You read from the socket until a newline is found, and you assume you have a full (encrypted) message when you do. There's two problems with that:

Start by encrypting the stream rather than each message. 

# Sender
$cipher->start('encrypting');
print $sock $cipher->crypt($_) while <STDIN>;
print $sock $cipher->finish();

[download]
# Receiver
$cipher->start('decrypting');
local $/ = \4096;
process_bytes($cipher->crypt($_)) while <$sock>;
process_bytes($cipher->finish());

[download]
# Interactive receiver
$cipher->start('decrypting');
for (;;) {
   my $rv = sysread($sock, my $buf='', 4096);
   die $! if !defined $rv
   last   if !$rv;
   process_bytes($cipher->crypt($buf));
}
process_bytes($cipher->finish());

[download]

I think $/=4096;<> will wait for 4096 bytes. sysread will return as soon as any bytes are available.

If you want to read a line at a time, you'll need to accumulate and find lines in the plaintext yourself.

Upgrade: Doh! Using sysread is not enough to be truly interactive. You'll need to pad your lines to a multiple of $cipher->blocksize() bytes.

Interactive or not, why not just use IO::Socket::SSL?

In reply to Re: Crypt::CBC and IO:Socket by ikegami
in thread Crypt::CBC and IO:Socket by WMP

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