block some USB command in hobble mode

shared/exceptions.py

@@ -19,10 +19,10 @@ class CCBusyError(RuntimeError):
 # HSM is blocking your action
 class HSMDenied(RuntimeError):
     pass
-
 class HSMCMDDisabled(RuntimeError):
     pass
 
+
 # PSBT / transaction related
 class FatalPSBTIssue(RuntimeError):
     pass
@@ -51,7 +51,7 @@ class QRDecodeExplained(ValueError):
 class UnknownAddressExplained(ValueError):
     pass
 
-# We're not going to co-sign using CCC feature
+# We're not going to co-sign using spending policy features
 class SpendPolicyViolation(RuntimeError):
     pass
 

shared/usb.py

@@ -11,7 +11,8 @@ from ustruct import pack, unpack_from
 from ckcc import watchpoint, is_simulator
 from utils import problem_file_line, call_later_ms
 from version import supports_hsm, is_devmode, MAX_TXN_LEN, MAX_UPLOAD_LEN
-from exceptions import FramingError, CCBusyError, HSMDenied, HSMCMDDisabled
+from exceptions import FramingError, CCBusyError, HSMDenied, HSMCMDDisabled, SpendPolicyViolation
+from pincodes import pa
 
 # Unofficial, unpermissioned... numbers
 COINKITE_VID = 0xd13e
@@ -68,6 +69,21 @@ HSM_DISABLE_CMDS = frozenset({
     "hsms",
 })
 
+# spending policy active: blacklist some commands
+# - 'pass' may be allowed if 'okeys' is enabled
+HOBBLED_CMDS = frozenset({
+    'enrl',             # no new multisigs during policy enforcement
+    'back',             # no backups
+    'bagi', 'dfu_',     # just in case
+
+    "user",             # same as HSM_DISABLE_CMDS
+    "rmur",
+    "nwur",
+    "gslr",
+    "hsts",
+    "hsms",
+})
+
 # singleton instance of USBHandler()
 handler = None
 
@@ -217,6 +233,8 @@ class USBHandler:
                 except CCBusyError:
                     # auth UX is doing something else
                     resp = b'busy'
+                except SpendPolicyViolation:
+                    resp = b'err_Spending policy in effect'
                 except HSMDenied:
                     resp = b'err_Not allowed in HSM mode'
                 except HSMCMDDisabled:
@@ -345,7 +363,7 @@ class USBHandler:
         except:
             raise FramingError('decode')
 
-        if cmd[0].isupper() and is_devmode:
+        if is_devmode and cmd[0].isupper():
             # special hacky commands to support testing w/ the simulator
             try:
                 from usb_test_commands import do_usb_command
@@ -358,7 +376,18 @@ class USBHandler:
             if cmd not in HSM_WHITELIST:
                 raise HSMDenied
 
-        if not settings.get('hsmcmd', False):
+        if pa.hobbled_mode:
+            # block some commands when we are hobbled.
+            if cmd in HOBBLED_CMDS:
+                raise SpendPolicyViolation
+
+            if cmd in {'pwok', 'pass'}:
+                from ccc import sssp_spending_policy
+                if not sssp_spending_policy('okeys'):
+                    raise SpendPolicyViolation
+            
+        elif not settings.get('hsmcmd', False):
+            # block these HSM-related command if not using feature
             if cmd in HSM_DISABLE_CMDS:
                 raise HSMCMDDisabled
 
@@ -741,7 +770,6 @@ class USBHandler:
         from glob import dis, hsm_active
         from utils import check_firmware_hdr
         from sigheader import FW_HEADER_OFFSET, FW_HEADER_SIZE, FW_HEADER_MAGIC
-        from pincodes import pa
 
         # maintain a running SHA256 over what's received
         if offset == 0:
@@ -754,8 +782,8 @@ class USBHandler:
         assert offset % 256 == 0, 'alignment'
         assert offset+len(data) <= total_size <= MAX_UPLOAD_LEN, 'long'
 
-        if hsm_active:
-            # additional restrictions in HSM mode
+        if hsm_active or pa.hobbled_mode:
+            # additional restriction in HSM mode or hobbled: must be PSBT
             assert offset+len(data) <= total_size <= MAX_TXN_LEN, 'psbt'
             if offset == 0:
                 assert data[0:5] == b'psbt\xff', 'psbt'
@@ -834,7 +862,6 @@ class USBHandler:
     def handle_bag_number(self, bag_num):
         import version, callgate
         from glob import dis, settings
-        from pincodes import pa
 
         if bag_num and version.is_factory_mode and not version.has_qr:
             # check state first

testing/test_hobble.py

@@ -12,26 +12,6 @@ from test_ephemeral import SEEDVAULT_TEST_DATA, WORDLISTS
 from test_ephemeral import confirm_tmp_seed, verify_ephemeral_secret_ui 
 from test_ux import word_menu_entry
 
-'''
-TODO -- When hobbled...
-
-- login sequence
-    1) system has lgto value: should get bypass pin, main pin, delay, then main pin again
-    2) using a trick PIN with delay, after bypass pin should delay
-    3) bypass pin + duress wallet PIN => should work => but not a useful trick combo
-   
-- word entry during login
-    - q1 vs mk4 style
-    - wrong values given, etc
-
-- verify whitelist of QR types is correct when in hobbled mode
-    - no private key material, no teleport starting, unless "okeys" is set
-
-- TODO: update menu tree w/ hobble mode view
-
-- verify that PSBT can be "signed" when SP enabled and delta-mode pin is active. seed not wiped.
-
-'''
 
 # NOTE: these are unit tests of the effects of hobble mode, not how it is enabled/disabled:
 #
@@ -386,6 +366,46 @@ def test_h_tempseeds(mode, set_hobble, pick_menu_item, cap_menu, settings_set, i
     pick_menu_item("Restore Master")
     press_select()
 
-# TODO: test usb commands are blocked
 
+@pytest.mark.parametrize('en_okeys', [ True, False])
+def test_h_usbcmds(en_okeys, set_hobble, dev):
+    # test various usb commands are blocked during hobble
+
+    from ckcc_protocol.protocol import CCProtoError
+
+    set_hobble(True, {'okeys'} if en_okeys else {})
+
+    block_list = [
+        'back', 'enrl', 'bagi', 'hsms', 'user', 'nwur', 'rmur', 
+    ]
+
+    if not en_okeys:
+        block_list.insert(0, 'pass')
+
+    for cmd in block_list:
+        with pytest.raises(CCProtoError) as ee:
+            got = dev.send_recv(cmd)
+        assert 'Spending policy in effect' in str(ee)
+
+# TODO: verify that PSBT can be "signed" when SP enabled and delta-mode pin is active. seed not wiped.
+
+
+# TODO verify whitelist of QR types is correct when in hobbled mode
+# - no private key material, no teleport starting, unless "okeys" is set
+
+
+# TODO Special Login Sequence
+
+'''
+- login sequence
+    1) system has lgto value: should get bypass pin, main pin, delay, then main pin again
+    2) using a trick PIN with delay, after bypass pin should delay
+    3) bypass pin + duress wallet PIN => should work => but not a useful trick combo
+   
+- word entry during login
+    - q1 vs mk4 style
+    - wrong values given, etc
+
+'''
+    
 # EOF