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Description of problem:
sshd by default (with no HostKey directive in sshd_config) loads only RSA and DSA keys. However, man page states that it should load also ECDSA key in this case. This is either documentation bug or bad behaviour of sshd.

Version-Release number of selected component (if applicable):
openssh-5.3p1-109.el6.x86_64

How reproducible:
always

Steps to Reproduce:
1. remove all HostKey directives from sshd_config
2. sshd -T |grep ^hostkey
3. man sshd_config


Actual results:
# sshd -T |grep ^hostkey
hostkey /etc/ssh/ssh_host_rsa_key
hostkey /etc/ssh/ssh_host_dsa_key

...
HostKey
             Specifies a file containing a private host key used by SSH.  The default is /etc/ssh/ssh_host_key for protocol version 1, and /etc/ssh/ssh_host_dsa_key, /etc/ssh/ssh_host_ecdsa_key and /etc/ssh/ssh_host_rsa_key for protocol version 2.
...

Expected results:
# sshd -T |grep ^hostkey
hostkey /etc/ssh/ssh_host_rsa_key
hostkey /etc/ssh/ssh_host_dsa_key
hostkey /etc/ssh/ssh_host_ecdsa_key

(or man page update)

Additional info:

This is probably bug in ECDSA keys backporting, but we don't want to change default behaviour in this late release so changing documentation seems like a reasonable idea.

The same information is also specified in the description of -h option in manual page for sshd.

The man page needs to be fixed. ECDSA algorithms are not used by default intentionally as it could create a regression for some setups with broken clients which can't handle bigger packets during a transport layer initialization.

See https://access.redhat.com/errata/RHSA-2014:1552 and https://access.redhat.com/solutions/711953

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://rhn.redhat.com/errata/RHSA-2016-0741.html