/* Unix SMB/CIFS implementation. An implementation of the arcfour algorithm Copyright (C) Andrew Tridgell 1998 This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>. */ #include "includes.h" #include "../lib/crypto/arcfour.h" /* initialise the arcfour sbox with key */ _PUBLIC_ void arcfour_init(struct arcfour_state *state, const DATA_BLOB *key) { int ind; uint8_t j = 0; for (ind = 0; ind < sizeof(state->sbox); ind++) { state->sbox[ind] = (uint8_t)ind; } for (ind = 0; ind < sizeof(state->sbox); ind++) { uint8_t tc; j += (state->sbox[ind] + key->data[ind%key->length]); tc = state->sbox[ind]; state->sbox[ind] = state->sbox[j]; state->sbox[j] = tc; } state->index_i = 0; state->index_j = 0; } /* crypt the data with arcfour */ _PUBLIC_ void arcfour_crypt_sbox(struct arcfour_state *state, uint8_t *data, int len) { int ind; for (ind = 0; ind < len; ind++) { uint8_t tc; uint8_t t; state->index_i++; state->index_j += state->sbox[state->index_i]; tc = state->sbox[state->index_i]; state->sbox[state->index_i] = state->sbox[state->index_j]; state->sbox[state->index_j] = tc; t = state->sbox[state->index_i] + state->sbox[state->index_j]; data[ind] = data[ind] ^ state->sbox[t]; } } /* arcfour encryption with a blob key */ _PUBLIC_ void arcfour_crypt_blob(uint8_t *data, int len, const DATA_BLOB *key) { struct arcfour_state state; arcfour_init(&state, key); arcfour_crypt_sbox(&state, data, len); } /* a variant that assumes a 16 byte key. This should be removed when the last user is gone */ _PUBLIC_ void arcfour_crypt(uint8_t *data, const uint8_t keystr[16], int len) { DATA_BLOB key = data_blob(keystr, 16); arcfour_crypt_blob(data, len, &key); data_blob_free(&key); }