ci: Remove bip32 and test Python 3.10-3.15

.github/workflows/pylint.yml

@@ -9,14 +9,16 @@ jobs:
   build:
     runs-on: ubuntu-latest
     strategy:
+      fail-fast: false
       matrix:
-        python-version: ["3.10", "3.11", "3.12", "3.13"]
+        python-version: ["3.10", "3.11", "3.12", "3.13", "3.14", "3.15"]
     steps:
     - uses: actions/checkout@v4
     - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v3
+      uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
       with:
         python-version: ${{ matrix.python-version }}
+        allow-prereleases: ${{ matrix.python-version == '3.15' }}
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip

.github/workflows/python-package.yml

@@ -19,14 +19,15 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["3.10", "3.11", "3.12", "3.13"]
+        python-version: ["3.10", "3.11", "3.12", "3.13", "3.14", "3.15"]
 
     steps:
     - uses: actions/checkout@v4
     - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v3
+      uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
       with:
         python-version: ${{ matrix.python-version }}
+        allow-prereleases: ${{ matrix.python-version == '3.15' }}
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip

README.md

@@ -13,17 +13,19 @@ Shamir secret sharing scheme (SSSS) interpolation helpers and helpers to build c
 - Regular checksum (13 chars) and long checksum (15 chars) support.
 - Construct codex32 strings from raw seed bytes via `from_seed`.
 - CRC-based default padding scheme for `from_seed`.
-- Default `from_seed` identifier is the bech32-encoded BIP32 fingerprint.
+- `from_seed` requires an explicit four-character identifier in its prefix.
 - Interpolate/recover shares via `interpolate_at`.
 - Parse codex32 strings and access parts via properties.
 - Mutate codex32 strings by reassigning `is_upper`, `hrp`, `k`, `ident`, `share_idx`, `data`, and `pad_val`.
 - Contains module and tests for Bech32/Bech32m and segwit addresses.
 
 ## Security
 Caution: This is reference code. Verify carefully before using with real funds.
+For wallet backups, obtain the identifier from a trusted wallet record;
+`from_seed` does not derive or verify a BIP32 fingerprint.
 
 ## Installation
-**Compatibility:** Python 3.10–3.14
+**Compatibility:** Python 3.10–3.15
 
 **Recommended:** use a virtual environment
 ### Linux / macOS
@@ -47,7 +49,7 @@ from codex32 import Codex32String
 # Create from seed bytes
 s = Codex32String.from_seed(
     bytes.fromhex('ffeeddccbbaa99887766554433221100'),
-    "ms13cashs",        # prefix string, (HRP + '1' + header)
+    "ms13cashs",        # prefix string with explicit identifier (HRP + '1' + header)
     0                   # padding value (default "CRC", otherwise integer)
 )
 print(s.s)              # codex32 string

pyproject.toml

@@ -10,7 +10,7 @@ authors = [
 ]
 description = "Python reference implementation for codex32 (BIP93) and codex32-encoded master seeds."
 readme = "README.md"
-requires-python = ">=3.10"
+requires-python = ">=3.10,<3.16"
 license = "MIT"
 license-files = ["LICENSE*"]
 maintainers = [
@@ -26,11 +26,13 @@ classifiers = [
   "Programming Language :: Python :: 3.11",
   "Programming Language :: Python :: 3.12",
   "Programming Language :: Python :: 3.13",
+  "Programming Language :: Python :: 3.14",
+  "Programming Language :: Python :: 3.15",
   "Operating System :: OS Independent",
   "Topic :: Security :: Cryptography",
   "Topic :: Software Development :: Libraries",
 ]
-dependencies = ["bip32>=5.0.0"]
+dependencies = []
 
 [project.optional-dependencies]
 dev = ["pytest", "flake8", "mypy", "black", "isort", "ruff"]

requirements.txt

@@ -1,2 +1 @@
-bip32
 pytest

src/codex32/bip93.py

@@ -27,8 +27,6 @@
 """Reference implementation for codex32/Long codex32 and codex32-encoded master seeds."""
 
 
-from bip32 import BIP32
-
 from codex32.bech32 import (
     CHARSET,
     chars_to_u5,
@@ -263,16 +261,14 @@ def interpolate_at(
 
     @classmethod
     def from_seed(
-        cls, data: bytes, prefix: str = "ms10", pad_val: int | str = "CRC"
+        cls, data: bytes, prefix: str, pad_val: int | str = "CRC"
     ) -> "Codex32String":
-        """Create Codex32String given prefix and bare seed data."""
+        """Create Codex32String from seed bytes and a prefix with an identifier."""
         hrp, data_part = u5_parse(prefix)
         header = u5_to_chars(data_part)
         k = "0" if not header else header[:1]
-        if not (ident := header[1 : max(5, len(header) - 1)]):
-            bip32_fingerprint = BIP32.from_seed(data).get_fingerprint()
-            ident = u5_to_chars(convertbits(bip32_fingerprint, 8, 5)[:4])
-        elif len(ident) != 4:
-            raise IdNotLength4(f"identifier had wrong length {len(ident)}")
+        ident = header[1 : max(5, len(header) - 1)]
+        if len(ident) != 4:
+            raise IdNotLength4(f"prefix must contain a four-character identifier, got {len(ident)}")
         share_idx = "s" if not header[5:] else header[5:6]
         return cls(encode(hrp, k + ident + share_idx, data, pad_val))

tests/test_bip93.py

@@ -1,5 +1,7 @@
 # tests/test_bip93.py
 """Tests for BIP-93 codex32 implementation."""
+import inspect
+
 import pytest
 from data.bip93_vectors import (
     VECTOR_1,
@@ -24,6 +26,7 @@
 )
 from codex32.bip93 import (
     Codex32String,
+    IdNotLength4,
     InvalidSeedLength,
     MismatchedHrp,
     MismatchedLength,
@@ -59,6 +62,15 @@ def test_parts():
     assert s.data.hex() == VECTOR_1["secret_hex"]
 
 
+def test_from_seed_requires_explicit_identifier():
+    """Seed encoding must not infer an identifier or import BIP32."""
+    seed = bytes.fromhex(VECTOR_3["secret_hex"])
+    prefix = inspect.signature(Codex32String.from_seed).parameters["prefix"]
+    assert prefix.default is inspect.Parameter.empty
+    with pytest.raises(IdNotLength4, match="four-character identifier"):
+        Codex32String.from_seed(seed, "ms10")
+
+
 def test_derive_and_recover():
     """Test Vector 2: derive new share and recover the secret"""
     a = Codex32String(VECTOR_2["share_A"])