2019-01-26 21:34:53 +02:00

589 lines
15 KiB
C

#include <string.h>
#include "stm32l4xx.h"
#include "nfc.h"
#include "ams.h"
#include "log.h"
#include "util.h"
#include "device.h"
#include "ctap_errors.h"
// Capability container
const CAPABILITY_CONTAINER NFC_CC = {
.cclen_hi = 0x00, .cclen_lo = 0x0f,
.version = 0x01,
.MLe_hi = 0x00, .MLe_lo = 0xff,
.MLc_hi = 0x00, .MLc_lo = 0xff,
.tlv = { 0x04,0x06,
0x11,0x11,
0x00,0xff,
0x00,0xff }
};
uint8_t NDEF_SAMPLE[] = "\x00\x13\xD1\x01\x0ET\x02enHello World";
static struct
{
uint8_t max_frame_size;
uint8_t cid;
uint8_t block_num;
uint8_t selected_applet;
} NFC_STATE;
void nfc_state_init()
{
memset(&NFC_STATE,0,sizeof(NFC_STATE));
NFC_STATE.max_frame_size = 32;
NFC_STATE.block_num = 1;
}
void nfc_init()
{
nfc_state_init();
ams_init();
}
void process_int0(uint8_t int0)
{
}
bool ams_wait_for_tx(uint32_t timeout_ms)
{
uint32_t tstart = millis();
while (tstart + timeout_ms > millis())
{
uint8_t int0 = ams_read_reg(AMS_REG_INT0);
if (int0) process_int0(int0);
if (int0 & AMS_INT_TXE)
return true;
delay(1);
}
return false;
}
//bool ams_receive_with_timeout(10, recbuf, sizeof(recbuf), &reclen))
bool ams_receive_with_timeout(uint32_t timeout_ms, uint8_t * data, int maxlen, int *dlen)
{
uint8_t buf[32];
*dlen = 0;
uint32_t tstart = millis();
while (tstart + timeout_ms > millis())
{
uint8_t int0 = ams_read_reg(AMS_REG_INT0);
uint8_t buffer_status2 = ams_read_reg(AMS_REG_BUF2);
if (buffer_status2 && (int0 & AMS_INT_RXE))
{
if (buffer_status2 & AMS_BUF_INVALID)
{
printf1(TAG_NFC,"Buffer being updated!\r\n");
}
else
{
uint8_t len = buffer_status2 & AMS_BUF_LEN_MASK;
ams_read_buffer(buf, len);
printf1(TAG_NFC,">> "); dump_hex1(TAG_NFC, buf, len);
*dlen = MIN(32, MIN(maxlen, len));
memcpy(data, buf, *dlen);
return true;
}
}
delay(1);
}
return false;
}
void nfc_write_frame(uint8_t * data, uint8_t len)
{
if (len > 32)
{
len = 32;
}
ams_write_command(AMS_CMD_CLEAR_BUFFER);
ams_write_buffer(data,len);
ams_write_command(AMS_CMD_TRANSMIT_BUFFER);
printf1(TAG_NFC,"<< "); dump_hex1(TAG_NFC, data, len);
}
bool nfc_write_response_ex(uint8_t req0, uint8_t * data, uint8_t len, uint16_t resp)
{
uint8_t res[32];
if (len > 32 - 3)
return false;
res[0] = NFC_CMD_IBLOCK | (req0 & 3);
if (len && data)
memcpy(&res[1], data, len);
res[len + 1] = resp >> 8;
res[len + 2] = resp & 0xff;
nfc_write_frame(res, 3 + len);
return true;
}
bool nfc_write_response(uint8_t req0, uint16_t resp)
{
return nfc_write_response_ex(req0, NULL, 0, resp);
}
void nfc_write_response_chaining(uint8_t req0, uint8_t * data, int len)
{
uint8_t res[32 + 2];
int sendlen = 0;
uint8_t iBlock = NFC_CMD_IBLOCK | (req0 & 3);
if (len <= 31)
{
uint8_t res[32] = {0};
res[0] = iBlock;
if (len && data)
memcpy(&res[1], data, len);
nfc_write_frame(res, len + 1);
} else {
do {
// transmit I block
int vlen = MIN(31, len - sendlen);
res[0] = iBlock;
memcpy(&res[1], &data[sendlen], vlen);
// if not a last block
if (vlen + sendlen < len)
{
res[0] |= 0x10;
}
// send data
nfc_write_frame(res, vlen + 1);
sendlen += vlen;
// wait for transmit (32 bytes aprox 2,5ms)
if (!ams_wait_for_tx(10))
{
printf1(TAG_NFC, "TX timeout. slen: %d \r\n", sendlen);
break;
}
// if needs to receive R block (not a last block)
if (res[0] & 0x10)
{
uint8_t recbuf[32] = {0};
int reclen;
if (!ams_receive_with_timeout(100, recbuf, sizeof(recbuf), &reclen))
{
printf1(TAG_NFC, "R block RX timeout.\r\n");
break;
}
if (reclen != 1)
{
printf1(TAG_NFC, "R block length error. len: %d \r\n", reclen);
break;
}
if (((recbuf[0] & 0x01) == (res[0] & 1)) && ((recbuf[0] & 0xf6) == 0xa2))
{
printf1(TAG_NFC, "R block error. txdata: %02x rxdata: %02x \r\n", res[0], recbuf[0]);
break;
}
}
iBlock ^= 0x01;
} while (sendlen < len);
}
}
int answer_rats(uint8_t parameter)
{
uint8_t fsdi = (parameter & 0xf0) >> 4;
uint8_t cid = (parameter & 0x0f);
NFC_STATE.cid = cid;
if (fsdi == 0)
NFC_STATE.max_frame_size = 16;
else if (fsdi == 1)
NFC_STATE.max_frame_size = 24;
else
NFC_STATE.max_frame_size = 32;
uint8_t res[3 + 11];
res[0] = sizeof(res);
res[1] = 2 | (1<<5); // 2 FSCI == 32 byte frame size, TB is enabled
// frame wait time = (256 * 16 / 13.56MHz) * 2^FWI
// FWI=0, FMT=0.3ms (min)
// FWI=4, FMT=4.8ms (default)
// FWI=10, FMT=309ms
// FWI=12, FMT=1237ms
// FWI=14, FMT=4949ms (max)
res[2] = (12<<4) | (0); // TB (FWI << 4) | (SGTI)
// historical bytes
memcpy(&res[3], (uint8_t *)"SoloKey tap", 11);
nfc_write_frame(res, sizeof(res));
ams_wait_for_tx(10);
return 0;
}
void rblock_acknowledge()
{
uint8_t buf[32];
NFC_STATE.block_num = !NFC_STATE.block_num;
buf[0] = NFC_CMD_RBLOCK | NFC_STATE.block_num;
nfc_write_frame(buf,1);
}
// Selects application. Returns 1 if success, 0 otherwise
int select_applet(uint8_t * aid, int len)
{
if (memcmp(aid,AID_FIDO,sizeof(AID_FIDO)) == 0)
{
NFC_STATE.selected_applet = APP_FIDO;
return 1;
}
return 0;
}
void nfc_process_iblock(uint8_t * buf, int len)
{
APDU_HEADER * apdu = (APDU_HEADER *)(buf + 1);
uint8_t * payload = buf + 1 + 5;
uint8_t plen = apdu->lc;
int selected;
uint8_t res[32];
uint32_t t1;
CTAP_RESPONSE ctap_resp;
int status;
printf1(TAG_NFC,">> ");
dump_hex1(TAG_NFC, buf, len);
// TODO this needs to be organized better
switch(apdu->ins)
{
case APDU_INS_SELECT:
if (plen > len - 6)
{
printf1(TAG_ERR, "Truncating APDU length %d\r\n", apdu->lc);
plen = len-6;
}
// if (apdu->p1 == 0 && apdu->p2 == 0x0c)
// {
// printf1(TAG_NFC,"Select NDEF\r\n");
//
// NFC_STATE.selected_applet = APP_NDEF_TAG;
// // Select NDEF file!
// res[0] = NFC_CMD_IBLOCK | (buf[0] & 1);
// res[1] = SW_SUCCESS>>8;
// res[2] = SW_SUCCESS & 0xff;
// nfc_write_frame(res, 3);
// printf1(TAG_NFC,"<< "); dump_hex1(TAG_NFC,res, 3);
// }
// else
{
selected = select_applet(payload, plen);
if (selected)
{
// block = buf[0] & 1;
// block = NFC_STATE.block_num;
// block = !block;
// NFC_STATE.block_num = block;
nfc_write_response_ex(buf[0], (uint8_t *)"U2F_V2", 6, SW_SUCCESS);
printf1(TAG_NFC, "FIDO applet selected.\r\n");
}
else
{
nfc_write_response(buf[0], SW_FILE_NOT_FOUND);
printf1(TAG_NFC, "NOT selected\r\n"); dump_hex1(TAG_NFC,res, 3);
}
}
break;
case APDU_FIDO_U2F_VERSION:
printf1(TAG_NFC, "U2F GetVersion command.\r\n");
nfc_write_response_ex(buf[0], (uint8_t *)"U2F_V2", 6, SW_SUCCESS);
break;
case APDU_FIDO_U2F_REGISTER:
printf1(TAG_NFC, "U2F Register command.\r\n");
ctap_response_init(&ctap_resp);
u2f_request(apdu, &ctap_resp);
status = ctap_resp.data[0];
printf1(TAG_NFC, "U2F resp: %d len: %d\r\n", status, ctap_resp.length);
// nfc_write_response(buf[0], SW_COND_USE_NOT_SATISFIED);
nfc_write_response_chaining(buf[0], ctap_resp.data, ctap_resp.length);
break;
case APDU_FIDO_U2F_AUTHENTICATE:
printf1(TAG_NFC, "U2F Authenticate command.\r\n");
nfc_write_response(buf[0], SW_COND_USE_NOT_SATISFIED);
break;
case APDU_FIDO_NFCCTAP_MSG:
t1 = millis();
printf1(TAG_NFC, "FIDO2 CTAP message. %d\r\n", t1);
ctap_response_init(&ctap_resp);
status = ctap_request(payload, plen, &ctap_resp);
printf1(TAG_NFC, "CTAP resp: %d len: %d\r\n", status, ctap_resp.length);
if (status == CTAP1_ERR_SUCCESS)
{
memmove(&ctap_resp.data[1], &ctap_resp.data[0], ctap_resp.length);
ctap_resp.length += 3;
} else {
ctap_resp.length = 3;
}
ctap_resp.data[0] = status;
ctap_resp.data[ctap_resp.length - 2] = SW_SUCCESS >> 8;
ctap_resp.data[ctap_resp.length - 1] = SW_SUCCESS & 0xff;
printf1(TAG_NFC,"CTAP processing %d (took %d)\r\n", millis(), millis() - t1);
nfc_write_response_chaining(buf[0], ctap_resp.data, ctap_resp.length);
printf1(TAG_NFC,"CTAP answered %d (took %d)\r\n", millis(), millis() - t1);
break;
case APDU_INS_READ_BINARY:
switch(NFC_STATE.selected_applet)
{
case APP_CAPABILITY_CONTAINER:
printf1(TAG_NFC,"APP_CAPABILITY_CONTAINER\r\n");
if (plen > 15)
{
printf1(TAG_ERR, "Truncating requested CC length %d\r\n", apdu->lc);
plen = 15;
}
memmove(res+1, &NFC_CC, plen);
break;
case APP_NDEF_TAG:
printf1(TAG_NFC,"APP_NDEF_TAG\r\n");
if (plen > (sizeof(NDEF_SAMPLE) - 1))
{
printf1(TAG_ERR, "Truncating requested CC length %d\r\n", apdu->lc);
plen = sizeof(NDEF_SAMPLE) - 1;
}
memmove(res+1, NDEF_SAMPLE, plen);
break;
default:
printf1(TAG_ERR, "No binary applet selected!\r\n");
return;
break;
}
res[0] = NFC_CMD_IBLOCK | (buf[0] & 1);
res[1+plen] = SW_SUCCESS>>8;
res[2+plen] = SW_SUCCESS & 0xff;
nfc_write_frame(res, 3+plen);
printf1(TAG_NFC,"APDU_INS_READ_BINARY\r\n");
printf1(TAG_NFC,"<< "); dump_hex1(TAG_NFC,res, 3+plen);
break;
default:
printf1(TAG_NFC, "Unknown INS %02x\r\n", apdu->ins);
nfc_write_response(buf[0], SW_INS_INVALID);
break;
}
}
void nfc_process_block(uint8_t * buf, int len)
{
static uint8_t ibuf[1024];
static int ibuflen = 0;
if (!len)
return;
if (IS_PPSS_CMD(buf[0]))
{
printf1(TAG_NFC, "NFC_CMD_PPSS\r\n");
}
else if (IS_IBLOCK(buf[0]))
{
if (buf[0] & 0x10)
{
printf1(TAG_NFC, "NFC_CMD_IBLOCK chaining blen=%d len=%d\r\n", ibuflen, len);
if (ibuflen + len > sizeof(ibuf))
{
printf1(TAG_NFC, "I block memory error! must have %d but have only %d\r\n", ibuflen + len, sizeof(ibuf));
nfc_write_response(buf[0], SW_INTERNAL_EXCEPTION);
return;
}
printf1(TAG_NFC,"i> ");
dump_hex1(TAG_NFC, buf, len);
if (len)
{
memcpy(&ibuf[ibuflen], &buf[1], len - 1);
ibuflen += len - 1;
}
// send R block
uint8_t rb = NFC_CMD_RBLOCK | NFC_CMD_RBLOCK_ACK | (buf[0] & 3);
nfc_write_frame(&rb, 1);
} else {
if (ibuflen)
{
if (len)
{
memcpy(&ibuf[ibuflen], &buf[1], len - 1);
ibuflen += len - 1;
}
memmove(&ibuf[1], ibuf, ibuflen);
ibuf[0] = buf[0];
ibuflen++;
printf1(TAG_NFC, "NFC_CMD_IBLOCK chaining last block. blen=%d len=%d\r\n", ibuflen, len);
printf1(TAG_NFC,"i> ");
dump_hex1(TAG_NFC, buf, len);
nfc_process_iblock(ibuf, ibuflen);
} else {
printf1(TAG_NFC, "NFC_CMD_IBLOCK\r\n");
nfc_process_iblock(buf, len);
}
ibuflen = 0;
}
}
else if (IS_RBLOCK(buf[0]))
{
rblock_acknowledge();
printf1(TAG_NFC, "NFC_CMD_RBLOCK\r\n");
}
else if (IS_SBLOCK(buf[0]))
{
if ((buf[0] & NFC_SBLOCK_DESELECT) == 0)
{
nfc_write_frame(buf, 1);
printf1(TAG_NFC, "NFC_CMD_SBLOCK, DESELECTED\r\n");
nfc_state_init();
}
else
{
printf1(TAG_NFC, "NFC_CMD_SBLOCK, Unknown\r\n");
}
dump_hex1(TAG_NFC, buf, len);
}
else
{
printf1(TAG_NFC, "unknown NFC request\r\n len[%d]:", len);
dump_hex1(TAG_NFC, buf, len);
}
}
void nfc_loop()
{
static uint32_t t1 = 0;
uint8_t buf[32];
AMS_DEVICE ams;
int len = 0;
// uint8_t def[] = "\x00\x00\x05\x40\x00\x00\x00\x00\x80\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x14\x02\x01\x00";
// if (millis() - t1 > interval)
if (1)
{
t1 = millis();
read_reg_block(&ams);
process_int0(ams.regs.int0);
// if (memcmp(def,ams.buf,sizeof(AMS_DEVICE)) != 0)
// {
// printf1(TAG_NFC,"regs: "); dump_hex1(TAG_NFC,ams.buf,sizeof(AMS_DEVICE));
// }
if (ams.regs.rfid_status)
{
// uint8_t state = AMS_STATE_MASK & ams.regs.rfid_status;
// if (state != AMS_STATE_SENSE)
// printf1(TAG_NFC," %s %d\r\n", ams_get_state_string(ams.regs.rfid_status), millis());
}
if (ams.regs.int0 & AMS_INT_INIT)
{
// Initialize chip!
nfc_state_init();
}
if (ams.regs.int1)
{
// ams_print_int1(ams.regs.int1);
}
if (ams.regs.buffer_status2 && (ams.regs.int0 & AMS_INT_RXE))
{
if (ams.regs.buffer_status2 & AMS_BUF_INVALID)
{
printf1(TAG_NFC,"Buffer being updated!\r\n");
}
else
{
len = ams.regs.buffer_status2 & AMS_BUF_LEN_MASK;
ams_read_buffer(buf, len);
}
}
if (len)
{
// ISO 14443-3
switch(buf[0])
{
case NFC_CMD_REQA:
printf1(TAG_NFC, "NFC_CMD_REQA\r\n");
break;
case NFC_CMD_WUPA:
printf1(TAG_NFC, "NFC_CMD_WUPA\r\n");
break;
case NFC_CMD_HLTA:
printf1(TAG_NFC, "HLTA/Halt\r\n");
break;
case NFC_CMD_RATS:
printf1(TAG_NFC,"RATS\r\n");
t1 = millis();
answer_rats(buf[1]);
NFC_STATE.block_num = 1;
printf1(TAG_NFC,"RATS answered %d (took %d)\r\n",millis(), millis() - t1);
break;
default:
// ISO 14443-4
nfc_process_block(buf,len);
break;
}
}
}
}