Develop Reference

Android ADB: Device unauthorized trying to connect to a port-forwarded remote emulator

Background:
I recently upgraded to an AMD processor and found that the Android device emulator was complaining about not having hardware acceleration. (This is an issue for another question). My old Intel computer worked fine, so I decided to run the emulator on the old Intel PC (emu-pc) and use my new AMD computer (dev-pc) to code.
Problem:
I wasn't able to directly have the emulator expose its ports on the emu-pc to connect to via adb on the dev-pc (again an issue for another question), so I installed the Windows 10 OpenSSH server (Microsoft instructions) and connected to it from my dev-pc, forwarding the proper ADB ports:
ssh {you}#<{remote ip} -L 5554:localhost:5554 -L 5555:localhost:5555
I then tried connecting to the remote emulator via adb:
adb connect localhost
I was met with
$ ./adb devices
List of devices attached
localhost:5555 unauthorized
I've tried a few of the posts stating you should disable and re-enable USB debugging or revoke all the USB debugging authorization or use the "Wipe Data" option in the AVD Manager. None of these worked. I also tried messing with the adbkeys on the emulator under /data/misc/adb/adbkeys but I get permission denied trying to do anything to that file. (I also can't ls it via an adb shell)
Any ideas?

I found something that worked for me. I was able to telnet to the emu-pc via port 5554, where I tried to auth on the Android console. The login message said:
Android Console: type 'auth <auth_token>' to authenticate
Android Console: you can find your <auth_token> in
'C:\Users\exile57\.emulator_console_auth_token'
I found that file and was able to log in. This made me think that the emulator thinks the connection is coming from the emu-pc, yet the keys that I was using were generated on the dev-pc. I found the keys on emu-pc in C:\Users\[your user]\.android as adbkey and adbkey.pub. I copied those to the dev-pc, killed the adb server, disconnected all devices, then tried reconnecting:
$ ./adb disconnect
./adb kill-server
./adb connect localhost
After a bit, I was able to connect and drive the device over adb:
$ ./adb devices
List of devices attached
localhost:5555 device
NOTE I'm not sure this is the whole story, as when testing this out for this answer, I deleted the dev-pc's adbkey and adbkey,pub and was still able to reconnect, so that seems a bit strange. It worked for me, but be aware, I'm not sure the mechanism.

In Android studio, Run menu > Run shows OFFLINE ... for the connected device.
Below is the procedure followed to solve it:
(Read the below note first) Delete the ~/.android/adbkey (or, rename to ~/.android/adbkey2, this is even better incase you want it back for some reason)
Note: I happened to do this step, but it didn't solve the problem, after doing all the below steps it worked, so unsure if this step is required.
Run locate platform-tools/adb
Note: use the path that comes from here in below commands
Kill adb server:
sudo ~/Android/Sdk/platform-tools/adb kill-server
You will get a Allow accept.. message popup on your device. Accept it. This is important, which solves the problem.
Start adb server:
sudo ~/Android/Sdk/platform-tools/adb start-server
In Android studio, do Run menu > Run again
It will show something like Samsung ... (your phone manufacture name).
Also installs the apk on device correctly this time without error.
Hope that helps.

Here is how I did it:
First you need to run the emulator on the host computer. I used Android Studio and I had to close it because I noticed that the adb process kept spawning.
Start port-forwarding using SSH in the development computer.
ssh -L 5554:localhost:5554 -L 5555:localhost:5555 user#emulator-host-ip
copy adbkey and adbkey.pub files found at: C:\Users\[your user]\.android from the host computer to the development computer. this step should get ride of the unauthorized problem
in the development computer kill the adb server and lookup connected devices:
$ ./adb kill-server
$ ./adb devices
List of devices attached
localhost:5555 device

No logcat output in eclipse

I recently switched to connecting to the phone via WiFi. I am able to compile and upload programs through Eclipse. However, I do not receive any logcat ouput. The phone is also shown in the DDMS view and when my program is started it also displays the name and pid. Is it possible to get the logcat trace via wireless or do I have to switch back to using a USB connection?
UPDATE:
Maybe I did not make it clear enough in my initial post. There is no problem with the connection itself. I can dump the logcat by using a terminal with 'adb logcat -d'. What I want is to see the live logcat in Eclipse's logcat viewer. Not sure if it is of any importance, but I am using Eclipse 3.8 in Debian Jessie.

(1) connect phone with usb, then type in command line:
adb tcpip 5555
you can disconnect your phone from usb now
(if the reason for using wifi is that usb does not work on your machine, just do the above on another computer
(2) find out the IP address of your mobile device (somewhere under settings .... phone status)
(3) in command line type:
adb connect [IP of your mobile]
NOTE: all devices need to be connected to same wifi; avoid using public wifis

In your eclipse,
just go to: windows->preferences->Android->logcat and follow the following setup:
1. double-click action: "go to problem (error line)
2. switch to: java
3. both checkboxes are checked
if setup is fine, clean the project and restart eclipse

Restart Your ADB Server
1) open cmd
2) change directory to platform-tools
3)type adb kill-server
4)then adb start-server

I am not sure what exactly happened, but it is working now. I did not do anything that I had not tried earlier. It just started working after several attempts. Might be a faulty Eclipse installation, it did crash earlier today.

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

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 to Samsung Galaxy Nexus, it is working fine. Can anyone advise how to solve my Samsung S4 problem?
=========================================
# adb devices
List of devices attached
4d00f9169907301b unauthorized
=========================================
Edit:
Found that this problem only happened to Android 4.2.2 and above. The following link explained that Google has implemented some new security features for using adb.
http://nelenkov.blogspot.com/2013/02/secure-usb-debugging-in-android-422.html
Appreciate if anyone can help on this.

Get the public key from the client phone (adb host)
cat /data/.android/adbkey.pub
copy the above public key to the target phone's /data/misc/adb/adb_keys location. (you may need to stop the adb daemon first with stop adbd)
cat /data/misc/adb/adb_keys
verify both cat outputs match.
try restarting adb daemon on target start adbd or just reboot them.
If you are having problems reading or writing to ADB KEYS in above steps, try setting environment variable ADB_KEYS_PATH with a temporary path (eg: /data/local/tmp). Refer to that link it goes into more details
"On the host, the user public/private key pair is automatically generated,
if it does not exist, when the adb daemon starts and is stored in
$HOME/.android/adb_key(.pub) or in $ANDROID_SDK_HOME on windows. If needed,
the ADB_KEYS_PATH env variable may be set to a :-separated (; under
Windows) list of private keys, e.g. company-wide or vendor keys.
On the device, vendors public keys are installed at build time in
/adb_keys. User-installed keys are stored in /data/misc/adb/adb_keys"

Check and uncheck the USB Debugging option in the device.
If that doesn't work unplug and plug in the USB a couple of times.
At some point, the device should show a message box to ask you to authorize the computer. Click yes and then the device will be authorized.

If anyone has similar issue of having a phone with a cracked screen and has a need to access adb:
Root your phone (mine was already rooted, so I was blessed at least with that).
If you forgot to enable developers mode and your adb isn't running, then do the following:
Reboot your phone into recovery.
Connect the phone with a cable.
Open terminal.
If you type adb devices you should see the device in the list.
If so, type:
adb shell mount /system
abd shell
echo "persist.service.adb.enable=1" >> default.prop
echo "persist.service.debuggable=1" >> default.prop
echo "persist.sys.usb.config=mtp,adb" >> default.prop
echo "persist.service.adb.enable=1" >> /system/build.prop
echo "persist.service.debuggable=1" >> /system/build.prop
echo "persist.sys.usb.config=mtp,adb" >> /system/build.prop
Now if you are going to reboot into your phone android will tell you "oh your adb is working but please tap on this OK button, so we can trust your PC". And obviously if we can't tap on the phone stay in the recovery mode and do the following (assuming you are not in the adb shell mode, if so first type exit):
cd ~/.android
adb push adbkey.pub /data/misc/adb/adb_keys
Hurray, it all should be hunky-dory now! Just reboot the phone and you should be able to access adb when the phone is running:
adb shell reboot
P.S. Was using OS X and Moto X Style that's with the cracked screen.

Have you tried
adb kill-server
adb shell
Sometimes adb gets stuck and first killing adb server and then starting some command forces authorization window to pop-up.
Also please check adb client version on your phone.
THis feature is supported from adb 1.0.31 as far as I remember.

Experience With: ASUS ZENFONE
If at all you have faced Missing Driver for Asus Zenfones
Follow This Link
(http://donandroid.com/how-to-install-adb-interface-drivers-windows-7-xp-vista-623)
I tried with
1) Killing and starting adb server at adb cmd.
2) Switching Usb Debugging on and Off and ...
This is What WORKED with me.
Step 1:Remove Connection with Device and Close Eclipse
Step 2:Navigate to C:/Users/User_name/.android/
Step 3:You Will Find adb_key
Step 4:Just delete it.
Step 5.Connect again and System will ask you Again.
Step 6.Ask Device to remember RSA Key when it Prompts. I think its done.
If you Face The Same Problem after couple of days, just disable and enable USB debugging

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.

Try this steps:
unplug device
adb kill-server
adb start-server
plug device
You need to allow Allow USB debugging in your device when popup.

You need to allow Allow USB debugging when the popup shows up when you first connect to the computer!

Delete the folder .android from C:/users/<user name>/.android. It solved the issue for me.

I had to check the box for the debugger on the phone "always allow on this phone". I then did a adb devices and then entered the adb command to clear the adds. It worked fine. Before that, it did not recognize the pm and other commands

For me, the emulator could not have Google Play Services enabled. It could have Google APIs or be x86 or x64 but not google play store.

Try a USB2 port if you're plugged into a USB3 port. At least through the Pixel3 line this makes a difference. Many people have observed the same problem but I'm not sure if anybody knows why. Perhaps there's a way to tell the kernel to not do something USB3-ish on the USB port that the phones can't handle.
I got here because I forgot this workaround, found this page, then remembered to use the other port.

Please follow following steps :
Unplug your phone from system
Go to developer options of the Cellphone and then click on "Allow USB debugging" then please select the radio button prompting "Allow USB debugging when the popup shows up when you first connect to the computer!".....
That's it.. run your command again :
adb devices

You must be prompted in your s4 screen to authorize that computer. You can tell it to remember it. This is for security reasons, occurring in Android 4.4+

I found one solution with Nexus 5, and TWRP installed. Basically format was the only solution I found and I tried all solutions listed here before: ADB Android Device Unauthorized
Ask Google to make backup of your apps. Save all important files you may have on your phone
Please note that I decline all liability in case of failure as what I did was quite risky but worked in my case:
Enable USB debugging in developer option (not sure if it helped as device was unauthorized but still...)
Make sure your phone is connected to computer and you can access storage
Download google img of your nexus: https://developers.google.com/android/nexus/images
unrar your files and places them in a new folder on your computer, name it factory (any name will do).
wipe ALL datas... you will have 0 file in your android accessed from computer.
Then reboot into BOOTLOADER mode... you will have the message "you have no OS installed are you sure you want to reboot ?"
Then execute (double click) the .bat file inside the "factory" folder.
You will see command line detailed installation of the OS. Of course avoid disconnecting cable during this phase...
Phone will take about 5mn to initialize.

adb install over usb not working

I have a bash script running in work which automates the install of various APK samples (some malicious, some not - for testing purposes) to a HTC Desire Z handset running Sophos AV.
Runs well but every now and then an APK will try to install and the shell prompt will just hang at install. At the same time Sophos detects it as malicious but instead of displaying a box offering to uninstall it, it displays a box to delete it instead. Whether this is connected to the adb install issue I'm not sure but it's happened everytime.
It appears to install ok (2539 KB/s (634874 bytes in 0.244s)) .Package size is 640k.
I am running the command adb install -s /location/of/sample.apk
Any ideas?
Sorry for the lengthy post
Thanks

In case this helps others I had a different problem with similar symptoms. ADB install -r "apk path" would hang indefinitely.
I troubleshooted a myriad of things and identified that it was my USB cable length.
I have an USB extender cable as that I plug my devices into. The combined length of my device's cable and the USB extender cable caused this issue. Removing the extension cable fix the issue and eventually I replaced my USB extender cable with a shorter extension cable for the final solution.

try restarting adb server:
adb kill-server
adb start-server

Have you added udev rules file that contains a USB configuration for type of device you want to use.Incase you havn't that may be a reason for this issue. Execute 'lsusb -v' in Terminal. This will give information regarding Unique Vendor id of each connected device in a list.Find the Vendor id of your device.Once you identify the vendor id follow the instructions given in the link for Ubuntu environment. link:http://zoumpis.wordpress.com/2013/06/09/using-hardware-devices-while-developing-and-android-application/

Android adb "Unable to open sync connection!"

I can run and debug my Android app on my phone just fine, most of the time. Then, seemingly randomly, when I try to run or debug my app from Eclipse, the Console in Eclipse says:
[2010-10-12 09:36:48 - myapp] Android Launch!
[2010-10-12 09:36:48 - myapp] adb is running normally.
[2010-10-12 09:36:48 - myapp] Performing com.mycompany.myapp.MyActivity activity launch
[2010-10-12 09:36:48 - myapp] Automatic Target Mode: using device 'HT01TP800561'
[2010-10-12 09:36:48 - myapp] Uploading myapp.apk onto device 'HT01TP800561'
[2010-10-12 09:36:48 - myapp] Failed to upload myapp.apk on device 'HT01TP800561'
[2010-10-12 09:36:48 - myapp] java.io.IOException: Unable to open sync connection!
[2010-10-12 09:36:48 - myapp] Launch canceled!
Retry: doesn't help, same messages.
Restart Eclipse: doesn't help.
Restart adb (adb kill-server && adb start-server): no errors, doesn't help.
Reconnect the phone: sometimes helps.
Reboot the computer: kind of drastic, haven't tried this yet.
Using Ubuntu 10.4, Eclipse Galileo 3.5.2, Android SDK 7, ADT plugin 0.9.6, Nexus One, Android 2.2.1.
Any bright ideas?

I was having exactly the same problem, but I already had my phone connected to the computer's USB port. Sometimes disconnecting and reconnecting the cord worked but then it stopped working completely.
However, disabling USB debugging on the phone and then re-enabling it has worked so far. Hopefully it keeps working! These fixes really seem like silly hacks.. I'm not sure what the underlying problem is.

I was able to clear this only by cycling the USB Debugging option on the phone.

This may also be related to a "too many open files" issue. I manually tried to install the app when getting the "sync" error above and that's when I got the "too many open files" clue. one brute workaround, based on some old posts, seems to be to restart the phone, and one google engineer suggested doing it twice, the second time before it goes into sleep mode the first time (details on why in the post).
That was a few years ago, and maybe they've fixed it, or just did some things to get around it in the usual cases and the reinstall-as-part-of-development is not a case that it addresses.

Nexus One here, CyanogenMod 7 (Android 2.3.7)... disable and reenable:
Settings > Applications > Development > USB debugging
And everything works now on Eclipse and Mac OS X 10.7.3.

I have been having the same problem when I have the phone connected through my keyboard's USB hub. IT went away when I connected straight to the computer's USB port.

I have had the same problem and restarting ADB wouldn't work for me. Sometimes rebooting my phone worked but not always, I was unable to program for about a week because of this glitch and I think I finally found a workaround! :-D
First of all, kill every program running on your phone. Having some kind of taskmanager makes this a quick task, otherwise you'll have to manually kill them all one at a time.
If that doesn't fix it, you will need to go to your phone settings, then go to "Applications", then go to "Running services", and kill every service in there. I'm using a Droid Incredible and I have yet to have this not work for me. :-)
So, the short answer is, kill all apps, and all services.
Also, keep in mind, you will need to close, and re-open eclipse to see if this fix has worked for you. I hope this works for you, I know it did for me! :-D

When this happens on the Kindle Fire I just power it off and back on again.

I fixed it just by disabling and enabling the debugging configuration on my device (SonyEricsson Xperia)

This error occurs when somehow the Android Debug Bridge , which is the tool to send data from our computer to the connected device, disconnects. As we know, there are some layers to get connected like the adb itself and of course, the last layer is the USB cable, so when you already tried to restart your adb script and seem not working, you just need to reconnect your cable.

I see this problem regularly in both attached devices (Phone or Tablet) and even the emulators. I noticed that the problem often follows periods of inactivity (after a lunch break for example). It may be that the Operating System on the development machine is trying to conserve resources and adb just isn't all that JIT friendly.
On windows I have to close the IDE and open Task Manager and force stop (kill) adb, then relaunch Eclipse. This always works for me...
I noticed if I set a higher priority in task manager for adb, this problem is greatly reduced--although it can still happen.

Restarting the phone has also fixed this problem for me whenever reseting the usb cable didnt fix it

The solution is likely to run on your android phone (on local terminal or ssh terminal):
$ stop adbd; start adb
I don't like overkill solutions like rebooting hte phone... and this is usually not needed under Linux. I experienced the same problem when connecting over Wifi, so USB is maybe not responsible at all. Reading the answer from user655489, I got the idea to run lsof, and then lsof | grep adbd | wc -l => I think I had over many sockets open with all FD from 0 to 1023 in use... how suspicious.
I ran killall adbd, then restarted adbd per How can I connect to Android with ADB over TCP? And the problem was gone.
The cause is that, at least when debugging and having to kill my non-working apps, that several of the sockets never get closed.

What helps for me is the following:
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
If you are debugging on AndroidX86 (or otherwise have root access to your Android developer machine)
Kill the "adbd" process.. and let it restart.
e.g.
[On Android VM]
kill adbd (e.g. kill `ps a| grep adbd | awk ' { print $2 } ' `)
/sbin/adbd will restart automatically
[On DEV station]
[dev station] ./adb disconnect
[dev station] ./adb connect
If you don't have root, probably toggling USB debugging, rebooting, etc could also help.
As it also restarts adbd
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

I have been experiencing this problem very often (I mean like every second time I launched Debug). I was using a rather long USB cable. I switched to the original HTC USB cable which is short and the problem was gone!

I experienced this problem when my USB cable was connected to PC via keyboard USB :O. When I connected it to PC directly my problem solved.
I hope this works.
Enjoy!

As per Maven Explanation I tried this solution. but I was getting the same problem. So I restarted the device. And it started working perfectly.

Try this,
Disabling USB debugging on the phone and then re-enabling under
Settings -> Applications -> Development -> USB debugging
its works fine.

This solution worked for me
Click Revoke USB debugging authorizations.
Click OK.
Reattach USB.
Click OK for Permissions.