| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * The RC5-32/12 block cipher |
| 4 | * |
| 5 | * (c) 1999 Straylight/Edgeware |
| 6 | */ |
| 7 | |
| 8 | /*----- Licensing notice --------------------------------------------------* |
| 9 | * |
| 10 | * This file is part of Catacomb. |
| 11 | * |
| 12 | * Catacomb is free software; you can redistribute it and/or modify |
| 13 | * it under the terms of the GNU Library General Public License as |
| 14 | * published by the Free Software Foundation; either version 2 of the |
| 15 | * License, or (at your option) any later version. |
| 16 | * |
| 17 | * Catacomb is distributed in the hope that it will be useful, |
| 18 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 20 | * GNU Library General Public License for more details. |
| 21 | * |
| 22 | * You should have received a copy of the GNU Library General Public |
| 23 | * License along with Catacomb; if not, write to the Free |
| 24 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
| 25 | * MA 02111-1307, USA. |
| 26 | */ |
| 27 | |
| 28 | /*----- Notes on the RC5 block cipher -------------------------------------* |
| 29 | * |
| 30 | * RC5 was designed by Ron Rivest as a test vehicle for the use of data- |
| 31 | * dependent rotations in cryptographic transformations. The algorithm is |
| 32 | * covered by a patent held by RSA Security Inc. (US Patent# 5,724,428). |
| 33 | * It's vulnerable to some clever differential attacks, which can break it in |
| 34 | * about %$2^{44}$% chosen plaintexts. I don't recommend the use of this |
| 35 | * cipher. |
| 36 | */ |
| 37 | |
| 38 | #ifndef CATACOMB_RC5_H |
| 39 | #define CATACOMB_RC5_H |
| 40 | |
| 41 | #ifdef __cplusplus |
| 42 | extern "C" { |
| 43 | #endif |
| 44 | |
| 45 | /*----- Header files ------------------------------------------------------*/ |
| 46 | |
| 47 | #include <mLib/bits.h> |
| 48 | |
| 49 | /*----- Magic numbers -----------------------------------------------------*/ |
| 50 | |
| 51 | #define RC5_ROUNDS 12 |
| 52 | #define RC5_KEYSZ 10 |
| 53 | #define RC5_BLKSZ 8 |
| 54 | #define RC5_CLASS (N, L, 64) |
| 55 | |
| 56 | extern const octet rc5_keysz[]; |
| 57 | |
| 58 | /*----- Data structures ---------------------------------------------------*/ |
| 59 | |
| 60 | typedef struct rc5_ctx { |
| 61 | uint32 s[2 * (RC5_ROUNDS + 1)]; |
| 62 | } rc5_ctx; |
| 63 | |
| 64 | /*----- Functions provided ------------------------------------------------*/ |
| 65 | |
| 66 | /* --- @rc5_init@ --- * |
| 67 | * |
| 68 | * Arguments: @rc5_ctx *k@ = pointer to a key block |
| 69 | * @const void *sbuf@ = pointer to key material |
| 70 | * @size_t sz@ = size of the key material |
| 71 | * |
| 72 | * Returns: --- |
| 73 | * |
| 74 | * Use: Initializes an RC5 key block. |
| 75 | */ |
| 76 | |
| 77 | extern void rc5_init(rc5_ctx */*k*/, const void */*sbuf*/, size_t /*sz*/); |
| 78 | |
| 79 | /* --- @rc5_eblk@, @rc5_dblk@ --- * |
| 80 | * |
| 81 | * Arguments: @const rc5_ctx *k@ = pointer to RC5 context block |
| 82 | * @const uint32 s[2]@ = pointer to source block |
| 83 | * @uint32 *d[2]@ = pointer to destination block |
| 84 | * |
| 85 | * Returns: --- |
| 86 | * |
| 87 | * Use: Low level block encryption and decryption. |
| 88 | */ |
| 89 | |
| 90 | extern void rc5_eblk(const rc5_ctx */*k*/, |
| 91 | const uint32 */*s*/, uint32 */*d*/); |
| 92 | extern void rc5_dblk(const rc5_ctx */*k*/, |
| 93 | const uint32 */*s*/, uint32 */*d*/); |
| 94 | |
| 95 | /*----- That's all, folks -------------------------------------------------*/ |
| 96 | |
| 97 | #ifdef __cplusplus |
| 98 | } |
| 99 | #endif |
| 100 | |
| 101 | #endif |