rc4, RC4_set_key, RC4 - RC4 encryption
RC4_KEY *key, int len, const unsigned char *data ); void RC4(
RC4_KEY *key, unsigned long len, const unsigned char *indata,
unsigned char *outdata );
This library implements the Alleged RC4 cipher, which is described in
Applied Cryptography. It is believed to be compatible with <trade‐
mark>RC4</trademark>, 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 decryp‐
The RC4_set_key() function sets up the RC4_KEY key using the len bytes
long key at data.
The RC4() function 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 XORed with a pseudo-random
key stream to produce the output), decryption uses the same function
calls as encryption.
Applications should use the higher level functions instead of calling
the RC4 functions directly. (See EVP_EncryptInit(3).)
Certain conditions have to be observed to securely use stream ciphers.
You cannot perform multiple encryptions using the same key stream.
The RC4_set_key() and RC4() functions do not return values.
The RC4_set_key() and RC4() functions are available in all versions of
SSLeay and OpenSSL.
Functions: blowfish(3), des(3), rc2(3)rc4(3)