Merge pull request #918 from ethereumjs/update-header-validation-methods

BlockHeader Validation Method Changes / Corresponding Block Methods

packages/block/CHANGELOG.md

@@ -141,6 +141,18 @@ try {
 }
 ```
 
+### Header Validation Methods > Signature Changes
+
+**Breaking**: The signatures of the following header validation methods have been updated to take a `parentBlockHeader` instead of a 
+`parentBlock` input parameter for consistency and removing a circling dependency with `Block`:
+
+- `BlockHeader.canonicalDifficulty(parentBlockHeader: BlockHeader): BN`
+- `BlockHeader.validateDifficulty(parentBlockHeader: BlockHeader): boolean`
+- `BlockHeader.validateGasLimit(parentBlockHeader: BlockHeader): boolean`
+
+On the `Block` library new corresponding methods have been added which both operate on a block instance and expect a `parentBlock`
+as an input parameter.
+
 ### New Default Hardfork
 
 **Breaking:** The default HF on the library has been updated from `petersburg` to `instanbul`, see PR [#906](https://github.com/ethereumjs/ethereumjs-vm/pull/906).

packages/block/src/block.ts

@@ -1,7 +1,7 @@
 /* eslint-disable no-dupe-class-members */
 
 import { BaseTrie as Trie } from 'merkle-patricia-tree'
-import { rlp, keccak256, KECCAK256_RLP } from 'ethereumjs-util'
+import { BN, rlp, keccak256, KECCAK256_RLP } from 'ethereumjs-util'
 import Common from '@ethereumjs/common'
 import { Transaction, TxOptions } from '@ethereumjs/tx'
 import { BlockHeader } from './header'
@@ -237,6 +237,33 @@ export class Block {
     }
   }
 
+  /**
+   * Returns the canonical difficulty for this block.
+   *
+   * @param parentBlock - the parent of this `Block`
+   */
+  canonicalDifficulty(parentBlock: Block): BN {
+    return this.header.canonicalDifficulty(parentBlock.header)
+  }
+
+  /**
+   * Checks that the block's `difficulty` matches the canonical difficulty.
+   *
+   * @param parentBlock - the parent of this `Block`
+   */
+  validateDifficulty(parentBlock: Block): boolean {
+    return this.header.validateDifficulty(parentBlock.header)
+  }
+
+  /**
+   * Validates the gasLimit.
+   *
+   * @param parentBlock - the parent of this `Block`
+   */
+  validateGasLimit(parentBlock: Block): boolean {
+    return this.header.validateGasLimit(parentBlock.header)
+  }
+
   /**
    * Returns the block in JSON format.
    */

packages/block/src/header.ts

@@ -12,7 +12,6 @@ import {
   zeros,
 } from 'ethereumjs-util'
 import { HeaderData, JsonHeader, BlockHeaderBuffer, Blockchain, BlockOptions } from './types'
-import { Block } from './block'
 
 const DEFAULT_GAS_LIMIT = new BN(Buffer.from('ffffffffffffff', 'hex'))
 
@@ -257,12 +256,12 @@ export class BlockHeader {
   /**
    * Returns the canonical difficulty for this block.
    *
-   * @param parentBlock - the parent `Block` of this header
+   * @param parentBlockHeader - the header from the parent `Block` of this header
    */
-  canonicalDifficulty(parentBlock: Block): BN {
+  canonicalDifficulty(parentBlockHeader: BlockHeader): BN {
     const hardfork = this._getHardfork()
     const blockTs = this.timestamp
-    const { timestamp: parentTs, difficulty: parentDif } = parentBlock.header
+    const { timestamp: parentTs, difficulty: parentDif } = parentBlockHeader
     const minimumDifficulty = new BN(
       this._common.paramByHardfork('pow', 'minimumDifficulty', hardfork)
     )
@@ -276,7 +275,7 @@ export class BlockHeader {
 
     if (this._common.hardforkGteHardfork(hardfork, 'byzantium')) {
       // max((2 if len(parent.uncles) else 1) - ((timestamp - parent.timestamp) // 9), -99) (EIP100)
-      const uncleAddend = parentBlock.header.uncleHash.equals(KECCAK256_RLP_ARRAY) ? 1 : 2
+      const uncleAddend = parentBlockHeader.uncleHash.equals(KECCAK256_RLP_ARRAY) ? 1 : 2
       let a = blockTs.sub(parentTs).idivn(9).ineg().iaddn(uncleAddend)
       const cutoff = new BN(-99)
       // MAX(cutoff, a)
@@ -341,19 +340,19 @@ export class BlockHeader {
   /**
    * Checks that the block's `difficulty` matches the canonical difficulty.
    *
-   * @param parentBlock - this block's parent
+   * @param parentBlockHeader - the header from the parent `Block` of this header
    */
-  validateDifficulty(parentBlock: Block): boolean {
-    return this.canonicalDifficulty(parentBlock).eq(this.difficulty)
+  validateDifficulty(parentBlockHeader: BlockHeader): boolean {
+    return this.canonicalDifficulty(parentBlockHeader).eq(this.difficulty)
   }
 
   /**
    * Validates the gasLimit.
    *
-   * @param parentBlock - this block's parent
+   * @param parentBlockHeader - the header from the parent `Block` of this header
    */
-  validateGasLimit(parentBlock: Block): boolean {
-    const parentGasLimit = parentBlock.header.gasLimit
+  validateGasLimit(parentBlockHeader: BlockHeader): boolean {
+    const parentGasLimit = parentBlockHeader.gasLimit
     const gasLimit = this.gasLimit
     const hardfork = this._getHardfork()
 
@@ -387,31 +386,31 @@ export class BlockHeader {
     }
 
     if (blockchain) {
-      const parentBlock = await this._getBlockByHash(blockchain, this.parentHash)
+      const header = await this._getHeaderByHash(blockchain, this.parentHash)
 
-      if (!parentBlock) {
-        throw new Error('could not find parent block')
+      if (!header) {
+        throw new Error('could not find parent header')
       }
 
       const { number } = this
-      if (!number.eq(parentBlock.header.number.addn(1))) {
+      if (!number.eq(header.number.addn(1))) {
         throw new Error('invalid number')
       }
 
-      if (this.timestamp.lte(parentBlock.header.timestamp)) {
+      if (this.timestamp.lte(header.timestamp)) {
         throw new Error('invalid timestamp')
       }
 
-      if (!this.validateDifficulty(parentBlock)) {
+      if (!this.validateDifficulty(header)) {
         throw new Error('invalid difficulty')
       }
 
-      if (!this.validateGasLimit(parentBlock)) {
+      if (!this.validateGasLimit(header)) {
         throw new Error('invalid gas limit')
       }
 
       if (height) {
-        const dif = height.sub(parentBlock.header.number)
+        const dif = height.sub(header.number)
         if (!(dif.cmpn(8) === -1 && dif.cmpn(1) === 1)) {
           throw new Error('uncle block has a parent that is too old or too young')
         }
@@ -490,9 +489,13 @@ export class BlockHeader {
     return this._common.hardfork() || this._common.activeHardfork(this.number.toNumber())
   }
 
-  private async _getBlockByHash(blockchain: Blockchain, hash: Buffer): Promise<Block | undefined> {
+  private async _getHeaderByHash(
+    blockchain: Blockchain,
+    hash: Buffer
+  ): Promise<BlockHeader | undefined> {
     try {
-      return blockchain.getBlock(hash)
+      const header = (await blockchain.getBlock(hash)).header
+      return header
     } catch (error) {
       if (error.type === 'NotFoundError') {
         return undefined

packages/block/test/difficulty.spec.ts

@@ -19,9 +19,9 @@ tape('[Header]: difficulty tests', (t) => {
   function runDifficultyTests(test: any, parentBlock: Block, block: Block, msg: string) {
     normalize(test)
 
-    const dif = block.header.canonicalDifficulty(parentBlock)
+    const dif = block.canonicalDifficulty(parentBlock)
     t.equal(dif.toString(), test.currentDifficulty.toString(), `test canonicalDifficulty (${msg})`)
-    t.assert(block.header.validateDifficulty(parentBlock), `test validateDifficulty (${msg})`)
+    t.assert(block.validateDifficulty(parentBlock), `test validateDifficulty (${msg})`)
   }
 
   const hardforkTestData: any = {

packages/block/test/header.spec.ts

@@ -49,7 +49,7 @@ tape('[Block]: Header functions', function (t) {
       const parentBlock = Block.fromRLPSerializedBlock(genesisRlp)
       const blockRlp = bcBlockGasLimitTestData[key].blocks[0].rlp
       const block = Block.fromRLPSerializedBlock(blockRlp)
-      st.equal(block.header.validateGasLimit(parentBlock), true)
+      st.equal(block.validateGasLimit(parentBlock), true)
     })
 
     st.end()

packages/blockchain/test/index.ts

@@ -81,7 +81,7 @@ tape('blockchain test', (t) => {
         header: {
           number,
           parentHash: lastBlock.hash(),
-          difficulty: lastBlock.header.canonicalDifficulty(lastBlock),
+          difficulty: lastBlock.canonicalDifficulty(lastBlock),
           timestamp: lastBlock.header.timestamp.addn(1),
           gasLimit,
         },
@@ -118,7 +118,7 @@ tape('blockchain test', (t) => {
       header: {
         number: 1,
         parentHash: genesis.hash(),
-        difficulty: genesis.header.canonicalDifficulty(genesis),
+        difficulty: genesis.canonicalDifficulty(genesis),
         timestamp: genesis.header.timestamp.addn(1),
         gasLimit,
       },
@@ -377,7 +377,7 @@ tape('blockchain test', (t) => {
     const headerData = {
       number: 15,
       parentHash: blocks[14].hash(),
-      difficulty: blocks[14].header.canonicalDifficulty(blocks[14]),
+      difficulty: blocks[14].canonicalDifficulty(blocks[14]),
       gasLimit: 8000000,
       timestamp: blocks[14].header.timestamp.addn(1),
     }
@@ -400,7 +400,7 @@ tape('blockchain test', (t) => {
     const headerData = {
       number: 15,
       parentHash: blocks[14].hash(),
-      difficulty: blocks[14].header.canonicalDifficulty(blocks[14]),
+      difficulty: blocks[14].canonicalDifficulty(blocks[14]),
       gasLimit: 8000000,
       timestamp: blocks[14].header.timestamp.addn(1),
     }
@@ -558,7 +558,7 @@ tape('blockchain test', (t) => {
     const headerData = {
       number: 1,
       parentHash: genesis.hash(),
-      difficulty: genesis.header.canonicalDifficulty(genesis),
+      difficulty: genesis.canonicalDifficulty(genesis),
       gasLimit,
       timestamp: genesis.header.timestamp.addn(1),
     }
@@ -595,7 +595,7 @@ tape('blockchain test', (t) => {
       header: {
         number: 1,
         parentHash: genesis.hash(),
-        difficulty: genesis.header.canonicalDifficulty(genesis),
+        difficulty: genesis.canonicalDifficulty(genesis),
         timestamp: genesis.header.timestamp.addn(3),
         gasLimit,
       },
@@ -605,7 +605,7 @@ tape('blockchain test', (t) => {
     const headerData1 = {
       number: 1,
       parentHash: genesis.hash(),
-      difficulty: genesis.header.canonicalDifficulty(genesis),
+      difficulty: genesis.canonicalDifficulty(genesis),
       timestamp: genesis.header.timestamp.addn(1),
       gasLimit,
     }
@@ -615,7 +615,7 @@ tape('blockchain test', (t) => {
     const headerData2 = {
       number: 2,
       parentHash: header1.hash(),
-      difficulty: header1.canonicalDifficulty(block),
+      difficulty: header1.canonicalDifficulty(block.header),
       timestamp: header1.timestamp.addn(1),
       gasLimit,
     }
@@ -655,7 +655,7 @@ tape('blockchain test', (t) => {
       header: {
         number: 1,
         parentHash: genesis.hash(),
-        difficulty: genesis.header.canonicalDifficulty(genesis),
+        difficulty: genesis.canonicalDifficulty(genesis),
         timestamp: genesis.header.timestamp.addn(1),
         gasLimit,
       },

packages/blockchain/test/util.ts

@@ -22,7 +22,7 @@ export const generateBlocks = (numberOfBlocks: number, existingBlocks?: Block[])
       header: {
         number: i,
         parentHash: lastBlock.hash(),
-        difficulty: lastBlock.header.canonicalDifficulty(lastBlock),
+        difficulty: lastBlock.canonicalDifficulty(lastBlock),
         gasLimit,
         timestamp: lastBlock.header.timestamp.addn(1),
       },