1 /* arcfour.h --- The arcfour stream cipher 2 * Copyright (C) 2000-2005, 2009-2021 Free Software Foundation, Inc. 3 * 4 * This file is free software: you can redistribute it and/or modify 5 * it under the terms of the GNU Lesser General Public License as 6 * published by the Free Software Foundation; either version 2.1 of the 7 * License, or (at your option) any later version. 8 * 9 * This file is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU Lesser General Public License for more details. 13 * 14 * You should have received a copy of the GNU Lesser General Public License 15 * along with this program. If not, see <https://www.gnu.org/licenses/>. 16 * 17 */ 18 19 /* Code from Libgcrypt adapted for gnulib by Simon Josefsson. */ 20 21 #ifndef ARCFOUR_H 22 # define ARCFOUR_H 23 24 # include <stddef.h> 25 # include <stdint.h> 26 27 #define ARCFOUR_SBOX_SIZE 256 28 29 typedef struct 30 { 31 char sbox[ARCFOUR_SBOX_SIZE]; 32 uint8_t idx_i, idx_j; 33 } arcfour_context; 34 35 /* Apply ARCFOUR stream to INBUF placing the result in OUTBUF, both of 36 LENGTH size. CONTEXT must be initialized with arcfour_setkey 37 before this function is called. */ 38 extern void 39 arcfour_stream (arcfour_context * context, 40 const char *inbuf, char *restrict outbuf, size_t length); 41 42 /* Initialize CONTEXT using encryption KEY of KEYLEN bytes. KEY 43 should be 40 bits (5 bytes) or longer. The KEY cannot be zero 44 length. */ 45 extern void 46 arcfour_setkey (arcfour_context * context, const char *key, size_t keylen); 47 48 #endif /* ARCFOUR_H */