Structural Preparations for PoA Support

packages/block/CHANGELOG.md

@@ -9,6 +9,8 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 ## 3.0.0-beta.2 - UNRELEASED
 
 - Added `freeze` option to allow for block freeze deactivation (e.g. to allow for subclassing block and adding additional parameters), see PR [#941](https://github.com/ethereumjs/ethereumjs-vm/pull/941)
+- **Breaking:** Difficulty-depending methods `canonicalDifficulty()` and `validateDifficulty()` in block and header now throw on non-PoW chains, see PR [#937](https://github.com/ethereumjs/ethereumjs-vm/pull/937)
+- **Breaking:** Non-blockchain dependent validation checks have been extracted from `validate()` to its own `Block.validateData()` function. For the `validate()` method in block and header `blockchain` is now a mandatory parameter, see PR [#942](https://github.com/ethereumjs/ethereumjs-vm/pull/942)
 - Fixed bug where block options have not been passed on to the main constructor from the static factory methods, see PR [#941](https://github.com/ethereumjs/ethereumjs-vm/pull/941)
 
 ## 3.0.0-beta.1 - 2020-10-22

packages/block/src/block.ts

@@ -148,7 +148,8 @@ export class Block {
   }
 
   /**
-   * Validates the transaction trie.
+   * Validates the transaction trie by generating a trie
+   * and do a check on the root hash.
    */
   async validateTransactionsTrie(): Promise<boolean> {
     if (this.transactions.length === 0) {
@@ -163,7 +164,7 @@ export class Block {
   }
 
   /**
-   * Validates the transactions.
+   * Validates transaction signatures and minimum gas requirements.
    *
    * @param stringError - If `true`, a string with the indices of the invalid txs is returned.
    */
@@ -184,7 +185,14 @@ export class Block {
   }
 
   /**
-   * Validates the block, throwing if invalid.
+   * Performs the following consistency checks on the block:
+   *
+   * - Value checks on the header fields
+   * - Signature and gasLimit validation for included txs
+   * - Validation of the tx trie
+   * - Consistency checks and header validation of included uncles
+   *
+   * Throws if invalid.
    *
    * @param blockchain - validate against a @ethereumjs/blockchain
    */
@@ -226,9 +234,12 @@ export class Block {
   }
 
   /**
-   * Validates the uncles that are in the block, if any. This method throws if they are invalid.
+   * Consistency checks and header validation for uncles included
+   * in the block, if any.
+   *
+   * Throws if invalid.
    *
-   * @param blockchain - additionally validate against a @ethereumjs/blockchain
+   * @param blockchain - additionally validate against an @ethereumjs/blockchain instance
    */
   async validateUncles(blockchain: Blockchain): Promise<void> {
     if (this.isGenesis()) {
@@ -268,7 +279,8 @@ export class Block {
   }
 
   /**
-   * Validates the gasLimit.
+   * Validates if the block gasLimit remains in the
+   * boundaries set by the protocol.
    *
    * @param parentBlock - the parent of this `Block`
    */

packages/block/src/header.ts

@@ -269,6 +269,12 @@ export class BlockHeader {
    * @param parentBlockHeader - the header from the parent `Block` of this header
    */
   canonicalDifficulty(parentBlockHeader: BlockHeader): BN {
+    if (this._common.consensusType() !== 'pow') {
+      throw new Error('difficulty calculation is only supported on PoW chains')
+    }
+    if (this._common.consensusAlgorithm() !== 'ethash') {
+      throw new Error('difficulty calculation currently only supports the ethash algorithm')
+    }
     const hardfork = this._getHardfork()
     const blockTs = this.timestamp
     const { timestamp: parentTs, difficulty: parentDif } = parentBlockHeader
@@ -351,11 +357,15 @@ export class BlockHeader {
    * @param parentBlockHeader - the header from the parent `Block` of this header
    */
   validateDifficulty(parentBlockHeader: BlockHeader): boolean {
+    if (this._common.consensusType() !== 'pow') {
+      throw new Error('difficulty validation is currently only supported on PoW chains')
+    }
     return this.canonicalDifficulty(parentBlockHeader).eq(this.difficulty)
   }
 
   /**
-   * Validates the gasLimit.
+   * Validates if the block gasLimit remains in the
+   * boundaries set by the protocol.
    *
    * @param parentBlockHeader - the header from the parent `Block` of this header
    */
@@ -412,8 +422,10 @@ export class BlockHeader {
       throw new Error('invalid timestamp')
     }
 
-    if (!this.validateDifficulty(header)) {
-      throw new Error('invalid difficulty')
+    if (this._common.consensusType() === 'pow') {
+      if (!this.validateDifficulty(header)) {
+        throw new Error('invalid difficulty')
+      }
     }
 
     if (!this.validateGasLimit(header)) {

packages/block/test/block.spec.ts

@@ -69,7 +69,7 @@ tape('[Block]: block functions', function (t) {
 
   const testData = require('./testdata/testdata.json')
 
-  t.test('should test block validation', async function (st) {
+  t.test('should test block validation on pow chain', async function (st) {
     const blockRlp = testData.blocks[0].rlp
     const block = Block.fromRLPSerializedBlock(blockRlp)
     const blockchain = new Mockchain()
@@ -80,6 +80,20 @@ tape('[Block]: block functions', function (t) {
     })
   })
 
+  t.test('should test block validation on poa chain', async function (st) {
+    const blockRlp = testData.blocks[0].rlp
+    const common = new Common({ chain: 'goerli' })
+    const block = Block.fromRLPSerializedBlock(blockRlp, { common })
+    const blockchain = new Mockchain()
+    await blockchain.putBlock(Block.fromRLPSerializedBlock(testData.genesisRLP))
+    try {
+      await block.validate(blockchain)
+    } catch (error) {
+      st.ok(error.toString().match(/block validation is currently only supported on PoW chains/))
+    }
+    st.end()
+  })
+
   async function testTransactionValidation(st: tape.Test, block: Block) {
     st.ok(block.validateTransactions())
     st.ok(await block.validateTransactionsTrie())

packages/blockchain/CHANGELOG.md

@@ -40,6 +40,7 @@ Genesis handling has been reworked to now be safer and reduce the risk of wiping
 **Testing and CI**
 
 - Dedicated `blockchain` reorg test setup and executable test, PR [#926](https://github.com/ethereumjs/ethereumjs-vm/pull/926)
+- **Breaking:** `validatePow` option has been renamed to `validateConsensus` to prepare for a future integration of non-PoW (PoA) consensus mechanisms, `validateConsensus` as well as `validateBlocks` options now throw when set to `true` for validation on a non-PoW chain (determined by `Common`, e.g. 'goerli'), see PR [#937](https://github.com/ethereumjs/ethereumjs-vm/pull/937)
 
 ## 5.0.0-beta.1 - 2020-10-22
 

packages/blockchain/src/index.ts

@@ -63,15 +63,19 @@ export interface BlockchainOptions {
   db?: LevelUp
 
   /**
-   * This flags indicates if Proof-of-work should be validated. Defaults to
-   * `true`.
+   * This flags indicates if a block should be validated along the consensus algorithm
+   * or protocol used by the chain, e.g. by verifying the PoW on the block.
+   *
+   * Supported: 'pow' with 'ethash' algorithm (taken from the `Common` instance)
+   * Default: `true`.
    */
-  validatePow?: boolean
+  validateConsensus?: boolean
 
   /**
-   * This flags indicates if blocks should be validated. See Block#validate for
-   * details. If `validate` is provided, this option takes its value. If neither
-   * `validate` nor this option are provided, it defaults to `true`.
+   * This flag indicates if protocol-given consistency checks on
+   * block headers and included uncles and transactions should be performed,
+   * see Block#validate for details.
+   *
    */
   validateBlocks?: boolean
 
@@ -91,7 +95,8 @@ export interface BlockchainOptions {
 export default class Blockchain implements BlockchainInterface {
   db: LevelUp
   dbManager: DBManager
-  ethash?: Ethash
+
+  _ethash?: Ethash
 
   private _genesis?: Buffer // the genesis hash of this blockchain
 
@@ -110,7 +115,7 @@ export default class Blockchain implements BlockchainInterface {
   private _lock: Semaphore
 
   private _common: Common
-  private readonly _validatePow: boolean
+  private readonly _validateConsensus: boolean
   private readonly _validateBlocks: boolean
 
   /**
@@ -137,14 +142,21 @@ export default class Blockchain implements BlockchainInterface {
       })
     }
 
-    this._validatePow = opts.validatePow !== undefined ? opts.validatePow : true
-    this._validateBlocks = opts.validateBlocks !== undefined ? opts.validateBlocks : true
+    this._validateConsensus = opts.validateConsensus ?? true
+    this._validateBlocks = opts.validateBlocks ?? true
 
     this.db = opts.db ? opts.db : level()
     this.dbManager = new DBManager(this.db, this._common)
 
-    if (this._validatePow) {
-      this.ethash = new Ethash(this.db)
+    if (this._validateConsensus) {
+      if (this._common.consensusType() !== 'pow') {
+        throw new Error('consensus validation only supported for pow chains')
+      }
+      if (this._common.consensusAlgorithm() !== 'ethash') {
+        throw new Error('consensus validation only supported for pow ethash algorithm')
+      }
+
+      this._ethash = new Ethash(this.db)
     }
 
     this._heads = {}
@@ -444,10 +456,12 @@ export default class Blockchain implements BlockchainInterface {
         await block.validate(this)
       }
 
-      if (this._validatePow && this.ethash) {
-        const valid = await this.ethash.verifyPOW(block)
-        if (!valid) {
-          throw new Error('invalid POW')
+      if (this._validateConsensus) {
+        if (this._ethash) {
+          const valid = await this._ethash.verifyPOW(block)
+          if (!valid) {
+            throw new Error('invalid POW')
+          }
         }
       }