65816-crypto/rc4.h
2024-06-26 20:46:58 -06:00

41 lines
1.5 KiB
C

/*
* Copyright (c) 2023 Stephen Heumann
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
struct rc4_context {
unsigned char i,j;
unsigned char S[256];
};
/*
* Initialize an RC4 context context with a specified key.
* This must be called before calling rc4_process.
*/
void rc4_init(struct rc4_context *context,
const unsigned char *key,
unsigned keylength);
/*
* Process data using RC4. This either encrypts or decrypts data,
* depending on whether in contains plaintext or ciphertext.
*
* To get the raw RC4 output stream, specify the input as all zeros.
* The same buffer may be used for in and out.
*/
void rc4_process(struct rc4_context *context,
const unsigned char *in,
unsigned char *out,
unsigned long length);