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authorjaseg <git@jaseg.de>2021-03-24 14:17:28 +0100
committerjaseg <git@jaseg.de>2021-03-24 14:17:28 +0100
commitdbb264c68d658e5c851c0b3926f5465196e486df (patch)
tree1c03c543bbb01e29533480ebbe6df1ed407b18f5 /fw
parent4fcc3337e21089b50a1034fa05c69d4bd7b84640 (diff)
downloadsecure-hid-dbb264c68d658e5c851c0b3926f5465196e486df.tar.gz
secure-hid-dbb264c68d658e5c851c0b3926f5465196e486df.tar.bz2
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Make keyboard emulation for debug work
Diffstat (limited to 'fw')
-rwxr-xr-xfw/hexnoise.py81
-rw-r--r--fw/src/demo.c204
2 files changed, 240 insertions, 45 deletions
diff --git a/fw/hexnoise.py b/fw/hexnoise.py
index 549f583..b0217e2 100755
--- a/fw/hexnoise.py
+++ b/fw/hexnoise.py
@@ -2,7 +2,9 @@
import time
import enum
+import os
import sys
+import binascii
from contextlib import contextmanager, suppress, wraps
import hashlib
import secrets
@@ -58,11 +60,12 @@ class Packetizer:
packet = self.ser.read_until(b'\0')
data = cobs.decode(packet[:-1])
+ pkt_type, data = PacketType(data[0]), data[1:]
+
if self.debug:
- print(f'\033[93mReceived {len(data)} bytes\033[0m')
+ print(f'\033[93mReceived {len(data)} bytes, packet type {pkt_type.name} ({pkt_type.value})\033[0m')
hexdump(print, data, self.width)
- pkt_type, data = PacketType(data[0]), data[1:]
if pkt_type is PacketType.COMM_ERROR:
raise ProtocolError('Device-side serial communication error')
elif pkt_type is PacketType.CRYPTO_ERROR:
@@ -253,6 +256,7 @@ class NoiseEngine:
msg_type, payload = self.packetizer.receive_packet()
rtype, data = self._decrypt(payload)
+ print(f'Received report {rtype.name} ({rtype.value})')
if rtype is ReportType.PAIRING_SUCCESS:
self.connected, self.paired = True, True
elif rtype is ReportType.PAIRING_START:
@@ -334,7 +338,7 @@ class NoiseEngine:
raise ProtocolError('Device-side pairing error') # FIXME find better exception subclass here
else:
- raise ProtocolError('Invalid report type')
+ raise ProtocolError(f'Invalid report type {msg_type}')
def uinput_passthrough(self):
mouse_foo = [uinput.BTN_LEFT, uinput.BTN_RIGHT, uinput.BTN_MIDDLE,
@@ -351,7 +355,6 @@ class NoiseEngine:
raise ValueError('Unsupported report length', report_len)
modbyte, _reserved, *keycodes = report
- import binascii
keys = { *KeyMapper.map_modifiers(modbyte), *KeyMapper.map_regulars(keycodes) }
if self.debug:
print('Emitting:', keys)
@@ -366,7 +369,6 @@ class NoiseEngine:
elif msg_type is ReportType.MOUSE:
if report_len < 3 or report_len > 8:
raise ValueError('Unsupported report length', report_len)
- import binascii
_report_type, buttons, a, b, c, w, _2 = report
x = ((b&0x0f)<<8) | a
y = ((b&0xf0) >> 4) | (c<<4)
@@ -393,22 +395,71 @@ if __name__ == '__main__':
parser.add_argument('baudrate')
parser.add_argument('-w', '--width', type=int, default=16, help='Number of bytes to display in one line')
parser.add_argument('-d', '--debug', action='store_true')
+ parser.add_argument('-r', '--random-key', action='store_true', help='Use random key instead of persisted key')
args = parser.parse_args()
+ if args.random_key:
+ host_key_private = NoiseEngine.generate_private_key_x25519()
+
+ else:
+ XDG_CONFIG_HOME = os.environ.get('XDG_CONFIG_HOME') or os.path.join(os.path.expandvars('$HOME'), '.config', 'secure_hid')
+ if not os.path.isdir(XDG_CONFIG_HOME):
+ os.mkdir(XDG_CONFIG_HOME)
+
+ private_key_file = os.path.join(XDG_CONFIG_HOME, 'host_key.pem')
+ if not os.path.isfile(private_key_file):
+ with open(private_key_file, 'w') as f:
+ f.write(binascii.hexlify(hexnoise.NoiseEngine.generate_private_key_x25519()).decode())
+
+ with open(private_key_file) as f:
+ host_key_private = binascii.unhexlify(f.read())
+
ser = serial.Serial(args.serial, args.baudrate)
packetizer = Packetizer(ser, debug=args.debug, width=args.width)
- temp_priv_key = NoiseEngine.generate_private_key_x25519()
- noise = NoiseEngine(temp_priv_key, packetizer, debug=args.debug)
+ noise = NoiseEngine(host_key_private, packetizer, debug=args.debug)
noise.perform_handshake()
- print('Handshake channel binding incantation:')
- print(noise.channel_binding_incantation())
+ if noise.connected and not noise.paired:
+ print('Handshake channel binding incantation:')
+ channel_binding_incantation = noise.channel_binding_incantation()
+ print(channel_binding_incantation)
+
+ def term_match(user_input, template):
+ out = ''
+ words_u = user_input.split(' ')
+ words_t = [ w for w in template.split(' ') if w != 'and' ]
+
+ for u_word in words_u:
+ if 'and'.startswith(u_word) or not u_word:
+ out += ' ' + u_word
+ continue
+
+ if not words_t:
+ out += '\033[91m'
+ continue
+
+ t_word, *words_t = words_t
+ if not t_word.startswith(u_word.strip(',')):
+ out += ' \033[91m' + u_word
+
+ else:
+ out += ' ' + u_word
+
+ return '\033[92m' + out[1:] + '\033[0m'
+
+ for user_input in noise.pairing_messages():
+ if not args.debug:
+ print('\033[2K\r', end='')
+ matched = term_match(user_input, channel_binding_incantation)
+ print('Pairing input:', matched, end='' if not args.debug else '\n', flush=True)
+ print()
+ print('Pairing success')
+
+ elif noise.connected and noise.paired:
+ print('Successfully re-connected')
- for user_input in noise.pairing_messages():
- if not args.debug:
- print('\033[2K\r', end='')
- print('Pairing input:', user_input, end='' if not args.debug else '\n', flush=True)
- print()
- print('Pairing success')
+ else:
+ print('Could not connect')
+ sys.exit(1)
noise.uinput_passthrough()
diff --git a/fw/src/demo.c b/fw/src/demo.c
index 69f8e8e..5ceecec 100644
--- a/fw/src/demo.c
+++ b/fw/src/demo.c
@@ -191,9 +191,12 @@ static void gpio_setup(void)
/* Mode button */
gpio_mode_setup(GPIOE, GPIO_MODE_INPUT, GPIO_PUPD_PULLUP, GPIO15);
+ /* Test button */
+ gpio_mode_setup(GPIOB, GPIO_MODE_INPUT, GPIO_PUPD_PULLUP, GPIO10);
+
/* Speaker */
- gpio_mode_setup(GPIOB, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, GPIO10);
- gpio_set(GPIOB, GPIO10);
+ //gpio_mode_setup(GPIOB, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, GPIO10);
+ //gpio_set(GPIOB, GPIO10);
/* USB OTG FS phy outputs */
gpio_mode_setup(GPIOA, GPIO_MODE_AF, GPIO_PUPD_NONE, GPIO11 | GPIO12);
@@ -222,7 +225,7 @@ void pairing_input(uint8_t modbyte, uint8_t keycode);
void pairing_parse_report(struct hid_report *buf, uint8_t len);
/* Minimum number of bytes of handshake hash to confirm during pairing */
-#define MIN_PAIRING_SEQUENCE_LENGTH 4
+#define MIN_PAIRING_SEQUENCE_LENGTH 1
int pairing_check(struct NoiseState *st, const char *buf) {
//LOG_PRINTF("Checking pairing\n");
@@ -439,6 +442,12 @@ struct dma_usart_file debug_out_s = {
struct dma_usart_file *debug_out = &debug_out_s;
/* FIXME start unsafe debug code */
+bool debug_emulate_pairing_input(char c);
+bool debug_fill_report_from_ascii(char c, struct hid_report *out);
+bool debug_send_encrypted_emulated_report(char c);
+bool debug_enqueue_emulated_input(char c);
+
+/* Feed keyboard input from debug UART into keyboard subsystem */
void usart1_isr(void) {
if (USART1_SR & USART_SR_ORE) { /* Overrun handling */
LOG_PRINTF("USART1 data register overrun\n");
@@ -448,30 +457,126 @@ void usart1_isr(void) {
}
uint8_t data = USART1_DR; /* This automatically acknowledges the IRQ */
+
+ LOG_PRINTF(" %02x ", data);
+ if (data == '\r')
+ LOG_PRINTF("\n");
+
+ if (noise_state.handshake_state == HANDSHAKE_DONE_UNKNOWN_HOST) {
+ if (!debug_emulate_pairing_input(data)) {
+ LOG_PRINTF("Error emulating pairing input\n");
+ }
+
+ } else {
+ if (!debug_enqueue_emulated_input(data)) {
+ LOG_PRINTF("Error enqueueing emulated keystroke\n");
+ }
+ }
+}
+
+size_t debug_keystroke_queue_wptr = 0;
+size_t debug_keystroke_queue_rptr = 0;
+#define ARRAY_LENGTH(x) (sizeof(x) / sizeof((x)[0]))
+char debug_keystroke_queue[64];
+
+bool debug_enqueue_emulated_input(char c) {
+ size_t next_wptr = (debug_keystroke_queue_wptr + 1) % ARRAY_LENGTH(debug_keystroke_queue);
+
+ if (next_wptr == debug_keystroke_queue_rptr)
+ return false; /* overflow */
+
+ debug_keystroke_queue[debug_keystroke_queue_wptr] = c;
+ debug_keystroke_queue_wptr = next_wptr;
+ return true;
+}
+
+int debug_dequeue_emulated_input() {
+ if (debug_keystroke_queue_rptr == debug_keystroke_queue_wptr) {
+ return -1; /* queue empty */
+ }
+
+ int rc = debug_keystroke_queue[debug_keystroke_queue_rptr];
+ debug_keystroke_queue_rptr = (debug_keystroke_queue_rptr + 1) % ARRAY_LENGTH(debug_keystroke_queue);
+ return (unsigned char)rc; /* cast into range 0-255 */
+}
+
+/* Lookup ASCII char and fill in corresponding HID keycode in HID report.
+ *
+ * Returns true if char was found in keycode mapping.
+ */
+bool debug_fill_report_from_ascii(char c, struct hid_report *out) {
+ memset(out, 0, sizeof(out));
+
for (size_t i=0; keycode_mapping[i].kc != KEY_NONE; i++) {
- struct hid_report report = {0};
- if (keycode_mapping[i].ch[0] == data)
- report.modifiers = 0;
- else if (keycode_mapping[i].ch[1] == data)
- report.modifiers = MOD_LSHIFT;
+ if (keycode_mapping[i].ch[0] == c)
+ out->modifiers = 0;
+ else if (keycode_mapping[i].ch[1] == c)
+ out->modifiers = MOD_LSHIFT;
else continue;
- report.keycodes[0] = keycode_mapping[i].kc;
- pairing_parse_report(&report, 8);
- break;
+ out->keycodes[0] = keycode_mapping[i].kc;
+ return true;
}
- LOG_PRINTF(" %02x ", data);
- if (data == 0x7f) {
- struct hid_report report = {.modifiers=0, .keycodes={KEY_BACKSPACE, 0}};
- pairing_parse_report(&report, 8);
- } else if (data == '\r') {
- struct hid_report report = {.modifiers=0, .keycodes={KEY_ENTER, 0}};
- pairing_parse_report(&report, 8);
- LOG_PRINTF("\n");
+
+ if (c == 0x7f) {
+ out->modifiers = 0;
+ out->keycodes[0] = KEY_BACKSPACE;
+ return true;
+
+ } else if (c == '\r') {
+ out->modifiers = 0;
+ out->keycodes[0] = KEY_ENTER;
+ return true;
+ }
+
+ return false; /* not found */
+}
+
+/* Returns true on success */
+bool debug_emulate_pairing_input(char c) {
+ struct hid_report report;
+ if (!debug_fill_report_from_ascii(c, &report)) {
+ return false;
}
- struct hid_report report = {0};
+ /* Emulate key press input */
+ pairing_parse_report(&report, 8);
+
+ /* key release */
+ memset(&report, 0, sizeof(report));
pairing_parse_report(&report, 8);
+
+ return true;
+}
+
+/* Returns true on success */
+bool debug_send_encrypted_emulated_report(char c) {
+ struct hid_report_packet pkt = {
+ .type = REPORT_KEYBOARD,
+ .report = {
+ .len = 8,
+ .report = {0}
+ }
+ };
+
+ /* key press */
+ if (!debug_fill_report_from_ascii(c, &pkt.report.report))
+ return false;
+
+ if (send_encrypted_message(&noise_state, (uint8_t *)&pkt, sizeof(pkt))) {
+ LOG_PRINTF("Error sending emulated HID report packet\n");
+ return false;
+ }
+
+ /* key release */
+ memset(&pkt.report.report, 0, sizeof(struct hid_report));
+
+ if (send_encrypted_message(&noise_state, (uint8_t *)&pkt, sizeof(pkt))) {
+ LOG_PRINTF("Error sending emulated HID report packet\n");
+ return false;
+ }
+
+ return true;
}
/* end unsafe debug code */
@@ -605,25 +710,64 @@ int main(void)
int spk_inc = 1;
gpio_clear(GPIOA, GPIO6);
gpio_clear(GPIOA, GPIO7);
- gpio_clear(GPIOB, GPIO10);
+ //gpio_clear(GPIOB, GPIO10);
- int last_btn_st = 0;
- int debounce_ctr = 0;
+ int last_btn_st_mode = 0;
+ int last_btn_st_test = 0;
+ int debounce_ctr_mode = 0;
+ int debounce_ctr_test = 0;
int mode_debug = 0;
#define DEBOUNCE_IVL 1000
gpio_set(GPIOE, GPIO13);
gpio_clear(GPIOE, GPIO14);
+ int dbg_keyem_ctr = 0;
+#define DBG_KEYEM_IVL 100
+
while (23) {
delay(1);
- if (debounce_ctr > 0) {
- debounce_ctr -= 1;
+ if (dbg_keyem_ctr <= 0) {
+ int rc = debug_dequeue_emulated_input();
+ if (rc >= 0) {
+ dbg_keyem_ctr = DBG_KEYEM_IVL;
+ if (!debug_send_encrypted_emulated_report((char) rc)) {
+ LOG_PRINTF("Error sending emulated keyboard input\n");
+ } else {
+ LOG_PRINTF("Sent emulated keypress %02x\n", (unsigned char)rc);
+ }
+ }
+ } else {
+ dbg_keyem_ctr -= 1;
+ }
+
+ if (debounce_ctr_test > 0) {
+ debounce_ctr_test -= 1;
+ } else {
+ if (!gpio_get(GPIOB, GPIO10)) {
+ if (last_btn_st_test) {
+ debounce_ctr_test = DEBOUNCE_IVL;
+
+ const char *s = "unicorn\r";
+ for (size_t i=0; i<8; i++) {
+ if (!debug_enqueue_emulated_input(s[i])) {
+ LOG_PRINTF("Error enqueuing emulated test input\n");
+ }
+ }
+ }
+ last_btn_st_test = 0;
+ } else {
+ last_btn_st_test = 1;
+ }
+ }
+
+ if (debounce_ctr_mode > 0) {
+ debounce_ctr_mode -= 1;
} else {
- if (gpio_get(GPIOE, GPIO15)) {
- if (!last_btn_st) {
- debounce_ctr = DEBOUNCE_IVL;
+ if (!gpio_get(GPIOE, GPIO15)) {
+ if (last_btn_st_mode) {
+ debounce_ctr_mode = DEBOUNCE_IVL;
mode_debug = !mode_debug;
@@ -637,10 +781,10 @@ int main(void)
}
}
- last_btn_st = 1;
+ last_btn_st_mode = 0;
} else {
- last_btn_st = 0;
+ last_btn_st_mode = 1;
}
}