Tag: ssh

Categories
Unix

SSH hangs when expecting SSH2_MSG_KEX_DH_GEX_GROUP

I encountered this odd issue when I went to SSH from a new CentOS 7 box to an older system, and it just hung with no response. Turning on verbose showed me where it was hanging:

debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP

I found a number of suggestions on the ‘net as to how to handle this, but the below worked for me. It is a compatibility issue with a newer openSSH connecting to an older one that doesn’t have ciphers as strong.

You need to edit /etc/ssh_config and I added the following to the bottom, so it is under the “host *” items:

SendEnv LANG LC_*
HashKnownHosts yes
GSSAPIDelegateCredentials no
Ciphers aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc
HostKeyAlgorithms ssh-rsa,ssh-dss
MACs hmac-md5,hmac-sha1,hmac-ripemd160

Categories
Unix

SVN in chroot says you don’t exist

You may one day set up a chroot environment and find you get this message when you try to ssh or use svn (using ssh):

You don’t exist, go away!
svn: Connection closed unexpectedly

In addition to my assurance that you do indeed exist in the universe, let me tell you how I fixed it.

Check your chroot /etc to make sure passwd and shadow exist for your user and the IDs are correct.

Then, note that when svn does a repository connection it uses libnss_files.so which can require proper DNS resolution. In my case, I had to add the repository domain name into the chroot /etc/hosts file.

Then I existed in more ways than one.