in reply to Re^4: sftp->do_write howto?
in thread sftp->do_write howto?

OK, I'm positive now: you have a permission problem om your remote host.
I've tried uploading to a directory with perm settings 000, and then I get the permission denied error message.

Here's a version with more testing code: 

#!/usr/bin/perl

# create a remote file, without creating a local file
#
use Net::SFTP;
use Net::SFTP::Constants qw/:flags/;
use strict;
use warnings;

my $filename  = "testfile.dat";
my $file_data = "qwertyuiop";
my %args = (
    user => 'insaniac', 
    password => 'xxxx'
);
#my $host = "moretrix.com";
my $host = "bear";
my $remote_path = 'not_allowed/'.$filename;
my ($err_code, $err_mesg);

print "Connecting to $host\n";
my $sftp;
eval { $sftp = Net::SFTP->new($host,%args) };
($err_code, $err_mesg) = $sftp->status;
if($err_code){
    print "Err_code:$err_code | err_mesg:$err_mesg\n"; 
    exit $err_code
};

print "Open $host:$remote_path\n";
my $remote_handle;
eval { 
    $remote_handle = $sftp->do_open($remote_path, SSH2_FXF_WRITE | SSH
+2_FXF_CREAT) };
($err_code, $err_mesg) = $sftp->status;
if($err_code){
    print "Err_code:$err_code | err_mesg:$err_mesg\n"; 
    exit $err_code
};

print "Write to remote file:\n$file_data\n";
eval { $sftp->do_write($remote_handle, 0, $file_data) };
($err_code, $err_mesg) = $sftp->status;
if($err_code){
    print "Err_code:$err_code | err_mesg:$err_mesg\n"; 
    exit $err_code
};

print "Close remote file handle\n";
$sftp->do_close($remote_handle);

[download]
The output of the script: 
Connecting to bear
Open bear:not_allowed/testfile.dat
Couldn't get handle: Permission denied at net_sftp.pl line 33
Err_code:3 | err_mesg:Permission denied

[download]
And the directory on the remote host is: 
bear: [/home/insaniac]# ls -ld not_allowed/
d---------  2 root root 4096 Sep 23 13:40 not_allowed/

[download]

HTH

to ask a question is a moment of shame
to remain ignorant is a lifelong shame

Replies are listed 'Best First'.
Re^6: sftp->do_write howto?
by chrism01 (Friar) on Sep 27, 2005 at 06:12 UTC
    Here's the latest with your debug code: 
    #!/usr/bin/perl
use Net::SFTP;
use Net::SFTP::Constants qw/:flags/;
use strict;
use warnings;

my (
        $filename,
        $payload,
        $host,
        $sftp,
        %args,
        $path,
        $handle,
        $err_code, $err_mesg
        );

$filename = "testfile.dat";
$payload = "qwertyuiop";

%args = (user => "yyyyyyyyyy",
                  password => "xxxxxx");
$host = "a.b.c.d";
$path = "/network/www/ticketattach/".$filename;

print "connecting\n";
eval { $sftp = Net::SFTP->new($host, %args) };
($err_code, $err_mesg) = $sftp->status;
if($err_code)
{
    print "Err_code:$err_code | err_mesg:$err_mesg\n";
    exit $err_code
};

print "open\n";
$handle = $sftp->do_open($path, SSH2_FXF_WRITE | SSH2_FXF_CREAT);
#$handle = $sftp->do_open($path, 0x02| 0x08);
($err_code, $err_mesg) = $sftp->status;
if($err_code)
{
    print "Err_code:$err_code | err_mesg:$err_mesg\n";
    exit $err_code
};
print "write\n";
$sftp->do_write($handle, 0, $payload);
($err_code, $err_mesg) = $sftp->status;
if($err_code)
{
    print "Err_code:$err_code | err_mesg:$err_mesg\n";
    exit $err_code
};

print "close\n";
$sftp->do_close($handle);
($err_code, $err_mesg) = $sftp->status;
if($err_code)
{
    print "Err_code:$err_code | err_mesg:$err_mesg\n";
    exit $err_code
};

    [download]
    and the response was...
    connecting
Can't call method "status" on an undefined value at ./sftp.pl line 28.

    [download]
    and as mentioned before I can ssh/sftp fine from the cmd line, but running this script from the same env manually does the above .. grrr... ie won't connect, forget about uploading.
    Cheers
    Chris
[reply]
[d/l]
[select]
      Hm... further investigations make me think there's a bug in Net::SSH::Perl or Net::SFTP.

      try adding this to your code: 

      my %args = (
    user     => 'user', 
    password => 'password',
    ssh_args  => [ 
        debug => 1,
        options => [
            "PreferredAuthentications 'keyboard-interactive,password,h
+ostbased,publickey'",
            ]
    ],
);

      [download]
      and then: 
      eval { $sftp = Net::SFTP->new($host, %args) };
die "Connection failed: $!\n" if $!;
die "No SFTP object\n" unless $sftp;

      [download]
      my output goes like: 
      wolf: Reading configuration data /home/insaniac/.ssh/config
wolf: Reading configuration data /etc/ssh_config
wolf: Connecting to bear, port 22.
wolf: Remote protocol version 2.0, remote software version OpenSSH_4.2
+p1 Debian-4
wolf: Net::SSH::Perl Version 1.28, protocol version 2.0.
wolf: No compat match: OpenSSH_4.2p1 Debian-4.
wolf: Connection established.
wolf: Sent key-exchange init (KEXINIT), wait response.
wolf: Algorithms, c->s: 3des-cbc hmac-sha1 none
wolf: Algorithms, s->c: 3des-cbc hmac-sha1 none
wolf: Entering Diffie-Hellman Group 1 key exchange.
wolf: Sent DH public key, waiting for reply.
wolf: Received host key, type 'ssh-dss'.
wolf: Host 'bear' is known and matches the host key.
wolf: Computing shared secret key.
wolf: Verifying server signature.
wolf: Waiting for NEWKEYS message.
wolf: Enabling incoming encryption/MAC/compression.
wolf: Send NEWKEYS, enable outgoing encryption/MAC/compression.
wolf: Sending request for user-authentication service.
wolf: Service accepted: ssh-userauth.
wolf: Trying empty user-authentication request.
wolf: Authentication methods that can continue: publickey,keyboard-int
+eractive.
wolf: Next method to try is publickey.
wolf: Trying pubkey authentication with key file '/home/insaniac/.ssh/
+id_dsa'
wolf: Authentication methods that can continue: publickey,keyboard-int
+eractive.
wolf: Next method to try is publickey.
Connection failed: No such file or directory

      [download]

      So when I try authenticating with an ssh-key, all works out perfectly. When I try to supply a username and a password, they seem to be ignored.. maybe we need to supply a specific value to ssh_args ?
      Per default, Net::SFTP uses the username that's executing the script as SSH username...

      I'll keep you informed if I find a solution...

      Cheers, Johnny

      to ask a question is a moment of shame
      to remain ignorant is a lifelong shame

[reply]
[d/l]
[select]
      Of course! How foolish of me... all we needed was debugging enabled ;-)

      You're remote SSH server is *probably* not accepting cleartext password tunneling. In other words, its /etc/ssh/sshd_config is saying something like: 

      PasswordAuthentication no

      [download]
      And that's what's causing (my) error when trying to use a username and password for authentication. When I changed it to yes, and restarted the remote SSH server, the scripts works, because debugging now said: 
      wolf: Sending request for user-authentication service.
wolf: Service accepted: ssh-userauth.
wolf: Trying empty user-authentication request.
wolf: Authentication methods that can continue: publickey,password,keyboard-interactive.
      Where it used to be (with PasswordAuthentication no): 
      wolf: Sending request for user-authentication service.
wolf: Service accepted: ssh-userauth.
wolf: Trying empty user-authentication request.
wolf: Authentication methods that can continue: publickey,keyboard-interactive.
      So the above debugging says that the remote SSH server only accepts ssh keys or a keyboard interactive password..

      My advise is: create an ssh-key for the user that runs your script, and add the public key of that user to the authorized_keys file of your remote user. This is more secure than enabling clear text password tunneling ;-)

      HTH

      to ask a question is a moment of shame
      to remain ignorant is a lifelong shame

[reply]
[d/l]
[select]
        Wolf,
        That's extremely enlightening and probably correct.
        The line in the config file is commented out, but I suspect it defaults to no (it's a BSD box).
        I certainly get the response you mentioned for 'no' when I added the debugging.
        It's been decided however that due to the low value of the info and multi-layer security (it's entirely an internal system) that we really don't need to take this any further.
        I'll certainly try and remember it for future ref though(!)
        I didn't realise there was a diff between interactive passwd and via a script. I assumed it'd use the same encryption/checking... wrong.. :-(
        Thx again
        Chris
        PS: how's your Net::SNMP? See my node 495954.
[reply]

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