1 /* salsa20.h 2 3 The Salsa20 stream cipher. 4 5 Copyright (C) 2012 Simon Josefsson 6 Copyright (C) 2001 Niels Möller 7 8 This file is part of GNU Nettle. 9 10 GNU Nettle is free software: you can redistribute it and/or 11 modify it under the terms of either: 12 13 * the GNU Lesser General Public License as published by the Free 14 Software Foundation; either version 3 of the License, or (at your 15 option) any later version. 16 17 or 18 19 * the GNU General Public License as published by the Free 20 Software Foundation; either version 2 of the License, or (at your 21 option) any later version. 22 23 or both in parallel, as here. 24 25 GNU Nettle is distributed in the hope that it will be useful, 26 but WITHOUT ANY WARRANTY; without even the implied warranty of 27 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 28 General Public License for more details. 29 30 You should have received copies of the GNU General Public License and 31 the GNU Lesser General Public License along with this program. If 32 not, see http://www.gnu.org/licenses/. 33 */ 34 35 #ifndef NETTLE_SALSA20_H_INCLUDED 36 #define NETTLE_SALSA20_H_INCLUDED 37 38 #include "nettle-types.h" 39 40 #ifdef __cplusplus 41 extern "C" { 42 #endif 43 44 /* Name mangling */ 45 #define salsa20_set_key nettle_salsa20_set_key 46 #define salsa20_128_set_key nettle_salsa20_128_set_key 47 #define salsa20_256_set_key nettle_salsa20_256_set_key 48 #define salsa20_set_nonce nettle_salsa20_set_nonce 49 #define salsa20_crypt nettle_salsa20_crypt 50 51 #define salsa20r12_crypt nettle_salsa20r12_crypt 52 53 /* Alias for backwards compatibility */ 54 #define salsa20_set_iv nettle_salsa20_set_nonce 55 56 /* In octets.*/ 57 #define SALSA20_128_KEY_SIZE 16 58 #define SALSA20_256_KEY_SIZE 32 59 #define SALSA20_BLOCK_SIZE 64 60 #define SALSA20_NONCE_SIZE 8 61 #define SALSA20_IV_SIZE SALSA20_NONCE_SIZE 62 63 /* Aliases */ 64 #define SALSA20_MIN_KEY_SIZE 16 65 #define SALSA20_MAX_KEY_SIZE 32 66 #define SALSA20_KEY_SIZE 32 67 68 #define _SALSA20_INPUT_LENGTH 16 69 70 struct salsa20_ctx 71 { 72 /* Indices 1-4 and 11-14 holds the key (two identical copies for the 73 shorter key size), indices 0, 5, 10, 15 are constant, indices 6, 7 74 are the IV, and indices 8, 9 are the block counter: 75 76 C K K K 77 K C I I 78 B B C K 79 K K K C 80 */ 81 uint32_t input[_SALSA20_INPUT_LENGTH]; 82 }; 83 84 void 85 salsa20_128_set_key(struct salsa20_ctx *ctx, const uint8_t *key); 86 void 87 salsa20_256_set_key(struct salsa20_ctx *ctx, const uint8_t *key); 88 89 void 90 salsa20_set_key(struct salsa20_ctx *ctx, 91 size_t length, const uint8_t *key); 92 93 void 94 salsa20_set_nonce(struct salsa20_ctx *ctx, const uint8_t *nonce); 95 96 void 97 salsa20_crypt(struct salsa20_ctx *ctx, 98 size_t length, uint8_t *dst, 99 const uint8_t *src); 100 101 void 102 salsa20r12_crypt(struct salsa20_ctx *ctx, 103 size_t length, uint8_t *dst, 104 const uint8_t *src); 105 106 #ifdef __cplusplus 107 } 108 #endif 109 110 #endif /* NETTLE_SALSA20_H_INCLUDED */ 111