From b51bd20c4de8f836889eacf7c35e4e25503c43d8 Mon Sep 17 00:00:00 2001
From: Conor <conorpp@vt.edu>
Date: Fri, 4 Mar 2016 20:30:13 -0500
Subject: [PATCH] initialize keys at init if needed

---
 firmware/inc/app.h       | 11 +++++----
 firmware/inc/eeprom.h    |  4 ++++
 firmware/src/callback.c  | 11 +++++----
 firmware/src/eeprom.c    | 12 +++++++++-
 firmware/src/main.c      | 22 ++++++++++++++++-
 firmware/src/u2f-atecc.c | 52 +++++++++++++++++++++++++++++++++++++++-
 6 files changed, 101 insertions(+), 11 deletions(-)

diff --git a/firmware/inc/app.h b/firmware/inc/app.h
index 99bba67..e992a1d 100644
--- a/firmware/inc/app.h
+++ b/firmware/inc/app.h
@@ -17,8 +17,6 @@ SI_SBIT (LED1, SFR_P1, 4);             // LED green
 // debug options
 #define U2F_PRINT
 
-#define KEYHANDLES_START 			(EEPROM_DATA_START + 30)
-#define KEYHANDLES_COUNT			14
 
 typedef enum
 {
@@ -47,17 +45,22 @@ APP_ERROR_CODE;
 
 struct APP_DATA
 {
-	uint8_t hidmsgbuf[64];
-	uint8_t tmp[10];
+	// must be at least 37 bytes
+	uint8_t tmp[40];
 	uint8_t state;
 	uint8_t error;
 };
 
+extern uint8_t hidmsgbuf[64];
+
 extern data struct APP_DATA appdata;
 
 
 void set_app_error(APP_ERROR_CODE ec);
 
+// should be called after initializing eeprom
+void u2f_init();
+
 
 
 
diff --git a/firmware/inc/eeprom.h b/firmware/inc/eeprom.h
index 4be4a23..be8f952 100644
--- a/firmware/inc/eeprom.h
+++ b/firmware/inc/eeprom.h
@@ -8,6 +8,10 @@
 #ifndef EEPROM_H_
 #define EEPROM_H_
 
+#include "app.h"
+
+void eeprom_init();
+
 void eeprom_read(uint16_t addr, uint8_t * buf, uint8_t len);
 
 void _eeprom_write(uint16_t addr, uint8_t * buf, uint8_t len, uint8_t flags);
diff --git a/firmware/src/callback.c b/firmware/src/callback.c
index 182773c..36d57d0 100644
--- a/firmware/src/callback.c
+++ b/firmware/src/callback.c
@@ -26,7 +26,7 @@
 
 uint8_t tmpBuffer;
 
-#define PRINT_EVENTS
+//#define PRINT_EVENTS
 
 #ifdef PRINT_EVENTS
 
@@ -144,21 +144,24 @@ USB_Status_TypeDef USBD_SetupCmdCb(
 }
 
 
+uint8_t hidmsgbuf[64];
+
 uint16_t USBD_XferCompleteCb(uint8_t epAddr, USB_Status_TypeDef status,
 		uint16_t xferred, uint16_t remaining) {
 
+
 	if (epAddr == EP1OUT)
 	{
 #ifdef U2F_PRINT
 		int i = 0;
-		for (i=0; i < sizeof(appdata.hidmsgbuf); i++)
+		for (i=0; i < sizeof(hidmsgbuf); i++)
 		{
-			uint8_t l = (uint8_t)appdata.hidmsgbuf[i];
+			uint8_t l = (uint8_t)hidmsgbuf[i];
 			u2f_putb(l);
 		}
 		u2f_prints("\r\n");
 #endif
-		u2f_hid_request((struct u2f_hid_msg*)appdata.hidmsgbuf);
+		u2f_hid_request((struct u2f_hid_msg*)hidmsgbuf);
 	}
 
 
diff --git a/firmware/src/eeprom.c b/firmware/src/eeprom.c
index 9455667..134e941 100644
--- a/firmware/src/eeprom.c
+++ b/firmware/src/eeprom.c
@@ -9,7 +9,17 @@
 
 #include "eeprom.h"
 
-
+void eeprom_init()
+{
+	uint8_t secbyte;
+	eeprom_read(0xFBFF,&secbyte,1);
+	if (secbyte == 0xff)
+	{
+		eeprom_erase(0xFBC0);
+		secbyte = -32;
+		eeprom_write(0xFBFF, &secbyte, 1);
+	}
+}
 
 void eeprom_read(uint16_t addr, uint8_t * buf, uint8_t len)
 {
diff --git a/firmware/src/main.c b/firmware/src/main.c
index bbd391c..5d35de8 100644
--- a/firmware/src/main.c
+++ b/firmware/src/main.c
@@ -24,6 +24,8 @@ static void init(struct APP_DATA* ap)
 	u2f_hid_init();
 	smb_init();
 	atecc_idle();
+	eeprom_init();
+	u2f_init();
 }
 
 void set_app_error(APP_ERROR_CODE ec)
@@ -32,9 +34,27 @@ void set_app_error(APP_ERROR_CODE ec)
 	appdata.error = ec;
 }
 
+
+void dump_eeprom()
+{
+	// 0xF800 - 0xFB7F
+	uint16_t i = 0xF800;
+	uint8_t eep;
+	for (; i <= 0xF800 + 196; i++)
+	{
+		eeprom_read(i,&eep,1);
+		u2f_putb(eep);
+		u2f_prints(" ");
+	}
+	u2f_prints("\r\n");
+}
+
 int8_t test_eeprom()
 {
 
+
+	dump_eeprom();
+	return 0;
 }
 
 #define ms_since(ms,num) (((uint16_t)get_ms() - (ms)) >= num ? (1|(ms=(uint16_t)get_ms())):0)
@@ -74,7 +94,7 @@ int16_t main(void) {
 		{
 			if (!USBD_EpIsBusy(EP1OUT) && !USBD_EpIsBusy(EP1IN))
 			{
-				USBD_Read(EP1OUT, appdata.hidmsgbuf, sizeof(appdata.hidmsgbuf), true);
+				USBD_Read(EP1OUT, hidmsgbuf, sizeof(hidmsgbuf), true);
 				u2f_prints("read added\r\n");
 			}
 
diff --git a/firmware/src/u2f-atecc.c b/firmware/src/u2f-atecc.c
index 26abc4f..d332b29 100644
--- a/firmware/src/u2f-atecc.c
+++ b/firmware/src/u2f-atecc.c
@@ -8,19 +8,69 @@
 #include "bsp.h"
 #include "u2f.h"
 #include "u2f_hid.h"
+#include "eeprom.h"
 #include "atecc508a.h"
 
+
+
 struct key_handle
 {
 	uint8_t index;
 	uint8_t entropy[3];
 };
 
+struct key_storage_header
+{
+	uint8_t num_keys;
+	uint16_t valid_keys;
+	uint8_t num_issued;
+} key_store;
+
+#define U2F_NUM_KEYS 			14
+#define U2F_KEY_HEADER_ADDR		0xF800
+#define U2F_KEYS_ADDR			(0xF800 + sizeof(struct key_storage_header))
+
+#define IS_KEY_VALID(mask,key)	((~mask) & (1<<key))
+
 static struct u2f_hid_msg res;
 static uint8_t* resbuf = (uint8_t*)&res;
 static uint8_t resoffset = 0;
 static uint8_t resseq = 0;
 
+static void flush_key_store()
+{
+	eeprom_write(U2F_KEY_HEADER_ADDR, (uint8_t* )&key_store, sizeof(struct key_storage_header));
+}
+
+void u2f_init()
+{
+	uint8_t i,j;
+	struct atecc_response res;
+
+	eeprom_read(U2F_KEY_HEADER_ADDR, (uint8_t* )&key_store, sizeof(struct key_storage_header));
+
+	// initialize key handles
+	if (key_store.num_keys != U2F_NUM_KEYS)
+	{
+		key_store.num_keys = U2F_NUM_KEYS;
+		key_store.valid_keys = 0;
+		key_store.num_issued = 0;
+		flush_key_store();
+
+		for (i=0; i < 2; i++)
+		{
+			atecc_send_recv(ATECC_CMD_RNG,ATECC_RNG_P1,ATECC_RNG_P2,
+							NULL, 0,
+							appdata.tmp,
+							sizeof(appdata.tmp), &res);
+			for (j=0; j < U2F_NUM_KEYS/2; j++) res.buf[j * U2F_KEY_HANDLE_SIZE] = j+1 + i*U2F_NUM_KEYS/2;
+			eeprom_write(U2F_KEYS_ADDR + i * (U2F_KEY_HANDLE_SIZE * U2F_NUM_KEYS/2),
+							res.buf, U2F_KEY_HANDLE_SIZE * U2F_NUM_KEYS/2);
+		}
+
+	}
+}
+
 void u2f_response_writeback(uint8_t * buf, uint8_t len)
 {
 	u2f_hid_writeback(buf, len);
@@ -91,7 +141,7 @@ void u2f_new_keypair(uint8_t * handle, uint8_t * pubkey)
 
 }
 
-code char __attest[] = ""
+code char __attest[] =
 "\x30\x82\x01\x72\x30\x82\x01\x18\x02\x01\x01\x30\x0a\x06\x08\x2a\x86\x48\xce\x3d"
 "\x04\x03\x02\x30\x45\x31\x0b\x30\x09\x06\x03\x55\x04\x06\x13\x02\x41\x55\x31\x13"
 "\x30\x11\x06\x03\x55\x04\x08\x0c\x0a\x53\x6f\x6d\x65\x2d\x53\x74\x61\x74\x65\x31"