openssh/contrib/make-ssh-known-hosts.pl

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#!/usr/bin/perl -w
# -*- perl -*-
######################################################################
# make-ssh-known-hosts.pl -- Make ssh-known-hosts file
# Copyright (c) 1995 Tero Kivinen
# All Rights Reserved.
#
# Make-ssh-known-hosts is distributed in the hope that it will be
# useful, but WITHOUT ANY WARRANTY. No author or distributor accepts
# responsibility to anyone for the consequences of using it or for
# whether it serves any particular purpose or works at all, unless he
# says so in writing. Refer to the GNU General Public License for full
# details.
#
# Everyone is granted permission to copy, modify and redistribute
# make-ssh-known-hosts, but only under the conditions described in
# the GNU General Public License. A copy of this license is supposed to
# have been given to you along with make-ssh-known-hosts so you can
# know your rights and responsibilities. It should be in a file named
# gnu-COPYING-GPL. Among other things, the copyright notice and this notice
# must be preserved on all copies.
######################################################################
# Program: make-ssh-known-hosts.pl
# $Source: /var/cvs/openssh/contrib/Attic/make-ssh-known-hosts.pl,v $
# Author : $Author: damien $
#
# (C) Tero Kivinen 1995 <Tero.Kivinen@hut.fi>
#
# Creation : 19:52 Jun 27 1995 kivinen
# Last Modification : 00:07 Jul 8 1998 kivinen
# Last check in : $Date: 2000/03/15 01:13:03 $
# Revision number : $Revision: 1.1 $
# State : $State: Exp $
# Version : 1.343
# Edit time : 242 min
#
# Description : Make ssh-known-host file from dns data.
#
# $Log: make-ssh-known-hosts.pl,v $
# Revision 1.1 2000/03/15 01:13:03 damien
# - Created contrib/ subdirectory. Included helpers from Phil Hands'
# Debian package, README file and chroot patch from Ricardo Cerqueira
# <rmcc@clix.pt>
# - Moved gnome-ssh-askpass.c to contrib directory and reomved config
# option.
# - Slight cleanup to doc files
#
# Revision 1.6 1998/07/08 00:44:23 kivinen
# Fixed to understand bind 8 nslookup output.
#
# Revision 1.5 1998/04/30 01:53:33 kivinen
# Moved kill before close and added sending SIGINT first and
# then 1 second sleep before sending SIGKILL.
#
# Revision 1.4 1998/04/17 00:39:19 kivinen
# Changed to close ssh program filedescriptor before killing it.
# Removed ^ from the password matching prompt.
#
# Revision 1.3 1997/04/17 04:21:27 kivinen
# Changed to use 3des by default.
#
# Revision 1.2 1997/03/26 07:14:01 kivinen
# Added EWOULDBLOCK.
#
# Revision 1.1.1.1 1996/02/18 21:38:10 ylo
# Imported ssh-1.2.13.
#
# Revision 1.4 1995/10/02 01:23:45 ylo
# Ping packet size fixes from Kivinen.
#
# Revision 1.3 1995/08/29 22:37:39 ylo
# Now uses GlobalKnownHostsFile and UserKnownHostsFile.
#
# Revision 1.2 1995/07/15 13:26:37 ylo
# Changes from kivinen.
#
# Revision 1.1.1.1 1995/07/12 22:41:05 ylo
# Imported ssh-1.0.0.
#
#
#
# If you have any useful modifications or extensions please send them to
# Tero.Kivinen@hut.fi
#
######################################################################
# initialization
require 5.000;
use Getopt::Long;
use FileHandle;
use POSIX;
use Socket;
use Fcntl;
$version = ' $Id: make-ssh-known-hosts.pl,v 1.1 2000/03/15 01:13:03 damien Exp $ ';
$command_line = "$0 ";
foreach $a (@ARGV) {
$command_line .= $a . " ";
}
STDERR->autoflush(1);
######################################################################
# default values for options
$debug = 5;
$defserver = '';
$bell='\a';
$public_key = '/etc/ssh_host_key.pub';
$private_ssh_known_hosts = "/tmp/ssh_known_hosts$$";
$timeout = 60;
$ping_timeout = 3;
$passwordtimeout = undef;
$trustdaemon = 1;
$domainnamesplit = 0;
$recursive = 1;
######################################################################
# Programs and their options
$nslookup = "nslookup";
$ssh="ssh -a -c 3des -x -o 'ConnectionAttempts 1' -o 'FallBackToRsh no' -o 'GlobalKnownHostsFile /dev/null' -o 'KeepAlive yes' -o 'StrictHostKeyChecking no' -o 'UserKnownHostsFile $private_ssh_known_hosts'";
$sshdisablepasswordoption="-o 'BatchMode yes' -o 'PasswordAuthentication no'";
######################################################################
# Cleanup and initialization
unlink($private_ssh_known_hosts);
$sockaddr = 'S n a4 x8';
($junk, $junk, $sshport) = getservbyname("ssh", "tcp");
if (!defined($sshport)) {
$sshport = 22;
}
($tcpprotoname, $junk, $tcpproto) = getprotobyname('tcp');
defined($tcpprotoname) || die "getprotobyname : $!";
######################################################################
# Parse options
GetOptions("initialdns=s", "server=s", "subdomains=s",
"debug=i", "timeout=i", "passwordtimeout=i",
"trustdaemon!", "domainnamesplit", "silent",
"nslookup=s", "pingtimeout=i", "recursive!",
"keyscan",
"ssh=s")
|| die "Getopt : $!";
if (defined($opt_initialdns)) { $defserver = $opt_initialdns; }
if (defined($opt_server)) { $server = $opt_server; }
if (defined($opt_subdomains)) { @subdomains = split(/,/, $opt_subdomains); }
if (defined($opt_debug)) { $debug = $opt_debug; }
if (defined($opt_timeout)) { $timeout = $opt_timeout; }
if (defined($opt_pingtimeout)) { $ping_timeout = $opt_pingtimeout; }
if (defined($opt_passwordtimeout)) {
$passwordtimeout = $opt_passwordtimeout;
$sshdisablepasswordoption = '';
}
if (defined($opt_trustdaemon)) { $trustdaemon = $opt_trustdaemon; }
if (defined($opt_recursive)) { $recursive = $opt_recursive; }
if (defined($opt_domainnamesplit)) { $domainnamesplit = $opt_domainnamesplit; }
if (defined($opt_silent)) { $bell = ''; }
if (defined($opt_nslookup)) { $nslookup = $opt_nslookup; }
if (defined($opt_ssh)) { $ssh = $opt_ssh; } else {
$ssh = "$ssh $sshdisablepasswordoption";
}
if ($#ARGV == 0) {
$domain = "\L$ARGV[0]\E";
$grep_yes = '.*';
$grep_no = '^$';
} elsif ($#ARGV == 1) {
$domain = "\L$ARGV[0]\E";
$grep_yes = $ARGV[1];
$grep_no = '^$';
} elsif ($#ARGV == 2) {
$domain = "\L$ARGV[0]\E";
$grep_yes = $ARGV[1];
$grep_no = $ARGV[2];
} else {
print(STDERR "$0 [--initialdns initial_dns_server] [--server dns_server] [--subdomains sub.sub.domain,sub.sub,sub,] [--debug debug_level] [--timeout ssh_exec_timeout_in_secs] [--pingtimeout ping_timeout_in_secs] [--passwordtimeout timeout_for_password_in_secs] [--notrustdaemon] [--norecursive] [--domainnamesplit] [--silent] [--keyscan] [--nslookup path_to_nslookup] [--ssh path_to_ssh] full.domain [ host_info_take_regexp [ host_info_remove_regex ]]\n");
exit(1);
}
######################################################################
# Check that ssh program exists
if (system("$ssh > /dev/null 2>&1 ") != 256) {
print(STDERR "Error: Could not run ssh program ($ssh): $!\nError: Try giving the path to it with --ssh option\n");
exit(1);
}
######################################################################
# Generate subdomains list
if (!$domainnamesplit) {
debug(6, "Auto splitting host entries");
} elsif (!defined(@subdomains)) {
debug(6, "Generating subdomain list");
# split domain to pieces
@domain_pieces = split(/\./, $domain);
# add empty domain part
push(@subdomains, '');
# add rest parts, except the one before full domain name
$entry='';
for(; $#domain_pieces > 1; ) {
$entry .= "." . shift(@domain_pieces);
push(@subdomains, $entry);
}
# add full domain name
push(@subdomains, ".$domain");
debug(5, "Subdomain list: " . join(',', @subdomains));
} else {
debug(5, "Using given subdomain list:" . join(',', @subdomains));
}
######################################################################
# finding SOA entry for domain
@other_servers = ();
if (!defined($server)) {
debug(6, "Finding DNS database SOA entry");
($server, @other_servers) = find_soa($domain, $defserver);
if (!defined($server)) {
print(STDERR "Error: Could not find DNS SOA entry from default dns server\nError: Try giving the initial nameserver with --initialdns option\n");
exit(1);
} else {
debug(5, "DNS server found : $server");
}
} else {
debug(5, "Using given DNS server : $server");
}
######################################################################
# Print header
($name, $junk, $junk, $junk, $junk, $junk, $gecos) = getpwuid($<);
$gecos =~ s/,.*$//g;
if (!defined($opt_keyscan)) {
print(STDOUT "# This file is generated with make-ssh-known-hosts.pl\n");
print(STDOUT "#$version\n");
print(STDOUT "# with command line :\n");
print(STDOUT "# $command_line\n");
print(STDOUT "#\n");
print(STDOUT "# The script was run by $gecos ($name) at " . localtime() . "\n");
print(STDOUT "# using perl ($^X) version $].\n");
}
######################################################################
# Get DNS database list from server
do {
$domains_done{$domain} = 1;
delete $domains_waiting{$domain};
$hostcnt = 0;
$cnamecnt = 0;
$lines = 0;
$soa = 0;
undef %host;
undef %cname;
undef %hostdata;
dnsagain:
debug(1, "Getting DNS database for $domain from server $server");
open(DNS, "echo ls -d $domain | nslookup - $server 2>&1 |") ||
die "Error: Could not start nslookup to make dns list : $!\nError: Try giving --nslookup option and telling the path to nslookup program\n";
while(<DNS>) {
$lines++;
chomp;
undef $hostname if/^\s*$/;
if (/^\s{0,1}([a-zA-Z0-9-]\S*)/) {
$hostname = "\L$1\E";
}
next unless defined $hostname;
if (/^.*\s(SOA)\s+(.*)\s*$/ || $hostname eq "SOA") {
undef $soa if(/^.*\s(SOA)\s+(.*)\s*$/);
$data = $_ if ($hostname eq "SOA");
$data = $2 unless $hostname eq "SOA";
$data =~ s/\s*;.*$//;
$data =~ s/^\s+//;
if( defined $soa ) {
$soa .= " \L$data\E";
} else {
$soa = "\L$data\E";
}
$hostname = "SOA";
} elsif (/^.*\s(A|CNAME|NS)\s+(.*)\s*$/) {
$host = $hostname;
$field = "\L$1\E";
$data = "\L$2\E";
debug(70, "Line = /$host/$field/$data/");
if ($host !~ /\.$/) {
$host .= ".$domain";
} else {
$host =~ s/\.$//g;
}
if ($field eq "a") {
if ($host =~ /$domain$/) {
if (defined($host{$host})) {
$host{$host} .= ",$data";
} else {
$host{$host} = "$data";
$hostcnt++;
}
debug(30, "$host A == $host{$host}");
}
} elsif ($field eq "cname") {
if ($data !~ /\.$/ && ! /^\s/ ) {
$data .= ".$domain";
} else {
$data =~ s/\.$//g;
}
if ($host =~ /$domain$/) {
if (defined($cname{$data})) {
$cname{$data} .= ",$host";
} else {
$cname{$data} = "$host";
$cnamecnt++;
}
debug(30, "$host CNAME $data");
$junk = $data;
$data = $host;
$host = $junk;
}
} elsif ($field eq "ns") {
if (!defined($domains_done{$host})) {
if (!defined($domains_waiting{$host})) {
debug(10, "Adding subdomain $host to domains list, with NS $data");
$domains_waiting{$host} = $data;
push(@domains_waiting, $host);
} else {
debug(10, "Adding NS $data for domain $host");
$domains_waiting{$host} .= ",$data";
}
}
}
if (!defined($hostdata{$host})) {
$hostdata{$host} = "$host\n$field=$data\n";
} else {
$hostdata{$host} .= "$field=$data\n";
}
}
}
close(DNS);
if ($hostcnt == 0 && $cnamecnt == 0) {
if ($#other_servers != -1) {
$server = shift(@other_servers);
goto dnsagain;
}
}
debug(1, "Found $hostcnt hosts, $cnamecnt CNAMEs (total $lines lines)");
if (!defined($opt_keyscan)) {
print(STDOUT "#\n");
print(STDOUT "# Domain = $domain, server = $server\n");
print(STDOUT "# Found $hostcnt hosts, $cnamecnt CNAMEs (total $lines lines)\n");
print(STDOUT "# SOA = $soa\n");
print(STDOUT "#\n");
}
######################################################################
# Loop through hosts and try to connect to hosts
foreach $i (sort (keys %host)) {
debug(50, "Host = $i, Hostdata = $hostdata{$i}");
if ($hostdata{$i} =~ /$grep_yes/im &&
$hostdata{$i} !~ /$grep_no/im &&
$i !~ /^localhost\./ &&
$host{$i} !~ /^127.0.0.1$|^127.0.0.1,|,127.0.0.1$|,127.0.0.1,/) {
debug(2, "Trying host $i");
@hostnames = ();
if (defined($cname{$i})) {
expand($i, \@hostnames, \@subdomains);
foreach $j (split(/,/, $cname{$i})) {
expand($j, \@hostnames, \@subdomains);
}
} else {
expand($i, \@hostnames, \@subdomains);
}
foreach $j (split(/,/, $host{$i})) {
push(@hostnames, $j);
}
$hostnames = join(',', (@hostnames));
if (defined($opt_keyscan)) {
printf(STDOUT "$host{$i}\t$hostnames\n");
} elsif (try_ping($i, $host{$i})) {
$trusted = 1;
$err = 'Timeout expired';
$ssh_key = try_ssh("$i");
if (!defined($ssh_key)) {
$ssh_key = find_host_from_known_hosts($i);
$trusted = 0;
}
if (defined($ssh_key)) {
if ($trusted) {
debug(2, "Ssh to $i succeded");
} else {
debug(2, "Ssh to $i failed, using local known_hosts entry");
}
debug(4, "adding entries : $hostnames");
$ssh_key =~ s/root@//i;
if (!$trusted && !$trustdaemon) {
print(STDOUT "# $hostnames $ssh_key\n");
} else {
print(STDOUT "$hostnames $ssh_key\n");
}
} else {
debug(2, "ssh failed : $err");
}
} else {
debug(2, "ping failed");
}
} else {
debug(10, "Skipped host $i");
}
}
again:
$domain = shift(@domains_waiting);
if (defined($domain)) {
$server = $domains_waiting{$domain};
@other_servers = split(',', $server);
$server = shift(@other_servers);
($server, @other_servers) = find_soa($domain, $server);
if(!defined($server)) {
debug(1, "Skipping domain $domain because no DNS SOA entry found");
$domains_done{$domain} = 1;
delete $domains_waiting{$domain};
goto again;
}
}
} while ($recursive && defined($domain));
unlink($private_ssh_known_hosts);
exit (0);
######################################################################
# try_ping -- try to ping to host and return 1 if success
# $success = try_ping($host, $list_ip_addrs);
sub try_ping {
my($host, $ipaddrs) = @_;
my(@ipaddrs, $ipaddr, $serv, $ip);
my($rin, $rout, $win, $wout, $nfound, $tmout, $buf, $len, $ret, $err);
$buf = '';
debug(51,"Trying to ping host $host");
@ipaddrs = split(/,/, $ipaddrs);
while ($ipaddr = shift(@ipaddrs)) {
debug(55,"Trying ipaddr $ipaddr");
#initialize socket
socket(PING, PF_INET, SOCK_STREAM, $tcpproto) ||
die "socket failed : $!";
setsockopt(PING, SOL_SOCKET, SO_REUSEADDR, 1) ||
die "setsockopt failed : $!";
PING->autoflush(1);
fcntl(PING, F_SETFL, fcntl(PING, F_GETFL, 0) | POSIX::O_NONBLOCK) ||
die "fcntl failed : $!";
$ip = pack('C4', split(/\./, $ipaddr, 4));
$serv = pack($sockaddr, AF_INET, $sshport, $ip);
again:
# try connect
$ret = connect(PING, $serv);
$err = $!;
if (!$ret) {
debug(60, "Connect failed : $err");
if ($err == EINTR) {
goto again;
}
# socket not yet connected, wait for result, it will
# wake up for writing when done
$tmout = $ping_timeout;
$rin = '';
$win = '';
vec($rin, fileno(PING), 1) = 1;
vec($win, fileno(PING), 1) = 1;
debug(60, "Waiting in select, rin = " . unpack('H*', $rin) .
", win = " . unpack('H*', $win));
($nfound) = select($rout = $rin, $wout = $win, undef, $tmout);
$err = $!;
debug(80, "Select returned $nfound, rout = " . unpack('H*', $rout) .
", wout = " . unpack('H*', $wout));
if ($nfound != 0) {
# connect done, read the status with sysread
$ret = sysread(PING, $buf, 1);
$err = $!;
if (defined($ret) || $err == EAGAIN || $err == EWOULDBLOCK) {
debug(60, "Select ok, read ok ($err), returning ok");
# connection done, return ok
shutdown(PING, 2);
close(PING);
return 1;
} else {
# connection failed, try next ipaddr
debug(60, "Select ok, read failed : $err, trying next");
close(PING);
}
} else {
# timeout exceeded, try next ipaddr
debug(60, "Select failed : $err, trying next");
close(PING);
}
} else {
# connect succeeded, return ok.
debug(60, "Connect ok, returning ok");
shutdown(PING, 2);
close(PING);
return 1;
}
}
debug(60, "Returning fail");
return 0;
}
######################################################################
# try_ssh -- try ssh connection to host and return ssh_key if success
# if failure return undef, and set $err string to contain error message.
# $ssh_key = try_ssh($host);
sub try_ssh {
my($host) = @_;
my($buf, $ret, $pos, $pid, $rin, $nfound, $tmout);
$pid = open(SSH, "$ssh $host cat $public_key 2>&1 |");
$err = undef;
if ($pid == 0) {
$err = "could not open ssh connection to host";
return undef;
}
$ret = 1;
$pos = 0;
$buf = '';
$tmout = $timeout;
debug(10, "Starting ssh select loop");
loop:
while (1) {
$rin = '';
vec($rin, fileno(SSH), 1) = 1;
($nfound, $tmout) = select($rin, undef, undef, $tmout);
# Timeout
if ($nfound <= 0) {
debug(20, "Ssh select timed out");
kill(2, $pid); sleep(1); kill(9, $pid);
close(SSH);
$err = "Timeout expired";
return undef;
}
$ret = sysread(SSH, $buf, 256, $pos);
# EOF or error
if ($ret <= 0) {
# Yes, close the pipe and return
close(SSH);
debug(20, "Ssh select closed status = $?");
$err = "No reply from ssh";
return undef;
}
$pos += $ret;
while ($buf =~ /^(.*)\n\r?([\000-\377]*)$/) {
$_ = $1;
$buf = $2;
$pos = length($buf);
debug(20, "Ssh select loop, line = \"$_\"");
if (/^connection.*refused/i) {
$err = "connection refused";
} elsif (/^permission/i) {
$err = "permission denied";
} elsif (/$public_key.*no\s+file/i) {
$err = "$public_key file not found";
} elsif (/$public_key.*permission\s+denied/i) {
$err = "$public_key file permission denied";
} elsif (/^\d+\s+\d+\s+\d/) {
kill(2, $pid); sleep(1); kill(9, $pid);
close(SSH);
return $_;
}
if (defined($err)) {
kill(2, $pid); sleep(1); kill(9, $pid);
close(SSH);
return undef;
}
}
if ($buf =~ /password: $/i) {
if (defined($passwordtimeout)) {
$tmout = $passwordtimeout;
print(STDERR "$bell\n\rPassword: ");
if ($tmout == 0) {
$tmout = undef;
}
} else {
$tmout = 0;
}
$buf = '';
$pos = 0;
}
}
}
######################################################################
# find_hosts_from_known_hosts -- find host key from private known_hosts file
# $ssh_key = find_host_from_known_hosts($host);
sub find_host_from_known_hosts {
my($host) = @_;
open(KNOWNHOSTS, "<$private_ssh_known_hosts") || return undef;
while(<KNOWNHOSTS>) {
@_ = split(/\s+/, $_);
if ($_[0] =~ /^$host$|^$host,|,$host$/) {
shift(@_);
close(KNOWNHOSTS);
return join(' ', @_);
}
}
close(KNOWNHOSTS);
return undef;
}
######################################################################
# expand -- insert expanded hostnames to hostnames table
# expand($hostname, \@hostnames, \@subdomains);
sub expand {
my($host, $hostnames, $subdomains) = @_;
my($newhost, $sub, $entry);
if (!$domainnamesplit) {
my(@domain_pieces);
# split domain to pieces
@domain_pieces = split(/\./, $host);
# add rest parts, except the one before full domain name
$entry = shift(@domain_pieces);
debug(20, "Adding autosplit entry $entry");
push(@$hostnames, $entry);
for(; $#domain_pieces > 1; ) {
$entry .= "." . shift(@domain_pieces);
debug(20, "Adding autosplit entry $entry");
push(@$hostnames, $entry);
}
# add full domain name
debug(20, "Adding autosplit entry $host");
push(@$hostnames, $host);
} else {
if ($host =~ /^(.*)$domain$/i) {
$newhost = $1;
$newhost =~ s/\.$//g;
foreach $sub (@$subdomains) {
$entry = $newhost . $sub;
$entry =~ s/^\.//g;
if ($entry ne '') {
debug(20, "Adding entry $entry");
push(@$hostnames, $entry);
}
}
}
}
}
######################################################################
# Print debug text
# debug(text_debug_level, string)
sub debug {
my($level, $str) = @_;
if ($debug > $level) {
print(STDERR "$0:debug[$level]: $str\n");
}
}
######################################################################
# find_soa -- find soa entry for domain
# ($soa_origin, @other_servers) = find_soa($domain, $initial_server)
sub find_soa {
my($domain, $initial_server) = @_;
my($field, $data, $server, @other_servers);
open(DNS, "$nslookup -type=soa $domain $initial_server 2>&1 |") ||
die "Error: Could not start nslookup to find SOA entry for $domain : $!\nError: Try giving the path to it with --nslookup option\n";
while (<DNS>) {
if (/^[^=]*origin\s*=\s*(.*)/) {
$server = $1;
debug(10, "Found origin : $1");
} elsif (/^[^=]*nameserver\s*=\s*(.*)\s*$/) {
push(@other_servers, $1);
debug(10, "Found nameserver : $1");
}
}
close(DNS);
return($server, @other_servers);
}
######################################################################
# make_perl_happy -- use some symbols, so perl doesn't complain so much
# make_perl_happy();
sub make_perl_happy {
if (0) {
print $opt_silent;
}
}
1;