diff --git a/src/block.js b/src/block.js
index 6f4721a..cb593ac 100644
--- a/src/block.js
+++ b/src/block.js
@@ -9,10 +9,8 @@ const typeforce = require('typeforce');
const varuint = require('varuint-bitcoin');
const errorMerkleNoTxes = new TypeError('Cannot compute merkle root for zero transactions');
const errorWitnessNotSegwit = new TypeError('Cannot compute witness commit for non-segwit block');
-const errorBufferTooSmall = new Error('Buffer too small (< 80 bytes)');
-function txesHaveWitness(transactions) {
- return transactions !== undefined &&
- transactions instanceof Array &&
+function txesHaveWitnessCommit(transactions) {
+ return transactions instanceof Array &&
transactions[0] &&
transactions[0].ins &&
transactions[0].ins instanceof Array &&
@@ -21,6 +19,14 @@ function txesHaveWitness(transactions) {
transactions[0].ins[0].witness instanceof Array &&
transactions[0].ins[0].witness.length > 0;
}
+function anyTxHasWitness(transactions) {
+ return transactions instanceof Array &&
+ transactions.some(tx => typeof tx === 'object' &&
+ tx.ins instanceof Array &&
+ tx.ins.some(input => typeof input === 'object' &&
+ input.witness instanceof Array &&
+ input.witness.length > 0));
+}
class Block {
constructor() {
this.version = 1;
@@ -34,7 +40,7 @@ class Block {
}
static fromBuffer(buffer) {
if (buffer.length < 80)
- throw errorBufferTooSmall;
+ throw new Error('Buffer too small (< 80 bytes)');
let offset = 0;
const readSlice = (n) => {
offset += n;
@@ -75,18 +81,10 @@ class Block {
const tx = readTransaction();
block.transactions.push(tx);
}
+ let witnessCommit = block.getWitnessCommit();
// This Block contains a witness commit
- if (block.hasWitnessCommit()) {
- // The merkle root for the witness data is in an OP_RETURN output.
- // There is no rule for the index of the output, so use filter to find it.
- // The root is prepended with 0xaa21a9ed so check for 0x6a24aa21a9ed
- // If multiple commits are found, the output with highest index is assumed.
- let witnessCommits = block.transactions[0].outs
- .filter(out => out.script.slice(0, 6).equals(Buffer.from('6a24aa21a9ed', 'hex')))
- .map(out => out.script.slice(6, 38));
- // Use the commit with the highest output (should only be one though)
- block.witnessCommit = witnessCommits[witnessCommits.length - 1];
- }
+ if (witnessCommit)
+ block.witnessCommit = witnessCommit;
return block;
}
static fromHex(hex) {
@@ -103,7 +101,7 @@ class Block {
typeforce([{ getHash: types.Function }], transactions);
if (transactions.length === 0)
throw errorMerkleNoTxes;
- if (forWitness && !txesHaveWitness(transactions))
+ if (forWitness && !txesHaveWitnessCommit(transactions))
throw errorWitnessNotSegwit;
const hashes = transactions.map(transaction => transaction.getHash(forWitness));
const rootHash = fastMerkleRoot(hashes, bcrypto.hash256);
@@ -111,8 +109,34 @@ class Block {
? bcrypto.hash256(Buffer.concat([rootHash, transactions[0].ins[0].witness[0]]))
: rootHash;
}
+ getWitnessCommit() {
+ if (!txesHaveWitnessCommit(this.transactions))
+ return null;
+ // The merkle root for the witness data is in an OP_RETURN output.
+ // There is no rule for the index of the output, so use filter to find it.
+ // The root is prepended with 0xaa21a9ed so check for 0x6a24aa21a9ed
+ // If multiple commits are found, the output with highest index is assumed.
+ let witnessCommits = this.transactions[0].outs
+ .filter(out => out.script.slice(0, 6).equals(Buffer.from('6a24aa21a9ed', 'hex')))
+ .map(out => out.script.slice(6, 38));
+ if (witnessCommits.length === 0)
+ return null;
+ // Use the commit with the highest output (should only be one though)
+ let result = witnessCommits[witnessCommits.length - 1];
+ if (!(result instanceof Buffer && result.length === 32))
+ return null;
+ return result;
+ }
hasWitnessCommit() {
- return txesHaveWitness(this.transactions);
+ if (this.witnessCommit instanceof Buffer &&
+ this.witnessCommit.length === 32)
+ return true;
+ if (this.getWitnessCommit() !== null)
+ return true;
+ return false;
+ }
+ hasWitness() {
+ return anyTxHasWitness(this.transactions);
}
byteLength(headersOnly) {
if (headersOnly || !this.transactions)
@@ -168,8 +192,13 @@ class Block {
return this.toBuffer(headersOnly).toString('hex');
}
checkTxRoots() {
+ // If the Block has segwit transactions but no witness commit,
+ // there's no way it can be valid, so fail the check.
+ let hasWitnessCommit = this.hasWitnessCommit();
+ if (!hasWitnessCommit && this.hasWitness())
+ return false;
return this.__checkMerkleRoot() &&
- (this.hasWitnessCommit() ? this.__checkWitnessCommit() : true);
+ (hasWitnessCommit ? this.__checkWitnessCommit() : true);
}
checkMerkleRoot() {
console.warn('Deprecation Warning: Block method checkMerkleRoot will be ' +
diff --git a/ts_src/block.ts b/ts_src/block.ts
index e5ea071..e3d1fc5 100644
--- a/ts_src/block.ts
+++ b/ts_src/block.ts
@@ -9,11 +9,9 @@ const varuint = require('varuint-bitcoin')
const errorMerkleNoTxes = new TypeError('Cannot compute merkle root for zero transactions')
const errorWitnessNotSegwit = new TypeError('Cannot compute witness commit for non-segwit block')
-const errorBufferTooSmall = new Error('Buffer too small (< 80 bytes)')
-function txesHaveWitness (transactions: Array<Transaction>): boolean {
- return transactions !== undefined &&
- transactions instanceof Array &&
+function txesHaveWitnessCommit (transactions: Array<Transaction>): boolean {
+ return transactions instanceof Array &&
transactions[0] &&
transactions[0].ins &&
transactions[0].ins instanceof Array &&
@@ -23,6 +21,19 @@ function txesHaveWitness (transactions: Array<Transaction>): boolean {
transactions[0].ins[0].witness.length > 0
}
+function anyTxHasWitness (transactions: Array<Transaction>): boolean {
+ return transactions instanceof Array &&
+ transactions.some(tx =>
+ typeof tx === 'object' &&
+ tx.ins instanceof Array &&
+ tx.ins.some(input =>
+ typeof input === 'object' &&
+ input.witness instanceof Array &&
+ input.witness.length > 0
+ )
+ )
+}
+
export class Block {
version: number
prevHash?: Buffer
@@ -45,7 +56,7 @@ export class Block {
}
static fromBuffer (buffer: Buffer): Block {
- if (buffer.length < 80) throw errorBufferTooSmall
+ if (buffer.length < 80) throw new Error('Buffer too small (< 80 bytes)')
let offset: number = 0
const readSlice = (n: number): Buffer => {
@@ -95,19 +106,9 @@ export class Block {
block.transactions.push(tx)
}
+ let witnessCommit = block.getWitnessCommit()
// This Block contains a witness commit
- if (block.hasWitnessCommit()) {
- // The merkle root for the witness data is in an OP_RETURN output.
- // There is no rule for the index of the output, so use filter to find it.
- // The root is prepended with 0xaa21a9ed so check for 0x6a24aa21a9ed
- // If multiple commits are found, the output with highest index is assumed.
- let witnessCommits = block.transactions[0].outs
- .filter(out => out.script.slice(0, 6).equals(Buffer.from('6a24aa21a9ed', 'hex')))
- .map(out => out.script.slice(6, 38))
-
- // Use the commit with the highest output (should only be one though)
- block.witnessCommit = witnessCommits[witnessCommits.length - 1]
- }
+ if (witnessCommit) block.witnessCommit = witnessCommit
return block
}
@@ -127,7 +128,7 @@ export class Block {
static calculateMerkleRoot (transactions: Array<Transaction>, forWitness?: boolean): Buffer {
typeforce([{ getHash: types.Function }], transactions)
if (transactions.length === 0) throw errorMerkleNoTxes
- if (forWitness && !txesHaveWitness(transactions)) throw errorWitnessNotSegwit
+ if (forWitness && !txesHaveWitnessCommit(transactions)) throw errorWitnessNotSegwit
const hashes = transactions.map(transaction => transaction.getHash(forWitness!))
@@ -138,8 +139,33 @@ export class Block {
: rootHash
}
+ getWitnessCommit (): Buffer | null {
+ if (!txesHaveWitnessCommit(this.transactions!)) return null
+
+ // The merkle root for the witness data is in an OP_RETURN output.
+ // There is no rule for the index of the output, so use filter to find it.
+ // The root is prepended with 0xaa21a9ed so check for 0x6a24aa21a9ed
+ // If multiple commits are found, the output with highest index is assumed.
+ let witnessCommits = this.transactions![0].outs
+ .filter(out => out.script.slice(0, 6).equals(Buffer.from('6a24aa21a9ed', 'hex')))
+ .map(out => out.script.slice(6, 38))
+ if (witnessCommits.length === 0) return null
+ // Use the commit with the highest output (should only be one though)
+ let result = witnessCommits[witnessCommits.length - 1]
+
+ if (!(result instanceof Buffer && result.length === 32)) return null
+ return result
+ }
+
hasWitnessCommit (): boolean {
- return txesHaveWitness(this.transactions!)
+ if (this.witnessCommit instanceof Buffer &&
+ this.witnessCommit.length === 32) return true
+ if (this.getWitnessCommit() !== null) return true
+ return false
+ }
+
+ hasWitness (): boolean {
+ return anyTxHasWitness(this.transactions!)
}
byteLength (headersOnly: boolean): number {
@@ -209,8 +235,12 @@ export class Block {
}
checkTxRoots (): boolean {
+ // If the Block has segwit transactions but no witness commit,
+ // there's no way it can be valid, so fail the check.
+ let hasWitnessCommit = this.hasWitnessCommit()
+ if (!hasWitnessCommit && this.hasWitness()) return false
return this.__checkMerkleRoot() &&
- (this.hasWitnessCommit() ? this.__checkWitnessCommit() : true)
+ (hasWitnessCommit ? this.__checkWitnessCommit() : true)
}
checkMerkleRoot (): boolean {
diff --git a/types/block.d.ts b/types/block.d.ts
index 3ff2926..8b4f2f1 100644
--- a/types/block.d.ts
+++ b/types/block.d.ts
@@ -14,7 +14,9 @@ export declare class Block {
static fromHex(hex: string): Block;
static calculateTarget(bits: number): Buffer;
static calculateMerkleRoot(transactions: Array<Transaction>, forWitness?: boolean): Buffer;
+ getWitnessCommit(): Buffer | null;
hasWitnessCommit(): boolean;
+ hasWitness(): boolean;
byteLength(headersOnly: boolean): number;
getHash(): Buffer;
getId(): string;