Tag data management skeleton

1 files changed, 59 insertions, 12 deletions

diff --git a/reader_yhy.c b/reader_yhy.c
index 41f20d8..92d5080 100644
--- a/reader_yhy.c
+++ b/reader_yhy.c
@@ -41,6 +41,60 @@ int handle(int fd){
 	return 0;
 }
 
+uint8_t read_ntag(nfc_tag_info_t* tag){
+	uint8_t data[16];
+	size_t bytes;
+
+	//read 16 bytes starting at block 2
+	//[0-3] UID, lock bytes
+	//[4-7] CC
+	//[8-11] Signature
+	//[12-15] Data block offsets & lengths
+	bytes = yhy_sync_read(reader_fd, 2, data, sizeof(data));
+	if(bytes != 16){
+		//read failed, probably not a usable tag
+		return FLAG_TAG_LOCKED;
+	}
+
+	//check for NTAG signature CC bytes
+	if(data[4] != 0xE1 || data[5] != 0x10 || data[7]){
+		return FLAG_TAG_LOCKED;
+	}
+
+	switch(data[6]){
+		case 0x12:
+			//NTAG213
+			tag->bytes_available = 144;
+			break;
+		case 0x3E:
+			//NTAG215
+			tag->bytes_available = 496;
+			break;
+		case 0x6D:
+			//NTAG216
+			tag->bytes_available = 872;
+			break;
+		default:
+			//unknown
+			return FLAG_TAG_LOCKED;
+	}
+
+	//TODO check lock bits
+
+	//check nfcommander signature
+	if(data[8] != 0xCB || data[9] != 'N' || data[10] != 'F' || data[11] != 'C'){
+		return FLAG_TAG_UNPROGRAMMED;
+	}
+
+	
+	return 0;
+}
+
+uint8_t read_mifare(nfc_tag_info_t* tag){
+	//TODO
+	return 0;
+}
+
 int scan(){
 	nfc_tag_info_t card = {
 		0
@@ -48,8 +102,7 @@ int scan(){
 
 	uint16_t atqa = 0;
 	uint8_t sak = 0;
-	uint8_t data[16];
-	uint8_t bytes;
+	uint8_t flags;
 
 	for(yhy_sync_request(reader_fd, 1, &atqa); atqa; yhy_sync_request(reader_fd, 0, &atqa)){
 		sak = 0;
@@ -63,7 +116,6 @@ int scan(){
 			card.type = tag_unknown;
 			if(atqa == 0x0044){
 				card.type = tag_ntag;
-				card.bytes_available = 140;
 				card.granularity = 4;
 			}
 			else{
@@ -85,20 +137,15 @@ int scan(){
 			}
 		}
 
-		if(reader_tag_present(0, card) == TAG_READ_REQUESTED){
+		if(reader_tag_present(0, &card) == TAG_READ_REQUESTED){
 			//read card data
 			if(card.type == tag_ntag){
-				//capability container in page 3, byte 2
-				//
-				//	//0x12 -> ntag213
-				//	//0x3e -> ntag215
-				//	//0x6d -> ntag216
-				//user data in pages 4 trough 39
-				bytes = yhy_sync_read(reader_fd, 3, data, sizeof(data));
+				flags = read_ntag(&card);
 			}
 			else if(card.type == tag_mifare1){
+				flags = read_mifare(&card);
 			}
-			reader_tag_present(FLAG_TAG_LOCKED, card);
+			reader_tag_present(flags, &card);
 		}
 
 		yhy_sync_hlta(reader_fd);