src/apps/common: rework PassphraseState behaviour

src/apps/common/cache.py

@@ -4,28 +4,26 @@ from apps.common import storage
 memory = {}
 _seed = None
 _passphrase = None
-_state_salt = None
 
 
-def get_state(salt: bytes=None, passphrase: str=None):
-    global _passphrase, _state_salt
-    if salt is None:
-        # generate a random salt if not provided and not already cached
-        if _state_salt is None:
-            _state_salt = random.bytes(32)
+def get_state(state: bytes=None, passphrase: str=None):
+
+    if state is None:
+        salt = random.bytes(32)  # generate a random salt if no state provided
     else:
-        # otherwise copy provided salt to cached salt
-        _state_salt = salt
+        salt = state[:32]        # use salt from provided state
+
+    if passphrase is None:
+        global _passphrase
+        if _passphrase is None:
+            return None
+        passphrase = _passphrase    # use cached passphrase
 
     # state = HMAC(passphrase, salt || device_id)
-    if passphrase is None:
-        key = _passphrase if _passphrase is not None else ''
-    else:
-        key = passphrase
-    msg = _state_salt + storage.get_device_id().encode()
-    state = hmac.new(key.encode(), msg, hashlib.sha256).digest()
+    msg = salt + storage.get_device_id().encode()
+    state = hmac.new(passphrase.encode(), msg, hashlib.sha256).digest()
 
-    return _state_salt + state
+    return salt + state
 
 
 def get_seed():
@@ -45,6 +43,4 @@ def has_passphrase():
 
 def clear():
     global _seed, _passphrase
-    global _state_salt
     _seed, _passphrase = None, None
-    _state_salt = None

src/apps/common/request_passphrase.py

@@ -3,6 +3,7 @@ from trezor.messages import ButtonRequestType, wire_types
 from trezor.messages.ButtonRequest import ButtonRequest
 from trezor.messages.FailureType import ActionCancelled, ProcessError
 from trezor.messages.PassphraseRequest import PassphraseRequest
+from trezor.messages.PassphraseStateRequest import PassphraseStateRequest
 from trezor.ui.entry_select import DEVICE, EntrySelector
 from trezor.ui.passphrase import CANCELLED, PassphraseKeyboard
 from trezor.ui.text import Text
@@ -53,15 +54,15 @@ async def request_passphrase_ack(ctx, on_device):
             raise wire.FailureError(ProcessError, 'Passphrase not provided')
         passphrase = ack.passphrase
 
-    return ack.state, passphrase
+    req = PassphraseStateRequest(state=get_state(state=ack.state, passphrase=passphrase))
+    ack = await ctx.call(req, wire_types.PassphraseStateAck, wire_types.Cancel)
+
+    return passphrase
 
 
 async def request_passphrase(ctx):
     on_device = await request_passphrase_entry(ctx) == DEVICE
-    state, passphrase = await request_passphrase_ack(ctx, on_device)
-    if state is not None:
-        if state != get_state(salt=state[:32], passphrase=passphrase):
-            raise wire.FailureError(ProcessError, 'Passphrase mismatch')
+    passphrase = await request_passphrase_ack(ctx, on_device)
     return passphrase
 
 

src/apps/homescreen/__init__.py

@@ -11,7 +11,7 @@ from apps.common import storage, coins, cache
 async def respond_Features(ctx, msg):
 
     if msg.__qualname__ == 'Initialize':
-        if msg.state is None or msg.state != cache.get_state(salt=msg.state[:32]):
+        if msg.state is None or msg.state != cache.get_state(state=msg.state):
             cache.clear()
 
     f = Features()
@@ -32,7 +32,6 @@ async def respond_Features(ctx, msg):
     f.needs_backup = storage.needs_backup()
     f.flags = storage.get_flags()
     f.model = 'T'
-    f.state = cache.get_state()
 
     return f
 

src/trezor/messages/Features.py

@@ -31,7 +31,6 @@ class Features(p.MessageType):
         24: ('fw_patch', p.UVarintType, 0),
         25: ('fw_vendor', p.UnicodeType, 0),
         26: ('fw_vendor_keys', p.BytesType, 0),
-        27: ('state', p.BytesType, 0),
     }
     MESSAGE_WIRE_TYPE = 17
 
@@ -63,7 +62,6 @@ class Features(p.MessageType):
         fw_patch: int = None,
         fw_vendor: str = None,
         fw_vendor_keys: bytes = None,
-        state: bytes = None,
         **kwargs,
     ):
         self.vendor = vendor
@@ -92,5 +90,4 @@ class Features(p.MessageType):
         self.fw_patch = fw_patch
         self.fw_vendor = fw_vendor
         self.fw_vendor_keys = fw_vendor_keys
-        self.state = state
         p.MessageType.__init__(self, **kwargs)

src/trezor/messages/MessageType.py

@@ -41,6 +41,8 @@ VerifyMessage = const(39)
 MessageSignature = const(40)
 PassphraseRequest = const(41)
 PassphraseAck = const(42)
+PassphraseStateRequest = const(77)
+PassphraseStateAck = const(78)
 EstimateTxSize = const(43)
 TxSize = const(44)
 RecoveryDevice = const(45)

src/trezor/messages/PassphraseStateAck.py

@@ -0,0 +1,12 @@
+# Automatically generated by pb2py
+import protobuf as p
+
+
+class PassphraseStateAck(p.MessageType):
+    MESSAGE_WIRE_TYPE = 78
+
+    def __init__(
+        self,
+        **kwargs,
+    ):
+        p.MessageType.__init__(self, **kwargs)

src/trezor/messages/PassphraseStateRequest.py

@@ -0,0 +1,17 @@
+# Automatically generated by pb2py
+import protobuf as p
+
+
+class PassphraseStateRequest(p.MessageType):
+    FIELDS = {
+        1: ('state', p.BytesType, 0),
+    }
+    MESSAGE_WIRE_TYPE = 77
+
+    def __init__(
+        self,
+        state: bytes = None,
+        **kwargs,
+    ):
+        self.state = state
+        p.MessageType.__init__(self, **kwargs)

src/trezor/messages/wire_types.py

@@ -63,6 +63,8 @@ NEMSignTx = const(69)
 NEMSignedTx = const(70)
 PassphraseAck = const(42)
 PassphraseRequest = const(41)
+PassphraseStateAck = const(78)
+PassphraseStateRequest = const(77)
 PinMatrixAck = const(19)
 PinMatrixRequest = const(18)
 Ping = const(1)

vendor/trezor-common

@@ -1 +1 @@
-Subproject commit d85f7ac6bbcccbc83012d85fdf25635e57c5f15b
+Subproject commit 0924bd6826bb63f66010e2e511356d54ea733df3