/usr/share/perl5/Net/SFTP/Foreign/Backend/Unix.pm is in libnet-sftp-foreign-perl 1.69+dfsg-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 | package Net::SFTP::Foreign::Backend::Unix;
our $VERSION = '1.68_08';
use strict;
use warnings;
use Carp;
our @CARP_NOT = qw(Net::SFTP::Foreign);
use Fcntl qw(O_NONBLOCK F_SETFL F_GETFL);
use POSIX ();
use Net::SFTP::Foreign::Helpers qw(_tcroak _ensure_list _debug _hexdump $debug);
use Net::SFTP::Foreign::Constants qw(SSH2_FX_BAD_MESSAGE
SFTP_ERR_REMOTE_BAD_MESSAGE);
sub _new { shift }
sub _defaults {
( default_queue_size => 32 )
}
sub _init_transport_streams {
my (undef, $sftp) = @_;
for my $dir (qw(ssh_in ssh_out)) {
binmode $sftp->{$dir};
my $flags = fcntl($sftp->{$dir}, F_GETFL, 0);
fcntl($sftp->{$dir}, F_SETFL, $flags | O_NONBLOCK);
}
}
sub _open_dev_null {
my $sftp = shift;
my $dev_null;
unless (open $dev_null, '>', "/dev/null") {
$sftp->_conn_failed("Unable to redirect stderr to /dev/null");
return;
}
$dev_null
}
sub _fileno_dup_over {
my ($good_fn, $fh) = @_;
if (defined $fh) {
my @keep_open;
my $fn = fileno $fh;
for (1..5) {
$fn >= $good_fn and return $fn;
$fn = POSIX::dup($fn);
push @keep_open, $fn;
}
POSIX::_exit(255);
}
undef;
}
sub _open4 {
my $backend = shift;
my $sftp = shift;
my ($dad_in, $dad_out, $child_in, $child_out);
unless (pipe ($dad_in, $child_out) and
pipe ($child_in, $dad_out)) {
$sftp->_conn_failed("Unable to created pipes: $!");
return;
}
my $pid = fork;
unless ($pid) {
unless (defined $pid) {
$sftp->_conn_failed("Unable to fork new process: $!");
return;
}
close ($dad_in);
close ($dad_out);
shift; shift;
my $child_err = shift;
my $pty = shift;
$pty->make_slave_controlling_terminal if defined $pty;
my $child_err_fno = eval { no warnings; fileno($child_err ? $child_err : *STDERR) };
my $child_err_safe; # passed handler may be tied, so we
# duplicate it in order to get a plain OS
# handler.
if (defined $child_err_fno and $child_err_fno >= 0) {
open $child_err_safe, ">&=$child_err_fno" or POSIX::_exit(1);
}
else {
open $child_err_safe, ">/dev/null" or POSIX::_exit(1);
}
my $child_in_fno = _fileno_dup_over(0 => $child_in );
my $child_out_fno = _fileno_dup_over(1 => $child_out );
my $child_err_safe_fno = _fileno_dup_over(2 => $child_err_safe);
unless (($child_in_fno == 0 or POSIX::dup2($child_in_fno, 0)) and
($child_out_fno == 1 or POSIX::dup2($child_out_fno, 1)) and
($child_err_safe_fno == 2 or POSIX::dup2($child_err_safe_fno, 2))) {
POSIX::_exit(1);
}
do { exec @_ };
POSIX::_exit(1);
}
close $child_in;
close $child_out;
$_[0] = $dad_in;
$_[1] = $dad_out;
$pid;
}
sub _init_transport {
my ($backend, $sftp, $opts) = @_;
my $transport = delete $opts->{transport};
if (defined $transport) {
if (ref $transport eq 'ARRAY') {
@{$sftp}{qw(ssh_in ssh_out pid)} = @$transport;
}
else {
$sftp->{ssh_in} = $sftp->{ssh_out} = $transport;
$sftp->{_ssh_out_is_not_dupped} = 1;
}
}
else {
my $pass = delete $opts->{passphrase};
my $pass_is_passphrase;
if (defined $pass) {
$pass_is_passphrase = 1;
}
else {
$pass = delete $opts->{password};
defined $pass and $sftp->{_password_authentication} = 1;
}
my $expect_log_user = delete $opts->{expect_log_user} || 0;
my $stderr_discard = delete $opts->{stderr_discard};
my $stderr_fh = ($stderr_discard ? undef : delete $opts->{stderr_fh});
my $open2_cmd = delete $opts->{open2_cmd};
my $ssh_cmd_interface = delete $opts->{ssh_cmd_interface};
my @open2_cmd;
if (defined $open2_cmd) {
@open2_cmd = _ensure_list($open2_cmd);
}
else {
my $host = delete $opts->{host};
defined $host or croak "sftp target host not defined";
my $key_path = delete $opts->{key_path};
my $ssh_cmd = delete $opts->{ssh_cmd};
$ssh_cmd = 'ssh' unless defined $ssh_cmd;
@open2_cmd = _ensure_list $ssh_cmd;
unless (defined $ssh_cmd_interface) {
$ssh_cmd_interface = ( "@open2_cmd" =~ /\bplink\b/i ? 'plink' :
"@open2_cmd" =~ /\bsshg3\b/i ? 'tectia' :
'ssh' );
}
my $port = delete $opts->{port};
my $user = delete $opts->{user};
my $ssh1 = delete $opts->{ssh1};
my $more = delete $opts->{more};
defined $more and !ref($more) and $more =~ /^-\w\s+\S/ and
warnings::warnif("Net::SFTP::Foreign", "'more' argument looks like it should be split first");
my @more = _ensure_list $more;
my @preferred_authentications;
if (defined $key_path) {
push @preferred_authentications, 'publickey' if defined $key_path;
push @open2_cmd, -i => $key_path;
}
if ($ssh_cmd_interface eq 'plink') {
push @open2_cmd, -P => $port if defined $port;
if (defined $pass and !$pass_is_passphrase) {
warnings::warnif("Net::SFTP::Foreign", "using insecure password authentication with plink");
push @open2_cmd, -pw => $pass;
undef $pass;
}
}
elsif ($ssh_cmd_interface eq 'ssh') {
push @open2_cmd, -p => $port if defined $port;
if (defined $pass and !$pass_is_passphrase) {
push @open2_cmd, -o => 'NumberOfPasswordPrompts=1';
push @preferred_authentications, ('keyboard-interactive', 'password');
}
if (@preferred_authentications
and not grep { $more[$_] eq '-o' and
$more[$_ + 1] =~ /^PreferredAuthentications\W/ } 0..$#more-1) {
push @open2_cmd, -o => 'PreferredAuthentications=' . join(',', @preferred_authentications);
}
}
elsif ($ssh_cmd_interface eq 'tectia') {
}
else {
die "Unsupported ssh_cmd_interface '$ssh_cmd_interface'";
}
push @open2_cmd, -l => $user if defined $user;
push @open2_cmd, @more;
push @open2_cmd, $host;
push @open2_cmd, ($ssh1 ? "/usr/lib/sftp-server" : -s => 'sftp');
}
my $redirect_stderr_to_tty = ( defined $pass and
( delete $opts->{redirect_stderr_to_tty} or $ssh_cmd_interface eq 'tectia' ) );
$redirect_stderr_to_tty and ($stderr_discard or $stderr_fh)
and croak "stderr_discard or stderr_fh can not be used together with password/passphrase "
. "authentication when Tectia client is used";
$debug and $debug & 1 and _debug "ssh cmd: @open2_cmd\n";
%$opts and return; # Net::SFTP::Foreign will find the
# unhandled options and croak
if (${^TAINT} and Scalar::Util::tainted($ENV{PATH})) {
_tcroak('Insecure $ENV{PATH}')
}
if ($stderr_discard) {
$stderr_fh = $backend->_open_dev_null($sftp) or return;
}
if (defined $pass) {
# user has requested to use a password or a passphrase for
# authentication we use Expect to handle that
eval { require IO::Pty };
$@ and croak "password authentication is not available, IO::Pty and Expect are not installed";
eval { require Expect };
$@ and croak "password authentication is not available, Expect is not installed";
local ($ENV{SSH_ASKPASS}, $ENV{SSH_AUTH_SOCK}) if $pass_is_passphrase;
my $name = $pass_is_passphrase ? 'Passphrase' : 'Password';
my $eto = $sftp->{_timeout} ? $sftp->{_timeout} * 4 : 120;
my $child;
my $expect;
my $pty = IO::Pty->new;
$expect = Expect->init($pty);
$expect->raw_pty(1);
$expect->log_user($expect_log_user);
$redirect_stderr_to_tty and $stderr_fh = $pty->slave;
$child = $backend->_open4($sftp, $sftp->{ssh_in}, $sftp->{ssh_out}, $stderr_fh, $pty, @open2_cmd);
unless (defined $child) {
$sftp->_conn_failed("Bad ssh command", $!);
return;
}
$sftp->{pid} = $child;
$sftp->{_expect} = $expect;
unless($expect->expect($eto, ':', '?')) {
$sftp->_conn_failed("$name not requested as expected", $expect->error);
return;
}
my $before = $expect->before;
if ($before =~ /^The authenticity of host /i or
$before =~ /^Warning: the \w+ host key for /i) {
$sftp->_conn_failed("the authenticity of the target host can not be established, connect from the command line first");
return;
}
$expect->send("$pass\n");
$sftp->{_password_sent} = 1;
unless ($expect->expect($eto, "\n")) {
$sftp->_conn_failed("$name interchange did not complete", $expect->error);
return;
}
$expect->close_slave();
}
else {
$sftp->{pid} = $backend->_open4($sftp, $sftp->{ssh_in}, $sftp->{ssh_out}, $stderr_fh, undef, @open2_cmd);
unless (defined $sftp->{pid}) {
$sftp->_conn_failed("Bad ssh command", $!);
return;
}
}
}
$backend->_init_transport_streams($sftp);
}
sub _after_init {
my ($backend, $sftp) = @_;
unless ($sftp->error) {
# do not propagate signals sent from the terminal to the
# slave SSH:
local ($@, $!);
eval { setpgrp($sftp->{pid}, 0) };
}
}
sub _do_io {
my (undef, $sftp, $timeout) = @_;
$debug and $debug & 32 and _debug(sprintf "_do_io connected: %s", $sftp->{_connected} || 0);
return undef unless $sftp->{_connected};
my $fnoout = fileno $sftp->{ssh_out};
my $fnoin = fileno $sftp->{ssh_in};
my ($rv, $wv) = ('', '');
vec($rv, $fnoin, 1) = 1;
vec($wv, $fnoout, 1) = 1;
my $bin = \$sftp->{_bin};
my $bout = \$sftp->{_bout};
local $SIG{PIPE} = 'IGNORE';
my $len;
while (1) {
my $lbin = length $$bin;
if (defined $len) {
return 1 if $lbin >= $len;
}
elsif ($lbin >= 4) {
$len = 4 + unpack N => $$bin;
if ($len > 256 * 1024) {
$sftp->_set_status(SSH2_FX_BAD_MESSAGE);
$sftp->_set_error(SFTP_ERR_REMOTE_BAD_MESSAGE,
"bad remote message received");
return undef;
}
return 1 if $lbin >= $len;
}
my $rv1 = $rv;
my $wv1 = length($$bout) ? $wv : '';
$debug and $debug & 32 and _debug("_do_io select(-,-,-, ". (defined $timeout ? $timeout : 'undef') .")");
my $n = select($rv1, $wv1, undef, $timeout);
if ($n > 0) {
if (vec($wv1, $fnoout, 1)) {
my $written = syswrite($sftp->{ssh_out}, $$bout, 64 * 1024);
if ($debug and $debug & 32) {
_debug (sprintf "_do_io write queue: %d, syswrite: %s, max: %d, \$!: %s",
length $$bout,
(defined $written ? $written : 'undef'),
64 * 1024, $!);
$debug & 2048 and $written and _hexdump(substr($$bout, 0, $written));
}
if ($written) {
substr($$bout, 0, $written, '');
}
elsif ($! != Errno::EAGAIN() and $! != Errno::EINTR()) {
$sftp->_conn_lost;
return undef;
}
}
if (vec($rv1, $fnoin, 1)) {
my $read = sysread($sftp->{ssh_in}, $$bin, 64 * 1024, length($$bin));
if ($debug and $debug & 32) {
_debug (sprintf "_do_io read sysread: %s, total read: %d, \$!: %s",
(defined $read ? $read : 'undef'),
length $$bin,
$!);
$debug & 1024 and $read and _hexdump(substr($$bin, -$read));
}
if (!$read and $! != Errno::EAGAIN() and $! != Errno::EINTR()) {
$sftp->_conn_lost;
return undef;
}
}
}
else {
$debug and $debug & 32 and _debug "_do_io select failed: $!";
next if ($n < 0 and ($! == Errno::EINTR() or $! == Errno::EAGAIN()));
return undef;
}
}
}
1;
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