Add extra checks to fix some edge cases (matter-labs#118)

lambdaclass · Sep 21, 2023 · 6ff795d · 6ff795d
1 parent 062fbcf
commit 6ff795d
Showing 1 changed file with 9 additions and 0 deletions.
diff --git a/precompiles/Modexp.yul b/precompiles/Modexp.yul
@@ -40,11 +40,20 @@ object "ModExp" {
                 return(0, 0)
             }
 
+            // Workaround to handle the case when all inputs are 0
+            if eq(calldatasize(), 96) {
+                return(0, modulus_length)
+            }
+
             // Handle a special case when both the base and mod length is zero
             if and(iszero(base_length), iszero(modulus_length)) {
                 return(0, 0)
             }
 
+            if and(iszero(base_length), iszero(exponent_length)) {
+                return(0, modulus_length)
+            }
+
             let base_pointer := 96
             let base_padding := sub(WORD_SIZE(), base_length)
             let padded_base_pointer := add(96, base_padding)