Manual Page Result
0
Command: RC4 | Section: 3 | Source: OpenBSD | File: RC4.3
RC4(3) FreeBSD Library Functions Manual RC4(3)
NAME
RC4_set_key, RC4 - RC4 encryption
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);
DESCRIPTION
This library implements the alleged RC4 cipher, which is described for
example in "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 RC4_KEY key using the len bytes long key at
data.
RC4() encrypts or decrypts the len bytes of data at indata using key and
places the result at outdata. Repeated RC4() calls with the same key
yield a continuous key stream.
Since RC4 is a stream cipher (the input is XOR'ed with a pseudo-random
key stream to produce the output), decryption uses the same function
calls as encryption.
SEE ALSO
blowfish(3), EVP_EncryptInit(3), EVP_rc4(3)
HISTORY
RC4_set_key() and RC4() appeared in SSLeay 0.4 or earlier and have been
available since OpenBSD 2.4.
BUGS
This cipher is broken and should no longer be used.
FreeBSD 14.1-RELEASE-p8 March 29, 2020 FreeBSD 14.1-RELEASE-p8