HD: encode x/y/z purpose to database

lib/hd/private.js

@@ -42,7 +42,7 @@ class HDPrivateKey {
    * Create an hd private key.
    * @constructor
    * @param {Object|String} options
-   * @param {string} options.keyType
+   * @param {string} options.purpose
    * @param {Number?} options.depth
    * @param {Number?} options.parentFingerPrint
    * @param {Number?} options.childIndex
@@ -51,7 +51,7 @@ class HDPrivateKey {
    */
 
   constructor(options) {
-    this.keyType = 'x';
+    this.purpose = 'x';
     this.depth = 0;
     this.parentFingerPrint = 0;
     this.childIndex = 0;
@@ -81,14 +81,14 @@ class HDPrivateKey {
     assert(Buffer.isBuffer(options.chainCode));
     assert(Buffer.isBuffer(options.privateKey));
 
-    if (options.keyType){
+    if (options.purpose) {
       assert(
-        ['x','y','z'].indexOf(options.keyType) !== -1,
-        'Bad key type'
+        ['x','y','z'].indexOf(options.purpose) !== -1,
+        'Bad purpose'
       );
-      this.keyType = options.keyType;
+      this.purpose = options.purpose;
     } else {
-      this.keyType = 'x';
+      this.purpose = 'x';
     }
 
     this.depth = options.depth;
@@ -121,7 +121,7 @@ class HDPrivateKey {
 
     if (!key) {
       key = new HDPublicKey();
-      key.keyType = this.keyType;
+      key.purpose = this.purpose;
       key.depth = this.depth;
       key.parentFingerPrint = this.parentFingerPrint;
       key.childIndex = this.childIndex;
@@ -231,7 +231,7 @@ class HDPrivateKey {
     }
 
     const child = new this.constructor();
-    child.keyType = this.keyType;
+    child.purpose = this.purpose;
     child.depth = this.depth + 1;
     child.parentFingerPrint = this.fingerPrint;
     child.childIndex = index;
@@ -450,7 +450,7 @@ class HDPrivateKey {
     if (!secp256k1.privateKeyVerify(left))
       throw new Error('Master private key is invalid.');
 
-    this.keyType = 'x';
+    this.purpose = 'x';
     this.depth = 0;
     this.parentFingerPrint = 0;
     this.childIndex = 0;
@@ -578,30 +578,28 @@ class HDPrivateKey {
 
   fromReader(br, network) {
     const version = br.readU32BE();
-
     const confirmNetwork = Network.fromPrivate(version, network);
-    
-    let type = null;
-    for (const label in confirmNetwork.keyPrefix){
-      if (confirmNetwork.keyPrefix[label] === version){
-        type = label;
+
+    let purpose = null;
+    for (const label in confirmNetwork.keyPrefix) {
+      if (confirmNetwork.keyPrefix[label] === version) {
+        purpose = label;
         break;
       }
     }
 
-    switch (type) {
+    switch (purpose) {
       case 'xprivkey':
-        this.keyType = 'x';
+        this.purpose = 'x';
         break;
       case 'yprivkey':
-        this.keyType = 'y';
+        this.purpose = 'y';
         break;
       case 'zprivkey':
-        this.keyType = 'z';
+        this.purpose = 'z';
         break;
       default:
-        throw new Error('Bad version/type bytes');
-        break;
+        throw new Error('Bad purpose bytes');
     }
 
     this.depth = br.readU8();
@@ -656,16 +654,16 @@ class HDPrivateKey {
   toWriter(bw, network) {
     network = Network.get(network);
 
-    switch (this.keyType) {
+    switch (this.purpose) {
+      case 'x':
+        bw.writeU32BE(network.keyPrefix.xprivkey);
+        break;
       case 'y':
         bw.writeU32BE(network.keyPrefix.yprivkey);
         break;
       case 'z':
         bw.writeU32BE(network.keyPrefix.zprivkey);
         break;
-      case 'x':
-      default:
-        bw.writeU32BE(network.keyPrefix.xprivkey);
     }
     bw.writeU8(this.depth);
     bw.writeU32BE(this.parentFingerPrint);

lib/hd/public.js

@@ -34,7 +34,7 @@ class HDPublicKey {
    * @constructor
    * @param {Object|Base58String} options
    * @param {Base58String?} options.xkey - Serialized base58 key.
-   * @param {string} options.keyType
+   * @param {string} options.purpose
    * @param {Number?} options.depth
    * @param {Number?} options.parentFingerPrint
    * @param {Number?} options.childIndex
@@ -43,7 +43,7 @@ class HDPublicKey {
    */
 
   constructor(options) {
-    this.keyType = 'x';
+    this.purpose = 'x';
     this.depth = 0;
     this.parentFingerPrint = 0;
     this.childIndex = 0;
@@ -70,14 +70,14 @@ class HDPublicKey {
     assert(Buffer.isBuffer(options.chainCode));
     assert(Buffer.isBuffer(options.publicKey));
 
-    if (options.keyType){
+    if (options.purpose) {
       assert(
-        ['x','y','z'].indexOf(options.keyType) !== -1,
-        'Bad key type'
+        ['x','y','z'].indexOf(options.purpose) !== -1,
+        'Bad purpose'
       );
-      this.keyType = options.keyType;
+      this.purpose = options.purpose;
     } else {
-      this.keyType = 'x';
+      this.purpose = 'x';
     }
 
     this.depth = options.depth;
@@ -448,27 +448,26 @@ class HDPublicKey {
 
     const confirmNetwork = Network.fromPublic(version, network);
 
-    let type = null;
-    for (const label in confirmNetwork.keyPrefix){
-      if (confirmNetwork.keyPrefix[label] === version){
-        type = label;
+    let purpose = null;
+    for (const label in confirmNetwork.keyPrefix) {
+      if (confirmNetwork.keyPrefix[label] === version) {
+        purpose = label;
         break;
       }
     }
 
-    switch (type) {
+    switch (purpose) {
       case 'xpubkey':
-        this.keyType = 'x';
+        this.purpose = 'x';
         break;
       case 'ypubkey':
-        this.keyType = 'y';
+        this.purpose = 'y';
         break;
       case 'zpubkey':
-        this.keyType = 'z';
+        this.purpose = 'z';
         break;
       default:
-        throw new Error('Bad version/type bytes');
-        break;
+        throw new Error('Bad purpose bytes');
     }
 
     this.depth = br.readU8();
@@ -507,22 +506,22 @@ class HDPublicKey {
    * Write the key to a buffer writer.
    * @param {BufferWriter} bw
    * @param {(Network|NetworkType)?} network
-   * @param {string} type 
+   * @param {string} type
    */
 
   toWriter(bw, network) {
     network = Network.get(network);
 
-    switch (this.keyType) {
+    switch (this.purpose) {
+      case 'x':
+        bw.writeU32BE(network.keyPrefix.xpubkey);
+        break;
       case 'y':
         bw.writeU32BE(network.keyPrefix.ypubkey);
         break;
       case 'z':
         bw.writeU32BE(network.keyPrefix.zpubkey);
         break;
-      case 'x':
-      default:
-        bw.writeU32BE(network.keyPrefix.xpubkey);
     }
     bw.writeU8(this.depth);
     bw.writeU32BE(this.parentFingerPrint);

lib/primitives/keyring.js

@@ -624,7 +624,7 @@ class KeyRing {
    */
 
   getAddress(enc, network) {
-    if (this.nested || this.addressFromKeyType === 'y')
+    if (this.nested || this.purpose === 'y')
       return this.getNestedAddress(enc, network);
 
     if (this.script)

lib/wallet/account.js

@@ -45,7 +45,7 @@ class Account {
     this.initialized = false;
     this.witness = wdb.options.witness === true;
     this.watchOnly = false;
-    this.keyType = 'x',
+    this.purpose = 'x',
     this.type = Account.types.PUBKEYHASH;
     this.m = 1;
     this.n = 1;
@@ -103,16 +103,16 @@ class Account {
       this.watchOnly = options.watchOnly;
     }
 
-    if (options.keyType != null) {
-      assert(typeof options.keyType === 'string');
+    if (options.purpose != null) {
+      assert(typeof options.purpose === 'string');
       assert(
-        ['x','y','z'].indexOf(options.keyType) !== -1,
-        'Bad key type'
+        ['x','y','z'].indexOf(options.purpose) !== -1,
+        'Bad purpose'
       );
-      this.keyType = options.keyType;
+      this.purpose = options.purpose;
     }
 
-    if (this.keyType === 'y' || this.keyType === 'z')
+    if (this.purpose === 'y' || this.purpose === 'z')
       this.witness = true;
 
     if (options.type != null) {
@@ -482,8 +482,8 @@ class Account {
     let key;
     if (master && master.key && !this.watchOnly) {
       const coinType = this.network.keyPrefix.coinType;
-      
-      switch (this.keyType) {
+
+      switch (this.purpose) {
         case 'x':
           key = master.key.deriveAccount(44, coinType, this.accountIndex);
           break;
@@ -500,7 +500,7 @@ class Account {
       key = this.accountKey.derive(branch).derive(index);
     }
 
-    key.keyType = this.keyType;
+    key.purpose = this.purpose;
     const ring = WalletKey.fromHD(this, key, branch, index);
 
     switch (this.type) {
@@ -563,9 +563,6 @@ class Account {
 
     for (let i = 0; i <= this.lookahead; i++) {
       const key = this.deriveReceive(i);
-
-console.log(key);  // ------ right here, the address is correct (nested)
-
       await this.saveKey(b, key);
     }
 
@@ -893,6 +890,9 @@ console.log(key);  // ------ right here, the address is correct (nested)
     if (this.witness)
       flags |= 2;
 
+    const purposeBits = Account.purposes[this.purpose];
+    flags |= (purposeBits << 6);
+
     bw.writeU8(flags);
     bw.writeU8(this.type);
     bw.writeU8(this.m);
@@ -921,6 +921,9 @@ console.log(key);  // ------ right here, the address is correct (nested)
     const br = bio.read(data);
     const flags = br.readU8();
 
+    const purposeBits = flags >> 6;
+    this.purpose = Account.purposesByVal[purposeBits];
+
     this.initialized = (flags & 1) !== 0;
     this.witness = (flags & 2) !== 0;
     this.type = br.readU8();
@@ -931,7 +934,6 @@ console.log(key);  // ------ right here, the address is correct (nested)
     this.nestedDepth = br.readU32();
     this.lookahead = br.readU8();
     this.accountKey = readKey(br);
-
     assert(this.type < Account.typesByVal.length);
 
     const count = br.readU8();
@@ -987,6 +989,26 @@ Account.typesByVal = [
   'MULTISIG'
 ];
 
+/**
+ * Account purposes.
+ * @enum {Number}
+ * @default
+ */
+
+Account.purposes = {
+  x: 0,
+  y: 1,
+  z: 2
+};
+
+/**
+ * Account purposes by value.
+ * @enum {Number}
+ * @default
+ */
+
+Account.purposesByVal = ['x', 'y', 'z'];
+
 /**
  * Default address lookahead.
  * @const {Number}

lib/wallet/wallet.js

@@ -58,7 +58,7 @@ class Wallet extends EventEmitter {
     this.writeLock = new Lock();
     this.fundLock = new Lock();
 
-    this.keyType = 'x';
+    this.purpose = 'x';
     this.wid = 0;
     this.id = null;
     this.watchOnly = false;
@@ -95,7 +95,7 @@ class Wallet extends EventEmitter {
       assert(HD.isPrivate(key),
         'Must create wallet with hd private key.');
 
-      this.keyType = key.keyType;
+      this.purpose = key.purpose;
     } else {
       mnemonic = new Mnemonic(options.mnemonic);
       key = HD.fromMnemonic(mnemonic, options.password);
@@ -596,11 +596,11 @@ class Wallet extends EventEmitter {
       if (!HD.isPublic(key))
         throw new Error('Must add HD public keys to watch only wallet.');
 
-      this.keyType = key.keyType;
+      this.purpose = key.purpose;
     } else {
       assert(this.master.key);
       const coinType = this.network.keyPrefix.coinType;
-      switch (this.keyType) {
+      switch (this.purpose) {
         case 'x':
           key = this.master.key.deriveAccount(44, coinType, this.accountDepth);
           break;
@@ -623,7 +623,7 @@ class Wallet extends EventEmitter {
       accountKey: key,
       accountIndex: this.accountDepth,
       type: options.type,
-      keyType: this.keyType,
+      purpose: this.purpose,
       m: options.m,
       n: options.n,
       keys: options.keys