1/* 2 Unix SMB/CIFS implementation. 3 4 An implementation of the arcfour algorithm 5 6 Copyright (C) Andrew Tridgell 1998 7 8 This program is free software; you can redistribute it and/or modify 9 it under the terms of the GNU General Public License as published by 10 the Free Software Foundation; either version 3 of the License, or 11 (at your option) any later version. 12 13 This program is distributed in the hope that it will be useful, 14 but WITHOUT ANY WARRANTY; without even the implied warranty of 15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 GNU General Public License for more details. 17 18 You should have received a copy of the GNU General Public License 19 along with this program. If not, see <http://www.gnu.org/licenses/>. 20*/ 21 22#include "includes.h" 23#include "../lib/crypto/arcfour.h" 24 25/* initialise the arcfour sbox with key */ 26_PUBLIC_ void arcfour_init(struct arcfour_state *state, const DATA_BLOB *key) 27{ 28 int ind; 29 uint8_t j = 0; 30 for (ind = 0; ind < sizeof(state->sbox); ind++) { 31 state->sbox[ind] = (uint8_t)ind; 32 } 33 34 for (ind = 0; ind < sizeof(state->sbox); ind++) { 35 uint8_t tc; 36 37 j += (state->sbox[ind] + key->data[ind%key->length]); 38 39 tc = state->sbox[ind]; 40 state->sbox[ind] = state->sbox[j]; 41 state->sbox[j] = tc; 42 } 43 state->index_i = 0; 44 state->index_j = 0; 45} 46 47/* crypt the data with arcfour */ 48_PUBLIC_ void arcfour_crypt_sbox(struct arcfour_state *state, uint8_t *data, int len) 49{ 50 int ind; 51 52 for (ind = 0; ind < len; ind++) { 53 uint8_t tc; 54 uint8_t t; 55 56 state->index_i++; 57 state->index_j += state->sbox[state->index_i]; 58 59 tc = state->sbox[state->index_i]; 60 state->sbox[state->index_i] = state->sbox[state->index_j]; 61 state->sbox[state->index_j] = tc; 62 63 t = state->sbox[state->index_i] + state->sbox[state->index_j]; 64 data[ind] = data[ind] ^ state->sbox[t]; 65 } 66} 67 68/* 69 arcfour encryption with a blob key 70*/ 71_PUBLIC_ void arcfour_crypt_blob(uint8_t *data, int len, const DATA_BLOB *key) 72{ 73 struct arcfour_state state; 74 arcfour_init(&state, key); 75 arcfour_crypt_sbox(&state, data, len); 76} 77 78/* 79 a variant that assumes a 16 byte key. This should be removed 80 when the last user is gone 81*/ 82_PUBLIC_ void arcfour_crypt(uint8_t *data, const uint8_t keystr[16], int len) 83{ 84 DATA_BLOB key = data_blob(keystr, 16); 85 86 arcfour_crypt_blob(data, len, &key); 87 88 data_blob_free(&key); 89} 90 91 92