Add negative value validation to tx approval

1 files changed, 10 insertions, 0 deletions

diff --git a/app/scripts/metamask-controller.js b/app/scripts/metamask-controller.js
index e94db2dfd..83827ec76 100644
--- a/app/scripts/metamask-controller.js
+++ b/app/scripts/metamask-controller.js
@@ -199,6 +199,9 @@ module.exports = class MetamaskController {
     const idStore = this.idStore
     var state = idStore.getState()
 
+    let err = this.enforceTxValidations(txParams)
+    if (err) return onTxDoneCb(err)
+
     // It's locked
     if (!state.isUnlocked) {
 
@@ -216,6 +219,13 @@ module.exports = class MetamaskController {
     }
   }
 
+  enforceTxValidations (txParams) {
+    if (txParams.value.indexOf('-') === 0) {
+      const msg = `Invalid transaction value of ${txParams.value} not a positive number.`
+      return new Error(msg)
+    }
+  }
+
   newUnsignedMessage (msgParams, cb) {
     var state = this.idStore.getState()
     if (!state.isUnlocked) {