add a masterpin which allows to change the pin

2 files changed, 97 insertions, 5 deletions

diff --git a/Makefile b/Makefile
index a44356e..7d24dc8 100644
--- a/Makefile
+++ b/Makefile
@@ -5,12 +5,16 @@ AOBJCOPY=avr-objcopy
 ALD=avr-ld
 ASIZE=avr-size
 CFLAGS=-Wall -Wextra -Wno-unused-parameter -pedantic -std=c99
 ifdef PIN
 DPIN=-DPIN=\"$(PIN)\"
 endif
+
+ifdef MASTER_PIN
+DPIN+=-DMASTER_PIN=\"$(MASTER_PIN)\"
+endif
 ACFLAGS=-g -mmcu=$(MCU) $(CFLAGS) $(DPIN) -Os -mcall-prologues
 # ALDFLAGS=-L/usr/avr/lib/avr4 -L/usr/lib/binutils/avr/2.18
 LD=gcc
 CC=gcc
 CXX=g++ -g
 LDXX=g++ -g
diff --git a/kbc.c b/kbc.c
index f343012..a1f70b8 100644
--- a/kbc.c
+++ b/kbc.c
@@ -9,12 +9,16 @@
 #include <util/delay.h>
 
 #ifndef PIN
 #error need to define a PIN
 #endif
 
+#ifndef MASTER_PIN
+#error need to define a MASTER_PIN
+#endif
+
 /* port B		RJ45
  *  0
  *  1 BEEP (OC1A)
  *  2 SS		up:8
  *  3 MOSI		up:2		was: LOCK - output broken!
  *  4 MISO		up:4		UNLOCK
@@ -51,12 +55,14 @@ enum state {
 	STATE_FAILURE,
 	STATE_POWERUP,
 	STATE_INITRESET,
 	STATE_CONFIG,
 	STATE_IDLE,
 	STATE_IDLEBLINK,
+	STATE_PASSWORD,
+	STATE_PASSWORD2,
 	STATE_INPUT,
 	STATE_ACCEPT,
 	STATE_REJECT,
 	STATE_KEYMATIC_RECHECK,
 	STATE_KEYMATIC_RECLOSE,
 #ifdef KILLSWITCH
@@ -338,12 +344,13 @@ static uint8_t wait_byte(void)
 #define WAIT_IDLE	3
 
 #define WAIT_IDLEBLINK	1	/* no full cycle */
 #define CNTR_BLINK	6
 #define CNTR_ERROR	61
 #define CNTR_BEEP	10
+#define CNTR_BEEP_ACK	30
 #define CNTR_BEEP_REJ	92
 
 #define WAIT_INPUT	6
 #define WAIT_ACCEPT	8
 #define WAIT_REJECT	8
 #define WAIT_KEYMATIC_RETRY	9
@@ -354,14 +361,16 @@ static uint8_t wait_byte(void)
 static uint8_t cntr = 0;
 static uint8_t close_try = 0;
 #ifdef KILLSWITCH
 static uint8_t error;
 #endif
 
-static const EEMEM uint8_t passwd[sizeof(PIN) - 1] = PIN;
+static EEMEM uint8_t passwd[sizeof(PIN) - 1] = PIN;
+static EEMEM uint8_t mpasswd[sizeof(MASTER_PIN) - 1] = MASTER_PIN;
 static uint8_t code[sizeof(PIN)];
+static uint8_t new_code[sizeof(PIN)];
 
 static void state_enter(void)
 {
 	switch (state) {
 	case STATE_NONE:
 	case STATE_FAILURE:
@@ -435,12 +444,21 @@ static void state_enter(void)
 		statecntr = WAIT_INPUT;
 		if (send_byte(0xed) != 0xfa)
 			break;
 		if (send_byte(KBLED_STATE) != 0xfa)
 			break;
 		break;
+	case STATE_PASSWORD:
+	case STATE_PASSWORD2:
+		toutstate = STATE_IDLE;
+		statecntr = WAIT_INPUT;
+		if (send_byte(0xed) != 0xfa)
+			break;
+		if (send_byte(KBLED_STATE | KBLED_OK) != 0xfa)
+			break;
+		break;
 	case STATE_ACCEPT:
 		toutstate = close_try ? STATE_KEYMATIC_RECHECK : STATE_IDLE;
 		statecntr = WAIT_ACCEPT;
 		if (send_byte(0xed) != 0xfa)
 			break;
 		if (send_byte(KBLED_OK) != 0xfa)
@@ -529,18 +547,19 @@ const PROGMEM uint8_t kbc[] = {
 	'_', '1', '_', '4', '7', '_', '_', '_', /* 68 - 6f */
 	'0', '_', '2', '5', '6', '8', ESC, ESC, /* 70 - 77 */
 	'_', '_', '3', '_', '_', '9'            /* 78 - 7f */
 };
 
 #define NUMPAD_ENTER 0xda	/* e0 5a */
+#define F12 0x07
 
 static uint8_t pressed = 0, e0 = 0, release = 0;
 
 static void handle_keypress(uint8_t data)
 {
-	uint8_t unlock, lock;
+	uint8_t unlock, lock, change_pass;
 	uint8_t ascii = '_';
 	uint8_t c;
 
 	if (release) {
 		pressed = 0;
 		release = 0;
@@ -570,14 +589,72 @@ static void handle_keypress(uint8_t data)
 		ascii = pgm_read_byte(kbc + data - KBC_BASE);
 
 	dbg_wr(0x03);
 	dbg_wr(0x80 | (ascii & 0xf));
 	dbg_wr(0x80 | (ascii >> 4));
 
-	lock = ascii == ESC;
-	unlock = ascii == ENT || data == NUMPAD_ENTER;
+	if (state != STATE_PASSWORD && state != STATE_PASSWORD2) {
+		lock = ascii == ESC;
+		unlock = ascii == ENT || data == NUMPAD_ENTER;
+		change_pass = data == F12;
+	} else {
+		lock = unlock = 0;
+		change_pass = ascii == ENT || data == NUMPAD_ENTER;
+	}
+
+	if (change_pass) {
+		uint8_t pos, ok = 1;
+		switch(state) {
+		default:
+			/* Check master password, change state to password input */
+			if (code[0])
+				ok = 0;
+
+			for (pos = 1; pos < sizeof(code); pos++)
+				if(code[pos] != eeprom_read_byte(mpasswd + pos - 1))
+					ok = 0;
+
+			if (ok) {
+				cntr = CNTR_BEEP_ACK;
+				nextstate = STATE_PASSWORD;
+			}
+			break;
+		case STATE_PASSWORD:
+			/* Check password and store it to buffer */
+			if (code[0])
+				ok = 0;
+
+			if (ok) {
+				memcpy(new_code, code, sizeof(code));
+				PORTB &= ~B_BEEP;
+				cntr = CNTR_BEEP_ACK;
+				nextstate = STATE_PASSWORD2;
+			}
+			break;
+		case STATE_PASSWORD2:
+			/* Compare password with buffer, write to eeprom */
+			if (memcmp(new_code, code, sizeof(code)))
+				ok = 0;
+			if (ok) {
+				eeprom_update_block(new_code + 1, passwd,
+						sizeof(new_code) - 1);
+				PORTB &= ~B_BEEP;
+				cntr = CNTR_BEEP_REJ;
+				nextstate = STATE_ACCEPT;
+			}
+			break;
+		}
+		if (!ok) {
+			PORTB &= ~B_BEEP;
+
+			cntr = CNTR_BEEP_REJ;
+			nextstate = STATE_REJECT;
+		}
+		memset(code, 0, sizeof(code));
+		return;
+	}
 
 	if (lock || unlock) {
 		uint8_t pos, ok = 1;
 
 		/* passwd:  a  b  c  d
 		 * code:   \0  a  b  c  d
@@ -619,13 +696,22 @@ static void handle_keypress(uint8_t data)
 	for (c = 0; c < sizeof(code) - 1; c++)
 		code[c] = code[c + 1];
 	code[c] = ascii;
 
 	PORTB &= ~B_BEEP;
 	cntr = CNTR_BEEP;
-	nextstate = STATE_INPUT;
+	switch (state) {
+	case STATE_PASSWORD:
+		nextstate = STATE_PASSWORD;
+		break;
+	case STATE_PASSWORD2:
+		nextstate = STATE_PASSWORD2;
+		break;
+	default:
+		nextstate = STATE_INPUT;
+	}
 }
 
 ISR(USART_RX_vect)
 {
 	uint8_t data = UDR0;
 
@@ -637,12 +723,14 @@ ISR(USART_RX_vect)
 	case STATE_INITRESET:
 		if (data == 0xaa)
 			nextstate = STATE_CONFIG;
 		break;
 	case STATE_IDLE:
 	case STATE_IDLEBLINK:
+	case STATE_PASSWORD:
+	case STATE_PASSWORD2:
 	case STATE_INPUT:
 		handle_keypress(data);
 	default:
 		break;
 	}
 }