#!/bin/sh
#
# ssh-host-config, Copyright 2000, 2001, 2002, 2003 Red Hat Inc.
#
# This file is part of the Cygwin port of OpenSSH.

# Subdirectory where the new package is being installed
PREFIX=/usr

# Directory where the config files are stored
SYSCONFDIR=/etc
LOCALSTATEDIR=/var

progname=$0
auto_answer=""
port_number=22

privsep_configured=no
privsep_used=yes
sshd_in_passwd=no
sshd_in_sam=no

request()
{
  if [ "${auto_answer}" = "yes" ]
  then
    return 0
  elif [ "${auto_answer}" = "no" ]
  then
    return 1
  fi

  answer=""
  while [ "X${answer}" != "Xyes" -a "X${answer}" != "Xno" ]
  do
    echo -n "$1 (yes/no) "
    read answer
  done
  if [ "X${answer}" = "Xyes" ]
  then
    return 0
  else
    return 1
  fi
}

# Check options

while :
do
  case $# in
  0)
    break
    ;;
  esac

  option=$1
  shift

  case "$option" in
  -d | --debug )
    set -x
    ;;

  -y | --yes )
    auto_answer=yes
    ;;

  -n | --no )
    auto_answer=no
    ;;

  -p | --port )
    port_number=$1
    shift
    ;;

  *)
    echo "usage: ${progname} [OPTION]..."
    echo
    echo "This script creates an OpenSSH host configuration."
    echo
    echo "Options:"
    echo "    --debug  -d     Enable shell's debug output."
    echo "    --yes    -y     Answer all questions with \"yes\" automatically."
    echo "    --no     -n     Answer all questions with \"no\" automatically."
    echo "    --port   -p <n> sshd listens on port n."
    echo
    exit 1
    ;;

  esac
done

# Check if running on NT
_sys="`uname -a`"
_nt=`expr "$_sys" : "CYGWIN_NT"`

# Check for running ssh/sshd processes first. Refuse to do anything while
# some ssh processes are still running

if ps -ef | grep -v grep | grep -q ssh
then
  echo
  echo "There are still ssh processes running. Please shut them down first."
  echo
  exit 1
fi

# Check for ${SYSCONFDIR} directory

if [ -e "${SYSCONFDIR}" -a ! -d "${SYSCONFDIR}" ]
then
  echo
  echo "${SYSCONFDIR} is existant but not a directory."
  echo "Cannot create global configuration files."
  echo
  exit 1
fi

# Create it if necessary

if [ ! -e "${SYSCONFDIR}" ]
then
  mkdir "${SYSCONFDIR}"
  if [ ! -e "${SYSCONFDIR}" ]
  then
    echo
    echo "Creating ${SYSCONFDIR} directory failed"
    echo
    exit 1
  fi
fi

# Create /var/log and /var/log/lastlog if not already existing

if [ -f ${LOCALSTATEDIR}/log ]
then
  echo "Creating ${LOCALSTATEDIR}/log failed\!"
else
  if [ ! -d ${LOCALSTATEDIR}/log ]
  then
    mkdir -p ${LOCALSTATEDIR}/log
  fi
  if [ -d ${LOCALSTATEDIR}/log/lastlog ]
  then
    echo "Creating ${LOCALSTATEDIR}/log/lastlog failed\!"
  elif [ ! -f ${LOCALSTATEDIR}/log/lastlog ]
  then
    cat /dev/null > ${LOCALSTATEDIR}/log/lastlog
    chmod 666 ${LOCALSTATEDIR}/log/lastlog
  fi
fi

# Create /var/empty file used as chroot jail for privilege separation
if [ -f ${LOCALSTATEDIR}/empty ]
then
  echo "Creating ${LOCALSTATEDIR}/empty failed\!"
else
  mkdir -p ${LOCALSTATEDIR}/empty
  if [ $_nt -gt 0 ]
  then
    chmod 755 ${LOCALSTATEDIR}/empty
  fi
fi

# First generate host keys if not already existing

if [ ! -f "${SYSCONFDIR}/ssh_host_key" ]
then
  echo "Generating ${SYSCONFDIR}/ssh_host_key"
  ssh-keygen -t rsa1 -f ${SYSCONFDIR}/ssh_host_key -N '' > /dev/null
fi

if [ ! -f "${SYSCONFDIR}/ssh_host_rsa_key" ]
then
  echo "Generating ${SYSCONFDIR}/ssh_host_rsa_key"
  ssh-keygen -t rsa -f ${SYSCONFDIR}/ssh_host_rsa_key -N '' > /dev/null
fi

if [ ! -f "${SYSCONFDIR}/ssh_host_dsa_key" ]
then
  echo "Generating ${SYSCONFDIR}/ssh_host_dsa_key"
  ssh-keygen -t dsa -f ${SYSCONFDIR}/ssh_host_dsa_key -N '' > /dev/null
fi

# Check if ssh_config exists. If yes, ask for overwriting

if [ -f "${SYSCONFDIR}/ssh_config" ]
then
  if request "Overwrite existing ${SYSCONFDIR}/ssh_config file?"
  then
    rm -f "${SYSCONFDIR}/ssh_config"
    if [ -f "${SYSCONFDIR}/ssh_config" ]
    then
      echo "Can't overwrite. ${SYSCONFDIR}/ssh_config is write protected."
    fi
  fi
fi

# Create default ssh_config from skeleton file in /etc/defaults/etc

if [ ! -f "${SYSCONFDIR}/ssh_config" ]
then
  echo "Generating ${SYSCONFDIR}/ssh_config file"
  cp ${SYSCONFDIR}/defaults/etc/ssh_config ${SYSCONFDIR}/ssh_config
  if [ "$port_number" != "22" ]
  then
    echo "Host localhost" >> ${SYSCONFDIR}/ssh_config
    echo "    Port $port_number" >> ${SYSCONFDIR}/ssh_config
  fi
fi

# Check if sshd_config exists. If yes, ask for overwriting

if [ -f "${SYSCONFDIR}/sshd_config" ]
then
  if request "Overwrite existing ${SYSCONFDIR}/sshd_config file?"
  then
    rm -f "${SYSCONFDIR}/sshd_config"
    if [ -f "${SYSCONFDIR}/sshd_config" ]
    then
      echo "Can't overwrite. ${SYSCONFDIR}/sshd_config is write protected."
    fi
  else
    grep -q UsePrivilegeSeparation ${SYSCONFDIR}/sshd_config && privsep_configured=yes
  fi
fi

# Prior to creating or modifying sshd_config, care for privilege separation

if [ "$privsep_configured" != "yes" ]
then
  if [ $_nt -gt 0 ]
  then
    echo "Privilege separation is set to yes by default since OpenSSH 3.3."
    echo "However, this requires a non-privileged account called 'sshd'."
    echo "For more info on privilege separation read /usr/doc/openssh/README.privsep."
    echo
    if request "Shall privilege separation be used?"
    then
      privsep_used=yes
      grep -q '^sshd:' ${SYSCONFDIR}/passwd && sshd_in_passwd=yes
      net user sshd >/dev/null 2>&1 && sshd_in_sam=yes
      if [ "$sshd_in_passwd" != "yes" ]
      then
        if [ "$sshd_in_sam" != "yes" ]
	then
	  echo "Warning: The following function requires administrator privileges!"
	  if request "Shall this script create a local user 'sshd' on this machine?"
	  then
	    dos_var_empty=`cygpath -w ${LOCALSTATEDIR}/empty`
	    net user sshd /add /fullname:"sshd privsep" "/homedir:$dos_var_empty" /active:no > /dev/null 2>&1 && sshd_in_sam=yes
	    if [ "$sshd_in_sam" != "yes" ]
	    then
	      echo "Warning: Creating the user 'sshd' failed!"
	    fi
	  fi
	fi
	if [ "$sshd_in_sam" != "yes" ]
	then
	  echo "Warning: Can't create user 'sshd' in ${SYSCONFDIR}/passwd!"
	  echo "         Privilege separation set to 'no' again!"
	  echo "         Check your ${SYSCONFDIR}/sshd_config file!"
	  privsep_used=no
	else
	  mkpasswd -l -u sshd | sed -e 's/bash$/false/' >> ${SYSCONFDIR}/passwd
	fi
      fi
    else
      privsep_used=no
    fi
  else
    # On 9x don't use privilege separation.  Since security isn't
    # available it just adds useless additional processes.
    privsep_used=no
  fi
fi

# Create default sshd_config from skeleton files in /etc/defaults/etc or
# modify to add the missing privsep configuration option

if [ ! -f "${SYSCONFDIR}/sshd_config" ]
then
  echo "Generating ${SYSCONFDIR}/sshd_config file"
  sed -e "s/^#UsePrivilegeSeparation yes/UsePrivilegeSeparation $privsep_used/
	  s/^#Port 22/Port $port_number/
	  s/^#StrictModes yes/StrictModes no/" \
      < ${SYSCONFDIR}/defaults/etc/sshd_config \
      > ${SYSCONFDIR}/sshd_config
elif [ "$privsep_configured" != "yes" ]
then
  echo >> ${SYSCONFDIR}/sshd_config
  echo "UsePrivilegeSeparation $privsep_used" >> ${SYSCONFDIR}/sshd_config
fi

# Care for services file
_my_etcdir="/ssh-host-config.$$"
if [ $_nt -gt 0 ]
then
  _win_etcdir="${SYSTEMROOT}\\system32\\drivers\\etc"
  _services="${_my_etcdir}/services"
else
  _win_etcdir="${WINDIR}"
  _services="${_my_etcdir}/SERVICES"
fi
_serv_tmp="${_my_etcdir}/srv.out.$$"

mount -t -f "${_win_etcdir}" "${_my_etcdir}"

# Depends on the above mount
_wservices=`cygpath -w "${_services}"`

# Remove sshd 22/port from services
if [ `grep -q 'sshd[ \t][ \t]*22' "${_services}"; echo $?` -eq 0 ]
then
  grep -v 'sshd[ \t][ \t]*22' "${_services}" > "${_serv_tmp}"
  if [ -f "${_serv_tmp}" ]
  then 
    if mv "${_serv_tmp}" "${_services}"
    then
      echo "Removing sshd from ${_wservices}"
    else
      echo "Removing sshd from ${_wservices} failed\!"
    fi 
    rm -f "${_serv_tmp}"
  else
    echo "Removing sshd from ${_wservices} failed\!"
  fi
fi

# Add ssh 22/tcp  and ssh 22/udp to services
if [ `grep -q 'ssh[ \t][ \t]*22' "${_services}"; echo $?` -ne 0 ]
then
  awk '{ if ( $2 ~ /^23\/tcp/ ) print "ssh                22/tcp                           #SSH Remote Login Protocol\nssh                22/udp                           #SSH Remote Login Protocol"; print $0; }' < "${_services}" > "${_serv_tmp}"
  if [ -f "${_serv_tmp}" ]
  then
    if mv "${_serv_tmp}" "${_services}"
    then
      echo "Added ssh to ${_wservices}"
    else
      echo "Adding ssh to ${_wservices} failed\!"
    fi
    rm -f "${_serv_tmp}"
  else
    echo "Adding ssh to ${_wservices} failed\!"
  fi
fi

umount "${_my_etcdir}"

# Care for inetd.conf file
_inetcnf="${SYSCONFDIR}/inetd.conf"
_inetcnf_tmp="${SYSCONFDIR}/inetd.conf.$$"

if [ -f "${_inetcnf}" ]
then
  # Check if ssh service is already in use as sshd
  with_comment=1
  grep -q '^[ \t]*sshd' "${_inetcnf}" && with_comment=0
  # Remove sshd line from inetd.conf
  if [ `grep -q '^[# \t]*sshd' "${_inetcnf}"; echo $?` -eq 0 ]
  then
    grep -v '^[# \t]*sshd' "${_inetcnf}" >> "${_inetcnf_tmp}"
    if [ -f "${_inetcnf_tmp}" ]
    then
      if mv "${_inetcnf_tmp}" "${_inetcnf}"
      then
        echo "Removed sshd from ${_inetcnf}"
      else
        echo "Removing sshd from ${_inetcnf} failed\!"
      fi
      rm -f "${_inetcnf_tmp}"
    else
      echo "Removing sshd from ${_inetcnf} failed\!"
    fi
  fi

  # Add ssh line to inetd.conf
  if [ `grep -q '^[# \t]*ssh' "${_inetcnf}"; echo $?` -ne 0 ]
  then
    if [ "${with_comment}" -eq 0 ]
    then
      echo 'ssh  stream  tcp     nowait  root    /usr/sbin/sshd sshd -i' >> "${_inetcnf}"
    else
      echo '# ssh  stream  tcp     nowait  root    /usr/sbin/sshd sshd -i' >> "${_inetcnf}"
    fi
    echo "Added ssh to ${_inetcnf}"
  fi
fi

# On NT ask if sshd should be installed as service
if [ $_nt -gt 0 ]
then
  echo
  echo "Do you want to install sshd as service?"
  if request "(Say \"no\" if it's already installed as service)"
  then
    echo
    echo "Which value should the environment variable CYGWIN have when"
    echo "sshd starts? It's recommended to set at least \"ntsec\" to be"
    echo "able to change user context without password."
    echo -n "Default is \"ntsec\".  CYGWIN="
    read _cygwin
    [ -z "${_cygwin}" ] && _cygwin="ntsec"
    if cygrunsrv -I sshd -d "CYGWIN sshd" -p /usr/sbin/sshd -a -D -e "CYGWIN=${_cygwin}"
    then
      echo
      echo "The service has been installed under LocalSystem account."
    fi
  fi
  # Now check if sshd has been installed as service.  This allows to
  # set the ownership of the affected files correctly.
  #
  # NOTE: This doesn't work flawlessly so far on Windows 2003 Server.
  # The SYSTEM account on 2003 has not the appropriate privileges to allow 
  # passwordless logon (pubkey authentication).  This requires to run the
  # service under a special account, which has administrator privileges
  # plus (at least, AFAIK) the SeCreateTokenPrivilege.
  # The next step will be, to extend this script to create an approriate
  # account for that, using the new editrights tool.
  if cygrunsrv -Q sshd > /dev/null 2>&1
  then
    chown system ${SYSCONFDIR}/ssh*
    chown system.system ${LOCALSTATEDIR}/empty
    if [ -f ${LOCALSTATEDIR}/log/sshd.log ]
    then
      chown system.system ${LOCALSTATEDIR}/log/sshd.log
    fi
  fi
fi

echo
echo "Host configuration finished. Have fun!"