How to solve ADB device unauthorized in Android ADB host device?

Question

When I\'m using a rooted Android device as ADB host to send adb command \"adb devices\" to Samsung S4, I received device unauthorized error message. However when I tried adb

Answer 1

For unknown reasons, I only had ~/.android/adbkey, but not ~/.android/adbkey.pub.

I guess that adb was unable to push the public key to the device, and thus the device could never show the authorization dialog.

After killing the adb server, removing the adbkey file and starting adb again, the authorization dialog popped up on the phone.