Added g1_linecomb without strict limit assertion

da/kzg_rs.py

@@ -1,17 +1,31 @@
 from itertools import batched
-from typing import List
+from typing import List, Sequence
 
 from eth2spec.eip7594.mainnet import (
-    blob_to_kzg_commitment, g1_lincomb, bit_reversal_permutation, KZG_SETUP_G1_LAGRANGE, Polynomial,
+    bit_reversal_permutation, KZG_SETUP_G1_LAGRANGE, Polynomial,
     BYTES_PER_FIELD_ELEMENT, bytes_to_bls_field, BLSFieldElement,
 )
 from eth2spec.eip7594.mainnet import KZGCommitment as Commitment, KZGProof as Proof
+from eth2spec.utils import bls
 
 
 class Polynomial(List[BLSFieldElement]):
     pass
 
 
+def g1_lincomb(points: Sequence[Commitment], scalars: Sequence[BLSFieldElement]) -> Commitment:
+    """
+    BLS multiscalar multiplication. This function can be optimized using Pippenger's algorithm and variants.
+    """
+    # we assert to have more points available than elements,
+    # this is dependent on the available kzg setup size
+    assert len(points) >= len(scalars)
+    result = bls.Z1()
+    for x, a in zip(points, scalars):
+        result = bls.add(result, bls.multiply(bls.bytes48_to_G1(x), a))
+    return Commitment(bls.G1_to_bytes48(result))
+
+
 def bytes_to_polynomial(b: bytearray) -> Polynomial:
     """
     Convert bytes to list of BLS field scalars.
@@ -23,4 +37,4 @@ def bytes_to_polynomial(b: bytearray) -> Polynomial:
 def bytes_to_kzg_commitment(b: bytearray) -> Commitment:
     return g1_lincomb(
         bit_reversal_permutation(KZG_SETUP_G1_LAGRANGE), bytes_to_polynomial(b)
-    )
+    )

da/test_kzg_rs.py

@@ -30,3 +30,10 @@ class TestKzgRs(TestCase):
         eth_commitment = blob_to_kzg_commitment(Blob(rand_bytes))
         commitment = bytes_to_kzg_commitment(rand_bytes)
         self.assertEqual(eth_commitment, commitment)
+
+    def test_small_bytes_kzg_commitment(self):
+        rand_bytes = bytearray(int.to_bytes(randrange(BLS_MODULUS), length=BYTES_PER_FIELD_ELEMENT))
+        commitment = bytes_to_kzg_commitment(rand_bytes)
+        rand_bytes = self.rand_bytes()
+        commitment2 = bytes_to_kzg_commitment(rand_bytes)
+        self.assertEqual(len(commitment), len(commitment2))