Codex32 (BIP93) BIP85 Application reference implementation

.gitignore

@@ -4,3 +4,4 @@ __pycache__
 build
 dist
 .coverage
+.vscode

README.md

@@ -49,6 +49,8 @@ bipsea offers four commands that work together:
 
 1. `mnemonic` creates BIP-39 seed mnemonics in 9 languages
 1. `validate` validates BIP-39 in 9 languages
+1. `codex32` creates BIP-93 codex32 backups
+1. `recover` validates BIP-93 strings and recovers seed
 1. `xprv` derives a BIP-32 extended private key
 1. `derive` applies BIP-85 to an xprv to derive child secrets
 
@@ -122,20 +124,51 @@ bipsea mnemonic -t spa -n 12 | bipsea validate -f spa
     relleno peón exilio vara grave hora boda terapia dinero vulgar vulgar goloso
 
 
+## `codex32`
+
+Suppose you want a 3-of-5 codex32 backup.
+
+```sh
+bipsea codex32
+```
+    ms13casha320zyxwvutsrqpnmlkjhgfedca2a8d0zehn8a0t ms13cashcacdefghjklmnpqrstuvwxyz023949xq35my48dr ms13cashd0wsedstcdcts64cd7wvy4m90lm28w4ffupqs7rm ms13casheekgpemxzshcrmqhaydlp6yhms3ws7320xyxsar9 ms13cashf8jh6sdrkpyrsp5ut94pj8ktehhw2hfvyrj48704
+
+Or a 2-of-3 with identifier 'NAME'.
+
+```sh
+bipsea codex32 -t2 -n3 -i'NAME' --pretty
+```
+    MS12NAMEA320ZYXWVUTSRQPNMLKJHGFEDCAXRPP870HKKQRM
+    MS12NAMECACDEFGHJKLMNPQRSTUVWXYZ023FTR2GDZMPY6PN
+    MS12NAMEDLL4F8JLH4E5VDVULDLFXU2JHDNLSM97XVENRXEG
+
+
+## `bipsea recover`
+
+BIP-93 codex32 backups contain a 48-124 characters, and include a checksum.
+`recover` checks the integrity of a codex32 string or set of shares, recovers the codex32 secret,
+then echoes the result so that you can pipe it to `bipsea xprv`.
+
+```sh
+echo "MS12NAMEDLL4F8JLH4E5VDVULDLFXU2JHDNLSM97XVENRXEG MS12NAMEA320ZYXWVUTSRQPNMLKJHGFEDCAXRPP870HKKQRM" | bipsea recover
+```
+    MS12NAMES6XQGUZTTXKEQNJSJZV4JV3NZ5K3KWGSPHUH6EVW
+
+
 ## `bipsea xprv`
 
 ```sh
 bipsea mnemonic | bipsea validate | bipsea xprv
 ```
     xprv9s21ZrQH143K41bKPQ9XHbPoqfdCDmZLBorYHay5E273HTu5yAFm27sSWRoCpisgQNH9vfrL9yVvVg5rBEbMCk2UwQ8K7qCFnZAY7aXhuqV
 
-`bipsea xprv` converts a mnemonic into a master node (the root of your wallet
+`bipsea xprv` converts a mnemonic or codex32 secret into a master node (the root of your wallet
 chain) that serializes as an xprv or _extended private key_.
 
 
 ### xprv from dice rolls (or any string)
 
-```
+```sh
 bipsea validate -f free -m "123456123456123456" | bipsea xprv
 ```
     Warning: Relative entropy of input seems low (0.42). Consider a more complex --mnemonic.
@@ -174,7 +207,7 @@ Below are several applications.
 
 
 ### base85 passwords
-```
+```sh
 bipsea validate -m $MNEMONIC | bipsea xprv | bipsea derive -a base85
 ```
     iu?42{I|2Ct{39IpEP5zBn=0
@@ -185,14 +218,38 @@ we get `-n 20` characters of a base85 password.
 
 ### mnemonic phrases
 
-```
+```sh
 bipsea validate -m "$MNEMONIC" | bipsea xprv | bipsea derive -a mnemonic -t jpn -n 12
 ```
     ちこく へいおん ふくざつ ゆらい あたりまえ けんか らくがき ずほう みじかい たんご いそうろう えいきょう
 
 As with all applications, you can change the child index from it's default of zero
 to get a fresh, repeatable secret.
 
+### codex32 strings
+```
+bipsea validate -m "$MNEMONIC" | bipsea xprv | bipsea derive -a codex32 -t 3 -id cash
+```
+    ms13casha320zyxwvutsrqpnmlkjhgfedca2a8d0zehn8a0t ms13cashcacdefghjklmnpqrstuvwxyz023949xq35my48dr ms13cashd0wsedstcdcts64cd7wvy4m90lm28w4ffupqs7rm
+
+As with all applications, you can change the child index from it's default of zero
+to get a fresh, repeatable secret. Note this increments the `--identifier` as it 
+should be unique for each secret.
+
+### codex32 strings
+
+```sh
+bipsea validate -m "$MNEMONIC" | bipsea xprv | bipsea derive -a codex32 -t 3
+```
+    ms13casha320zyxwvutsrqpnmlkjhgfedca2a8d0zehn8a0t ms13cashcacdefghjklmnpqrstuvwxyz023949xq35my48dr ms13cashd0wsedstcdcts64cd7wvy4m90lm28w4ffupqs7rm
+
+The output will always be the first threshold t initial shares, or a codex32 secret if `-t 0` these may be passed to `codex32` to generate a backup of -n shares.
+
+```sh
+bipsea validate -m "$MNEMONIC" | bipsea xprv | bipsea derive -a codex32 -t 3 | bipsea codex32 -n 5
+```
+    ms13casha320zyxwvutsrqpnmlkjhgfedca2a8d0zehn8a0t ms13cashcacdefghjklmnpqrstuvwxyz023949xq35my48dr ms13cashd0wsedstcdcts64cd7wvy4m90lm28w4ffupqs7rm ms13casheekgpemxzshcrmqhaydlp6yhms3ws7320xyxsar9 ms13cashf8jh6sdrkpyrsp5ut94pj8ktehhw2hfvyrj48704
+
 
 ### DRNG, enter the matrix
 
@@ -347,7 +404,7 @@ See [Makefile](./Makefile) for more commands.
 
 ## Is the bipsea implementation correct?
 
-bipsea passes all BIP-32, BIP-39, and BIP-85 test vectors in all BIP-39 languages
+bipsea passes all BIP-32, BIP-39, BIP-85 and BIP-93 test vectors in all BIP-39 languages
 plus its own unit tests.
 
 There is a single BIP-85 vector, which we believe to be incorrect in the spec,
@@ -364,6 +421,8 @@ mnemonic seed words
 generalized BIP-32 paths
 1. [BIP-85](https://github.com/bitcoin/bips/blob/master/bip-0085.mediawiki)
 generalized cryptographic entropy
+1. [BIP-93](https://github.com/bitcoin/bips/blob/master/bip-0094.mediawiki)
+checksummed SSSS-aware BIP-32 seeds
 
 
 # TODO

pyproject.toml

@@ -11,7 +11,7 @@ authors = ["Aneesh Karve <bonded_metals_0u@icloud.com>"]
 license = "Apache-2.0"
 homepage = "https://github.com/akarve/bipsea"
 repository = "https://github.com/akarve/bipsea"
-keywords = ["Bitcoin", "BIP-32", "BIP-39", "BIP-85", "cryptography", "secrets", "ECDSA", "entropy"]
+keywords = ["Bitcoin", "BIP-32", "BIP-39", "BIP-85", "BIP-93", "cryptography", "secrets", "ECDSA", "entropy"]
 classifiers = [
     "Development Status :: 4 - Beta",
     "Intended Audience :: Developers",
@@ -32,6 +32,7 @@ click = "~8.1.3"
 base58 = "~2.1.1"
 build = "~1.2.1"
 ecdsa = "~0.19.0"
+codex32 = "~0.1.0"
 
 [tool.poetry.group.dev.dependencies]
 black = "~24.4.2"

src/bipsea/bip85.py

@@ -6,6 +6,12 @@
 from typing import Dict, Union
 
 import base58
+from codex32.codex32 import (
+    CHARSET,
+    bech32_decode,
+    Codex32String,
+    entropy_to_strings,
+)
 
 from .bip32 import VERSIONS, ExtendedKey
 from .bip32 import derive_key as derive_key_bip32
@@ -23,10 +29,13 @@
     "drng": "0'",
     "hex": "128169'",
     "mnemonic": "39'",
+    "codex32": "93'",
     "wif": "2'",
     "xprv": "32'",
 }
 
+# TODO lots to copy in from patch-1!
+
 RANGES = {
     "base64": (20, 86),
     "base85": (10, 80),
@@ -51,6 +60,11 @@
     "9'": "portuguese",  # not in BIP-85 but in BIP-39 test vectors
 }
 
+INDEX_TO_HRP = {
+    "0'": "ms",
+    "1'": "cl",
+}
+
 assert set(INDEX_TO_LANGUAGE.values()) == set(LANGUAGES.keys())
 
 
@@ -83,6 +97,34 @@ def apply_85(derived_key: ExtendedKey, path: str) -> Dict[str, Union[bytes, str]
             "entropy": trimmed_entropy,
             "application": " ".join(words),
         }
+    elif app == APPLICATIONS["codex32"]:
+        header, n_bytes = indexes[:2]
+        hrp, data = bech32_decode(header)
+        if hrp not in INDEX_TO_HRP:
+            raise ValueError(f"Unsupported human-readable prefix: {hrp}.")
+        k = int(CHARSET[data[0]])
+        if k == 1:
+            raise ValueError(
+                f"Threshold '{k}' is not an allowed value (2 through 9, or 0)."
+            )
+        ident = header[1:5]
+        byte_length = int(n_bytes.rstrip("'"))
+        if not 16 <= byte_length <= 64:
+            raise ValueError(
+                f"Byte length '{byte_length}' is not an allowed value (16 through 64)."
+            )
+        drng = DRNG(entropy)
+        alphabetized_charset = "sacdefghjk"  # threshold above 9 is invalid
+        shares = []
+        for share_idx in alphabetized_charset[bool(k) : k + 1]:
+            shares += Codex32String.from_seed(
+                drng.read(byte_length), ident, hrp, k, share_idx
+            ).s
+
+        return {
+            "entropy": entropy,
+            "application": " ".join(shares),
+        }
     elif app == APPLICATIONS["wif"]:
         trimmed_entropy = entropy[: 256 // 8]
         prefix = b"\x80" if derived_key.get_network() == "mainnet" else b"\xef"

src/bipsea/bipsea.py

@@ -5,6 +5,10 @@
 import sys
 
 import click
+from codex32.codex32 import (
+    CHARSET,
+    entropy_to_codex32,
+)
 
 from .bip32 import to_master_key
 from .bip32types import parse_ext_key, validate_prv_str
@@ -21,6 +25,7 @@
     APPLICATIONS,
     DRNG,
     INDEX_TO_LANGUAGE,
+    INDEX_TO_HRP,
     PURPOSE_CODES,
     RANGES,
     apply_85,
@@ -137,16 +142,49 @@ def validate(from_, mnemonic):
     click.echo(" ".join(words))
 
 
+# TODO: paste codex32 cli here
+
+
+@click.command(
+    name="recover",
+    help="Validate a set of codex32 strings and recover the secret or share at target share index",
+)
+@click.option(
+    "-t", "--target", help="Share index to recover at. Default is the secret `s`."
+)
+def recover(strings, target="s"):
+    click.echo(Codex32String.interpolate_at(strings, target))
+
+
 @click.command(
     name="xprv",
     help="Derive a BIP-32 XPRV from arbitrary string. Use bipsea validate` to validate!",
 )
 @click.option("-m", "--mnemonic", help="Mnemonic. Pipe from `bipsea validate`.")
+@click.option("-c", "--codex32", help="Codex32 secret. Pipe from `bipsea recover`.")
 @click.option("-p", "--passphrase", default="", help="BIP-39 passphrase.")
 @click.option("--mainnet/--testnet", is_flag=True, default=True)
-def xprv(mnemonic, passphrase, mainnet):
+def xprv(mnemonic, codex32, passphrase, mainnet):
     if mnemonic:
         mnemonic = mnemonic.strip()
+    elif codex32:
+        codex32 = codex32.strip()
+        no_empty_param("--codex32", codex32)
+        if len(codex32) < 48:
+            raise click.BadOptionUsage(
+                option_name="--codex32",
+                message="Suspiciously short codex32 secret. Try `bipsea recover`.",
+            )
+        if passphrase:
+            raise click.BadOptionUsage(
+                option_name="--passphrase",
+                message="No passphrase support for codex32 secrets. Try `bipsea recover`.",
+            )
+        seed = Codex32String.from_string(codex32).parts().data()
+        prv = to_master_key(seed, mainnet=mainnet, private=True)
+
+        click.echo(prv)
+        return
     else:
         mnemonic = try_for_pipe_input()
     no_empty_param("--mnemonic", mnemonic)
@@ -206,6 +244,8 @@ def xprv(mnemonic, passphrase, mainnet):
     help="Output language for `--application mnemonic`.",
 )
 def derive_cli(application, number, index, special, xprv, to):
+    # TODO Write the "glue" between the bip85 codex32 logic and CLI last as it's the hardest step.
+    # TODO Copy unfinished work from patch-1
     if xprv:
         xprv = xprv.strip()
     else:
@@ -241,8 +281,25 @@ def derive_cli(application, number, index, special, xprv, to):
 
     if application == "mnemonic":
         language = ISO_TO_LANGUAGE[to]
-        code_85 = next(i for i, l in INDEX_TO_LANGUAGE.items() if l == language)
+        code_85 = next(
+            i for i, l in INDEX_TO_LANGUAGE.items() if l == language
+        )  # noqa: E741
+        path += f"/{code_85}/{number}'/{index}'"
+    if application == "codex32":
+        code_85 = next(i for i, l in INDEX_TO_HRP.items() if l == "ms")  # noqa: E741
         path += f"/{code_85}/{number}'/{index}'"
+    elif application == "codex32":
+        hrp, data = bech32_decode("ms1" + str(0) + "test")
+        code_85 = ISO_TO_HRP[hrp] + int.from_bytes(
+            convertbits(data, 5, 8)
+        )  # serialization must fit in 32-bits
+        # 3.2 for threshold, 20 for identifier, 1 for hrp if just 0,1 dict + 4 more for default IDs
+        # add the {index} to the encoded indentifier so that it increments as the index is. That gives 2^20 seeds before we reuse the original identifier
+        # this gives the amazing property for fingerprint IDs when you know the master fingerprint
+        # that you can subtract them and see what index was used to generate that codex32 backup.
+        # be sure it rolls over at 2^20 so that the threshold doesn't increment as well which will
+        # break things.
+        path += f"/{code_85}'/{number}'/{index}'"
     elif application in ("wif", "xprv"):
         path += f"/{index}'"
     elif application in ("base64", "base85", "hex"):
@@ -271,6 +328,8 @@ def cli():
 
 cli.add_command(mnemonic)
 cli.add_command(validate)
+cli.add_command(codex32)
+cli.add_command(recover)
 cli.add_command(xprv)
 cli.add_command(derive_cli)