RC4_set_key(3)

     rc4(3)                 0.9.6h (2000-02-25)                 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 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.

     RETURN VALUES
          RC4_set_key() 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)

     HISTORY

     Page 1                                         (printed 1/19/103)

     rc4(3)                 0.9.6h (2000-02-25)                 rc4(3)

          RC4_set_key() and RC4() are available in all versions of
          SSLeay and OpenSSL.

     Page 2                                         (printed 1/19/103)