Derive additional change addresses for postmix account

lib/bitcoin/hd-accounts-helper.js

@@ -16,6 +16,7 @@ const activeNet = network.network
 const keys = require('../../keys/')[network.key]
 const addrHelper = require('./addresses-helper')
 
+const MAX_SAFE_INT_32 = Math.pow(2, 31) - 1;
 
 /**
  * A singleton providing HD Accounts helper functions
@@ -32,6 +33,12 @@ class HDAccountsHelper {
     this.BIP84  = 2
     this.LOCKED = 1<<7
 
+    // known HD accounts
+    this.RICOCHET_ACCT = MAX_SAFE_INT_32;
+    this.POSTMIX_ACCT = MAX_SAFE_INT_32 - 1;
+    this.PREMIX_ACCT = MAX_SAFE_INT_32 - 2;
+    this.BADBANK_ACCT = MAX_SAFE_INT_32 - 3;
+
     // Magic numbers
     this.MAGIC_XPUB = 0x0488b21e
     this.MAGIC_TPUB = 0x043587cf
@@ -292,7 +299,7 @@ class HDAccountsHelper {
    * @param {bip32} chainNode - Parent bip32 used for derivation
    * @param {number} index - index to be derived
    * @param {number} type - type of derivation
-   * @returns {Promise<object>} returns an object {address: '...', chain: <int>, index: <int>}
+   * @returns {Promise<object>} returns an object {address: '...', chain: <int>, index: <int>, publicKey: <Buffer>}
    */
   async deriveAddress(chain, chainNode, index, type) {
     // Derive M/chain/index
@@ -300,7 +307,8 @@ class HDAccountsHelper {
 
     const addr = {
       chain: chain,
-      index: index
+      index: index,
+      publicKey: indexNode.publicKey
     }
 
     switch (type) {
@@ -344,6 +352,13 @@ class HDAccountsHelper {
 
       const info = this.classify(type)
 
+      // Detect postmix account
+      const index = node[2].index
+      const threshold = Math.pow(2,31)
+      const hardened = (index >= threshold)
+      const account = hardened ? (index - threshold) : index
+      const isPostmixAcct = account === this.POSTMIX_ACCT
+
       // Node at M/chain
       const chainNode = node[chain]
 
@@ -355,10 +370,18 @@ class HDAccountsHelper {
       ) {
         // Few addresses to be derived or external derivation deactivated
         // Let's do it here
-        let promises = indices.map(index => {
+        const addresses = await Promise.all(indices.map(index => {
           return this.deriveAddress(chain, chainNode, index, info.type)
-        })
-        return Promise.all(promises)
+        }))
+
+        // Generate additional change address types for postmix account
+        if (isPostmixAcct && chain === 1) {
+          const additionalPostmixAddresses = this.generateAdditionalChangeAddresses(addresses)
+
+          addresses.push(...additionalPostmixAddresses)
+        }
+
+        return addresses;
 
       } else {
         // Many addresses to be derived
@@ -375,6 +398,13 @@ class HDAccountsHelper {
             const msg = await this.derivationPool.exec('deriveAddresses', [data])
 
             if (msg.status === 'ok') {
+              // Generate additional change address types for postmix account
+              if (isPostmixAcct && chain === 1) {
+                const additionalPostmixAddresses = this.generateAdditionalChangeAddresses(msg.addresses)
+
+                msg.addresses.push(...additionalPostmixAddresses)
+              }
+
               resolve(msg.addresses)
             } else {
               Logger.error(null, 'HdAccountsHelper : A problem was met during parallel addresses derivation')
@@ -393,6 +423,25 @@ class HDAccountsHelper {
     }
   }
 
+  /**
+   * @description Derive additional change addresses (P2PKH & P2SH) for postmix account
+   * @param addresses {object[]} - list of derived addresses
+   * @returns {Array<object>} - array of additional address types
+   */
+  generateAdditionalChangeAddresses(addresses) {
+    const additionalPostmixAddresses = addresses.map((address) => {
+      const newP2PKHAddress = {...address}
+      const newP2SHAddress = {...address}
+
+      newP2PKHAddress.address = addrHelper.p2pkhAddress(address.publicKey)
+      newP2SHAddress.address = addrHelper.p2wpkhP2shAddress(address.publicKey)
+
+      return [newP2PKHAddress, newP2SHAddress];
+    })
+
+    return additionalPostmixAddresses.flat()
+  }
+
 }
 
 module.exports = new HDAccountsHelper()

lib/bitcoin/hd-accounts-service.js

@@ -152,8 +152,8 @@ class HDAccountsService {
   /**
    * Rescan the blockchain for a hd account
    * @param {string} xpub - xpub
-   * @param {number} gapLimit - (optional) gap limit for derivation
-   * @param {number} startIndex - (optional) rescan shall start from this index
+   * @param {number=} gapLimit - (optional) gap limit for derivation
+   * @param {number=} startIndex - (optional) rescan shall start from this index
    * @returns {Promise}
    */
   async rescan(xpub, gapLimit, startIndex) {

lib/bitcoin/parallel-address-derivation.js

@@ -25,7 +25,7 @@ const BIP84  = 2
  * @param {bip32} chainNode - Parent bip32 used for derivation
  * @param {number} index - index to be derived
  * @param {number} type - type of derivation
- * @returns {Promise<object>} returns an object {address: '...', chain: <int>, index: <int>}
+ * @returns {Promise<object>} returns an object {address: '...', chain: <int>, index: <int>, publicKey: <Buffer>}
  */
 async function deriveAddress(chain, chainNode, index, type) {
   // Derive M/chain/index
@@ -33,7 +33,8 @@ async function deriveAddress(chain, chainNode, index, type) {
 
   const addr = {
     chain: chain,
-    index: index
+    index: index,
+    publicKey: indexNode.publicKey
   }
 
   switch (type) {

tracker/transaction.js

@@ -365,7 +365,8 @@ class Transaction {
         const indices = _.range(minIdx, maxIdx)
 
         const derived = await hdaHelper.deriveAddresses(xpub, chain, indices, hdType)
-        Array.prototype.push.apply(newAddresses, derived)
+
+        newAddresses.push(...derived)
 
         Logger.info(`Tracker : Derived hdID(${hdAccount.hdID}) M/${chain}/${indices.join(',')}`)