Difference with Net::SSH::Perl on perl 5.12 and 5.14

Question

I have the following code (of course I replaced myremoteserver.com):

use Modern::Perl;
use Net::SSH::Perl;
use Data::Dumper;

my $ssh = Net::SSH::Perl->new('myremoteserver.com', debug => 1, port => 2999);

$ssh->login('root');
print Dumper $ssh->cmd('uptime');

On a keyless environment, I'm running it both on perl 5.12 and 5.14.

On perl 5.12 it seems to work:

$ perl5.12 /tmp/sshtest.pl 
ko.local: Reading configuration data /Users/david/.ssh/config
ko.local: Reading configuration data /etc/ssh_config
ko.local: Connecting to myremoteserver.com, port 2999.
ko.local: Remote protocol version 2.0, remote software version OpenSSH_5.8p1 Debian-1ubuntu3
Math::BigInt: couldn't load specified math lib(s), fallback to Math::BigInt::Calc at /opt/local/lib/perl5/site_perl/5.12.3/Crypt/DH.pm line 6
ko.local: Net::SSH::Perl Version 1.34, protocol version 2.0.
.o.local: No compat match: OpenSSH_5.8p1 Debian-1ubuntu3
ko.local: Connection established.
ko.local: Sent key-exchange init (KEXINIT), wait response.
ko.local: Algorithms, c->s: 3des-cbc hmac-sha1 none
ko.local: Algorithms, s->c: 3des-cbc hmac-sha1 none
ko.local: Entering Diffie-Hellman Group 1 key exchange.
ko.local: Sent DH public key, waiting for reply.
ko.local: Received host key, type 'ssh-dss'.
ko.local: Host 'myremoteserver.com' is known and matches the host key.
ko.local: Computing shared secret key.
ko.local: Verifying server signature.
ko.local: Waiting for NEWKEYS message.
ko.local: Send NEWKEYS.
ko.local: Enabling encryption/MAC/compression.
ko.local: Sending request for user-authentication service.
ko.local: Service accepted: ssh-userauth.
ko.local: Trying empty user-authentication request.
ko.local: Authentication methods that can continue: publickey.
ko.local: Next method to try is publickey.
ko.local: Publickey: testing agent key '/Users/david/.ssh/github_rsa'
ko.local: Authentication methods that can continue: publickey.
ko.local: Next method to try is publickey.
Permission denied at /tmp/sshtest.pl line 9

But on perl 5.14:

$ perl5.14 /tmp/sshtest.pl 
ko.local: Reading configuration data /Users/david/.ssh/config
ko.local: Reading configuration data /etc/ssh_config
ko.local: Connecting to myremoteserver.com, port 2999.
ko.local: Remote protocol version 2.0, remote software version OpenSSH_5.8p1 Debian-1ubuntu3
ko.local: Net::SSH::Perl Version 1.34, protocol version 2.0.
.o.local: No compat match: OpenSSH_5.8p1 Debian-1ubuntu3
ko.local: Connection established.
ko.local: Sent key-exchange init (KEXINIT), wait response.
ko.local: Algorithms, c->s: 3des-cbc hmac-sha1 none
ko.local: Algorithms, s->c: 3des-cbc hmac-sha1 none
ko.local: Entering Diffie-Hellman Group 1 key exchange.
ko.local: Sent DH public key, waiting for reply.
ko.local: Received host key, type 'ssh-dss'.
ko.local: Host 'myremoteserver.com' is known and matches the host key.
ko.local: Computing shared secret key.
ko.local: Verifying server signature.
Key verification failed for server host key at /opt/local/lib/perl5/site_perl/5.14.1/Net/SSH/Perl/SSH2.pm line 92

The only difference I see is Math::BigInt returns a warning on perl 5.12.

Some debugging info:

~ $ perl5.12 -MNet::SSH::Perl -e 'print $Net::SSH::Perl::VERSION, "\n";'
1.34
~ $ perl5.14 -MNet::SSH::Perl -e 'print $Net::SSH::Perl::VERSION, "\n";'
1.34
~ $ perl5.12 -MMath::BigInt -e 'print $Math::BigInt::VERSION, "\n";'
1.997
~ $ perl5.14 -MMath::BigInt -e 'print $Math::BigInt::VERSION, "\n";'
1.997

Any idea what the problem here is?

Answer 1

There was a change to the default value for a configuration option that controlled how https validation was performed (specifically, the PERL_LWP_SSL_VERIFY_HOSTNAMES environment variable), when LWP::Protocol::https was pulled out of the main LWP library - now hostname checking is on by default, where it was off previously. It is possible that your perl 5.14 library picked up these new changes, and 5.12 is using the old versions.

There is also more information in "Now you need LWP::Protocol::https".