From 2c8ee40a9a80ed6f4c4f91cbb1d4222913ff5104 Mon Sep 17 00:00:00 2001
From: Kiyomichi Kosaka <ddeus.kkhub@mailnull.com>
Date: Mon, 5 Apr 2021 13:07:27 +0200
Subject: [PATCH] Make HD wallet compatible with wallets generated on
 https://bip32.org and bitcoin-cli.

---
 index.html    | 17 +++++++++++++++--
 js/coin.js    |  8 +++++++-
 js/coinbin.js | 17 ++++++++++++++---
 3 files changed, 36 insertions(+), 6 deletions(-)

diff --git a/index.html b/index.html
index 691dbd5b..da938878 100644
--- a/index.html
+++ b/index.html
@@ -1193,14 +1193,14 @@ <h4>Key Derivation</h4>
 							<div class="row">
 								<div class="col-md-8">
 									<b>Path</b><br>
-									<select class="form-control" id="hdpathtype"">
+									<select class="form-control" id="hdpathtype">
 										<option value="simple">Simple: m/i</option>
 										<option value="custom">Custom</option>
 									</select>
 
 									<div id="hdpath" class="hidden" style="margin-top:4px">
 										<span class="input-group">
-											<input type="text" class="form-control" value="m/0/1">  <br>
+											<input type="text" class="form-control" value="m/0/1" title="WARNING: see #settings page when using hardened paths!">  <br>
 											<span class="input-group-addon"> / </span>
 										</span>
 									</div>
@@ -1456,6 +1456,19 @@ <h2>Settings <small> making coinb.in even better!</small></h2>
 							</div>
 						</div>
 
+						<hr>
+
+						<div class="row">
+							<div class="col-md-12">
+								<b>HD wallet hardened path derivation</b>: <br>
+								<p class="text-muted">The path derivation for hardened paths was calculated wrong in earlier versions of coinb.in. Please select the old path derivation to recover HD wallet keys generated with older version of coinb.in.</p>
+								<select class="form-control" id="coinjs_derivation">
+									<option value="bip32_derivation">BIP32 compliant derivation</option>
+									<option value="coinbin_broken">Old (broken) coinb.in path derivation</option>
+								</select>
+							</div>
+						</div>
+
 						<br>
 
 						<div id="statusSettings" class="hidden alert">
diff --git a/js/coin.js b/js/coin.js
index d8f5388f..3e1aa924 100644
--- a/js/coin.js
+++ b/js/coin.js
@@ -18,6 +18,8 @@
 
 	coinjs.compressed = false;
 
+	coinjs.hd_derivation = "bip32_derivation";
+
 	/* other vars */
 	coinjs.developer = '33tht1bKDgZVxb39MnZsWa8oxHXHvUYE4G'; //bitcoin
 
@@ -685,7 +687,11 @@
 		r.derive = function(i){
 
 			i = (i)?i:0;
-			var blob = (Crypto.util.hexToBytes(this.keys.pubkey)).concat(coinjs.numToBytes(i,4).reverse());
+			if ((i >= 0x80000000) && (coinjs.hd_derivation == "bip32_derivation")) {
+				var blob = (Crypto.util.hexToBytes("00").concat(Crypto.util.hexToBytes(this.keys.privkey)).concat(coinjs.numToBytes(i,4).reverse()));
+			} else {
+				var blob = (Crypto.util.hexToBytes(this.keys.pubkey)).concat(coinjs.numToBytes(i,4).reverse());
+			}
 
 			var j = new jsSHA(Crypto.util.bytesToHex(blob), 'HEX');
  			var hash = j.getHMAC(Crypto.util.bytesToHex(r.chain_code), "HEX", "SHA-512", "HEX");
diff --git a/js/coinbin.js b/js/coinbin.js
index afc98f17..1a3cccba 100644
--- a/js/coinbin.js
+++ b/js/coinbin.js
@@ -1701,15 +1701,23 @@ $(document).ready(function() {
 
 	function deriveHDaddress() {
 		var hd = coinjs.hd($("#verifyHDaddress .hdKey").html());
-		var index_start = $("#verifyHDaddress .derivation_index_start").val()*1;
-		var index_end = $("#verifyHDaddress .derivation_index_end").val()*1;
+		var index_start = $("#verifyHDaddress .derivation_index_start").val();
+		if ((index_start.length > 1) && (index_start[index_start.length - 1] == '\'')) {
+			var use_private_index = '\'';
+			index_start = index_start.replace(/[']/, "") * 1;
+		} else {
+			var use_private_index = '';
+			index_start = index_start.replace(/[']/, "") * 1;
+		}
+		var index_end = $("#verifyHDaddress .derivation_index_end").val().replace(/[']/, "") * 1;
+		$("#verifyHDaddress .derivation_index_end").val(index_end + use_private_index);
 		var html = '';
 		$("#verifyHDaddress .derived_data table tbody").html("");
 		for(var i=index_start;i<=index_end;i++){
 			if($("#hdpathtype option:selected").val()=='simple'){
 				var derived = hd.derive(i);
 			} else {
-				var derived = hd.derive_path(($("#hdpath input").val().replace(/\/+$/, ""))+'/'+i);
+				var derived = hd.derive_path(($("#hdpath input").val().replace(/\/+$/, ""))+'/'+i+use_private_index);
 			}
 			html += '<tr>';
 			html += '<td>'+i+'</td>';
@@ -1914,6 +1922,8 @@ $(document).ready(function() {
 			coinjs.hdkey.pub =  $("#coinjs_hdpub").val()*1;
 			coinjs.hdkey.prv =  $("#coinjs_hdprv").val()*1;
 
+			coinjs.hd_derivation =  $("#coinjs_derivation").val();
+
 			configureBroadcast();
 			configureGetUnspentTx();
 
@@ -1959,6 +1969,7 @@ $(document).ready(function() {
 		$("#coinjs_multisig").val(o[2]);
 		$("#coinjs_hdpub").val(o[3]);
 		$("#coinjs_hdprv").val(o[4]);
+		$("#coinjs_derivation").val(o[7]);
 
 		// hide/show custom screen
 		if($("option:selected",this).val()=="custom"){