empty keccak

HerodotusDev · Oct 17, 2023 · 6790a2d · 6790a2d
1 parent fa12c59
commit 6790a2d
Show file tree

Hide file tree

Showing 2 changed files with 12 additions and 2 deletions.
diff --git a/src/data_structures/eth_mpt.cairo b/src/data_structures/eth_mpt.cairo
@@ -265,12 +265,16 @@ impl MPTImpl of MPTTrait {
 
                     if prefix == 0 {
                         match second.try_into() {
-                            Option::Some(n) => Result::Ok(MPTNode::Extension((first, n, 2, n_nibbles - 1))),
+                            Option::Some(n) => Result::Ok(
+                                MPTNode::Extension((first, n, 2, n_nibbles - 1))
+                            ),
                             Option::None(_) => Result::Err('Invalid next node')
                         }
                     } else if prefix == 1 {
                         match second.try_into() {
-                            Option::Some(n) => Result::Ok(MPTNode::Extension((first, n, 1, n_nibbles))),
+                            Option::Some(n) => Result::Ok(
+                                MPTNode::Extension((first, n, 1, n_nibbles))
+                            ),
                             Option::None(_) => Result::Err('Invalid next node')
                         }
                     } else if prefix == 2 {

diff --git a/src/hashing/keccak.cairo b/src/hashing/keccak.cairo
@@ -1,10 +1,16 @@
 use cairo_lib::utils::types::words64::{Words64, bytes_used_u64};
 use keccak::cairo_keccak;
 
+const EMPTY_KECCAK: u256 = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
+
 // @notice Wrapper arround cairo_keccak that format the input for compatibility with EVM
 // @param words The input data, as a list of 64-bit little-endian words
 // @return The keccak hash of the input, matching the output of the EVM's keccak256 opcode
 fn keccak_cairo_words64(words: Words64) -> u256 {
+    if words.is_empty() {
+        return EMPTY_KECCAK;
+    }
+
     let n = words.len();
 
     let mut keccak_input = ArrayTrait::new();