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it_tips:ssh [2017/05/03 16:49]
florido [SSH key pair quick setup]
it_tips:ssh [2017/05/03 17:40] (current)
florido [SSH key pair quick setup]
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 ==== SSH key pair quick setup ==== ==== SSH key pair quick setup ====
 +
 +We will generate a public/​private key pair called //​myid_rsa//​ and //​myid_rsa.pub//​ and copy it to a machine called ''​watto.matfys.lth.se''​ in order to login to it.
  
   - Generate a private/​public keypair **with password** and strong encryption((NIST complexity recommendations,​ http://​nvlpubs.nist.gov/​nistpubs/​SpecialPublications/​NIST.SP.800-57Pt3r1.pdf)):​ Command: <​code:​bash>​ ssh-keygen -b 4096 -f ~/​.ssh/​myid_rsa</​code>​Result:<​code:​bash>​   - Generate a private/​public keypair **with password** and strong encryption((NIST complexity recommendations,​ http://​nvlpubs.nist.gov/​nistpubs/​SpecialPublications/​NIST.SP.800-57Pt3r1.pdf)):​ Command: <​code:​bash>​ ssh-keygen -b 4096 -f ~/​.ssh/​myid_rsa</​code>​Result:<​code:​bash>​
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   - Try to login to the server **using the identity created**: Command:<​code:​bash>​ssh -i ~/​.ssh/​myid_rsa.pub pflorido@watto.matfys.lth.se</​code>​   - Try to login to the server **using the identity created**: Command:<​code:​bash>​ssh -i ~/​.ssh/​myid_rsa.pub pflorido@watto.matfys.lth.se</​code>​
  
-==== Debugging problems ====+You can now create entries in your ''​~/​.ssh/​config''​ file to use tunnelling as described in [[#Speedup connection using tunneling]],​ and the agent should automatically forward your keys. 
 + 
 +===== Debugging ​SSH problems ​and useful commands ===== 
 + 
 +The best to debug is to enable ssh verbose mode: 
 + 
 +<​code:​bash>​ssh -vv pflorido@watto.matfys.lth.se</​code>​ 
 + 
 +==== See which keys are tried by the agent ==== 
 + 
 +<​code:​bash>​ssh-add -l</​code>​ 
 + 
 +==== Delete a key from the agent keyring ==== 
 + 
 +<​code:​bash>​ssh-add -d ~/​.ssh/​myid_rsa</​code>​ 
 + 
 +==== Check if the agent is running ==== 
 + 
 +<​code:​bash>​ps aux | grep ssh-agent</​code>​ 
 + 
 +==== Remove an offending key from known_hosts ==== 
 + 
 +<​code:​bash>​ssh-keygen -R <​hostname></​code>​ 
 + 
 +==== Remove an offending key from known_hosts ​====
  
 +<​code:​bash>​ssh-keygen -R <​hostname or IP></​code>​
 ====== References ====== ====== References ======
  
   * Arch linux SSH PKI tutorial, https://​wiki.archlinux.org/​index.php/​SSH_Keys ​   * Arch linux SSH PKI tutorial, https://​wiki.archlinux.org/​index.php/​SSH_Keys ​
it_tips/ssh.1493822964.txt.gz · Last modified: 2017/05/03 16:49 by florido