mcrypt_generic(3) [php man page]

MCRYPT_GENERIC(3)							 1							 MCRYPT_GENERIC(3)

mcrypt_generic - This function encrypts data

SYNOPSIS

       string mcrypt_generic (resource	$td, string  $data)

DESCRIPTION

	This function encrypts data. The data is padded with " " to make sure the length of the data is n * blocksize. This function returns the
       encrypted data. Note that the length of the returned string can in fact be longer than the input, due to the padding of the data.

	If you want to store the encrypted data in a database make sure to store the entire string as returned by mcrypt_generic,  or  the  string
       will not entirely decrypt properly. If your original string is 10 characters long and the block size is 8 (use mcrypt_enc_get_block_size(3)
       to determine the blocksize), you would need at least 16 characters in your database field. Note the string returned by  mdecrypt_generic(3)
       will be 16 characters as well...use rtrim($str, "") to remove the padding.

	If you are for example storing the data in a MySQL database remember that varchar fields automatically have trailing spaces removed during
       insertion. As encrypted data can end in a space (ASCII 32), the data will be damaged by this removal. Store data in a tinyblob/tinytext (or
       larger) field instead.

PARAMETERS

	      o $td
		-  The encryption descriptor.  The encryption handle should always be initialized with mcrypt_generic_init(3) with a key and an IV
		before	calling  this  function.  Where  the  encryption  is  done,  you  should  free	 the   encryption   buffers   by   calling
		mcrypt_generic_deinit(3). See mcrypt_module_open(3) for an example.

	      o $data
		- The data to encrypt.

RETURN VALUES

	Returns the encrypted data.

SEE ALSO

       mdecrypt_generic(3), mcrypt_generic_init(3), mcrypt_generic_deinit(3).

PHP Documentation Group 													 MCRYPT_GENERIC(3)

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)