Basic NTAG support

3 files changed, 79 insertions, 15 deletions

diff --git a/nfcommander.h b/nfcommander.h
index 79b8790..b4622a1 100644
--- a/nfcommander.h
+++ b/nfcommander.h
@@ -7,12 +7,11 @@
 #endif
 
 typedef enum {
-	tag_unset,
+	tag_unset, /*unknown tag type*/
+	tag_unknown, /*unsupported tag*/
 	tag_mifare1,
 	tag_ntag,
-	tag_desfire,
-	tag_ultralight,
-	tag_ultralightc
+	tag_desfire
 } nfc_tag_t;
 
 #define FLAG_TAG_DATA_VALID 1
@@ -25,6 +24,9 @@ typedef struct {
 	nfc_tag_t type;
 	uint8_t uid_length;
 	uint8_t uid[10];
+	//storage
+	size_t bytes_available;
+	size_t granularity;
 } nfc_tag_info_t;
 
 typedef int (*reader_plugin_init)(void);
diff --git a/reader.c b/reader.c
index f37ade4..0ca56cf 100644
--- a/reader.c
+++ b/reader.c
@@ -86,6 +86,24 @@ int reader_init(){
 	return reader_init_backend();
 }
 
+static void reader_print_tag(nfc_tag_info_t tag){
+	size_t n = 0;
+	char* type = "UNST";
+	switch(tag.type){
+		case tag_unset: type = "UNST"; break;
+		case tag_unknown: type = "UNKN"; break;
+		case tag_mifare1: type = "MFR1"; break;
+		case tag_ntag: type = "NTAG"; break;
+		case tag_desfire: type = "DESF"; break;
+	}
+
+	printf("[%s", type);
+	for(n = 0; n < tag.uid_length; n++){
+		printf(" %02X", tag.uid[n]);
+	}
+	printf("]");
+}
+
 static void reader_expire(){
 	size_t n = 0;
 	for(n = 0; n < MAX_TAGS; n++){
@@ -101,16 +119,22 @@ static int reader_process(){
 				//new tag
 				tags[n].flags |= FLAG_ACTIVE;
 				if(tags[n].flags & FLAG_TAG_LOCKED){
-					printf("A tag was detected (slot %lu), but no key is known\n", n);
+					printf("Slot %2lu: ", n);
+					reader_print_tag(tags[n].info);
+					printf(" locked, unusable\n");
 					return 0;
 				}
 				if(tags[n].flags & FLAG_TAG_UNPROGRAMMED){
-					printf("Unprogrammed tag detected (slot %lu)\n", n);
+					printf("Slot %2lu: ", n);
+					reader_print_tag(tags[n].info);
+					printf(" unprogrammed\n");
 					//TODO
 					return 0;
 				}
 				if(tags[n].flags & FLAG_TAG_DATA_VALID){
-					printf("Command tag detected (slot %lu)\n", n);
+					printf("Slot %2lu: ", n);
+					reader_print_tag(tags[n].info);
+					printf(" valid\n");
 					//TODO
 					return 0;
 				}
@@ -136,7 +160,7 @@ int reader_tag_present(uint8_t flags, nfc_tag_info_t tag){
 	size_t n = 0;
 
 	//sanitize input flags
-	flags &= (FLAG_TAG_DATA_VALID | FLAG_TAG_UNPROGRAMMED | FLAG_TAG_LOCKED);
+	flags &= (TAG_STATUS_FLAGS);
 
 	//check if tag already known
 	for(n = 0; n < MAX_TAGS; n++){
diff --git a/reader_yhy.c b/reader_yhy.c
index 7e0d8c3..41f20d8 100644
--- a/reader_yhy.c
+++ b/reader_yhy.c
@@ -48,18 +48,56 @@ int scan(){
 
 	uint16_t atqa = 0;
 	uint8_t sak = 0;
+	uint8_t data[16];
+	uint8_t bytes;
 
 	for(yhy_sync_request(reader_fd, 1, &atqa); atqa; yhy_sync_request(reader_fd, 0, &atqa)){
-		card.uid_length = yhy_sync_anticoll(reader_fd, card.uid, sizeof(card.uid));
-		if(!card.uid_length){
-			return 0;
+		sak = 0;
+		//ATQA should normally not be used as an indicator for UID length
+		//However, the YHY UL_SELECT command does not seem to work after CL1 anticollision for some reason
+
+		//extended length UIDs
+		if(atqa & 0x00C0){
+			card.uid_length = yhy_sync_ulselect(reader_fd, card.uid, sizeof(card.uid));
+			//since we dont get either the CL2 SAK or any other method of identifying the particular type of PICC, just guess whether it's an NTAG
+			card.type = tag_unknown;
+			if(atqa == 0x0044){
+				card.type = tag_ntag;
+				card.bytes_available = 140;
+				card.granularity = 4;
+			}
+			else{
+				printf("PICC Parameters: ATQA %04X\n", atqa);
+			}
+		}
+		else{
+			card.uid_length = yhy_sync_anticoll(reader_fd, card.uid, sizeof(card.uid));
+			yhy_sync_select(reader_fd, card.uid, card.uid_length, &sak);
+
+			card.type = tag_unknown;
+			if(atqa == 0x0004 && sak == 0x08){
+				card.type = tag_mifare1;
+				card.bytes_available = 752;
+				card.granularity = 16;
+			}
+			else{
+				printf("PICC Parameters: ATQA %04X SAK %02X\n", atqa, sak);
+			}
 		}
-
-		yhy_sync_select(reader_fd, card.uid, card.uid_length, &sak);
-		//TODO parse ATQA and SAK to detect tag type
 
 		if(reader_tag_present(0, card) == TAG_READ_REQUESTED){
-			//TODO read card data
+			//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));
+			}
+			else if(card.type == tag_mifare1){
+			}
 			reader_tag_present(FLAG_TAG_LOCKED, card);
 		}