encrypt(2) [plan9 man page]

ENCRYPT(2)							System Calls Manual							ENCRYPT(2)

NAME

       encrypt, decrypt, netcrypt - DES encryption

SYNOPSIS

       #include <u.h>
       #include <libc.h>

       int  encrypt(void *key, void *data, int len)

       int  decrypt(void *key, void *data, int len)

       int  netcrypt(void *key, void *data)

DESCRIPTION

       Encrypt	and  decrypt  perform DES encryption and decryption.  Key is an array of DESKEYLEN (defined as 7 in <auth.h>) bytes containing the
       encryption key.	Data is an array of len bytes; it must be at least 8 bytes long.  The bytes are encrypted or decrypted in place.

       The DES algorithm encrypts an individual 8 byte block of data.  Encrypt uses the following method to encrypt data longer than 8 bytes.  The
       first 8 bytes are encrypted as usual.  The last byte of the encrypted result is prefixed to the next 7 unencrypted bytes to make the next 8
       bytes to encrypt.  This is repeated until fewer than 7 bytes remain unencrypted.  Any remaining unencrypted bytes are encrypted with enough
       of the preceding encrypted bytes to make a full 8 byte block.  Decrypt uses the inverse algorithm.

       Netcrypt  performs  the	same encryption as a SecureNet Key.  Data points to an ASCII string of decimal digits with numeric value between 0
       and 10000.  These digits are copied into an 8 byte buffer with trailing binary zero fill and encrypted as one DES block.   The  first  four
       bytes are each formatted as two digit ASCII hexadecimal numbers, and the string is copied into data.

SOURCE

       /sys/src/libc/port

DIAGNOSTICS

       These routines return 1 if the data was encrypted, and 0 if the encryption fails.  Encrypt and decrypt fail if the data passed is less than
       8 bytes long.  Netcrypt can fail if it is passed invalid data.

SEE ALSO

       securenet(8)

BUGS

       The source is not included in public distributions.  The implementation is broken in a way  that  makes	it  unsuitable	for  anything  but
       authentication.

																	ENCRYPT(2)

DES(3)							User Contributed Perl Documentation						    DES(3)

NAME

       Crypt::DES - Perl DES encryption module

SYNOPSIS

	   use Crypt::DES;

DESCRIPTION

       The module implements the Crypt::CBC interface, which has the following methods

       blocksize =item keysize =item encrypt =item decrypt

FUNCTIONS

       blocksize
	   Returns the size (in bytes) of the block cipher.

       keysize
	   Returns the size (in bytes) of the key. Optimal size is 8 bytes.

       new
		   my $cipher = new Crypt::DES $key;

	   This creates a new Crypt::DES BlockCipher object, using $key, where $key is a key of "keysize()" bytes.

       encrypt
		   my $cipher = new Crypt::DES $key;
		   my $ciphertext = $cipher->encrypt($plaintext);

	   This function encrypts $plaintext and returns the $ciphertext where $plaintext and $ciphertext should be of "blocksize()" bytes.

       decrypt
		   my $cipher = new Crypt::DES $key;
		   my $plaintext = $cipher->decrypt($ciphertext);

	   This function decrypts $ciphertext and returns the $plaintext where $plaintext and $ciphertext should be of "blocksize()" bytes.

EXAMPLE

	       my $key = pack("H16", "0123456789ABCDEF");
	       my $cipher = new Crypt::DES $key;
	       my $ciphertext = $cipher->encrypt("plaintex");  # NB - 8 bytes
	       print unpack("H16", $ciphertext), "
";

NOTES

       Do note that DES only uses 8 byte keys and only works on 8 byte data blocks.  If you're intending to encrypt larger blocks or entire files,
       please use Crypt::CBC in conjunction with this module.  See the Crypt::CBC documentation for proper syntax and use.

       Also note that the DES algorithm is, by today's standard, weak encryption.  Crypt::Blowfish is highly recommended if you're interested in
       using strong encryption and a faster algorithm.

SEE ALSO

       Crypt::Blowfish Crypt::IDEA

       Bruce Schneier, Applied Cryptography, 1995, Second Edition, published by John Wiley & Sons, Inc.

COPYRIGHT

       The implementation of the DES algorithm was developed by, and is copyright of, Eric Young (eay@mincom.oz.au).  Other parts of the perl
       extension and module are copyright of Systemics Ltd ( http://www.systemics.com/ ).  Cross-platform work and packaging for single algorithm
       distribution is copyright of W3Works, LLC.

MAINTAINER

       This single-algorithm package and cross-platform code is maintained by Dave Paris <amused@pobox.com>.

perl v5.12.1							    2005-12-08								    DES(3)