)
+    %}
+
+    // Compute the amount of chunks (rounded up).
+    let (local n_chunks, _) = unsigned_div_rem(n + N_PACKED_INSTANCES - 1, N_PACKED_INSTANCES);
+    let blake2s_ptr = blake2s_ptr_start;
+    _finalize_blake2s_inner{blake2s_ptr=blake2s_ptr}(n=n_chunks, sigma=sigma);
+    return ();
+}
+
+
+func main{range_check_ptr, bitwise_ptr: BitwiseBuiltin*}() {
+    alloc_locals;
+    let inputs: felt* = alloc();
+    assert inputs[0] = 'Hell';
+    assert inputs[1] = 'o Wo';
+    assert inputs[2] = 'rld';
+    let (local blake2s_ptr_start) = alloc();
+    let blake2s_ptr = blake2s_ptr_start;
+    let (output) = blake2s{range_check_ptr=range_check_ptr, blake2s_ptr=blake2s_ptr}(inputs, 9);
+    finalize_blake2s(blake2s_ptr_start, blake2s_ptr);
+    return ();
+}

src/hint_processor/builtin_hint_processor/builtin_hint_processor_definition.rs

@@ -308,7 +308,9 @@ impl HintProcessor for BuiltinHintProcessor {
             hint_code::REDUCE => {
                 reduce(vm, exec_scopes, &hint_data.ids_data, &hint_data.ap_tracking)
             }
-            hint_code::BLAKE2S_FINALIZE | hint_code::BLAKE2S_FINALIZE_V2 => {
+            hint_code::BLAKE2S_FINALIZE
+            | hint_code::BLAKE2S_FINALIZE_V2
+            | hint_code::BLAKE2S_FINALIZE_V3 => {
                 finalize_blake2s(vm, &hint_data.ids_data, &hint_data.ap_tracking)
             }
             hint_code::BLAKE2S_ADD_UINT256 => {

src/hint_processor/builtin_hint_processor/hint_code.rs

@@ -454,6 +454,27 @@ output = blake2s_compress(
 padding = (modified_iv + message + [0, 0xffffffff] + output) * (_n_packed_instances - 1)
 segments.write_arg(ids.blake2s_ptr_end, padding)"#;
 
+pub const BLAKE2S_FINALIZE_V3: &str = r#"# Add dummy pairs of input and output.
+from starkware.cairo.common.cairo_blake2s.blake2s_utils import IV, blake2s_compress
+
+_n_packed_instances = int(ids.N_PACKED_INSTANCES)
+assert 0 <= _n_packed_instances < 20
+_blake2s_input_chunk_size_felts = int(ids.BLAKE2S_INPUT_CHUNK_SIZE_FELTS)
+assert 0 <= _blake2s_input_chunk_size_felts < 100
+
+message = [0] * _blake2s_input_chunk_size_felts
+modified_iv = [IV[0] ^ 0x01010020] + IV[1:]
+output = blake2s_compress(
+    message=message,
+    h=modified_iv,
+    t0=0,
+    t1=0,
+    f0=0xffffffff,
+    f1=0,
+)
+padding = (message + modified_iv + [0, 0xffffffff] + output) * (_n_packed_instances - 1)
+segments.write_arg(ids.blake2s_ptr_end, padding)"#;
+
 pub const BLAKE2S_ADD_UINT256: &str = r#"B = 32
 MASK = 2 ** 32 - 1
 segments.write_arg(ids.data, [(ids.low >> (B * i)) & MASK for i in range(4)])

src/tests/cairo_run_test.rs

@@ -905,6 +905,13 @@ fn ec_double_assign_new_x_v3() {
     run_program_simple(program_data.as_slice());
 }
 
+#[test]
+#[cfg_attr(target_arch = "wasm32", wasm_bindgen_test)]
+fn finalize_blake2s_v3() {
+    let program_data = include_bytes!("../../cairo_programs/blake2s_finalize_v3.json");
+    run_program_simple_with_memory_holes(program_data.as_slice(), 20);
+}
+
 #[test]
 #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test)]
 fn nondet_bigint3_v2() {