Merge pull request #94 from LedgerHQ/slip21-stableprotobuf

Add optional paths_slip21 field to manifest, and (de)serialization (stable_protobuf_version branch)

Author: bigspider

.pre-commit-config.yaml

@@ -33,7 +33,7 @@ repos:
           - types-toml
 
   - repo: https://github.com/PyCQA/bandit
-    rev: 1.7.4
+    rev: 1.8.6
     hooks:
       - id: bandit
         args:

CHANGELOG.md

@@ -5,13 +5,18 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.5.4] - 2025-11-25
+
+### Added
+
+- Support for `path_slip21` in the manifest.
+
 ## [0.5.3] - 2025-08-27
 
 ### Added
 
 - Support for Apex P and Apex M devices
 
-
 ## [0.5.2] - 2024-12-09
 
 ### Fixed

ledgerwallet/manifest.py

@@ -260,6 +260,7 @@ def assert_compatible_device(self, device_id: int):
     def serialize_derivation_path(self, value):
         derivation_paths: Dict[str, Optional[int]] = {
             "paths": None,
+            "paths_slip21": None,
             "curve": None,
         }
         for derivation_entry in value:
@@ -272,9 +273,13 @@ def serialize_derivation_path(self, value):
                         curves |= params.CURVE_PRIME256R1
                     elif curve == "ed25519":
                         curves |= params.CURVE_ED25519
+                    elif curve == "slip21":
+                        curves |= params.CURVE_SLIP21
                     elif curve == "bls12381g1":
                         curves |= params.CURVE_BLS12381G1
                     derivation_paths["curve"] = curves
             elif derivation_entry == "paths":
                 derivation_paths["paths"] = value["paths"]
+            elif derivation_entry == "paths_slip21":
+                derivation_paths["paths_slip21"] = value["paths_slip21"]
         return derivation_paths

ledgerwallet/params.py

@@ -66,6 +66,69 @@ def _emitprimitivetype(self, ksy, bitwise):
         return "asn1_der_len"
 
 
+# A byte with value < 0x80
+@singleton
+class LowByte(Construct):
+    def _parse(self, stream, context, path):
+        b = byte2int(stream_read(stream, 1, path))
+        if b >= 0x80:
+            raise IntegerError("BIP32 path length prefix must be < 0x80")
+        return b
+
+    def _build(self, obj, stream, context, path):
+        if not isinstance(obj, int):
+            raise IntegerError("length must be an integer")
+        if not (0 <= obj < 0x80):
+            raise IntegerError("BIP32 path length must be < 0x80")
+        stream_write(stream, int2byte(obj), 1, path)
+        return obj
+
+
+# A byte with value >= 0x80, decoded as (byte - 0x80)
+# This is used to encode the length of SLIP-21 paths
+@singleton
+class Slip21LenByte(Construct):
+    def _parse(self, stream, context, path):
+        b = byte2int(stream_read(stream, 1, path))
+        if b < 0x80:
+            raise IntegerError("SLIP-21 length prefix must be >= 0x80")
+        return b - 0x80
+
+    def _build(self, obj, stream, context, path):
+        if not isinstance(obj, int):
+            raise IntegerError("length must be an integer")
+        if not (0 <= obj <= 0x7F):
+            raise IntegerError("SLIP-21 decoded length must be in [0, 0x7F]")
+        stream_write(stream, int2byte(0x80 + obj), 1, path)
+        return obj
+
+
+class Slip21PathAdapter(Adapter):
+    def _decode(self, obj, context, path):
+        # obj is now a list/array of bytes (ints 0–255)
+        if not obj:
+            return str()
+
+        # First byte must be zero prefix
+        if obj[0] != 0x00:
+            raise IntegerError("invalid SLIP-21 path prefix")
+
+        # Remaining bytes are UTF-8 chars
+        return bytes(obj[1:]).decode("utf-8")
+
+    def _encode(self, obj, context, path):
+        if not isinstance(obj, str):
+            raise IntegerError("SLIP-21 path must be a string")
+
+        payload = b"\0" + obj.encode("utf-8")
+        length = len(payload)
+        if length > 0x7F:
+            raise IntegerError("SLIP-21 path too long")
+
+        # Return list of ints so PrefixedArray(Slip21LenByte, Byte) can handle it
+        return list(payload)
+
+
 # noinspection PyAbstractClass
 class Bip32PathAdapter(Adapter):
     def _decode(self, obj, context, path):
@@ -90,7 +153,8 @@ def _encode(self, obj, context, path):
         return out
 
 
-Bip32Path = Bip32PathAdapter(PrefixedArray(Byte, Int32ub))
+Bip32Path = Bip32PathAdapter(PrefixedArray(LowByte, Int32ub))
+Slip21Path = Slip21PathAdapter(PrefixedArray(Slip21LenByte, Byte))
 
 PrefixedString = PascalString(Asn1Length, "utf8")
 
@@ -101,18 +165,27 @@ def _encode(self, obj, context, path):
 CURVE_SECP256K1 = 1
 CURVE_PRIME256R1 = 2
 CURVE_ED25519 = 4
+CURVE_SLIP21 = (
+    8  # not really a curve, but used to indicate the presence of SLIP-21 paths
+)
 CURVE_BLS12381G1 = 16
 
 Curve = FlagsEnum(
     Byte,
     secp256k1=CURVE_SECP256K1,
     prime256r1=CURVE_PRIME256R1,
     ed25519=CURVE_ED25519,
+    slip21=CURVE_SLIP21,
     bls12381g1=CURVE_BLS12381G1,
 )
 
 DerivationPath = Prefixed(
-    Asn1Length, Struct(curve=Curve, paths=Optional(GreedyRange(Bip32Path)))
+    Asn1Length,
+    Struct(
+        curve=Curve,
+        paths=Optional(GreedyRange(Bip32Path)),
+        paths_slip21=Optional(GreedyRange(Slip21Path)),
+    ),
 )
 
 Dependency = Prefixed(
@@ -163,8 +236,9 @@ def main():
             {
                 "type_": "BOLOS_TAG_DERIVEPATH",
                 "value": {
-                    "curve": Curve.prime256r1 | Curve.ed25519,
+                    "curve": Curve.prime256r1 | Curve.ed25519 | Curve.slip21,
                     "paths": ["44'/535348'", "13'", "17'"],
+                    "paths_slip21": ["MYPATH"],
                 },
             },
         ]
@@ -175,8 +249,9 @@ def main():
         b"\x02\x05\x30\x2E\x30\x2E\x34\x03\x29\x01\x00\x00\x00\x00\xFF"
         b"\xFF\xFF\x00\x00\x18\xFC\x24\x02\x24\x0A\x24\x1A\x7E\x32\x66"
         b"\x62\x6E\x62\x7E\x32\x00\x1A\x40\x0A\x5F\x02\x5F\x02\x40\x02"
-        b"\x40\xFE\x7F\x00\x00\x04\x14\x06\x02\x80\x00\x00\x2C\x80\x08"
-        b"\x2B\x34\x01\x80\x00\x00\x0D\x01\x80\x00\x00\x11"
+        b"\x40\xFE\x7F\x00\x00\x04\x1c\x0E\x02\x80\x00\x00\x2C\x80\x08"
+        b"\x2B\x34\x01\x80\x00\x00\x0D\x01\x80\x00\x00\x11\x87\x00\x4D"
+        b"\x59\x50\x41\x54\x48"
     )
     assert params1 == params2