| 1 | /* arcfour.h --- The arcfour stream cipher |
| 2 | * Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005 |
| 3 | * Free Software Foundation, Inc. |
| 4 | * |
| 5 | * This file is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License as published |
| 7 | * by the Free Software Foundation; either version 2, or (at your |
| 8 | * option) any later version. |
| 9 | * |
| 10 | * This file is distributed in the hope that it will be useful, but |
| 11 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 13 | * General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License |
| 16 | * along with this file; if not, write to the Free Software |
| 17 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 18 | * 02110-1301, USA. |
| 19 | * |
| 20 | */ |
| 21 | /** @file lib/arcfour.h |
| 22 | * @brief Arcfour (RC4-compatible) stream cipher implementation |
| 23 | */ |
| 24 | |
| 25 | /* Code from Libgcrypt adapted for gnulib by Simon Josefsson. */ |
| 26 | |
| 27 | #ifndef ARCFOUR_H |
| 28 | # define ARCFOUR_H |
| 29 | |
| 30 | # include <stddef.h> |
| 31 | # include <stdint.h> |
| 32 | |
| 33 | #define ARCFOUR_SBOX_SIZE 256 |
| 34 | |
| 35 | /** @brief Context structture for Arcfour stream cipher */ |
| 36 | typedef struct |
| 37 | { |
| 38 | char sbox[ARCFOUR_SBOX_SIZE]; |
| 39 | uint8_t idx_i, idx_j; |
| 40 | } arcfour_context; |
| 41 | |
| 42 | /* Apply ARCFOUR stream to INBUF placing the result in OUTBUF, both of |
| 43 | LENGTH size. CONTEXT must be initialized with arcfour_setkey |
| 44 | before this function is called. */ |
| 45 | extern void |
| 46 | arcfour_stream (arcfour_context * context, |
| 47 | const char *inbuf, char *outbuf, size_t length); |
| 48 | |
| 49 | /* Initialize CONTEXT using encryption KEY of KEYLEN bytes. KEY |
| 50 | should be 40 bits (5 bytes) or longer. The KEY cannot be zero |
| 51 | length. */ |
| 52 | extern void |
| 53 | arcfour_setkey (arcfour_context * context, const char *key, size_t keylen); |
| 54 | |
| 55 | #endif /* ARCFOUR_H */ |