I have been tinkering around with a forking server in Perl. Since I wanted the ability to shell out and execute commands and have their output sent back over the socket, I took advantage of redirecting STDIN/STDOUT to the socket. This works perfectly if I am not doing SSL. With SSL, it does not work. Here is an example of me using IO::Socket::INET, which works:

#!/usr/bin/perl -w

use strict;
use IO::Socket::INET;

my $port = 12345;

my $server = IO::Socket::INET->new(
    LocalAddr => '127.0.0.1',
    LocalPort => $port,
    Listen => 10,
    Reuse => 1,
) or die "failed to listen: $!";


my $client = $server->accept;

my $cf = $client->fileno;
open(STDIN,  "<&$cf") || die "Couldn't dup client to stdin";
open(STDOUT, ">&$cf") || die "Couldn't dup client to stdout";
print "The client should see this message.\n";

close($client);
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Here is an example of me using IO::Socket::SSL, which does not work:

#!/usr/bin/perl -w

use strict;
use IO::Socket::SSL;

my $port = 12345;

my $server = IO::Socket::SSL->new(
    LocalAddr => '127.0.0.1',
    LocalPort => $port,
    Listen => 10,
    Reuse => 1,
    SSL_cert_file => 'cert.pem',
    SSL_key_file => 'key.pem',
) or die "failed to listen: $!";


my $client = $server->accept;

my $cf = $client->fileno;
open(STDIN,  "<&$cf") || die "Couldn't dup client to stdin";
open(STDOUT, ">&$cf") || die "Couldn't dup client to stdout";
print "The client should see this message.\n";

close($client);
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Here is the output of each script when ran:

$ nc localhost 12345
The client should see this message.

$ nc --ssl localhost 12345
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There are plenty of examples about how to do a forking server with the IO::Socket module with STDIN/STDOUT redirection. As soon as the IO::Socket module is flipped to SSL, the redirection no longer works. The above examples do not do what I really wanted, which is to shell out and execute a command. If I can't get a basic print statement to work with IO redirection, then shelling out won't work either.

I looked at other modules too. Net::Server was more useful to me and seemed to work better. Here is an example without using SSL:

#!/usr/bin/perl -w

package NetServer;

use strict;
use base qw(Net::Server::Fork);

sub process_request {
    my $self = shift;

    ### COMMAND PIPE
    print "Executing Command Pipe\n";
    open DATA, "/usr/bin/echo ==== Command Pipe Successful|" or
        die "Couldn't open command: $!";
    while (defined(my $line = <DATA>)) {
        chomp($line);
        print "$line\n";
    }
    close DATA;

    ### SYSTEM COMMAND
    print "Executing System Command\n";
    system("/usr/bin/echo ==== System Command Successful");

    ### EXEC COMMAND
    print "Executing Exec Command\n";
    exec "/usr/bin/echo ==== Exec Command Successful" or
        die "Couldn't exec command: $!";
}

NetServer->run(port=>12345);
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The above works perfectly. All three echo commands go over the socket. Here is the SSL example:

#!/usr/bin/perl -w

package NetServer;

use strict;
use base qw(Net::Server::Fork);

sub SSL_key_file  { "key.pem" }
sub SSL_cert_file { "cert.pem" }

sub process_request {
    my $self = shift;

    ### COMMAND PIPE
    print "Executing Command Pipe\n";
    open DATA, "/usr/bin/echo ==== Command Pipe Successful|" or
        die "Couldn't open command: $!";
    while (defined(my $line = <DATA>)) {
        chomp($line);
        print "$line\n";
    }
    close DATA;

    ### SYSTEM COMMAND
    print "Executing System Command\n";
    system("/usr/bin/echo ==== System Command Successful");

    ### EXEC COMMAND
    print "Executing Exec Command\n";
    exec "/usr/bin/echo ==== Exec Command Successful" or
        die "Couldn't exec command: $!";
}

#NetServer->run(proto => 'ssl', port=>12345);
NetServer->run(proto => 'ssleay', port=>12345);
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I tried it with both "ssl" and "ssleay" and the results were identical. Surprisingly, I get the output from the Command Pipe, but I don't get output from the other two. The following is the output from the non-ssl and the ssl example scripts from above:

$ nc localhost 12345
Executing Command Pipe
==== Command Pipe Successful
Executing System Command
==== System Command Successful
Executing Exec Command
==== Exec Command Successful

$ nc --ssl localhost 12345
Executing Command Pipe
==== Command Pipe Successful
Executing System Command
Executing Exec Command
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Just to be sure the Command Pipe section wasn't interfering with the other two sections, I did play around with commenting all but one section at a time and the results were the same... the Command Pipe works but the System Command and Exec Command sections do not.

I spent the last several days researching this on the Internet, reading up in my books and playing around extensively in code. I now ask for Wisdom from the Perl Monks community. I would like to know why redirection doesn't work at all with IO::Socket::SSL and what am I missing with regards to the system() and exec() calls that prevents redirection working with the Net::Server module.

Thank you,
Zucan