Bug #36626 for Net-SSH-Perl: BUG-CMD hangs on over large amount of data

*Hi, The bug is not new and there is a post on resolved bug on cpanforum.orgwith ID number 7910. I was trying to send a about 32KB data to remote machine and write to a file. Here is my script.* ============================================================================================== #! /usr/bin/perl -w use Time::HiRes qw(time); use Net::SSH::Perl; $TIME=time; printf "Time before %.8f\n",$TIME; system "scp perl-ssh-test.dat lxh\@arches-n1:perl-ssh-test.dat.ssh"; $TIME=time; printf "Time after 1 %.8f\n",$TIME; $OUT="perl-ssh-test.dat.perl"; open (FILE,"perl-ssh-test.dat"); $LOG = do { local $/; <FILE> }; #@LOG = <FILE>; close(FILE); %params=(protocol => 2,debug=>1); $ssh = Net::SSH::Perl->new("arches-n1",%params); $ssh->login("lxh"); my ($stdout, $stderr, $exit)=$ssh->cmd("cat - > $OUT" , $LOG); #printf "OUTPUT %s\n",$stderr; $TIME=time; printf "Time after 2 %.8f\n",$TIME; ============================================================================================== *I found that I got the following error: Received disconnect message: Corrupted MAC on input. I read about the post 7910, and did what the post suggest to do and this time. I got no message and the program will just hang there forever. I turned on the debug option and this is where the program hangs:* =============================================================================================== bl-chem-iyengar3: Reading configuration data /home/xl5/.ssh/config bl-chem-iyengar3: Reading configuration data /etc/ssh_config bl-chem-iyengar3: Connecting to arches-n1, port 22. bl-chem-iyengar3: Remote version string: SSH-1.99-OpenSSH_4.6 bl-chem-iyengar3: Remote protocol version 1.99, remote software version OpenSSH_4.6 bl-chem-iyengar3: Net::SSH::Perl Version 1.30, protocol version 2.0. bl-chem-iyengar3: No compat match: OpenSSH_4.6. bl-chem-iyengar3: Connection established. bl-chem-iyengar3: Sent key-exchange init (KEXINIT), wait response. bl-chem-iyengar3: Algorithms, c->s: 3des-cbc hmac-sha1 none bl-chem-iyengar3: Algorithms, s->c: 3des-cbc hmac-sha1 none bl-chem-iyengar3: Entering Diffie-Hellman Group 1 key exchange. bl-chem-iyengar3: Sent DH public key, waiting for reply. bl-chem-iyengar3: Received host key, type 'ssh-dss'. bl-chem-iyengar3: Host 'arches-n1' is known and matches the host key. bl-chem-iyengar3: Computing shared secret key. bl-chem-iyengar3: Verifying server signature. bl-chem-iyengar3: Waiting for NEWKEYS message. bl-chem-iyengar3: Enabling incoming encryption/MAC/compression. bl-chem-iyengar3: Send NEWKEYS, enable outgoing encryption/MAC/compression. bl-chem-iyengar3: Sending request for user-authentication service. bl-chem-iyengar3: Service accepted: ssh-userauth. bl-chem-iyengar3: Trying empty user-authentication request. bl-chem-iyengar3: Authentication methods that can continue: publickey,password,keyboard-interactive,hostbased. bl-chem-iyengar3: Next method to try is publickey. bl-chem-iyengar3: Trying pubkey authentication with key file '/home/xl5/.ssh/id_dsa' bl-chem-iyengar3: Login completed, opening dummy shell channel. bl-chem-iyengar3: channel 0: new [client-session] bl-chem-iyengar3: Requesting channel_open for channel 0. bl-chem-iyengar3: channel 0: open confirm rwindow 0 rmax 32768 bl-chem-iyengar3: Got channel open confirmation, requesting shell. bl-chem-iyengar3: Requesting service shell on channel 0. bl-chem-iyengar3: channel 1: new [client-session] bl-chem-iyengar3: Requesting channel_open for channel 1. bl-chem-iyengar3: Entering interactive session. bl-chem-iyengar3: Sending command: cat > perl-ssh-test.dat.perl bl-chem-iyengar3: Requesting service exec on channel 1. bl-chem-iyengar3: channel 1: send eof bl-chem-iyengar3: channel 1: open confirm rwindow 99072 rmax 32768 ================================================================================================== *when I tried to use the example script pscp to scp the same 32KB file, I got an error message Broken Pipe. In the post ID 7910, someone has posted a test script to test the critical value of the size of the data which will trigger the bug. I used this result and found that this test script will not give consistent results at different runs. Here I give a few different scenarios. Case 1 ====================================================================================== *Net::SSH::Perl bug test... host=arches-n1 user=lxh remoteCmd=cat xferChars=932779|-Error, down to 466390 chars Received disconnect message: Corrupted MAC on input. xferChars=466390|-Error, down to 233195 chars Received disconnect message: Corrupted MAC on input. xferChars=233195|-Error, down to 116598 chars Received disconnect message: Corrupted MAC on input. xferChars=116598|-Broken pipe * ======================================================================================= Case 2 ======================================================================================= *Net::SSH::Perl bug test... host=arches-n1 user=lxh remoteCmd=cat xferChars=932779|-Error, down to 466390 chars Received disconnect message: Corrupted MAC on input. xferChars=466390|-Broken pipe * ======================================================================================== Case 3 ======================================================================================== *Net::SSH::Perl bug test... host=arches-n1 user=lxh remoteCmd=cat xferChars=932779|-Error, down to 466390 chars Received disconnect message: Corrupted MAC on input. xferChars=466390|-Error, down to 233195 chars Received disconnect message: Corrupted MAC on input. xferChars=233195|-Error, down to 116598 chars Received disconnect message: Corrupted MAC on input. xferChars=116598|-Error, down to 58299 chars Received disconnect message: Corrupted MAC on input. xferChars=58299|-Error, down to 29150 chars Received disconnect message: Corrupted MAC on input. xferChars=29150|-Error, down to 14575 chars alarm handler 10 second timeout xferChars=14575|-OK, back up to 21862 chars xferChars=21862|-Error, down to 18219 chars alarm handler 10 second timeout xferChars=18219|-Error, down to 16397 chars alarm handler 10 second timeout xferChars=16397|-Error, down to 15486 chars alarm handler 10 second timeout xferChars=15486|-OK, back up to 15941 chars xferChars=15941|-OK, back up to 16169 chars xferChars=16169|-OK, back up to 16283 chars xferChars=16283|-OK, back up to 16340 chars xferChars=16340|-OK, back up to 16368 chars xferChars=16368|-OK, back up to 16382 chars xferChars=16382|-OK, back up to 16389 chars xferChars=16389|-OK, back up to 16393 chars xferChars=16393|-OK, back up to 16395 chars xferChars=16395|-OK, back up to 16396 chars xferChars=16396|-OK, back up to 16396 chars Report for remote host: arches-n1... xferChars=16396 works, xferChars=16397 hangs on timeout=10. exiting... * ======================================================================================== Case 4 ======================================================================================== *Net::SSH::Perl bug test... host=arches-n1 user=lxh remoteCmd=cat xferChars=932779|-Error, down to 466390 chars Received disconnect message: Corrupted MAC on input. xferChars=466390|-Error, down to 233195 chars Received disconnect message: Corrupted MAC on input. xferChars=233195|-Error, down to 116598 chars Received disconnect message: Corrupted MAC on input. xferChars=116598|-Error, down to 58299 chars Received disconnect message: Corrupted MAC on input. xferChars=58299|-Error, down to 29150 chars Received disconnect message: Corrupted MAC on input. xferChars=29150|-Error, down to 14575 chars alarm handler 10 second timeout xferChars=14575|-OK, back up to 21862 chars xferChars=21862|-Error, down to 18219 chars alarm handler 10 second timeout xferChars=18219|-Error, down to 16397 chars alarm handler 10 second timeout xferChars=16397|-Error, down to 15486 chars alarm handler 10 second timeout xferChars=15486|-OK, back up to 15941 chars xferChars=15941|-Error, down to 15714 chars alarm handler 10 second timeout xferChars=15714|-OK, back up to 15827 chars xferChars=15827|-OK, back up to 15884 chars xferChars=15884|-Error, down to 15856 chars alarm handler 10 second timeout xferChars=15856|-Error, down to 15842 chars alarm handler 10 second timeout xferChars=15842|-OK, back up to 15849 chars xferChars=15849|-Error, down to 15846 chars alarm handler 10 second timeout xferChars=15846|-OK, back up to 15847 chars xferChars=15847|-OK, back up to 15848 chars xferChars=15848|-Error, down to 15848 chars Received disconnect message: Corrupted MAC on input. Bug did not trigger with 15848 chars on this system. exiting...* ======================================================================================= This bug is very confusing. As it's reported on cpanforum, it's resolved, but in fact it's not resolved and the test script there seems to have bugs too. it would be very helpful if you can look into this problem. i'm using suse 10.1 with kernel 2.6.16.53-0.8-default and perl 5.8.8. Thanks, Xiaohu *