feat(legacy): Implement UnlockPath.

legacy/firmware/fsm.c

@@ -71,6 +71,8 @@ static uint8_t msg_resp[MSG_OUT_DECODED_SIZE] __attribute__((aligned));
 // Authorization message type triggered by DoPreauthorized.
 static MessageType authorization_type = 0;
 
+static uint32_t unlock_path = 0;
+
 #define RESP_INIT(TYPE)                                                    \
   TYPE *resp = (TYPE *)(void *)msg_resp;                                   \
   _Static_assert(sizeof(msg_resp) >= sizeof(TYPE), #TYPE " is too large"); \
@@ -407,6 +409,7 @@ void fsm_abortWorkflows(void) {
   recovery_abort();
   signing_abort();
   authorization_type = 0;
+  unlock_path = 0;
 #if !BITCOIN_ONLY
   ethereum_signing_abort();
   stellar_signingAbort();

legacy/firmware/fsm.h

@@ -88,6 +88,7 @@ void fsm_msgGetOwnershipProof(const GetOwnershipProof *msg);
 void fsm_msgAuthorizeCoinJoin(const AuthorizeCoinJoin *msg);
 void fsm_msgCancelAuthorization(const CancelAuthorization *msg);
 void fsm_msgDoPreauthorized(const DoPreauthorized *msg);
+void fsm_msgUnlockPath(const UnlockPath *msg);
 
 // crypto
 void fsm_msgCipherKeyValue(const CipherKeyValue *msg);

legacy/firmware/fsm_msg_coin.h

@@ -35,13 +35,15 @@ void fsm_msgGetPublicKey(const GetPublicKey *msg) {
     curve = msg->ecdsa_curve_name;
   }
 
-  // Do not allow access to SLIP25 paths.
+  // UnlockPath is required to access SLIP25 paths.
-  if (msg->address_n_count > 0 && msg->address_n[0] == PATH_SLIP25_PURPOSE &&
+  if (msg->address_n_count > 0 && msg->address_n[0] == PATH_SLIP25_PURPOSE) {
-      config_getSafetyCheckLevel() == SafetyCheckLevel_Strict) {
+    // Verify that the desired path lies in the unlocked subtree.
+    if (msg->address_n[0] != unlock_path) {
       fsm_sendFailure(FailureType_Failure_DataError, _("Forbidden key path"));
       layoutHome();
       return;
     }
+  }
 
   // derive m/0' to obtain root_fingerprint
   uint32_t root_fingerprint;
@@ -720,3 +722,65 @@ void fsm_msgDoPreauthorized(const DoPreauthorized *msg) {
   msg_write(MessageType_MessageType_PreauthorizedRequest, resp);
   layoutHome();
 }
+
+void fsm_msgUnlockPath(const UnlockPath *msg) {
+  (void)msg;
+
+  RESP_INIT(UnlockedPathRequest);
+
+  CHECK_INITIALIZED
+
+  CHECK_PIN
+
+  const char *KEYCHAIN_MAC_KEY_PATH[] = {"TREZOR", "Keychain MAC key"};
+
+  // UnlockPath is relevant only for SLIP-25 paths.
+  // Note: Currently we only allow unlocking the entire SLIP-25 purpose subtree
+  // instead of per-coin or per-account unlocking in order to avoid UI
+  // complexity.
+  if (msg->address_n_count != 1 || msg->address_n[0] != PATH_SLIP25_PURPOSE) {
+    fsm_sendFailure(FailureType_Failure_DataError, _("Invalid path"));
+    layoutHome();
+    return;
+  }
+
+  uint8_t keychain_mac_key[32] = {0};
+  if (!fsm_getSlip21Key(KEYCHAIN_MAC_KEY_PATH, 2, keychain_mac_key)) {
+    return;
+  }
+
+  HMAC_SHA256_CTX hctx;
+  hmac_sha256_Init(&hctx, keychain_mac_key, sizeof(keychain_mac_key));
+  for (size_t i = 0; i < msg->address_n_count; ++i) {
+    hmac_sha256_Update(&hctx, (const uint8_t *)&msg->address_n[i],
+                       sizeof(uint32_t));
+  }
+  hmac_sha256_Final(&hctx, resp->mac.bytes);
+
+  // Require confirmation to access SLIP25 paths unless already authorized.
+  if (msg->has_mac) {
+    uint8_t diff = 0;
+    for (size_t i = 0; i < SHA256_DIGEST_LENGTH; i++) {
+      diff |= (msg->mac.bytes[i] - resp->mac.bytes[i]);
+    }
+
+    if (msg->mac.size != SHA256_DIGEST_LENGTH || diff != 0) {
+      fsm_sendFailure(FailureType_Failure_DataError, _("Invalid MAC"));
+      layoutHome();
+      return;
+    }
+  } else {
+    layoutConfirmCoinjoinAccess();
+    if (!protectButton(ButtonRequestType_ButtonRequest_Other, false)) {
+      fsm_sendFailure(FailureType_Failure_ActionCancelled, NULL);
+      layoutHome();
+      return;
+    }
+  }
+
+  unlock_path = msg->address_n[0];
+  resp->mac.size = SHA256_DIGEST_LENGTH;
+  resp->has_mac = true;
+  msg_write(MessageType_MessageType_UnlockedPathRequest, resp);
+  layoutHome();
+}

legacy/firmware/layout2.c

@@ -721,6 +721,12 @@ void layoutAuthorizeCoinJoin(const CoinInfo *coin, uint64_t max_rounds,
                     NULL, NULL);
 }
 
+void layoutConfirmCoinjoinAccess(void) {
+  layoutDialogSwipe(&bmp_icon_question, _("Cancel"), _("Confirm"), NULL,
+                    _("Do you want to allow"), _("access to your"),
+                    _("coinjoin account?"), NULL, NULL, NULL);
+}
+
 void layoutVerifyAddress(const CoinInfo *coin, const char *address) {
   render_address_dialog(coin, address, _("Confirm address?"),
                         _("Message signed by:"), 0);

legacy/firmware/layout2.h

@@ -76,6 +76,7 @@ void layoutConfirmNondefaultLockTime(uint32_t lock_time,
                                      bool lock_time_disabled);
 void layoutAuthorizeCoinJoin(const CoinInfo *coin, uint64_t max_rounds,
                              uint32_t max_fee_per_kvbyte);
+void layoutConfirmCoinjoinAccess(void);
 void layoutVerifyAddress(const CoinInfo *coin, const char *address);
 void layoutCipherKeyValue(bool encrypt, const char *key);
 void layoutEncryptMessage(const uint8_t *msg, uint32_t len, bool signing);

legacy/firmware/protob/Makefile

@@ -4,7 +4,7 @@ endif
 
 SKIPPED_MESSAGES := Binance Cardano DebugMonero Eos Monero Ontology Ripple SdProtect Tezos WebAuthn \
 	DebugLinkRecordScreen DebugLinkEraseSdCard DebugLinkWatchLayout \
-	DebugLinkLayout GetNonce SetBusy UnlockPath \
+	DebugLinkLayout GetNonce SetBusy \
 	TxAckInput TxAckOutput TxAckPrev TxAckPaymentRequest \
 	EthereumSignTypedData EthereumTypedDataStructRequest EthereumTypedDataStructAck \
 	EthereumTypedDataValueRequest EthereumTypedDataValueAck

tests/device_tests/bitcoin/test_authorize_coinjoin.py

@@ -43,9 +43,8 @@ PIN = "1234"
 ROUND_ID_LEN = 32
 SLIP25_PATH = parse_path("m/10025h")
 
-pytestmark = pytest.mark.skip_t1
-
 
+@pytest.mark.skip_t1
 @pytest.mark.setup_client(pin=PIN)
 def test_sign_tx(client: Client):
     # NOTE: FAKE input tx
@@ -252,6 +251,7 @@ def test_sign_tx(client: Client):
         )
 
 
+@pytest.mark.skip_t1
 def test_sign_tx_large(client: Client):
     # NOTE: FAKE input tx
 
@@ -399,6 +399,7 @@ def test_sign_tx_large(client: Client):
     assert delay <= max_expected_delay
 
 
+@pytest.mark.skip_t1
 def test_sign_tx_spend(client: Client):
     # NOTE: FAKE input tx
 
@@ -473,6 +474,7 @@ def test_sign_tx_spend(client: Client):
     )
 
 
+@pytest.mark.skip_t1
 def test_wrong_coordinator(client: Client):
     # Ensure that a preauthorized GetOwnershipProof fails if the commitment_data doesn't match the coordinator.
 
@@ -499,6 +501,7 @@ def test_wrong_coordinator(client: Client):
         )
 
 
+@pytest.mark.skip_t1
 def test_wrong_account_type(client: Client):
     params = {
         "client": client,
@@ -525,6 +528,7 @@ def test_wrong_account_type(client: Client):
     )
 
 
+@pytest.mark.skip_t1
 def test_cancel_authorization(client: Client):
     # Ensure that a preauthorized GetOwnershipProof fails if the commitment_data doesn't match the coordinator.
 
@@ -608,6 +612,7 @@ def test_get_public_key(client: Client):
         assert resp.xpub == EXPECTED_XPUB
 
 
+@pytest.mark.skip_t1
 def test_get_address(client: Client):
     # Ensure that the SLIP-0025 external chain is inaccessible without user confirmation.
     with pytest.raises(TrezorFailure, match="Forbidden key path"):
@@ -689,6 +694,7 @@ def test_get_address(client: Client):
         )
 
 
+@pytest.mark.skip_t1
 def test_multisession_authorization(client: Client):
     # Authorize CoinJoin with www.example1.com in session 1.
     btc.authorize_coinjoin(

tests/ui_tests/fixtures.json

@@ -1,6 +1,7 @@
 {
 "T1": {
 "device_tests": {
+"T1_bitcoin-test_authorize_coinjoin.py::test_get_public_key": "9b3c916759b79048a4ab3e3fe8ce0ea0cf8d4ae6cfb66a5d712f21edfdb01782",
 "T1_bitcoin-test_bcash.py::test_attack_change_input": "6111e313995d38c3970c92e48047fe4088c83666c64c6c859f69a232ad62829b",
 "T1_bitcoin-test_bcash.py::test_send_bch_change": "6111e313995d38c3970c92e48047fe4088c83666c64c6c859f69a232ad62829b",
 "T1_bitcoin-test_bcash.py::test_send_bch_multisig_change": "0962a2e630e06b6d20282cc241be40f41bc1648d0a26247c7c008f32a197d0cb",