2009
03.26

error:
# ssh user@someserver
_dns_getaddrinfo() name = 'someserver'
res_searchN() name = 'someserver'
ssh: Warning: Reading the random source seems to have blocked.
If you experience problems, you probably need to find a better entropy source.
fuck…

quick reference as taken from wikipedia:
“begin knowledge”: Entropy (computing)

In computing, entropy is the randomness collected by an operating system or application for use in cryptography or other uses that require random data. This randomness is often collected from hardware sources, either pre-existing ones such as mouse movements or specially provided randomness generators. “/end knowledge”

hmm. ok – now its all coming together…

after some playing around i found a fix.

this assumes that you have busybox installed on android and have your path set (dont ask – use the google).

this is a pretty straight walk through

# ./adb remount
# ./adb shell
# cd /dev/
# mv random random_BAK
# ln -s urandom random

now test your ssh again:
# ssh user@someserver
_dns_getaddrinfo() name = 'someserver'
res_searchN() name = 'someserver'
ssh: Warning: failed creating //.ssh: Read-only file system
Host 'someserver' is not in the trusted hosts file.

profit!!

10 comments so far

Add Your Comment
  1. From Russia with thanks)

  2. Thanks a lot! It works for me!

  3. echo 256 > /proc/sys/kernel/random/read_wakeup_threshold

    for plenty of entropy. Or look on Play Store for Entropy Fixer (requires root) and set the read_wakeup_threshold that way.

  4. Every time I cat /proc/sys/kernel/random/entropy_avail the number goes up. Eventually when it is over 1000 dropbear starts to work.

  5. danke sehr… ohne diese könnte ich nicht ssh nützen!

  6. Thanks a lot.

  7. I had the same problem, but it was when I had the screen off. Apparently I had used up all the entropy in the real random device, so the solution was to turn the screen on and wiggle it around for a bit to get more entropy. If you use /dev/urandom instead of /dev/random, it will always work, but the random numbers you get are not considered to be cryptographically safe, as they can be predicted based on previous random numbers. In most environments, that’s not a big concern, though.

  8. Well done!It help me!!!

  9. Thanks! This is my solution http://www.heiher.info/1592.html

  10. Thank you! It helped me!