4746f25ac6
[skip ci] Reviewed-by: Matt Caswell <matt@openssl.org> (Merged from https://github.com/openssl/openssl/pull/7829)
66 lines
1.9 KiB
Text
66 lines
1.9 KiB
Text
=pod
|
|
|
|
=head1 NAME
|
|
|
|
RC4_set_key, RC4 - RC4 encryption
|
|
|
|
=head1 SYNOPSIS
|
|
|
|
#include <openssl/rc4.h>
|
|
|
|
void RC4_set_key(RC4_KEY *key, int len, const unsigned char *data);
|
|
|
|
void RC4(RC4_KEY *key, unsigned long len, const unsigned char *indata,
|
|
unsigned char *outdata);
|
|
|
|
=head1 DESCRIPTION
|
|
|
|
This library implements the Alleged RC4 cipher, which is described for
|
|
example in I<Applied Cryptography>. It is believed to be compatible
|
|
with RC4[TM], a proprietary cipher of RSA Security Inc.
|
|
|
|
RC4 is a stream cipher with variable key length. Typically, 128 bit
|
|
(16 byte) keys are used for strong encryption, but shorter insecure
|
|
key sizes have been widely used due to export restrictions.
|
|
|
|
RC4 consists of a key setup phase and the actual encryption or
|
|
decryption phase.
|
|
|
|
RC4_set_key() sets up the B<RC4_KEY> B<key> using the B<len> bytes long
|
|
key at B<data>.
|
|
|
|
RC4() encrypts or decrypts the B<len> bytes of data at B<indata> using
|
|
B<key> and places the result at B<outdata>. Repeated RC4() calls with
|
|
the same B<key> yield a continuous key stream.
|
|
|
|
Since RC4 is a stream cipher (the input is XORed with a pseudo-random
|
|
key stream to produce the output), decryption uses the same function
|
|
calls as encryption.
|
|
|
|
=head1 RETURN VALUES
|
|
|
|
RC4_set_key() and RC4() do not return values.
|
|
|
|
=head1 NOTE
|
|
|
|
Applications should use the higher level functions
|
|
L<EVP_EncryptInit(3)> etc. instead of calling these
|
|
functions directly.
|
|
|
|
It is difficult to securely use stream ciphers. For example, do not perform
|
|
multiple encryptions using the same key stream.
|
|
|
|
=head1 SEE ALSO
|
|
|
|
L<EVP_EncryptInit(3)>
|
|
|
|
=head1 COPYRIGHT
|
|
|
|
Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved.
|
|
|
|
Licensed under the Apache License 2.0 (the "License"). You may not use
|
|
this file except in compliance with the License. You can obtain a copy
|
|
in the file LICENSE in the source distribution or at
|
|
L<https://www.openssl.org/source/license.html>.
|
|
|
|
=cut
|