1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
|
# vim:set ft=sshdconfig
HostKey /srv/code/hostkeys/rsa_key
HostKey /srv/code/hostkeys/ed25519_key
Protocol 2
Port 22
SyslogFacility AUTH
LogLevel INFO
StrictModes yes
PidFile none
PubkeyAuthentication yes
HostbasedAuthentication no
IgnoreRhosts yes
PasswordAuthentication no
PermitEmptyPasswords no
PermitRootLogin no
ChallengeResponseAuthentication no
# Limit the number of authentication attemps per connection. SSH will log
# failues once attempts reach half this number so this should also log all
# authentication failures as well.
PermitTTY no
MaxAuthTries 2
# This turns off reverse lookups of the originating host which hang sshd
# on DNS timeouts when DNS is down. This also breaks "from=" lines in
# authorizd_keys files which must be converted to dotted quad ip addrs.
UseDNS no
AcceptEnv LANG LC_*
# Disconnect after this period of time if the user hasn't provided
# a correct password.
LoginGraceTime 120
# After 66 seconds of inactivity, request a keep-alive from the
# client. If they don't respond after ten requests, kill the
# connection.
ClientAliveInterval 66
ClientAliveCountMax 10
# Allow up to 100 simultaneous unauthenticated connections. Any
# connections beyond that limit will be dropped.
MaxStartups 100
# The maxiumum number of sessions which can be served on one
# multi-plexing connection. ssh does not fail gracefully when this
# number is exceeded, so we keep it high.
MaxSessions 100
X11Forwarding no
PrintMotd no
# Used hardened crypto algorithms
# Based on: https://stribika.github.io/2015/01/04/secure-secure-shell.html
# And also: https://access.redhat.com/discussions/3121481
# And also: https://infosec.mozilla.org/guidelines/openssh
KexAlgorithms curve25519-sha256@libssh.org,diffie-hellman-group-exchange-sha256
Ciphers chacha20-poly1305@openssh.com,aes256-gcm@openssh.com,aes128-gcm@openssh.com,aes256-ctr,aes192-ctr,aes128-ctr
MACs hmac-sha2-512-etm@openssh.com,hmac-sha2-256-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-512,hmac-sha2-256,umac-128@openssh.com
|
