RC4_set_key, RC4 - RC4 encryption
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);
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.
sets up the RC4_KEY key
using the len
bytes long key at data
encrypts or decrypts the len
bytes of data at indata
and places the result at outdata
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 EVP_EncryptInit(3)
etc. instead of calling the RC4 functions directly.
do not return values.
Certain conditions have to be observed to securely use stream ciphers. It is not
permissible to perform multiple encryptions using the same key stream.
are available in all versions of SSLeay