some code cleanup

git-svn-id: https://svn.spreadspace.org/avr/trunk@90 aa12f405-d877-488e-9caf-2d797e2a1cc7

1 files changed, 101 insertions, 125 deletions

diff --git a/usb-i2c-sl018/tuer-rfid.c b/usb-i2c-sl018/tuer-rfid.c
index 492d32d..af53d41 100644
--- a/usb-i2c-sl018/tuer-rfid.c
+++ b/usb-i2c-sl018/tuer-rfid.c
@@ -20,15 +20,6 @@
  *  along with spreadspace avr utils. If not, see <http://www.gnu.org/licenses/>.

  */

 

-#define TAG_STA_PIN PINB

-#define TAG_STA_BIT 7

-// #define PIN_B_INTERRUPT 1<<TAG_STA_BIT

-//#define PIN_C_INTERRUPT 0

-//#define PIN_D_INTERRUPT 0

-// #define CARD_IN 0xe1

-// #define CARD_OUT 0xe0

-#define CARD_BOOL ( (TAG_STA_PIN >> TAG_STA_BIT) & 1)

-

 #include <avr/io.h>

 #include <avr/wdt.h>

 #include <avr/interrupt.h>

@@ -52,13 +43,16 @@ typedef union
 } keyslot_t;

 keyslot_t EEMEM keyslots[EEPROM_SIZE/sizeof(keyslot_t)];

 

+#define TAG_STA_PIN PINB

+#define TAG_STA_BIT 7

+#define CARD_PRESENT (!((TAG_STA_PIN >> TAG_STA_BIT) & 1))

+

 const uint8_t SL018_ADDR = 0xa0;

 const uint8_t SL018_WRITE = 0;

 const uint8_t SL018_READ  = 1;

 //============================================

 //  Command List, preamble + length + command 

 //============================================

-

 const unsigned char SL018CMD_ComSelectCard[]          ={1,1};                                               

 const unsigned char SL018CMD_ComRedLedOn[]            ={2,0x40,1};

 const unsigned char SL018CMD_ComRedLedOff[]           ={2,0x40,0};

@@ -72,25 +66,14 @@ typedef struct __attribute__((__packed__))
   uint8_t status;

   unsigned char data[sizeof(twi_rcv_buff)-3];

   uint8_t len;

-} SL018CMD_MESSAGE;

+} sl018_message_t;

 

-SL018CMD_MESSAGE * twi_message = (SL018CMD_MESSAGE *) &twi_rcv_buff;

+sl018_message_t* twi_message = (sl018_message_t *) &twi_rcv_buff;

 uint8_t card_status =0;

 

 FILE stdio_stream;

 FILE * stdio = &stdio_stream;

 

-#define KEY_LEN_MAX (sizeof(keyslot_t) - 1)

-

-/* this generates a Fletcher8 checksum  */

-/* code from: http://stackoverflow.com/questions/13491700/8-bit-fletcher-checksum-of-16-byte-data */

-unsigned char generate_csum(unsigned char* data)

-{

-  uint16_t sum1 = 0xf, sum2 = 0xf, len = KEY_LEN_MAX;

-  do { sum2 += ( sum1 += *data++ ); } while (--len);

-  return sum2<<4 | sum1;

-}

-

 

 /*

              LUFA Library

@@ -142,71 +125,61 @@ void EVENT_USB_Device_Disconnect(void)
 /* end LUFA CDC-ACM specific definitions*/

 

 

-unsigned char sl018_send_buffer(const unsigned char * buffer)

+

+bool sl018_cmd_raw(const unsigned char * buffer)

 {

-    uint8_t len = 0;

-    uint8_t pos = 0;

-    //unsigned char ret;

-    len = buffer[0];

-    if (TWI_StartTransmission(SL018_ADDR | SL018_WRITE,10) == TWI_ERROR_NoError)

-    {

-        for(pos=0; pos<=len; pos++)

-          if( ! TWI_SendByte(buffer[pos]))

-          {

-             TWI_StopTransmission();

-             return 1;

-          }

-        // Must stop transmission afterwards to release the bus

+  uint8_t len = 0;

+  uint8_t pos = 0;

+      //unsigned char ret;

+  len = buffer[0];

+  if (TWI_StartTransmission(SL018_ADDR | SL018_WRITE,10) == TWI_ERROR_NoError) {

+    for(pos=0; pos<=len; pos++)

+      if( ! TWI_SendByte(buffer[pos])) {

         TWI_StopTransmission();

-    } else {

-     return 1;

-    }

-    _delay_ms(50);

-    if (TWI_StartTransmission(SL018_ADDR | SL018_READ,10) == TWI_ERROR_NoError)

-    {

-        TWI_ReceiveByte(&len, 0);

-        twi_rcv_buff[255]=len;

-        for(pos=0; pos<len; pos++)

-          if (! TWI_ReceiveByte(&twi_rcv_buff[pos], (pos == len-1) ? 1:0 ) )

-          {

-             TWI_StopTransmission();

-             return 1;

-          }

+        return 1;

+      }

         // Must stop transmission afterwards to release the bus

+    TWI_StopTransmission();

+  } else 

+    return 1;

+

+  _delay_ms(50);

+  if (TWI_StartTransmission(SL018_ADDR | SL018_READ,10) == TWI_ERROR_NoError) {

+    TWI_ReceiveByte(&len, 0);

+    twi_rcv_buff[255]=len;

+    for(pos=0; pos<len; pos++)

+      if (! TWI_ReceiveByte(&twi_rcv_buff[pos], (pos == len-1) ? 1:0 ) ) {

         TWI_StopTransmission();

-    } else {

-     return 1;

-    }

-    return 0;

-}

+        return 1;

+      }

+        // Must stop transmission afterwards to release the bus

+    TWI_StopTransmission();

+  } else

+    return 1;

 

+  return 0;

+}

 

-bool check_card(unsigned char * uid, uint8_t uid_len)

+bool sl018_cmd(const unsigned char * buffer)

 {

-  keyslot_t card;

-  keyslot_t eeprom_ks;

-  card.uint=0;

-  for (uint8_t pos=0; pos<uid_len; pos++)

-    card.byte[pos]=uid[uid_len-pos-1];

-  card.byte[KEY_LEN_MAX]=generate_csum(&card.byte[0]);

-  keyslot_t * ks=keyslots;

-  bool valid=0;

-  for(uint8_t ks_num=0;ks_num<(EEPROM_SIZE/sizeof(card));ks_num++)

-  {

-    eeprom_read_block(&eeprom_ks,&ks[ks_num],sizeof(eeprom_ks));

-    if(card.uint==eeprom_ks.uint)

-    {

-      valid=1;

-      // break; //this breaks security

+  sl018_message_t * send_twi_message = (sl018_message_t *) (buffer+1);

+  if(sl018_cmd_raw(buffer)) {

+    fprintf(stdio, "I2C error\n\r");

+    return 0;

+  } else {

+    if(twi_message->status) {

+      fprintf(stdio,"SL018 Cmd,Error: %02X,%02X\n\r",twi_message->command,twi_message->status);

+      return 0;

+    }

+    if(send_twi_message->command != twi_message->command) {

+      fprintf(stdio,"SL018 Cmd missmatch: send, rcv: %02X,%02X\n\r",send_twi_message->command,twi_message->command);

     }

   }

-  if (valid)

-  {

-    return 1;

-  } 

-  return 0;

+  return 1;

 }

 

+

+

 void flash_eeprom_from_stdio(void)

 {

   keyslot_t keyslot;

@@ -214,14 +187,12 @@ void flash_eeprom_from_stdio(void)
   uint8_t byte_pos=0;

   fprintf(stdio,"Flashing keys:\n\r");

   fflush(stdio);

-  for(keyslot_pos=0;keyslot_pos<EEPROM_SIZE/sizeof(keyslot);)

-  {

+  for(keyslot_pos=0;keyslot_pos<EEPROM_SIZE/sizeof(keyslot);) {

     int16_t BytesReceived = CDC_Device_BytesReceived(&VirtualSerial_CDC_Interface);

     while(BytesReceived >0) {

       keyslot.byte[byte_pos++]=fgetc(stdio);

       BytesReceived--;

-      if (byte_pos == sizeof(keyslot))

-      {

+      if (byte_pos == sizeof(keyslot)) {

         byte_pos=0;

         eeprom_update_block(&keyslot,&keyslots[keyslot_pos],sizeof(keyslot));

         keyslot_pos++;

@@ -241,8 +212,7 @@ void dump_eeprom_to_stdio(void)
   keyslot_t keyslot;

   uint8_t keyslot_pos=0;

 

-  for(keyslot_pos=0;keyslot_pos<EEPROM_SIZE/sizeof(keyslot);keyslot_pos++)

-  {

+  for(keyslot_pos=0;keyslot_pos<EEPROM_SIZE/sizeof(keyslot);keyslot_pos++) {

     eeprom_read_block(&keyslot,&keyslots[keyslot_pos],sizeof(keyslot));

     for (uint8_t i=0; i< sizeof(keyslot); i++)

       fprintf(stdio,"%02X",keyslot.byte[i]);

@@ -250,50 +220,29 @@ void dump_eeprom_to_stdio(void)
   }

 }

 

-bool sl018_send_buffer_check_error(const unsigned char * buffer)

-{

-  SL018CMD_MESSAGE * send_twi_message = (SL018CMD_MESSAGE *) (buffer+1);

-  if(sl018_send_buffer(buffer))

-  {

-    fprintf(stdio, "I2C error\n\r");

-    return 0;

-  } else {

-    if(twi_message->status)

-    {

-      fprintf(stdio,"SL018 Cmd,Error: %02X,%02X\n\r",twi_message->command,twi_message->status);

-      return 0;

-    }

-    if(send_twi_message->command != twi_message->command)

-    {

-      fprintf(stdio,"SL018 Cmd missmatch: send, rcv: %02X,%02X\n\r",send_twi_message->command,twi_message->command);

-    }

-  }

-  return 1;

-}

-

 

 void handle_cmd(uint8_t cmd)

 {  

   switch(cmd) {

     case 'r': reset2bootloader(); break;

     case 'f': //get cardreader firmware version

-             if(sl018_send_buffer_check_error(SL018CMD_ComGetFirmwareVersion))

+             if(sl018_cmd(SL018CMD_ComGetFirmwareVersion))

              {

                fprintf(stdio, "%s\n\r",twi_message->data);

              }  

              break;

     case '4': //turn cardreader led off

-             if(sl018_send_buffer_check_error(SL018CMD_ComRedLedOff))

+             if(sl018_cmd(SL018CMD_ComRedLedOff))

                fprintf(stdio, "ok\n\r");

              break;

     case '5': //turn cardreader led on

-             if(sl018_send_buffer_check_error(SL018CMD_ComRedLedOn))

+             if(sl018_cmd(SL018CMD_ComRedLedOn))

                fprintf(stdio, "ok\n\r");

              break;

     case 'e': //flash eeprom

              flash_eeprom_from_stdio();

              break;

-    case 'd': //flash eeprom

+    case 'd': //dump eeprom - this breaks security!

              dump_eeprom_to_stdio();

              break;

     case 's': //get eeprom size

@@ -303,26 +252,56 @@ void handle_cmd(uint8_t cmd)
   }

 }

 

-void card_in_action(void)

+

+

+/* this generates a Fletcher8 checksum  */

+/* code from: http://stackoverflow.com/questions/13491700/8-bit-fletcher-checksum-of-16-byte-data */

+unsigned char generate_csum(unsigned char* data)

+{

+  uint16_t sum1 = 0xf, sum2 = 0xf, len = sizeof(keyslot_t) - 1;

+  do { sum2 += ( sum1 += *data++ ); } while (--len);

+  return sum2<<4 | sum1;

+}

+

+bool check_card(const unsigned char * uid, uint8_t uid_len)

+{

+  keyslot_t card;

+  keyslot_t eeprom_ks;

+  card.uint=0;

+  for (uint8_t pos=0; pos<uid_len; pos++)

+    card.byte[pos]=uid[uid_len-pos-1];

+  card.byte[sizeof(keyslot_t) - 1]=generate_csum(&card.byte[0]);

+  keyslot_t * ks=keyslots;

+  bool valid=0;

+  for(uint8_t ks_num=0;ks_num<(EEPROM_SIZE/sizeof(card));ks_num++) {

+    eeprom_read_block(&eeprom_ks,&ks[ks_num],sizeof(eeprom_ks));

+    if(card.uint==eeprom_ks.uint) { // this breaks security (not const time)

+      valid=1;

+      break; //this breaks security (not const time)

+    }

+  }

+  if(valid)

+    return 1;

+  return 0;

+}

+

+void handle_card(void)

 {

   uint8_t pos;

   fprintf(stdio, "CARD IN: ");

-  if(sl018_send_buffer_check_error(SL018CMD_ComSelectCard))

+  if(sl018_cmd(SL018CMD_ComSelectCard))

   {

     for (pos=twi_message->len - 4 ; pos< 255; pos--)

-    {

       fprintf(stdio,"%02X",twi_message->data[pos]);

-    }

+

     fprintf(stdio, "\n\r");

     uint8_t type = twi_message->data[twi_message->len-1-sizeof(twi_message->command)-sizeof(twi_message->status)];

-    if (0<type && type < 7)

-    {

-      if(check_card(&twi_message->data[0],twi_message->len-1-sizeof(twi_message->command)-sizeof(twi_message->status)))

-      {

-        sl018_send_buffer_check_error(SL018CMD_ComRedLedOn);

+    if (0<type && type < 7) {

+      if(check_card(&twi_message->data[0],twi_message->len-1-sizeof(twi_message->command)-sizeof(twi_message->status))) {

+        sl018_cmd(SL018CMD_ComRedLedOn);

         fprintf(stdio,"open\n\r");

         _delay_ms(255);

-        sl018_send_buffer_check_error(SL018CMD_ComRedLedOff);

+        sl018_cmd(SL018CMD_ComRedLedOff);

       }

     } else {

       fprintf(stdio,"Unknown Card Type %02x\n\r",type);

@@ -347,13 +326,10 @@ int main(void)
     if(BytesReceived > 0) {

       handle_cmd(fgetc(stdio));

     }

-    if(CARD_BOOL != card_status)

-    {

-      card_status = CARD_BOOL;

-      if (!card_status)

-      {

-        card_in_action();

-      }

+    if(CARD_PRESENT != card_status) {

+      card_status = CARD_PRESENT;

+      if(card_status)

+        handle_card();

     }

     CDC_Device_USBTask(&VirtualSerial_CDC_Interface);

     USB_USBTask();