Add encryption logic to back end.

7 files changed, 141 insertions, 130 deletions

diff --git a/lock/Scan.Makefile b/lock/Bend.Makefile
index eedf079..a88257e 100644
--- a/lock/Scan.Makefile
+++ b/lock/Bend.Makefile
@@ -1,8 +1,8 @@
 CC = avr-gcc
 MCU = atmega328p
-TARGET = scan
+TARGET = bend
 
-SRC = scan.c uart.c nrfm.c util.c
+SRC = bend.c uart.c nrfm.c util.c
 OBJ = $(SRC:.c=.o)
 
 CFLAGS = -std=gnu99
diff --git a/lock/Servo.Makefile b/lock/Fend.Makefile
index d4f8e0c..a525854 100644
--- a/lock/Servo.Makefile
+++ b/lock/Fend.Makefile
@@ -1,8 +1,8 @@
 CC = avr-gcc
 MCU = atmega328p
-TARGET = servo
+TARGET = fend
 
-SRC = servo.c uart.c nrfm.c util.c
+SRC = fend.c uart.c nrfm.c util.c
 OBJ = $(SRC:.c=.o)
 
 CFLAGS = -std=gnu99
diff --git a/lock/bend.c b/lock/bend.c
new file mode 100644
index 0000000..0b1061d
--- /dev/null
+++ b/lock/bend.c
@@ -0,0 +1,134 @@
+/* Lock back, connected to the servo */
+
+#include <stdint.h>
+#include <string.h>
+
+#include <avr/interrupt.h>
+#include <avr/wdt.h>
+#include <util/delay.h>
+
+#include "nrfm.h"
+#include "uart.h"
+#include "util.h"
+
+#define PWM_MIN      500
+#define PWM_MID      1500
+#define PWM_MAX      2500
+#define PWM_TOP      20000
+
+#define SERVO_PIN    PB1
+#define LOCK_BTN     PD6
+#define UNLOCK_BTN   PD7
+
+#define RX_PIN       PD7
+#define RX_DDR       DDRD
+#define RX_PORT      PORTD
+#define RX_PCIE      PCIE2
+#define RX_PCINT     PCINT23
+#define RX_PCMSK     PCMSK2
+#define RX_PCINTVEC  PCINT2_vect
+
+static char tab[] = {
+	'0', '8', '3', '6', 'a', 'Z', '$', '4', 'v', 'R', '@',
+	'E', '1', 'o', '#', ')', '2', '5', 'q', ';', '.', 'I',
+	'c', '7', '9', '*', 'L', 'V', '&', 'k', 'K', '!', 'm',
+	'N', '(', 'O', 'Q', 'A', '>', 'T', 't', '?', 'S', 'h',
+	'w', '/', 'n', 'W', 'l', 'M', 'e', 'H', 'j', 'g', '[',
+	'P', 'f', ':', 'B', ']', 'Y', '^', 'F', '%', 'C', 'x'
+};
+
+static uint8_t syn = 0;
+static volatile uint8_t rxdr = 0;
+static uint16_t tablen = sizeof(tab) / sizeof(tab[0]);
+
+static inline void keygen(char *buf, uint8_t n)
+{
+	int i, imax;
+	uint8_t sreg;
+	uint16_t seed; 
+	
+	sreg = SREG;
+	cli();
+	seed = TCNT1; 
+	SREG = sreg;
+
+	for (i = 0, imax = n - 1; i < imax; i++, seed++)
+		buf[i] = tab[(seed % tablen)];
+	buf[imax] = '\0';
+}
+
+static inline void keydel(char *buf, uint8_t n)
+{
+	int i;
+
+	for (i = 0; i < n; i++)
+		buf[i] = 0;
+}
+
+static inline void servo_init(void)
+{
+	DDRB |= (1 << SERVO_PIN);
+
+	TCCR1A |= (1 << WGM11) | (1 << COM1A1);
+	TCCR1B |= (1 << WGM13) | (1 << CS11);
+	ICR1 = PWM_TOP;
+
+	DDRD &= ~((1 << LOCK_BTN) | (1 << UNLOCK_BTN));
+	PORTD |= (1 << LOCK_BTN) | (1 << UNLOCK_BTN);
+}
+
+int main(void)
+{
+	uint8_t n;
+	uint8_t rxaddr[ADDRLEN] = { 194, 178, 83 };
+	uint8_t txaddr[ADDRLEN] = { 194, 178, 82 };
+
+	char buf[WDLEN + 1], key[WDLEN + 1], msg[WDLEN + 1];
+
+	RX_DDR &= ~(1 << RX_PIN);
+	RX_PORT |= (1 << RX_PIN); 
+	PCICR |= (1 << RX_PCIE);
+	RX_PCMSK |= (1 << RX_PCINT);
+
+	uart_init();
+	servo_init();
+	radio_init(rxaddr);
+	radio_print_config();
+
+	sei();
+	radio_listen();
+
+	for (;;) {
+		if (rxdr) {
+			rxdr = 0;
+			n = radio_recv(buf, WDLEN);
+			buf[n] = '\0';	
+			if (!syn) {
+				xor(KEY, buf, msg, WDLEN);
+				if (strncmp(msg, SYN, WDLEN) == 0) {
+					keygen(key, WDLEN + 1);
+					xor(KEY, key, buf, WDLEN);
+					radio_sendto(txaddr, buf, WDLEN);
+					syn = 1;
+				}
+			} else {
+				syn = 0;
+				xor(key, buf, msg, WDLEN);
+				if (strncmp(msg, LOCK, WDLEN) == 0) {
+					// todo: lock
+				} else if (strncmp(msg, UNLOCK, WDLEN) == 0) {
+					// todo: unlock
+				}
+				keydel(buf, WDLEN);
+			}
+		} else {
+			// todo: sleep
+		}
+	}
+	return 0;
+}
+
+ISR(RX_PCINTVEC)
+{
+	rxdr = 1;
+}
diff --git a/lock/scan.c b/lock/fend.c
index 6784e9a..7d86ab1 100644
--- a/lock/scan.c
+++ b/lock/fend.c
@@ -15,15 +15,10 @@ int main(void)
 {
 	uint8_t n;
 	uint8_t rxaddr[ADDRLEN] = { 194, 178, 82 };
+	uint8_t txaddr[ADDRLEN] = { 194, 178, 83 };
 
 	char buf[WDLEN + 1], msg[WDLEN + 1];
 
-	/* timer for keygen */
-	TCCR1A |= (1 << WGM11) | (1 << COM1A1);
-	TCCR1B |= (1 << WGM13) | (1 << CS11);
-	ICR1 = 20000;
-
-	wdt_init();
 	uart_init();
 	radio_init(rxaddr);
 	radio_print_config();
@@ -31,7 +26,6 @@ int main(void)
 	sei();
 
 	for (;;) {
-		wdt_reset();
 		_delay_ms(2000);
 	}
 
diff --git a/lock/servo.c b/lock/servo.c
deleted file mode 100644
index 9b735ea..0000000
--- a/lock/servo.c
+++ /dev/null
@@ -1,80 +0,0 @@
-/* Lock back, connected to the servo */
-
-#include <stdint.h>
-#include <string.h>
-
-#include <avr/interrupt.h>
-#include <avr/wdt.h>
-#include <util/delay.h>
-
-#include "nrfm.h"
-#include "uart.h"
-#include "util.h"
-
-#define PWM_MIN      500
-#define PWM_MID      1500
-#define PWM_MAX      2500
-#define PWM_TOP      20000
-
-#define SERVO_PIN    PB1
-#define LOCK_BTN     PD6
-#define UNLOCK_BTN   PD7
-
-#define RX_PIN       PD7
-#define RX_DDR       DDRD
-#define RX_PORT      PORTD
-#define RX_PCIE      PCIE2
-#define RX_PCINT     PCINT23
-#define RX_PCMSK     PCMSK2
-#define RX_PCINTVEC  PCINT2_vect
-
-static volatile uint8_t rxdr = 0;
-
-static inline void servo_init(void)
-{
-	DDRB |= (1 << SERVO_PIN);
-
-	TCCR1A |= (1 << WGM11) | (1 << COM1A1);
-	TCCR1B |= (1 << WGM13) | (1 << CS11);
-
-	ICR1 = PWM_TOP;
-
-	DDRD &= ~((1 << LOCK_BTN) | (1 << UNLOCK_BTN));
-	PORTD |= (1 << LOCK_BTN) | (1 << UNLOCK_BTN);
-}
-
-int main(void)
-{
-	uint8_t n;
-	uint8_t rxaddr[ADDRLEN] = { 194, 178, 83 };
-
-	char buf[WDLEN + 1], key[WDLEN + 1], msg[WDLEN + 1];
-
-	RX_DDR &= ~(1 << RX_PIN);
-	RX_PORT |= (1 << RX_PIN); 
-	PCICR |= (1 << RX_PCIE);
-	RX_PCMSK |= (1 << RX_PCINT);
-
-	wdt_init();
-	uart_init();
-	servo_init();
-	radio_init(rxaddr);
-	radio_print_config();
-
-	sei();
-	radio_listen();
-
-	for (;;) {
-		wdt_reset();
-		if (rxdr) {
-		} else {
-			_delay_ms(2000);
-		}
-	}
-	return 0;
-}
-
-ISR(RX_PCINTVEC)
-{
-	rxdr = 1;
-}
diff --git a/lock/util.c b/lock/util.c
index 6810c1e..32a1fcf 100644
--- a/lock/util.c
+++ b/lock/util.c
@@ -4,40 +4,6 @@
 
 #include "util.h"
 
-static char tab[] = {
-	'0', '8', '3', '6', 'a', 'Z', '$', '4', 'v', 'R', '@',
-	'E', '1', 'o', '#', ')', '2', '5', 'q', ';', '.', 'I',
-	'c', '7', '9', '*', 'L', 'V', '&', 'k', 'K', '!', 'm',
-	'N', '(', 'O', 'Q', 'A', '>', 'T', 't', '?', 'S', 'h',
-	'w', '/', 'n', 'W', 'l', 'M', 'e', 'H', 'j', 'g', '[',
-	'P', 'f', ':', 'B', ']', 'Y', '^', 'F', '%', 'C', 'x'
-};
-
-static uint16_t tablen = sizeof(tab) / sizeof(tab[0]);
-
-void wdt_init(void)
-{
-	wdt_reset();
-	WDTCSR |= (1 << WDCE) | (1 << WDE);
-	WDTCSR = (1 << WDE) | (1 << WDP3) | (1 << WDP0);
-}
-
-void keygen(char *buf, uint8_t n)
-{
-	int i, imax;
-	uint8_t sreg;
-	uint16_t seed; 
-	
-	sreg = SREG;
-	cli();
-	seed = TCNT1; 
-	SREG = sreg;
-
-	for (i = 0, imax = n - 1; i < imax; i++, seed++)
-		buf[i] = tab[(seed % tablen)];
-	buf[imax] = '\0';
-}
-
 void xor(const char *k, const char *s, char *d, uint8_t n)
 {
 	int i;
diff --git a/lock/util.h b/lock/util.h
index cb4e86f..32dbcad 100644
--- a/lock/util.h
+++ b/lock/util.h
@@ -4,15 +4,12 @@
 #include <stdint.h>
 
 #define KEY     "dM>}jdb,6gsnC$J^K 8(I5vyPemPs%;K"
+#define SYN     "dM>}jdb,6gsnC$J^K 8(I5vyPemPs%;O"
 #define LOCK    "R,I7l^E4j]KyLR9'*Q{Jd'zu.~!84}Ij"
-#define UNLOCK  "R,I7l^E4j]KyLR9'*Q{Jd'zu.~!84}Ik"
+#define UNLOCK  "R,I7l^E4j]KyLR9'*Q{Jd'zu.~!84}IL"
 
 #define WDLEN   32
 
-void wdt_init(void);
-
-void keygen(char *buf, uint8_t n);
-
 void xor(const char *k, const char *s, char *d, uint8_t n);
 
 #endif /* MY_UTIL_H */