Net::SSH::Perl::CipherUseroContributed PerlNet::SSH::Perl::Cipher::Blowfish(3)NAMENet::SSH::Perl::Cipher::Blowfish - Wrapper for SSH Blowfish support
SYNOPSIS
use Net::SSH::Perl::Cipher;
my $cipher = Net::SSH::Perl::Cipher->new('Blowfish', $key);
print $cipher->encrypt($plaintext);
DESCRIPTIONNet::SSH::Perl::Cipher::Blowfish provides Blowfish encryption support
for Net::SSH::Perl. To do so it wraps around either Crypt::Blowfish or
Crypt::Blowfish_PP; the former is a C/XS implementation of the blowfish
algorithm, and the latter is a Perl implementation.
Net::SSH::Perl::Cipher::Blowfish prefers to use Crypt::Blowfish,
because it's faster, so we try to load that first. If it fails, we fall
back to Crypt::Blowfish_PP. Note that, when using Crypt::Blowfish_PP,
you'll experience a very noticeable decrease in performance.
The blowfish used here is in CBC filter mode with a key length of 32
bytes.
SSH1 adds an extra wrinkle with respect to its blowfish algorithm:
before and after encryption/decryption, we have to swap the bytes in
the string to be encrypted/decrypted. The byte-swapping is done four
bytes at a time, and within each of those four-byte blocks we reverse
the bytes. So, for example, the string "foobarba" turns into
"boofabra". We swap the bytes in this manner in the string before we
encrypt/decrypt it, and swap the encrypted/decrypted string again when
we get it back.
This byte-swapping is not done when Blowfish is used in the SSH2
protocol.
AUTHOR & COPYRIGHTS
Please see the Net::SSH::Perl manpage for author, copyright, and
license information.
perl v5.14.12001-05-0Net::SSH::Perl::Cipher::Blowfish(3)
