Can someone explain how sshd does privilege separation?
Feb 27, 2016 · Follow up question (I know it has been some time): When running sshd from the command line on ubuntu (sudo /usr/sbin/sshd), it complains: "Missting privilege separation direcoty". This directory, as far as I can see is created in /etc/init.d/ssh. There is a function called check_privsep_dir, that does just that.
openssh - ssh-keygen: sshd host key setup - Information Security …
Dec 7, 2016 · 2. You can safely remove the keys stored in /etc/ssh, generate new keys and restart sshd. There is nothing more to it than that. But please note that every client that have the old key stored in their known_hosts file will complain. You will need to remove that record from your clients. This can be done using ssh-keygen -R <hostname>.
Where is sshd log file and how to explain the log info?
Feb 25, 2017 · journalctl _COMM=sshd -f Feb 16 06:34:40 localhost sshd[324]: Bad protocol version identification 'GET / HTTP/1.0' from 23.252.100.22 port 38876 Feb 16 06:34:40 localhost sshd[325]: Did not receive identification string from 23.252.100.22 Feb 16 07:34:40 localhost sshd[326]: Bad protocol version identification 'GET / HTTP/1.0' from 23.252.100 ...
rsa - Is allowing root login in SSH with "PermitRootLogin without ...
Nov 29, 2017 · First let's see what does it mean:. PermitRootLogin. Specifies whether root can log in using ssh(1). The argument must be yes, prohibit-password, forced-commands-only, or no.
Creating port-specific SSH authentication for the same user
2. You could run two ssh daemons listening on separate ports by using two sshd_config files and the -f option of sshd. One configuration file would include the OTP/pam module whilst the other would only allow key-based authentication.. Both would then authenticate the user against their own private key regardless.
Secure Configuration of Ciphers/MACs/Kex available in SSH
In order to remove the cbc ciphers, Add or modify the "Ciphers" line in /etc/ssh/sshd_config as below: Ciphers aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,arcfour. In order to remove HMAC MD5 Add or modify the MACs line in /etc/ssh/sshd_config as below : MACs hmac-sha1,hmac-ripemd160. Restart SSHD to apply the changes: service sshd ...
OpenSSH AuthorizedPrincipalsFile Allows Any User
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What's the importance of sshd's setting RekeyLimit?
Dec 9, 2014 · The idea behind rekeying is that session keys may be susceptible to some unspecified attack, such as direct cryptanalysis or side-channel attack. A common theme in most attacks is that they require the analysis of a large amount of encrypted data to execute. By limiting the amount of data transmitted with a single session key, you can ...
OpenSSH default/preferred ciphers, hash, etc for SSH2
So it may depend on the software vendor, software version, operating system distribution, and sysadmin choices. On an Ubuntu 12.10, man ssh_config indicates that the default order for encryption is: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128, aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc, aes256-cbc,arcfour.
How to set up OpenSSH to use x509 PKI for authentication?
Add the certificate for the CA in the directory set by CACertificatePath directive in sshd_config file (normally /etc/ssh/ca/crt, I think) with a link for the hash of the certificate. For creating the link use openssl.