This can be done by querying the “Hidden Service Descriptor”.

By default, Onion Services publish a “Hidden Service Descriptor” to the Tor network’s distributed Hidden Service Directory (HDir) every 3 hours.

The Hidden Service Descriptor returned by the HDir contains the metadata necessary for a client to connect to the Onion Service.

If a given Onion Service’s Hidden Service Descriptor cannot be found, then the Onion Service is likely dead.

Script

Here’s a simple python script that queries the HDir for a list of onions

from stem.control import Controller
from stem.descriptor.hidden_service import HiddenServiceDescriptorV3

onions = ['2n3tvihf4n27pqyqdtcqywl33kbjuv2kj3eeq6qvbtud57jwiaextmid.onion', '32qywqnlnqzbry42nmotr47ebts3k6lhiwfob6xniosmepz2tsnsx7ad.onion', '4colmnerbjz3xtsjmqogehtpbt5upjzef57huilibbq3wfgpsylub7yd.onion', '6voaf7iamjpufgwoulypzwwecsm2nu7j5jpgadav2rfqixmpl4d65kid.onion', '6w5iasklrbr2kw53zqrsjktgjapvjebxodoki3gjnmvb4dvcbmz7n3qd.onion', '7drfpncjeom3svqkyjitif26ezb3xvmtgyhgplcvqa7wwbb4qdbsjead.onion', 'ae3w7fkzr3elfwsk6mhittjj7e7whme2tumdrhw3dfumy2hsiwomc3yd.onion', 'chillingguw3yu2rmrkqsog4554egiry6fmy264l5wblyadds3c2lnyd.onion', 'fzdx522fvinbaqgwxdet45wryluchpplrkkzkry33um5tufkjd3wdaqd.onion', 'gku6irp4e65ikfkbrdx576zz6biapv37vv2cmklo2qyrtobugwz5iaad.onion', 'gois4b6fahhrlsieupl56xd6ya226m33abzuv26vgfpuvv44wf6vbdad.onion', 'j4dhkkxfcsvzvh3p5djkmuehhgd6t6l7wmzih6b4ss744hegwkiae7ad.onion', 'jabjabdea2eewo3gzfurscj2sjqgddptwumlxi3wur57rzf5itje2rid.onion', 'jaswtrycaot3jzkr7znje4ebazzvbxtzkyyox67frgvgemwfbzzi6uqd.onion', 'jeirlvruhz22jqduzixi6li4xyoweytqglwjons4mbuif76fgslg5uad.onion', 'jukrlvyhgguiedqswc5lehrag2fjunfktouuhi4wozxhb6heyzvshuyd.onion', 'mrbenqxl345o4u7yaln25ayzz5ut6ab3kteulzqusinjdx6oh7obdlad.onion', 'nixnet54icmeh25qsmcsereuoareofzevjqjnw3kki6oxxey3jonwwyd.onion', 'qawb5xl3mxiixobjsw2d45dffngyyacp4yd3wjpmhdrazwvt4ytxvayd.onion', 'qwikoouqore6hxczat3gwbe2ixjpllh3yuhaecixyenprbn6r54mglqd.onion', 'qwikxxeiw4kgmml6vjw2bsxtviuwjce735dunai2djhu6q7qbacq73id.onion', 'razpihro3mgydaiykvxwa44l57opvktqeqfrsg3vvwtmvr2srbkcihyd.onion', 'rurcblzhmdk22kttfkel2zduhyu3r6to7knyc7wiorzrx5gw4c3lftad.onion', 'szd7r26dbcrrrn4jthercrdypxfdmzzrysusyjohn4mpv2zbwcgmeqqd.onion', 'xdkriz6cn2avvcr2vks5lvvtmfojz2ohjzj4fhyuka55mvljeso2ztqd.onion', 'xiynxwxxpw7olq76uhrbvx2ts3i7jagqnqix7arfbknmleuoiwsmt5yd.onion', 'xmppccwrohw3lmfap6e3quep2yzx3thewkfhw4vptb5gwgnkttlq2vyd.onion', 'ynnuxkbbiy5gicdydekpihmpbqd4frruax2mqhpc35xqjxp5ayvrjuqd.onion', 'yxkc2uu3rlwzzhxf2thtnzd7obsdd76vtv7n34zwald76g5ogbvjbbqd.onion']

controller = Controller.from_port(port=9051)
controller.authenticate()
if controller.is_alive():
print( "INFO: Confirmed that Tor is working." )

print( "INFO: Trying get_hidden_service_descriptor()" )
for onion in onions:
print( onion )
try:
desc = controller.get_hidden_service_descriptor(onion)
print( "\tOK" )
except Exception as e:
print( "\tNo Descriptor Found" )

Example

And an example execution of the above script follows

user@disp6307:~$ time sudo python3 get_hidden_service_descriptor.py
INFO: Confirmed that Tor is working.
INFO: Trying get_hidden_service_descriptor()
2n3tvihf4n27pqyqdtcqywl33kbjuv2kj3eeq6qvbtud57jwiaextmid.onion
OK
32qywqnlnqzbry42nmotr47ebts3k6lhiwfob6xniosmepz2tsnsx7ad.onion
OK
4colmnerbjz3xtsjmqogehtpbt5upjzef57huilibbq3wfgpsylub7yd.onion
OK
6voaf7iamjpufgwoulypzwwecsm2nu7j5jpgadav2rfqixmpl4d65kid.onion
OK
6w5iasklrbr2kw53zqrsjktgjapvjebxodoki3gjnmvb4dvcbmz7n3qd.onion
No Descriptor Found
7drfpncjeom3svqkyjitif26ezb3xvmtgyhgplcvqa7wwbb4qdbsjead.onion
No Descriptor Found
ae3w7fkzr3elfwsk6mhittjj7e7whme2tumdrhw3dfumy2hsiwomc3yd.onion
OK
chillingguw3yu2rmrkqsog4554egiry6fmy264l5wblyadds3c2lnyd.onion
OK
fzdx522fvinbaqgwxdet45wryluchpplrkkzkry33um5tufkjd3wdaqd.onion
OK
gku6irp4e65ikfkbrdx576zz6biapv37vv2cmklo2qyrtobugwz5iaad.onion
OK
gois4b6fahhrlsieupl56xd6ya226m33abzuv26vgfpuvv44wf6vbdad.onion
OK
j4dhkkxfcsvzvh3p5djkmuehhgd6t6l7wmzih6b4ss744hegwkiae7ad.onion
OK
jabjabdea2eewo3gzfurscj2sjqgddptwumlxi3wur57rzf5itje2rid.onion
OK
jaswtrycaot3jzkr7znje4ebazzvbxtzkyyox67frgvgemwfbzzi6uqd.onion
OK
jeirlvruhz22jqduzixi6li4xyoweytqglwjons4mbuif76fgslg5uad.onion
OK
jukrlvyhgguiedqswc5lehrag2fjunfktouuhi4wozxhb6heyzvshuyd.onion
No Descriptor Found
mrbenqxl345o4u7yaln25ayzz5ut6ab3kteulzqusinjdx6oh7obdlad.onion
No Descriptor Found
nixnet54icmeh25qsmcsereuoareofzevjqjnw3kki6oxxey3jonwwyd.onion
OK
qawb5xl3mxiixobjsw2d45dffngyyacp4yd3wjpmhdrazwvt4ytxvayd.onion
No Descriptor Found
qwikoouqore6hxczat3gwbe2ixjpllh3yuhaecixyenprbn6r54mglqd.onion
OK
qwikxxeiw4kgmml6vjw2bsxtviuwjce735dunai2djhu6q7qbacq73id.onion
OK
razpihro3mgydaiykvxwa44l57opvktqeqfrsg3vvwtmvr2srbkcihyd.onion
No Descriptor Found
rurcblzhmdk22kttfkel2zduhyu3r6to7knyc7wiorzrx5gw4c3lftad.onion
OK
szd7r26dbcrrrn4jthercrdypxfdmzzrysusyjohn4mpv2zbwcgmeqqd.onion
OK
xdkriz6cn2avvcr2vks5lvvtmfojz2ohjzj4fhyuka55mvljeso2ztqd.onion
OK
xiynxwxxpw7olq76uhrbvx2ts3i7jagqnqix7arfbknmleuoiwsmt5yd.onion
OK
xmppccwrohw3lmfap6e3quep2yzx3thewkfhw4vptb5gwgnkttlq2vyd.onion
OK
ynnuxkbbiy5gicdydekpihmpbqd4frruax2mqhpc35xqjxp5ayvrjuqd.onion
No Descriptor Found
yxkc2uu3rlwzzhxf2thtnzd7obsdd76vtv7n34zwald76g5ogbvjbbqd.onion
OK

real  0m53.311s
user  0m0.005s
sys   0m0.006s
user@disp6307:~$

Attribution

This script was originally published here.

| | | | | Check if Tor .onion is alive or dead |

• Check if Tor Onion Service is alive (python stem get_hidden_service_descriptor) - Michael Altfield’s Tech Blog

For more information, see the article linked-to above.