1 /* arctwo.h --- The arctwo block cipher 2 * Copyright (C) 2000-2003, 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 ARCTWO_H 22 # define ARCTWO_H 23 24 # include <stddef.h> 25 # include <stdint.h> 26 27 typedef struct 28 { 29 uint16_t S[64]; 30 } arctwo_context; 31 32 #define ARCTWO_BLOCK_SIZE 8 33 34 /* Initialize CONTEXT using KEY of KEYLEN length. If 35 EFFECTIVE_KEYLEN, truncate the key (using a special algorithm) to 36 only be of EFFECTIVE_KEYLEN bits. Normally, you use 37 EFFECTIVE_KEYLEN of 0, but see RFC 2268 for more information. */ 38 void 39 arctwo_setkey_ekb (arctwo_context *context, 40 size_t keylen, const char *key, size_t effective_keylen); 41 42 #define arctwo_setkey(context,keylen,key) \ 43 arctwo_setkey_ekb (context, keylen, key, 8 * (keylen)) 44 45 /* Encrypt INBUF of size LENGTH into OUTBUF. LENGTH must be a 46 multiple of ARCTWO_BLOCK_SIZE. CONTEXT hold the encryption key, 47 and must have been initialized with arctwo_setkey or 48 arctwo_setkey_ekb. */ 49 extern void 50 arctwo_encrypt (arctwo_context *context, const char *inbuf, 51 char *restrict outbuf, size_t length); 52 53 /* Decrypt INBUF of size LENGTH into OUTBUF. LENGTH must be a 54 multiple of ARCTWO_BLOCK_SIZE. CONTEXT hold the decryption key, 55 and must have been initialized with arctwo_setkey or 56 arctwo_setkey_ekb. */ 57 extern void 58 arctwo_decrypt (arctwo_context *context, const char *inbuf, 59 char *restrict outbuf, size_t length); 60 61 #endif /* ARCTWO_H */