//-----------------------------------------------------------------------------
// Copyright (C) 2015 Piwi
//
// This code is licensed to you under the terms of the GNU GPL, version 2 or,
// at your option, any later version. See the LICENSE.txt file for the text of
// the license.
//-----------------------------------------------------------------------------
// High frequency Topaz (NFC Type 1) commands
//-----------------------------------------------------------------------------
#include "cmdhftopaz.h"

#define TOPAZ_STATIC_MEMORY	(0x0f * 8)		// 15 blocks with 8 Bytes each

// a struct to describe a memory area which contains lock bits and the corresponding lockable memory area
typedef struct dynamic_lock_area {
	struct dynamic_lock_area *next;
	uint16_t	byte_offset;			// the address of the lock bits
	uint16_t	size_in_bits;
	uint16_t	first_locked_byte;		// the address of the lockable area
	uint16_t	bytes_locked_per_bit;
} dynamic_lock_area_t;


static struct {
	uint8_t HR01[2];
	uint8_t uid[7];
	uint16_t size;
	uint8_t data_blocks[TOPAZ_STATIC_MEMORY/8][8];	// this memory is always there
	uint8_t *dynamic_memory;						// this memory can be there
	dynamic_lock_area_t *dynamic_lock_areas;		// lock area descriptors
} topaz_tag;

static void topaz_switch_on_field(void) {
	UsbCommand c = {CMD_READER_ISO_14443a, {ISO14A_CONNECT | ISO14A_NO_SELECT | ISO14A_NO_DISCONNECT | ISO14A_TOPAZMODE | ISO14A_NO_RATS, 0, 0}};
	SendCommand(&c);
}

static void topaz_switch_off_field(void) {
	UsbCommand c = {CMD_READER_ISO_14443a, {0, 0, 0}};
	SendCommand(&c);
}

// send a raw topaz command, returns the length of the response (0 in case of error)
static int topaz_send_cmd_raw(uint8_t *cmd, uint8_t len, uint8_t *response) {
	UsbCommand c = {CMD_READER_ISO_14443a, {ISO14A_RAW | ISO14A_NO_DISCONNECT | ISO14A_TOPAZMODE | ISO14A_NO_RATS, len, 0}};
	memcpy(c.d.asBytes, cmd, len);
	SendCommand(&c);

	UsbCommand resp;
	WaitForResponse(CMD_ACK, &resp);

	if (resp.arg[0] > 0) {
		memcpy(response, resp.d.asBytes, resp.arg[0]);
	}
	
	return resp.arg[0];
}


// calculate CRC bytes and send topaz command, returns the length of the response (0 in case of error) 
static int topaz_send_cmd(uint8_t *cmd, uint8_t len, uint8_t *response) {
	if (len > 1) {
        uint8_t b1, b2;
		compute_crc(CRC_14443_B, cmd, len-2, &b1, &b2);
        cmd[len-2] = b1;
        cmd[len-1] = b2;
	}

	return topaz_send_cmd_raw(cmd, len, response);
}


// select a topaz tag. Send WUPA and RID.
static int topaz_select(uint8_t *atqa, uint8_t *rid_response) {
	// ToDo: implement anticollision

	uint8_t wupa_cmd[] = {TOPAZ_WUPA};
	uint8_t rid_cmd[] = {TOPAZ_RID, 0, 0, 0, 0, 0, 0, 0, 0};

	topaz_switch_on_field();

	if (!topaz_send_cmd(wupa_cmd, sizeof(wupa_cmd), atqa)) {
		topaz_switch_off_field();
		return -1;		// WUPA failed
	}

	if (!topaz_send_cmd(rid_cmd, sizeof(rid_cmd), rid_response)) {
		topaz_switch_off_field();
		return -2;		// RID failed
	}
	
	return 0;		// OK
}


// read all of the static memory of a selected Topaz tag.
static int topaz_rall(uint8_t *uid, uint8_t *response) {
	uint8_t rall_cmd[] = {TOPAZ_RALL, 0, 0, 0, 0, 0, 0, 0, 0};

	memcpy(&rall_cmd[3], uid, 4);
	if (!topaz_send_cmd(rall_cmd, sizeof(rall_cmd), response)) {
		topaz_switch_off_field();
		return -1;		// RALL failed
	}
	
	return 0;
}


// read a block (8 Bytes) of a selected Topaz tag.
static int topaz_read_block(uint8_t *uid, uint8_t blockno, uint8_t *block_data)
{
	uint8_t read8_cmd[] = {TOPAZ_READ8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
	uint8_t read8_response[11];
	
	read8_cmd[1] = blockno;
	memcpy(&read8_cmd[10], uid, 4);
	if (!topaz_send_cmd(read8_cmd, sizeof(read8_cmd), read8_response)) {
		topaz_switch_off_field();
		return -1;		// READ8 failed
	}
	memcpy(block_data, &read8_response[1], 8);
	return 0;
}

// read a segment (16 blocks = 128 Bytes) of a selected Topaz tag. Works only for tags with dynamic memory.
static int topaz_read_segment(uint8_t *uid, uint8_t segno, uint8_t *segment_data) {
	uint8_t rseg_cmd[] = {TOPAZ_RSEG, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
	uint8_t rseg_response[131];
	
	rseg_cmd[1] = segno << 4;
	memcpy(&rseg_cmd[10], uid, 4);
	if (!topaz_send_cmd(rseg_cmd, sizeof(rseg_cmd), rseg_response)) {
		topaz_switch_off_field();
		return -1;		// RSEG failed
	}
	memcpy(segment_data, &rseg_response[1], 128);
	return 0;
}

// search for the lock area descriptor for the lockable area including byteno 
static dynamic_lock_area_t *get_dynamic_lock_area(uint16_t byteno) {
	dynamic_lock_area_t *lock_area;	
	lock_area = topaz_tag.dynamic_lock_areas;
	
	while (lock_area != NULL) {
		if (byteno < lock_area->first_locked_byte) {
			lock_area = lock_area->next;
		} else {
			return lock_area;
		}
	}
	return NULL;
}

// check if a memory byte is locked.
static bool topaz_byte_is_locked(uint16_t byteno) {
	uint8_t *lockbits;
	uint16_t locked_bytes_per_bit;
	dynamic_lock_area_t *lock_area;
	
	if (byteno < TOPAZ_STATIC_MEMORY) {
		lockbits = &topaz_tag.data_blocks[0x0e][0];
		locked_bytes_per_bit = 8;
	} else {
		lock_area = get_dynamic_lock_area(byteno);
		if (lock_area == NULL) {
			return false;
		} else {
			lockbits = &topaz_tag.dynamic_memory[lock_area->byte_offset - TOPAZ_STATIC_MEMORY];
			locked_bytes_per_bit = lock_area->bytes_locked_per_bit;
			byteno = byteno - lock_area->first_locked_byte;
		}
	}

	uint16_t blockno = byteno / locked_bytes_per_bit;
	if(lockbits[blockno/8] & (0x01 << (blockno % 8))) {
		return true;
	} else {
		return false;
	}
}


// read and print the Capability Container
static int topaz_print_CC(uint8_t *data) {
	if (data[0] != 0xe1) {
		topaz_tag.size = TOPAZ_STATIC_MEMORY;
		return -1;		// no NDEF message
	}

	PrintAndLogEx(NORMAL, "Capability Container: %02x %02x %02x %02x", data[0], data[1], data[2], data[3]);
	PrintAndLogEx(NORMAL, "  %02x: NDEF Magic Number", data[0]); 
	PrintAndLogEx(NORMAL, "  %02x: version %d.%d supported by tag", data[1], (data[1] & 0xF0) >> 4, data[1] & 0x0f);
	uint16_t memsize = (data[2] + 1) * 8;
	topaz_tag.size = memsize;
	topaz_tag.dynamic_memory = malloc(memsize - TOPAZ_STATIC_MEMORY);
	PrintAndLogEx(NORMAL, "  %02x: Physical Memory Size of this tag: %d bytes", data[2], memsize);
	PrintAndLogEx(NORMAL, "  %02x: %s / %s", data[3], 
				(data[3] & 0xF0) ? "(RFU)" : "Read access granted without any security", 
				(data[3] & 0x0F)==0 ? "Write access granted without any security" : (data[3] & 0x0F)==0x0F ? "No write access granted at all" : "(RFU)");
	return 0;				
}


// return type, length and value of a TLV, starting at memory position *TLV_ptr 
static void get_TLV(uint8_t **TLV_ptr, uint8_t *TLV_type, uint16_t *TLV_length, uint8_t **TLV_value) {
	*TLV_length = 0;
	*TLV_value = NULL;

	*TLV_type = **TLV_ptr;
	*TLV_ptr += 1;
	switch (*TLV_type) {
		case 0x00:			// NULL TLV.
		case 0xFE:			// Terminator TLV.
			break;
		case 0x01:			// Lock Control TLV
		case 0x02:			// Reserved Memory TLV
		case 0x03:			// NDEF message TLV
		case 0xFD:			// proprietary TLV
			*TLV_length = **TLV_ptr;
			*TLV_ptr += 1;
			if (*TLV_length == 0xff) {
				*TLV_length = **TLV_ptr << 8;
				*TLV_ptr += 1;
				*TLV_length |= **TLV_ptr;
				*TLV_ptr += 1;
			}
			*TLV_value = *TLV_ptr;
			*TLV_ptr += *TLV_length;
			break;
		default:			// RFU
			break;
	}
}


// lock area TLVs contain no information on the start of the respective lockable area. Lockable areas
// do not include the lock bits and reserved memory. We therefore need to adjust the start of the 
// respective lockable areas accordingly
static void adjust_lock_areas(uint16_t block_start, uint16_t block_size) {
	dynamic_lock_area_t *lock_area = topaz_tag.dynamic_lock_areas;
	while (lock_area != NULL) {
		if (lock_area->first_locked_byte <= block_start) {
			lock_area->first_locked_byte += block_size;
		}
		lock_area = lock_area->next;
	}
}


// read and print the lock area and reserved memory TLVs
static void topaz_print_control_TLVs(uint8_t *memory) {
	uint8_t *TLV_ptr = memory;
	uint8_t TLV_type = 0;
	uint16_t TLV_length;
	uint8_t *TLV_value;
	bool lock_TLV_present = false;
	bool reserved_memory_control_TLV_present = false;
	uint16_t next_lockable_byte = 0x0f * 8;				// first byte after static memory area
	
	while (*TLV_ptr != 0x03 && *TLV_ptr != 0xFD && *TLV_ptr != 0xFE) {	
		// all Lock Control TLVs shall be present before the NDEF message TLV, the proprietary TLV (and the Terminator TLV)
		get_TLV(&TLV_ptr, &TLV_type, &TLV_length, &TLV_value);
		if (TLV_type == 0x01) {			// a Lock Control TLV
			uint8_t pages_addr = TLV_value[0] >> 4;
			uint8_t byte_offset = TLV_value[0] & 0x0f;
			uint16_t size_in_bits = TLV_value[1] ? TLV_value[1] : 256;
			uint16_t size_in_bytes = (size_in_bits + 7)/8;
			uint16_t bytes_per_page = 1 << (TLV_value[2] & 0x0f);
			uint16_t bytes_locked_per_bit = 1 << (TLV_value[2] >> 4);
			uint16_t area_start = pages_addr * bytes_per_page + byte_offset;
			PrintAndLogEx(NORMAL, "Lock Area of %d bits at byte offset 0x%04x. Each Lock Bit locks %d bytes.", 
						size_in_bits,
						area_start,
						bytes_locked_per_bit);
			lock_TLV_present = true;
			dynamic_lock_area_t *old = topaz_tag.dynamic_lock_areas;
			dynamic_lock_area_t *new = topaz_tag.dynamic_lock_areas;
			if (old == NULL) {
				new = topaz_tag.dynamic_lock_areas = (dynamic_lock_area_t *)malloc(sizeof(dynamic_lock_area_t));
			} else {
				while(old->next != NULL) {
					old = old->next;
				}
				new = old->next = (dynamic_lock_area_t *)malloc(sizeof(dynamic_lock_area_t));
			}
			new->next = NULL;
			if (area_start <= next_lockable_byte) {
				// lock areas are not lockable
				next_lockable_byte += size_in_bytes;
			}
			new->first_locked_byte = next_lockable_byte;
			new->byte_offset = area_start;
			new->size_in_bits = size_in_bits;
			new->bytes_locked_per_bit = bytes_locked_per_bit;
			next_lockable_byte += size_in_bits * bytes_locked_per_bit;		
		}
		if (TLV_type == 0x02) {			// a Reserved Memory Control TLV
			uint8_t pages_addr = TLV_value[0] >> 4;
			uint8_t byte_offset = TLV_value[0] & 0x0f;
			uint16_t size_in_bytes = TLV_value[1] ? TLV_value[1] : 256;
			uint8_t bytes_per_page = 1 << (TLV_value[2] & 0x0f);
			uint16_t area_start = pages_addr * bytes_per_page + byte_offset;
			PrintAndLogEx(NORMAL, "Reserved Memory of %d bytes at byte offset 0x%02x.", 
						size_in_bytes,
						area_start);
			reserved_memory_control_TLV_present = true;
			adjust_lock_areas(area_start, size_in_bytes);  // reserved memory areas are not lockable
			if (area_start <= next_lockable_byte) {
				next_lockable_byte += size_in_bytes;
			}
		}
	}
	
	if (!lock_TLV_present) {
		PrintAndLogEx(NORMAL, "(No Lock Control TLV present)");
	}
	
	if (!reserved_memory_control_TLV_present) {
		PrintAndLogEx(NORMAL, "(No Reserved Memory Control TLV present)");
	}	
}

// read all of the dynamic memory
static int topaz_read_dynamic_data(void){
	// first read the remaining block of segment 0
	if (topaz_read_block(topaz_tag.uid, 0x0f, &topaz_tag.dynamic_memory[0]) == -1) {
		PrintAndLogEx(WARNING, "Error while reading dynamic memory block %02x. Aborting...", 0x0f);
		return -1;
	}
	
	// read the remaining segments
	uint8_t max_segment = topaz_tag.size / 128 - 1;
	for (uint8_t segment = 1; segment <= max_segment; segment++) {
		if (topaz_read_segment(topaz_tag.uid, segment, &topaz_tag.dynamic_memory[(segment-1)*128+8]) == -1) {
			PrintAndLogEx(WARNING, "Error while reading dynamic memory block %02x. Aborting...", 0x0f);
			return -1;
		}
	}	
	return 0;
}
	

// read and print the dynamic memory
static void topaz_print_dynamic_data(void) {
	if (topaz_tag.size > TOPAZ_STATIC_MEMORY) {
		PrintAndLogEx(NORMAL, "Dynamic Data blocks:");
		if (topaz_read_dynamic_data() == 0) {
			PrintAndLogEx(NORMAL, "block# | offset | Data                    | Locked(y/n)");
			char line[80];
			for (uint16_t blockno = 0x0f; blockno < topaz_tag.size/8; blockno++) {
				uint8_t *block_data = &topaz_tag.dynamic_memory[(blockno-0x0f)*8];
				char lockbits[9];
				for (uint16_t j = 0; j < 8; j++) {
					sprintf(&line[3*j], "%02x ", block_data[j]);
					lockbits[j] = topaz_byte_is_locked(blockno*8+j) ? 'y' : 'n';
				}
				lockbits[8] = '\0';
				PrintAndLogEx(NORMAL, "  0x%02x | 0x%04x | %s|   %-3s", blockno, blockno*8, line, lockbits);
			}
		}
	}
}

static void topaz_print_lifecycle_state(uint8_t *data) {
	// to be done
}

static void topaz_print_NDEF(uint8_t *data) {
	// to be done. 
}
	
// read a Topaz tag and print some useful information	
int CmdHFTopazReader(const char *Cmd) {
	int status;
	uint8_t atqa[2];
	uint8_t rid_response[8];
	uint8_t *uid_echo = &rid_response[2];
	uint8_t rall_response[124];
	bool verbose = true;

	char ctmp = param_getchar(Cmd, 0);
	if ( ctmp == 'S' || ctmp == 's') verbose = false;
	
	status = topaz_select(atqa, rid_response);

	if (status == -1) {
		if (verbose) PrintAndLogEx(WARNING, "Error: couldn't receive ATQA");
		return -1;
	}

	PrintAndLogEx(NORMAL, "ATQA : %02x %02x", atqa[1], atqa[0]);
	if (atqa[1] != 0x0c && atqa[0] != 0x00) {
		PrintAndLogEx(NORMAL, "Tag doesn't support the Topaz protocol.");
		topaz_switch_off_field();
		return -1;
	}
	
	if (status == -2) {
		PrintAndLogEx(WARNING, "Error: tag didn't answer to RID");
		topaz_switch_off_field();
		return -1;
	}

	topaz_tag.HR01[0] = rid_response[0];
	topaz_tag.HR01[1] = rid_response[1];
	
	// ToDo: CRC check
	PrintAndLogEx(NORMAL, "HR0  : %02x (%sa Topaz tag (%scapable of carrying a NDEF message), %s memory map)", rid_response[0], 
						(rid_response[0] & 0xF0) == 0x10 ? "" : "not ",
						(rid_response[0] & 0xF0) == 0x10 ? "" : "not ",
						(rid_response[0] & 0x0F) == 0x01 ? "static" : "dynamic");
	PrintAndLogEx(NORMAL, "HR1  : %02x", rid_response[1]);
	
	status = topaz_rall(uid_echo, rall_response);

	if (status == -1) {
		PrintAndLogEx(WARNING, "Error: tag didn't answer to RALL");
		topaz_switch_off_field();
		return -1;
	}

	memcpy(topaz_tag.uid, rall_response+2, 7);
	PrintAndLogEx(NORMAL, "UID  : %02x %02x %02x %02x %02x %02x %02x", 
			topaz_tag.uid[6], 
			topaz_tag.uid[5], 
			topaz_tag.uid[4], 
			topaz_tag.uid[3], 
			topaz_tag.uid[2], 
			topaz_tag.uid[1], 
			topaz_tag.uid[0]);
			
	PrintAndLogEx(NORMAL, "       UID[6] (Manufacturer Byte) = %02x, Manufacturer: %s", 
			topaz_tag.uid[6], 
			getTagInfo(topaz_tag.uid[6]));
	
	memcpy(topaz_tag.data_blocks, rall_response+2, 0x0f*8);
	PrintAndLogEx(NORMAL, "");
	PrintAndLogEx(NORMAL, "Static Data blocks 00 to 0c:");
	PrintAndLogEx(NORMAL, "block# | offset | Data                    | Locked");
	char line[80];
	for (uint16_t i = 0; i <= 0x0c; i++) {
		char lockbits[9];
		for (uint16_t j = 0; j < 8; j++) {
			sprintf(&line[3*j], "%02x ", topaz_tag.data_blocks[i][j] /*rall_response[2 + 8*i + j]*/);
			lockbits[j] = topaz_byte_is_locked(i*8+j) ? 'y' : 'n';
		}
		lockbits[8] = '\0';
		PrintAndLogEx(NORMAL, "  0x%02x | 0x%02x | %s|   %-3s", i, i*8, line, lockbits);
	}
	
	PrintAndLogEx(NORMAL, "");
	PrintAndLogEx(NORMAL, "Static Reserved block 0d:");
	for (uint16_t j = 0; j < 8; j++) {
		sprintf(&line[3*j], "%02x ", topaz_tag.data_blocks[0x0d][j]);
	}
	PrintAndLogEx(NORMAL, "  0x%02x |  0x%02x  | %s|   %-3s", 0x0d, 0x0d*8, line, "n/a");
	
	PrintAndLogEx(NORMAL, "");
	PrintAndLogEx(NORMAL, "Static Lockbits and OTP Bytes:");
	for (uint16_t j = 0; j < 8; j++) {
		sprintf(&line[3*j], "%02x ", topaz_tag.data_blocks[0x0e][j]);
	}
	PrintAndLogEx(NORMAL, "  0x%02x |  0x%02x  | %s|   %-3s", 0x0e, 0x0e*8, line, "n/a");

	PrintAndLogEx(NORMAL, "");

	status = topaz_print_CC(&topaz_tag.data_blocks[1][0]);
	
	if (status == -1) {
		PrintAndLogEx(NORMAL, "No NDEF message data present");
		topaz_switch_off_field();
		return 0;
	}

	PrintAndLogEx(NORMAL, "");
	topaz_print_control_TLVs(&topaz_tag.data_blocks[1][4]);
	
	PrintAndLogEx(NORMAL, "");
	topaz_print_dynamic_data();
	
	topaz_print_lifecycle_state(&topaz_tag.data_blocks[1][0]);

	topaz_print_NDEF(&topaz_tag.data_blocks[1][0]);
	
	topaz_switch_off_field();
	return 0;
}

int CmdHFTopazSim(const char *Cmd) {
	PrintAndLogEx(NORMAL, "not yet implemented");
	return 0;
}

int CmdHFTopazCmdRaw(const char *Cmd) {
	PrintAndLogEx(NORMAL, "not yet implemented. Use hf 14 raw with option -T.");
	return 0;
}

int CmdHFTopazList(const char *Cmd) {
	CmdTraceList("topaz");
	return 0;
}

static int CmdHelp(const char *Cmd);

static command_t CommandTable[] = {
	{"help",	CmdHelp,			1, "This help"},
	{"reader",	CmdHFTopazReader,	0, "Act like a Topaz reader"},
	{"sim",		CmdHFTopazSim,		0, "<UID> -- Simulate Topaz tag"},
	{"sniff",	CmdHF14ASniff,		0, "Sniff Topaz reader-tag communication"},
	{"raw",		CmdHFTopazCmdRaw,	0, "Send raw hex data to tag"},
	{"list",	CmdHFTopazList,		0, "[Deprecated] List Topaz history"},
	{NULL,		NULL,				0, NULL}
};

int CmdHFTopaz(const char *Cmd) {
	clearCommandBuffer();
	CmdsParse(CommandTable, Cmd);
	return 0;
}

static int CmdHelp(const char *Cmd) {
	CmdsHelp(CommandTable);
	return 0;
}