OpenSL                                             rc4(3openssl)



NAME
     RC4setkey, RC4 - RC4 encryption

SYNOPSIS
      #include 

      void RC4setkey(RC4KEY *key, int len, const unsigned char *data);

      void RC4(RC4KEY *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.

     RC4setkey() sets up the RC4KEY 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 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
     EVPEncryptInit(3) etc. instead of calling the RC4 functions
     directly.

RETURN VALUES
     RC4setkey() and RC4() do not return values.

NOTE
     Certain conditions have to be observed to securely use
     stream ciphers.  It is not permissible to perform multiple
     encryptions using the same key stream.

SEE ALSO
     blowfish(3), des(3), rc2(3)





OpenSL-0.9.8       Last change: Oct 11 2005                    1






OpenSL                                             rc4(3openssl)



HISTORY
     RC4setkey() and RC4() are available in all versions of
     SLeay and OpenSL.




















































OpenSL-0.9.8       Last change: Oct 11 2005                    2