From eee52b591f31a10895bcaae69ecbcc8a8920df79 Mon Sep 17 00:00:00 2001
From: Christian Franke <nobody@nowhere.ws>
Date: Mon, 3 Sep 2012 00:00:16 +0200
Subject: add a masterpin which allows to change the pin

---
 Makefile |  4 +++
 kbc.c    | 98 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++----
 2 files changed, 97 insertions(+), 5 deletions(-)

diff --git a/Makefile b/Makefile
index a44356e..7d24dc8 100644
--- a/Makefile
+++ b/Makefile
@@ -8,6 +8,10 @@ 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
diff --git a/kbc.c b/kbc.c
index f343012..a1f70b8 100644
--- a/kbc.c
+++ b/kbc.c
@@ -12,6 +12,10 @@
 #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)
@@ -54,6 +58,8 @@ enum state {
 	STATE_CONFIG,
 	STATE_IDLE,
 	STATE_IDLEBLINK,
+	STATE_PASSWORD,
+	STATE_PASSWORD2,
 	STATE_INPUT,
 	STATE_ACCEPT,
 	STATE_REJECT,
@@ -341,6 +347,7 @@ static uint8_t wait_byte(void)
 #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
@@ -357,8 +364,10 @@ static uint8_t close_try = 0;
 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)
 {
@@ -438,6 +447,15 @@ static void state_enter(void)
 		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;
@@ -532,12 +550,13 @@ const PROGMEM uint8_t kbc[] = {
 };
 
 #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;
 
@@ -573,8 +592,66 @@ static void handle_keypress(uint8_t data)
 	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;
@@ -622,7 +699,16 @@ static void handle_keypress(uint8_t data)
 
 	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)
@@ -640,6 +726,8 @@ ISR(USART_RX_vect)
 		break;
 	case STATE_IDLE:
 	case STATE_IDLEBLINK:
+	case STATE_PASSWORD:
+	case STATE_PASSWORD2:
 	case STATE_INPUT:
 		handle_keypress(data);
 	default:
-- 
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