Merge PR #1162 from 'Vasu-08/descriptor-3'

lib/descriptor/abstractdescriptor.js

@@ -39,6 +39,7 @@ const stringType = {
  * (size 1 for PK, PKH, WPKH; any size for WSH and Multisig).
  * @property {AbstractDescriptor[]} subdescriptors - sub-descriptor arguments
  * for the descriptor (empty for everything but SH and WSH)
+ * @property {String} scriptContext
  * @property {Network} network
  */
 
@@ -52,6 +53,7 @@ class AbstractDescriptor {
     this.type = null;
     this.keyProviders = [];
     this.subdescriptors = [];
+    this.scriptContext = common.scriptContext.TOP;
     this.network = null;
   }
 
@@ -232,6 +234,58 @@ class AbstractDescriptor {
   isSingleType() {
     return true;
   }
+
+  /**
+   * Get scripts for the descriptor at a specified position.
+   * @param {Number} pos
+   * @returns {Script[]}
+   */
+
+  generateScripts(pos) {
+    const pubkeys = [];
+    const subscripts = [];
+
+    for (const subdesc of this.subdescriptors) {
+      const outscripts = subdesc.generateScripts(pos);
+      assert(outscripts.length === 1);
+      subscripts.push(outscripts[0]);
+    }
+
+    for (const provider of this.keyProviders) {
+      const pubkey = provider.getPublicKey(pos);
+      pubkeys.push(pubkey);
+    }
+
+    return this._getScripts(pubkeys, subscripts);
+  }
+
+  /**
+   * Get the scripts (helper function).
+   * @returns {Script[]}
+   */
+
+  _getScripts() {
+    throw new Error('Abstract method.');
+  }
+
+  /**
+   * Derive addresses for the descriptor at a specified position.
+   * @param {Number} pos
+   * @returns {Address[]}
+   */
+
+  getAddresses(pos) {
+    const scripts = this.generateScripts(pos);
+    const addresses = [];
+
+    for (const script of scripts) {
+      const address = script.getAddress();
+      assert(address, 'Descriptor does not have a corresponding address');
+      addresses.push(address.toString(this.network));
+    }
+
+    return addresses;
+  }
 }
 
 /*

lib/descriptor/keyprovider.js

@@ -263,6 +263,24 @@ class KeyProvider {
   hasPrivateKey() {
     return this.ring.privateKey !== null;
   }
+
+  /**
+   * Get the public key
+   * @returns {Buffer}
+   */
+
+  getPublicKey() {
+    return this.ring.publicKey;
+  }
+
+  /**
+   * Get the private key (if available)
+   * @returns {Buffer}
+   */
+
+  getPrivateKey() {
+    return this.ring.privateKey;
+  }
 }
 
 /**
@@ -407,6 +425,87 @@ class HDKeyProvider extends KeyProvider {
     }
     return null;
   }
+
+  /**
+   * Derive private key at a given position..
+   * @returns {HDPrivateKey}
+   */
+
+  getHDPrivateKey(pos) {
+    assert(
+      this.hdkey.privateKey,
+      'Private key not available for hardened derivation.'
+    );
+
+    let childkey = this.hdkey;
+
+    if (this.path.length > 0) {
+      const path = 'm' + HD.common.format(this.path, this.hardenedMarker);
+      childkey = childkey.derivePath(path);
+    }
+
+    if (this.type === deriveType.UNHARDENED) {
+      childkey = childkey.derive(pos, false);
+    } else if (this.type === deriveType.HARDENED) {
+      childkey = childkey.derive(pos, true);
+    }
+
+    return childkey;
+  }
+
+  /**
+   * Derive public key at a given position
+   * @param {Number} pos
+   * @returns {HDPublicKey}
+   */
+
+  getHDPublicKey(pos) {
+    if (this.isHardened()) {
+      const childprivkey = this.getHDPrivateKey(pos);
+      return childprivkey.toPublic();
+    }
+
+    let childkey = this.hdkey;
+
+    if (this.hdkey instanceof HD.PrivateKey) {
+      childkey = this.hdkey.toPublic();
+    }
+
+    if (this.path.length > 0) {
+      const path = 'm' + HD.common.format(this.path, this.hardenedMarker);
+      childkey = childkey.derivePath(path);
+    }
+
+    if (this.type === deriveType.UNHARDENED) {
+      childkey = childkey.derive(pos);
+    }
+
+    assert(this.type !== deriveType.HARDENED);
+
+    return childkey;
+  }
+
+  /**
+   * Get public key at a given position
+   * @param {Number} pos
+   * @returns {Buffer} public key
+   */
+
+  getPublicKey(pos) {
+    const hdkey = this.getHDPublicKey(pos);
+    return hdkey.publicKey;
+  }
+
+  /**
+   * Get private key at a given position
+   * @param {Number} pos
+   * @returns {Buffer} private key
+   */
+
+  getPrivateKey(pos) {
+    const hdkey = this.getHDPrivateKey(pos);
+    return hdkey.privateKey;
+  }
 }
 
 /**
@@ -424,7 +523,7 @@ function getHardenedMarker(path) {
 
   let hardenedMarker = null;
   for (const p of path) {
-   const last = p[p.length - 1];
+    const last = p[p.length - 1];
     if (last === '\'' || last === 'h') {
       hardenedMarker = last;
     }

lib/descriptor/type/addr.js

@@ -12,13 +12,15 @@ const common = require('../common');
 const {isType, strip, checkChecksum, scriptContext, types} = common;
 const Address = require('../../primitives/address');
 const Network = require('../../protocol/network');
+const Script = require('../../script/script');
 
 /**
  * AddressDescriptor
  * Represents the output script produced by the address in the descriptor.
  * @see https://github.com/bitcoin/bips/blob/master/bip-0385.mediawiki#addr
  * @property {String} type
  * @property {Address} address
+ * @property {String} scriptContext
  * @property {Network} network
  * @extends AbstractDescriptor
  */
@@ -118,6 +120,15 @@ class AddressDescriptor extends AbstractDescriptor {
   isSolvable() {
     return false;
   }
+
+  /**
+   * Get the scripts (helper function).
+   * @returns {Script[]}
+   */
+
+  _getScripts() {
+    return [Script.fromAddress(this.address)];
+  }
 }
 
 /*

lib/descriptor/type/combo.js

@@ -12,13 +12,16 @@ const common = require('../common');
 const {isType, strip, checkChecksum, scriptContext, types} = common;
 const KeyProvider = require('../keyprovider');
 const Network = require('../../protocol/network');
+const hash160 = require('bcrypto/lib/hash160');
+const Script = require('../../script/script');
 
 /**
  * ComboDescriptor
  * Represents a P2PK, P2PKH, P2WPKH, and P2SH-P2WPKH output scripts.
  * @see https://github.com/bitcoin/bips/blob/master/bip-0384.mediawiki
  * @property {String} type
  * @property {KeyProvider[]} keyProviders
+ * @property {String} scriptContext
  * @property {Network} network
  * @extends AbstractDescriptor
  */
@@ -112,6 +115,31 @@ class ComboDescriptor extends AbstractDescriptor {
   isSolvable() {
     return true;
   }
+
+  /**
+   * Get the scripts (helper function).
+   * @param {Buffer[]} pubkeys
+   * @returns {Script[]}
+   */
+
+  _getScripts(pubkeys) {
+    assert(Array.isArray(pubkeys) && pubkeys.length === 1);
+    assert(Buffer.isBuffer(pubkeys[0]));
+
+    const scripts = [];
+    scripts.push(Script.fromPubkey(pubkeys[0])); // P2PK
+    const pubkeyhash = hash160.digest(pubkeys[0]);
+    scripts.push(Script.fromPubkeyhash(pubkeyhash)); // P2PKH
+
+    if (pubkeys[0].length === 33) {
+      const p2wpkh = Script.fromProgram(0, pubkeyhash);
+      scripts.push(p2wpkh); // P2WPKH
+      const p2sh = Script.fromScripthash(p2wpkh.hash160()); // P2SH-P2WPKH
+      scripts.push(p2sh);
+    }
+
+    return scripts;
+  }
 }
 
 /*

lib/descriptor/type/multisig.js

@@ -14,13 +14,15 @@ const {MAX_SCRIPT_PUSH, MAX_MULTISIG_PUBKEYS} = consensus;
 const KeyProvider = require('../keyprovider');
 const Network = require('../../protocol/network');
 const assert = require('bsert');
+const Script = require('../../script/script');
 
 /**
  * MultisigDescriptor
  * Represents a multisig output script.
  * @see https://github.com/bitcoin/bips/blob/master/bip-0383.mediawiki
  * @property {String} type
  * @property {KeyProvider[]} keyProviders
+ * @property {String} scriptContext
  * @property {Number} threshold
  * @property {Boolean} isSorted - true if descriptor is sortedmulti
  * @property {Network} network
@@ -148,6 +150,7 @@ class MultisigDescriptor extends AbstractDescriptor {
     this.keyProviders = providers;
     this.isSorted = isSorted;
     this.network = Network.get(network);
+    this.scriptContext = context;
 
     return this;
   }
@@ -167,6 +170,36 @@ class MultisigDescriptor extends AbstractDescriptor {
   toStringExtra() {
     return this.threshold.toString();
   }
+
+  /**
+   * Get the scripts (helper function).
+   * @param {Buffer[]} pubkeys
+   * @returns {Script[]}
+   */
+
+  _getScripts(pubkeys) {
+    assert(Array.isArray(pubkeys) && pubkeys.length > 0);
+
+    for (const pubkey of pubkeys) {
+      assert(Buffer.isBuffer(pubkey));
+    }
+
+    const m = this.threshold;
+    const n = pubkeys.length;
+    const isWitness =  this.scriptContext === scriptContext.P2WSH;
+
+    return [Script.fromMultisig(m, n, pubkeys, this.isSorted, isWitness)];
+  }
+
+  /**
+   * Derive addresses from scripts.
+   * @param {Script[]} scripts
+   * @returns {Address[]}
+   */
+
+  getAddresses(scripts) {
+    throw new Error('Descriptor does not have a corresponding address');
+  }
 }
 
 /**

lib/descriptor/type/pk.js

@@ -12,12 +12,14 @@ const {isType, strip, checkChecksum, scriptContext, types} = common;
 const assert = require('bsert');
 const KeyProvider = require('../keyprovider');
 const Network = require('../../protocol/network');
+const Script = require('../../script/script');
 
 /**
  * PKDescriptor
  * Represents a P2PK output script.
  * @see https://github.com/bitcoin/bips/blob/master/bip-0381.mediawiki#pk
  * @property {String} type
+ * @property {String} scriptContext
  * @property {KeyProvider[]} keyProviders
  * @property {Network} network
  * @extends AbstractDescriptor
@@ -88,6 +90,7 @@ class PKDescriptor extends AbstractDescriptor {
 
     this.keyProviders = [provider];
     this.network = Network.get(network);
+    this.scriptContext = context;
 
     return this;
   }
@@ -103,6 +106,19 @@ class PKDescriptor extends AbstractDescriptor {
   static fromString(str, network, context = scriptContext.TOP) {
     return new this().fromString(str, network, context);
   }
+
+  /**
+   * Get the scripts (helper function).
+   * @param {Buffer[]} pubkeys
+   * @returns {Script[]}
+   */
+
+  _getScripts(pubkeys) {
+    assert(Array.isArray(pubkeys) && pubkeys.length === 1);
+    assert(Buffer.isBuffer(pubkeys[0]));
+
+    return [Script.fromPubkey(pubkeys[0])];
+  }
 }
 
 /*