Add keygen() to utils.

1 files changed, 136 insertions, 0 deletions

diff --git a/lock/servo.c b/lock/servo.c
new file mode 100644
index 0000000..dd4938a
--- /dev/null
+++ b/lock/servo.c
@@ -0,0 +1,136 @@
+/* Door back, connected to the fingerprint scanner */
+
+#include <stdint.h>
+#include <string.h>
+
+#include <avr/io.h>
+#include <avr/interrupt.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 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 chars[] = {
+	'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 volatile int rxdr = 0;
+static uint8_t charslen = sizeof(chars) / sizeof(chars[0]);
+
+static inline void await_reply(void)
+{
+	int i;
+
+	radio_listen();
+	for (i = 0; i < 500 && rxdr == 0; i += 100)
+		_delay_ms(100);
+}
+
+static inline void keygen(char *buf, uint8_t n)
+{
+	int i;
+	uint8_t sreg;
+	uint16_t idx; 
+	
+	sreg = SREG;
+	cli();
+	idx = TCNT1; 
+	SREG = sreg;
+
+	for (i = 0; i < n; i++, idx++)
+		buf[i] = chars[(idx % charslen)]  ;
+	buf[n - 1] = '\0';
+}
+
+static inline void timer_init(void)
+{
+	TCCR1A |= (1 << WGM11) | (1 << COM1A1);
+	TCCR1B |= (1 << WGM13) | (1 << CS11);
+	ICR1 = PWM_TOP; /* we use the same timer for servo's PWM */
+}
+
+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();
+	timer_init();
+	radio_init(rxaddr);
+	radio_print_config();
+
+	sei();
+	radio_listen();
+
+	for (;;) {
+		if (rxdr) {
+			n = radio_recv(buf, WDLEN);
+			buf[n] = '\0';
+			rxdr = 0;
+
+			xor(KEY, buf, msg, WDLEN);
+			uart_write("DEBUG: msg recv = ");
+			uart_write_line(msg);
+
+			if (strncmp(msg, SYN, WDLEN) == 0) {
+				keygen(key, WDLEN);
+				uart_write("DEBUG: session key = ");
+				uart_write_line(key);
+
+				xor(KEY, key, msg, WDLEN);
+				radio_sendto(txaddr, msg, WDLEN);
+				await_reply();
+
+				if (rxdr) {
+					n = radio_recv(buf, WDLEN);
+					buf[n] = '\0';
+					rxdr = 0;
+					xor(key, buf, msg, WDLEN);
+					uart_write("DEBUG: msg = ");
+					uart_write_line(msg);
+
+					xor(key, ACK, msg, WDLEN);
+					radio_sendto(txaddr, msg, WDLEN);
+				}
+			} else {
+				uart_write_line("ERROR: handshake failed");
+			}
+		} else {
+			uart_write_line("DEBUG: no new packets");
+			_delay_ms(2000);
+		}
+	}
+	return 0;
+}
+
+ISR(RX_PCINTVEC)
+{
+	rxdr = 1;
+}