explicitly check for blockchain.cliqueActiveSigners() in `BlockHead…

…er.validateCliqueDifficulty()`
ethereumjs · Jan 29, 2021 · d58a901 · d58a901
1 parent 47b36cc
commit d58a901
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Showing 2 changed files with 8 additions and 3 deletions.
diff --git a/packages/block/src/header.ts b/packages/block/src/header.ts
@@ -378,14 +378,20 @@ export class BlockHeader {
 
   /**
    * For poa, validates `difficulty` is correctly identified as INTURN or NOTURN.
+   * Returns false if invalid.
    */
   validateCliqueDifficulty(blockchain: Blockchain): boolean {
     if (!this.difficulty.eq(CLIQUE_DIFF_INTURN) && !this.difficulty.eq(CLIQUE_DIFF_NOTURN)) {
       throw new Error(
         `difficulty for clique block must be INTURN (2) or NOTURN (1), received: ${this.difficulty.toString()}`
       )
     }
-    const signers = blockchain.cliqueActiveSigners()
+    if ('cliqueActiveSigners' in blockchain === false) {
+      throw new Error(
+        'PoA blockchain requires method blockchain.cliqueActiveSigners() to validate clique difficulty'
+      )
+    }
+    const signers = (blockchain as any).cliqueActiveSigners()
     if (signers.length === 0) {
       // abort if signers are unavailable
       return true

diff --git a/packages/block/src/types.ts b/packages/block/src/types.ts
@@ -1,4 +1,4 @@
-import { Address, AddressLike, BNLike, BufferLike } from 'ethereumjs-util'
+import { AddressLike, BNLike, BufferLike } from 'ethereumjs-util'
 import Common from '@ethereumjs/common'
 import { TxData, JsonTx } from '@ethereumjs/tx'
 import { Block } from './block'
@@ -135,5 +135,4 @@ export interface JsonHeader {
 
 export interface Blockchain {
   getBlock(hash: Buffer): Promise<Block>
-  cliqueActiveSigners(): Address[]
 }