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|
#!/bin/sh -e
action="$1"
oldversion="$2"
. /usr/share/debconf/confmodule
db_version 2.0
umask 022
if [ "$action" != configure ]
then
exit 0
fi
check_idea_key() {
#check for old host_key files using IDEA, which openssh does not support
if [ -f /etc/ssh/ssh_host_key ] ; then
if ssh-keygen -p -N '' -f /etc/ssh/ssh_host_key 2>&1 | \
grep -q 'unknown cipher' 2>/dev/null ; then
mv /etc/ssh/ssh_host_key /etc/ssh/ssh_host_key.old
mv /etc/ssh/ssh_host_key.pub /etc/ssh/ssh_host_key.pub.old
fi
fi
}
create_key() {
local msg="$1"
shift
local file="$1"
shift
if [ ! -f "$file" ] ; then
echo -n $msg
ssh-keygen -q -f "$file" -N '' "$@"
echo
fi
}
create_keys() {
db_get ssh/protocol2_only
if [ "$RET" = "false" ] ; then
create_key "Creating SSH1 key; this may take some time ..." \
/etc/ssh/ssh_host_key -t rsa1
fi
create_key "Creating SSH2 RSA key; this may take some time ..." \
/etc/ssh/ssh_host_rsa_key -t rsa
create_key "Creating SSH2 DSA key; this may take some time ..." \
/etc/ssh/ssh_host_dsa_key -t dsa
}
create_sshdconfig() {
if [ -e /etc/ssh/sshd_config ] ; then
if dpkg --compare-versions "$oldversion" lt-nl 1:1.3 ; then
db_get ssh/new_config
if [ "$RET" = "false" ] ; then return 0; fi
else return 0
fi
fi
#Preserve old sshd_config before generating a new on
if [ -e /etc/ssh/sshd_config ] ; then
mv /etc/ssh/sshd_config /etc/ssh/sshd_config.dpkg-old
fi
cat <<EOF > /etc/ssh/sshd_config
# Package generated configuration file
# See the sshd(8) manpage for defails
# What ports, IPs and protocols we listen for
Port 22
# Use these options to restrict which interfaces/protocols sshd will bind to
#ListenAddress ::
#ListenAddress 0.0.0.0
EOF
db_get ssh/protocol2_only
if [ "$RET" = "false" ]; then
cat <<EOF >> /etc/ssh/sshd_config
Protocol 2,1
# HostKeys for protocol version 1
HostKey /etc/ssh/ssh_host_key
# HostKeys for protocol version 2
HostKey /etc/ssh/ssh_host_rsa_key
HostKey /etc/ssh/ssh_host_dsa_key
EOF
else
cat <<EOF >> /etc/ssh/sshd_config
Protocol 2
# HostKeys for protocol version 2
HostKey /etc/ssh/ssh_host_rsa_key
HostKey /etc/ssh/ssh_host_dsa_key
EOF
fi
db_get ssh/privsep_ask
if [ "$RET" = "false" ]; then
cat <<EOF >> /etc/ssh/sshd_config
#Explicitly set PrivSep off, as requested
UsePrivilegeSeparation no
# Use PAM authentication via keyboard-interactive so PAM modules can
# properly interface with the user
PAMAuthenticationViaKbdInt yes
EOF
else
cat <<EOF >> /etc/ssh/sshd_config
#Privilege Separation is turned on for security
UsePrivilegeSeparation yes
# ...but breaks Pam auth via kbdint, so we have to turn it off
# Use PAM authentication via keyboard-interactive so PAM modules can
# properly interface with the user (off due to PrivSep)
PAMAuthenticationViaKbdInt no
EOF
fi
cat <<EOF >> /etc/ssh/sshd_config
# Lifetime and size of ephemeral version 1 server key
KeyRegenerationInterval 3600
ServerKeyBits 768
# Logging
SyslogFacility AUTH
LogLevel INFO
# Authentication:
LoginGraceTime 600
PermitRootLogin yes
StrictModes yes
RSAAuthentication yes
PubkeyAuthentication yes
#AuthorizedKeysFile %h/.ssh/authorized_keys
# rhosts authentication should not be used
RhostsAuthentication no
# Don't read the user's ~/.rhosts and ~/.shosts files
IgnoreRhosts yes
# For this to work you will also need host keys in /etc/ssh_known_hosts
RhostsRSAAuthentication no
# similar for protocol version 2
HostbasedAuthentication no
# Uncomment if you don't trust ~/.ssh/known_hosts for RhostsRSAAuthentication
#IgnoreUserKnownHosts yes
# To enable empty passwords, change to yes (NOT RECOMMENDED)
PermitEmptyPasswords no
# Change to no to disable s/key passwords
#ChallengeResponseAuthentication yes
# To disable tunneled clear text passwords, change to no here!
PasswordAuthentication yes
# To change Kerberos options
#KerberosAuthentication no
#KerberosOrLocalPasswd yes
#AFSTokenPassing no
#KerberosTicketCleanup no
# Kerberos TGT Passing does only work with the AFS kaserver
#KerberosTgtPassing yes
X11Forwarding no
X11DisplayOffset 10
PrintMotd no
PrintLastLog yes
KeepAlive yes
#UseLogin no
#MaxStartups 10:30:60
#Banner /etc/issue.net
#ReverseMappingCheck yes
Subsystem sftp /usr/lib/sftp-server
EOF
}
fix_rsh_diversion() {
# get rid of mistaken rsh diversion (circa 1.2.27-1)
if [ -L /usr/bin/rsh ] &&
dpkg-divert --list '/usr/bin/rsh.real/rsh' | grep -q ' ssh$' ; then
for cmd in rlogin rsh rcp ; do
[ -L /usr/bin/$cmd ] && rm /usr/bin/$cmd
dpkg-divert --package ssh --remove --rename \
--divert /usr/bin/rsh.real/$cmd /usr/bin/$cmd
[ -L /usr/man/man1/$cmd.1.gz ] && rm /usr/man/man1/$$cmd.1.gz
dpkg-divert --package ssh --remove --rename \
--divert /usr/man/man1/$cmd.real.1.gz /usr/man/man1/$cmd.1.gz
done
rmdir /usr/bin/rsh.real
fi
}
fix_statoverride() {
# Remove an erronous override for sshd (we should have overridden ssh)
if [ -x /usr/sbin/dpkg-statoverride ]; then
if dpkg-statoverride --list /usr/sbin/sshd >/dev/null ; then
dpkg-statoverride --remove /usr/sbin/sshd
fi
fi
}
create_alternatives() {
# Create alternatives for the various r* tools.
# Make sure we don't change existing alternatives that a user might have
# changed, but clean up after some old alternatives that mistakenly pointed
# rlogin and rcp to ssh.
update-alternatives --quiet --remove rlogin /usr/bin/ssh
update-alternatives --quiet --remove rcp /usr/bin/ssh
for cmd in rsh rlogin rcp; do
scmd="s${cmd#r}"
if ! update-alternatives --display "$cmd" | \
grep -q "$scmd"; then
update-alternatives --quiet --install "/usr/bin/$cmd" "$cmd" "/usr/bin/$scmd" 20 \
--slave "/usr/share/man/man1/$cmd.1.gz" "$cmd.1.gz" "/usr/share/man/man1/$scmd.1.gz"
fi
done
}
setup_sshd_user() {
if ! getent passwd | grep -q '^sshd:'; then
adduser --quiet --system --no-create-home --home /var/run/sshd sshd
fi
}
set_sshd_permissions() {
if dpkg --compare-versions "$oldversion" lt-nl 1:3.4p1-1 ; then
if [ -x /usr/sbin/dpkg-statoverride ] ; then
if dpkg-statoverride --list /usr/bin/ssh >/dev/null; then
dpkg-statoverride --remove /usr/bin/ssh >/dev/null
fi
fi
fi
if [ ! -x /usr/sbin/dpkg-statoverride ] || \
! dpkg-statoverride --list /usr/lib/ssh-keysign >/dev/null ; then
db_get ssh/SUID_client
if [ "$RET" = "false" ] ; then
chmod 0755 /usr/lib/ssh-keysign
elif [ "$RET" = "true" ] ; then
chmod 4755 /usr/lib/ssh-keysign
fi
fi
}
fix_ssh_group() {
# Try to remove non-system group mistakenly created by 1:3.5p1-1.
# set_ssh_agent_permissions() below will re-create it properly.
if getent group | grep -q '^ssh:'; then
delgroup --quiet ssh || true
fi
}
set_ssh_agent_permissions() {
if ! getent group | grep -q '^ssh:'; then
addgroup --system --quiet ssh
fi
if ! [ -x /usr/sbin/dpkg-statoverride ] || \
! dpkg-statoverride --list /usr/bin/ssh-agent >/dev/null ; then
chgrp ssh /usr/bin/ssh-agent
chmod 2755 /usr/bin/ssh-agent
fi
}
fix_conffile_permissions() {
# Clean up after executable /etc/default/ssh in 1:3.5p1-5. dpkg
# doesn't do this for us; see bug #192981.
chmod 644 /etc/default/ssh
}
setup_startup() {
db_get ssh/run_sshd
if [ "$RET" = "false" ] ; then
/etc/init.d/ssh stop 2>&1 >/dev/null
touch /etc/ssh/sshd_not_to_be_run
else
rm -f /etc/ssh/sshd_not_to_be_run 2>/dev/null
fi
}
setup_init() {
if [ -e /etc/init.d/ssh ]; then
update-rc.d ssh defaults >/dev/null
/etc/init.d/ssh restart
fi
}
check_idea_key
create_keys
create_sshdconfig
fix_rsh_diversion
fix_statoverride
create_alternatives
setup_sshd_user
set_sshd_permissions
if [ "$2" = "1:3.5p1-1" ]; then
fix_ssh_group
fi
set_ssh_agent_permissions
if dpkg --compare-versions "$2" lt 1:3.6.1p2-2; then
fix_conffile_permissions
fi
setup_startup
setup_init
db_stop
exit 0
|