| Allegro CL version 8.2 Unrevised from 8.1 to 8.2. 8.1 version |
Arguments: value &key key end context pad in-place (external-format :utf-8) (mode :ecb) iv
This function encrypts value using the specified
key or context and returns
two values: an (unsigned-byte 8) array holding the encryption and an
integer specifying the index into that array just after the end of the
encrypted result (equivalently, the length of the encrypted
result). The second value will also be the length of the array
returned as the first value if the in-place is
nil
(which is its default). If
in-place is true, the second returned value will
be less than or equal to the length of the first returned value.
The arguments are:
nil
.
If an integer, the length of the portion of value
to be encrypted. If nil
, then the whole of
value is encrypted. (The
in-place argument to both this function and to
blowfish-decrypt allows
using an existing (unsigned-byte 8) array, which may be larger than
necessary to hold the encrypted value. This argument allows you to
specify the portion of interest and ignore the remainder of the
array.)
t
): if
pad is true then the value to be encrypted will
be padded out to have an octet length that is a multiple of 8. The
pad is constructed such that it contains information specifying how
much padding was added so that when the result is decrypted, the
padding can be removed. Thus if pad is true then
at least one and as many as eight more octets will be added to the
returned value. If pad is
:pkcs5
, then standard PKCS#5 padding will be used.
If pad is :zero
, then null padding will be used.
Note that null padding is only suitable if the value to be encrypted
contains no null octets. If pad is nil
then
an error is signaled if the value to be encrypted doesn't have a
length that is a multiple of 8.
:utf-8
and that is in
general a good choice. When
:default
is specified, the value returned by
(find-external-format :default)
is used
(see find-external-format).
That value is not recommended because the value of the default
external format (which depends on the value of *locale*
) may change between
encryption and decryption.
:ecb
, meaning use
ECB. Specify :cbc
for CBC. The text must be
decrypted in the same mode. If CBC encryption mode is requested, the
initialization vector (IV) must be provided by using keyword argument
iv. The IV must be a usb8 array of at least 8
elements. The IV will be modified so that it may be used for
subsequent encrypt/decrypt calls. CBC encryption is generally
considered superior to ECB encryption and should be used unless there
is a reason not to.
:cbc
. When mode is
:cbc
, the value, called the initialization vector
or IV, must be an (unsigned-byte 8) array of at least 8 elements. The IV
will be modified so that it may be used for subsequent
encrypt/decrypt calls.
See also the new auxilliary functions hex-string-to-usb8-array and usb8-array-to-hex-string.
See also blowfish-decrypt and blowfish-init.
See Support for Blowfish encryption in miscellaneous.htm for information on Blowfish encryption and Blowfish encryption support in Allegro CL. There are examples of blowfish encryption and decryption in that section. Support for encryption in the same document discusses encryption support in Allegro CL in general.
Copyright (c) 1998-2016, Franz Inc. Oakland, CA., USA. All rights reserved.
This page was not revised from the 8.1 page.
Created 2010.1.21.
| Allegro CL version 8.2 Unrevised from 8.1 to 8.2. 8.1 version |