From 7b84f250c17abbaa1651194851d59ddaedc35ed9 Mon Sep 17 00:00:00 2001
From: Daniel Lugo <danlugo92@gmail.com>
Date: Tue, 3 Nov 2020 13:55:43 -0400
Subject: [PATCH] check for invoice amt mismatch

---
 services/gunDB/contact-api/actions.js | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/services/gunDB/contact-api/actions.js b/services/gunDB/contact-api/actions.js
index c067b4d3..77d72556 100644
--- a/services/gunDB/contact-api/actions.js
+++ b/services/gunDB/contact-api/actions.js
@@ -9,7 +9,10 @@ const Gun = require('gun')
 
 const { ErrorCode } = Constants
 
-const { sendPaymentV2Invoice } = require('../../../utils/lightningServices/v2')
+const {
+  sendPaymentV2Invoice,
+  decodePayReq
+} = require('../../../utils/lightningServices/v2')
 
 /**
  * @typedef {import('../../../utils/lightningServices/types').PaymentV2} PaymentV2
@@ -1040,6 +1043,21 @@ const sendSpontaneousPayment = async (
       throw new Error(orderResponse.response)
     }
 
+    logger.info('Will now check for invoice amount mismatch')
+
+    const encodedInvoice = orderResponse.response
+
+    const { num_satoshis: decodedAmt } = await decodePayReq(encodedInvoice)
+
+    if (decodedAmt !== amount.toString()) {
+      throw new Error('Invoice amount mismatch')
+    }
+
+    // double check
+    if (Number(decodedAmt) !== amount) {
+      throw new Error('Invoice amount mismatch')
+    }
+
     logger.info('Will now send payment through lightning')
 
     const payment = await sendPaymentV2Invoice({