2 * Copyright © 2011 Keith Packard <keithp@keithp.com>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; version 2 of the License.
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public License along
14 * with this program; if not, write to the Free Software Foundation, Inc.,
15 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
20 #define AO_CMAC_KEY_LEN AO_AES_LEN
21 #define AO_CMAC_MAX_LEN (128 - AO_CMAC_KEY_LEN)
23 static __xdata uint8_t ao_radio_cmac_mutex;
24 __pdata int16_t ao_radio_cmac_rssi;
25 static __xdata uint8_t cmac_data[AO_CMAC_MAX_LEN + AO_CMAC_KEY_LEN + 2 + AO_CMAC_KEY_LEN];
26 static __pdata uint8_t ao_radio_cmac_len;
33 b = ao_cmd_hexchar(getchar());
35 ao_cmd_status = ao_cmd_lex_error;
51 round_len(uint8_t len)
55 /* Make sure we transfer at least one packet, and
56 * then make sure every packet is full. Note that
57 * there is no length encoded, and that the receiver
58 * must deal with any extra bytes in the packet
60 if (len < AO_CMAC_KEY_LEN)
61 len = AO_CMAC_KEY_LEN;
62 rem = len % AO_CMAC_KEY_LEN;
64 len += (AO_CMAC_KEY_LEN - rem);
69 * Sign and deliver the data sitting in the cmac buffer
72 radio_cmac_send(uint8_t len) __reentrant
77 /* Make sure the AES key is loaded */
84 ao_mutex_get(&ao_aes_mutex);
85 ao_aes_set_mode(ao_aes_mode_cbc_mac);
86 ao_aes_set_key(ao_config.aes_key);
88 for (i = 0; i < len; i += AO_CMAC_KEY_LEN) {
89 if (i + AO_CMAC_KEY_LEN < len)
90 ao_aes_run(&cmac_data[i], NULL);
92 ao_aes_run(&cmac_data[i], &cmac_data[len]);
94 ao_mutex_put(&ao_aes_mutex);
96 ao_radio_send(cmac_data, len + AO_CMAC_KEY_LEN);
100 * Receive and validate an incoming packet
104 radio_cmac_recv(uint8_t len, uint16_t timeout) __reentrant
108 len = round_len(len);
115 i = ao_radio_recv(cmac_data, len + AO_CMAC_KEY_LEN + 2);
119 ao_radio_cmac_rssi = 0;
120 return AO_RADIO_CMAC_TIMEOUT;
123 ao_radio_cmac_rssi = (int16_t) (((int8_t) cmac_data[len + AO_CMAC_KEY_LEN]) >> 1) - 74;
124 if (!(cmac_data[len + AO_CMAC_KEY_LEN +1] & AO_RADIO_STATUS_CRC_OK))
125 return AO_RADIO_CMAC_CRC_ERROR;
129 /* Compute the packet signature
131 ao_mutex_get(&ao_aes_mutex);
132 ao_aes_set_mode(ao_aes_mode_cbc_mac);
133 ao_aes_set_key(ao_config.aes_key);
135 for (i = 0; i < len; i += AO_CMAC_KEY_LEN) {
136 if (i + AO_CMAC_KEY_LEN < len)
137 ao_aes_run(&cmac_data[i], NULL);
139 ao_aes_run(&cmac_data[i], &cmac_data[len + AO_CMAC_KEY_LEN + 2]);
141 ao_mutex_put(&ao_aes_mutex);
143 /* Check the packet signature against the signature provided
147 if (memcmp(&cmac_data[len],
148 &cmac_data[len + AO_CMAC_KEY_LEN + 2],
149 AO_CMAC_KEY_LEN) != 0) {
150 return AO_RADIO_CMAC_MAC_ERROR;
153 return AO_RADIO_CMAC_OK;
157 ao_radio_cmac_send(__xdata void *packet, uint8_t len) __reentrant
159 if (len > AO_CMAC_MAX_LEN)
160 return AO_RADIO_CMAC_LEN_ERROR;
161 ao_mutex_get(&ao_radio_cmac_mutex);
162 ao_xmemcpy(cmac_data, packet, len);
164 ao_led_on(AO_LED_TX);
166 radio_cmac_send(len);
168 ao_led_off(AO_LED_TX);
170 ao_mutex_put(&ao_radio_cmac_mutex);
171 return AO_RADIO_CMAC_OK;
175 ao_radio_cmac_recv(__xdata void *packet, uint8_t len, uint16_t timeout) __reentrant
178 if (len > AO_CMAC_MAX_LEN)
179 return AO_RADIO_CMAC_LEN_ERROR;
180 ao_mutex_get(&ao_radio_cmac_mutex);
182 ao_led_on(AO_LED_RX);
184 i = radio_cmac_recv(len, timeout);
186 ao_led_off(AO_LED_RX);
188 if (i == AO_RADIO_CMAC_OK)
189 ao_xmemcpy(packet, cmac_data, len);
190 ao_mutex_put(&ao_radio_cmac_mutex);
195 radio_cmac_send_cmd(void) __reentrant
201 if (ao_cmd_status != ao_cmd_success)
204 if (len > AO_CMAC_MAX_LEN) {
205 ao_cmd_status = ao_cmd_syntax_error;
209 ao_mutex_get(&ao_radio_cmac_mutex);
211 for (i = 0; i < len; i++) {
212 cmac_data[i] = getbyte();
213 if (ao_cmd_status != ao_cmd_success)
216 radio_cmac_send(len);
217 ao_mutex_put(&ao_radio_cmac_mutex);
221 radio_cmac_recv_cmd(void) __reentrant
227 if (ao_cmd_status != ao_cmd_success)
231 if (ao_cmd_status != ao_cmd_success)
233 timeout = AO_MS_TO_TICKS(ao_cmd_lex_i);
234 ao_mutex_get(&ao_radio_cmac_mutex);
235 i = radio_cmac_recv(len, timeout);
236 if (i == AO_RADIO_CMAC_OK) {
238 for (i = 0; i < len; i++)
239 printf("%02x", cmac_data[i]);
240 printf (" %d\n", ao_radio_cmac_rssi);
242 printf ("ERROR %d %d\n", i, ao_radio_cmac_rssi);
243 ao_mutex_put(&ao_radio_cmac_mutex);