vm: stateManager: add getProof EIP-1186

packages/vm/lib/state/stateManager.ts

@@ -9,7 +9,9 @@ import {
   keccak256,
   KECCAK256_NULL,
   unpadBuffer,
-  PrefixedHexString
+  PrefixedHexString,
+  bnToHex,
+  bufferToHex,
 } from 'ethereumjs-util'
 import { encode, decode } from 'rlp'
 import Common from '@ethereumjs/common'
@@ -23,19 +25,18 @@ const debug = createDebugLogger('vm:state')
 
 type AddressHex = string
 
-
 type StorageProof = {
-  key: PrefixedHexString,
-  proof: PrefixedHexString[],
+  key: PrefixedHexString
+  proof: PrefixedHexString[]
   value: PrefixedHexString
 }
 
 type Proof = {
-  balance: PrefixedHexString,
-  codeHash: PrefixedHexString,
-  nonce: PrefixedHexString,
-  storageHash: PrefixedHexString,
-  accountProof: PrefixedHexString[],
+  balance: PrefixedHexString
+  codeHash: PrefixedHexString
+  nonce: PrefixedHexString
+  storageHash: PrefixedHexString
+  accountProof: PrefixedHexString[]
   storageProof: StorageProof[]
 }
 
@@ -445,8 +446,42 @@ export default class DefaultStateManager implements StateManager {
     }
   }
 
+  /**
+   * Get an EIP-1186 proof
+   * @param address - address to get proof of
+   * @param storageSlots - storage slots to get proof of
+   */
   async getProof(address: Address, storageSlots: Buffer[] = []): Promise<Proof> {
-    this._trie.walkTrie()
+    const account = await this.getAccount(address)
+    const accountProof: PrefixedHexString[] = (
+      await Trie.createProof(this._trie, address.buf)
+    ).map((e: Buffer) => bufferToHex(e))
+    const storageProof: StorageProof[] = []
+    const storageTrie = await this._getStorageTrie(address)
+
+    await Promise.all(
+      storageSlots.map(async (storageKey: Buffer) => {
+        const proof = (await Trie.createProof(storageTrie, storageKey)).map((e: Buffer) =>
+          bufferToHex(e)
+        )
+        const proofItem: StorageProof = {
+          key: bufferToHex(storageKey),
+          value: bufferToHex(await this.getContractStorage(address, storageKey)),
+          proof,
+        }
+        storageProof.push(proofItem)
+      })
+    )
+
+    const returnValue: Proof = {
+      balance: bnToHex(account.balance),
+      codeHash: bufferToHex(account.codeHash),
+      nonce: bnToHex(account.nonce),
+      storageHash: bufferToHex(account.stateRoot),
+      accountProof,
+      storageProof,
+    }
+    return returnValue
   }
 
   /**