Merge pull request #11 from lalanza808/mnemonics

Seed class for interacting with Monero secret seeds

monero/__init__.py

@@ -1,3 +1,3 @@
-from . import address, account, daemon, wallet, numbers, prio
+from . import address, account, daemon, wallet, numbers, prio, wordlists, seed
 
 __version__ = '0.1.2'

monero/seed.py

@@ -0,0 +1,168 @@
+#!/usr/bin/env python
+
+# Electrum - lightweight Bitcoin client
+# Copyright (C) 2011 thomasv@gitorious
+#
+# Permission is hereby granted, free of charge, to any person
+# obtaining a copy of this software and associated documentation files
+# (the "Software"), to deal in the Software without restriction,
+# including without limitation the rights to use, copy, modify, merge,
+# publish, distribute, sublicense, and/or sell copies of the Software,
+# and to permit persons to whom the Software is furnished to do so,
+# subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be
+# included in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+# BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+# ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+#
+# Note about US patent no 5892470: Here each word does not represent a given digit.
+# Instead, the digit represented by a word is variable, it depends on the previous word.
+#
+# Copied 17 February 2018 from MoneroPy, originally from Electrum:
+#     https://github.com/bigreddmachine/MoneroPy/blob/master/moneropy/mnemonic.py ch: 80cc16c39b16c55a8d052fbf7fae68644f7a5f02
+#     https://github.com/spesmilo/electrum/blob/master/lib/old_mnemonic.py ch:9a0aa9b4783ea03ea13c6d668e080e0cdf261c5b
+
+from monero import wordlists
+from binascii import crc32, hexlify
+from os import urandom
+
+class Seed(object):
+    """Creates a seed object either from local system randomness or an imported phrase.
+
+    :rtype: :class:`Seed <monero.seed.Seed>`
+    """
+
+    n = 1626
+    wordlist = wordlists.english.wordlist # default english for now
+
+    phrase = "" #13 or 25 word mnemonic word string
+    hex = "" # hexadecimal
+
+    def __init__(self, phrase=""):
+        """If user supplied a seed string to the class, break it down and determine
+        if it's hexadecimal or mnemonic word string. Gather the values and store them.
+        If no seed is passed, automatically generate a new one from local system randomness.
+
+        :rtype: :class:`Seed <monero.seed.Seed>`
+        """
+        if phrase:
+            seed_split = phrase.split(" ")
+            if len(seed_split) >= 24:
+                # standard mnemonic
+                self.phrase = phrase
+                if len(seed_split) == 25:
+                    # with checksum
+                    self.validate_checksum()
+                self.hex = self.decode_seed()
+            elif len(seed_split) >= 12:
+                # mymonero mnemonic
+                self.phrase = phrase
+                if len(seed_split) == 13:
+                    # with checksum
+                    self.validate_checksum()
+                self.hex = self.decode_seed()
+            elif len(seed_split) == 1:
+                # single string, probably hex, but confirm
+                if not len(phrase) % 8 == 0:
+                    raise ValueError("Not valid hexadecimal: {hex}".format(hex=phrase))
+                self.hex = phrase
+                self.phrase = self.encode_seed()
+            else:
+                raise ValueError("Not valid mnemonic phrase: {phrase}".format(phrase=phrase))
+        else:
+            self.hex = generate_hex()
+            self.encode_seed()
+
+
+    def endian_swap(self, word):
+        """Given any string, swap bits and return the result.
+
+        :rtype: str
+        """
+        return "".join([word[i:i+2] for i in [6, 4, 2, 0]])
+
+    def encode_seed(self):
+        """Given a hexadecimal string, return it's mnemonic word representation with checksum.
+
+        :rtype: str
+        """
+        assert self.hex, "Seed hex not set"
+        assert len(self.hex) % 8 == 0, "Not valid hexadecimal"
+        out = []
+        for i in range(len(self.hex) // 8):
+            word = self.endian_swap(self.hex[8*i:8*i+8])
+            x = int(word, 16)
+            w1 = x % self.n
+            w2 = (x // self.n + w1) % self.n
+            w3 = (x // self.n // self.n + w2) % self.n
+            out += [self.wordlist[w1], self.wordlist[w2], self.wordlist[w3]]
+        checksum = get_checksum(" ".join(out))
+        out.append(checksum)
+        self.phrase = " ".join(out)
+        return self.phrase
+
+    def decode_seed(self):
+        """Given a mnemonic word string, return it's hexadecimal representation.
+
+        :rtype: str
+        """
+        assert self.phrase, "Seed phrase not set"
+        phrase = self.phrase.split(" ")
+        assert len(phrase) >= 12, "Not valid mnemonic phrase"
+        out = ""
+        for i in range(len(phrase) // 3):
+            word1, word2, word3 = phrase[3*i:3*i+3]
+            w1 = self.wordlist.index(word1)
+            w2 = self.wordlist.index(word2) % self.n
+            w3 = self.wordlist.index(word3) % self.n
+            x = w1 + self.n *((w2 - w1) % self.n) + self.n * self.n * ((w3 - w2) % self.n)
+            out += self.endian_swap("%08x" % x)
+        self.hex = out
+        return self.hex
+
+    def validate_checksum(self):
+        """Given a mnemonic word string, confirm seed checksum (last word) matches the computed checksum.
+
+        :rtype: bool
+        """
+        assert self.phrase, "Seed phrase not set"
+        phrase = self.phrase.split(" ")
+        assert len(phrase) > 12, "Not valid mnemonic phrase"
+        is_match = get_checksum(self.phrase) == phrase[-1]
+        assert is_match, "Not valid checksum"
+        return is_match
+
+
+def get_checksum(phrase):
+    """Given a mnemonic word string, return a string of the computed checksum.
+
+    :rtype: str
+    """
+    phrase_split = phrase.split(" ")
+    assert len(phrase_split) >= 12, "Not valid mnemonic phrase"
+    if len(phrase_split) > 13:
+        # Standard format
+        phrase = phrase_split[:24]
+    else:
+        # MyMonero format
+        phrase = phrase_split[:12]
+    wstr = "".join(word[:3] for word in phrase)
+    z = ((crc32(wstr.encode()) & 0xffffffff) ^ 0xffffffff ) >> 0
+    z2 = ((z ^ 0xffffffff) >> 0) % len(phrase)
+    return phrase_split[z2]
+
+def generate_hex(n_bytes=32):
+    """Generate a secure and random hexadecimal string. 32 bytes by default, but arguments can override.
+
+    :rtype: str
+    """
+    h = hexlify(urandom(n_bytes))
+    return "".join(h.decode("utf-8"))

monero/wordlists/__init__.py

@@ -0,0 +1 @@
+from . import english

tests/__init__.py

@@ -3,3 +3,4 @@ from . import test_numbers
 from . import test_transaction
 from . import test_wallet
 from . import test_jsonrpcwallet
+from . import test_seed

tests/test_seed.py

@@ -0,0 +1,65 @@
+#!/usr/bin/env python
+
+import unittest
+from monero.seed import Seed, get_checksum
+
+class SeedTestCase(unittest.TestCase):
+
+    def test_mnemonic_seed(self):
+        # Known good 25 word seed phrases should construct a class, validate checksum, and register valid hex
+        seed = Seed("wedge going quick racetrack auburn physics lectures light waist axes whipped habitat square awkward together injury niece nugget guarded hive obnoxious waxing faked folding square")
+        self.assertTrue(seed.validate_checksum())
+        self.assertEqual(seed.hex, "8ffa9f586b86d294d93731765d192765311bddc76a4fa60311f8af36bbf6fb06")
+
+        # Known good 24 word seed phrases should construct a class, store phrase with valid checksum, and register valid hex
+        seed = Seed("wedge going quick racetrack auburn physics lectures light waist axes whipped habitat square awkward together injury niece nugget guarded hive obnoxious waxing faked folding")
+        seed.encode_seed()
+        self.assertTrue(seed.validate_checksum())
+        self.assertEqual(seed.hex, "8ffa9f586b86d294d93731765d192765311bddc76a4fa60311f8af36bbf6fb06")
+
+        # Known good 25 word hexadecimal strings should construct a class, store phrase with valid checksum, and register valid hex
+        seed = Seed("8ffa9f586b86d294d93731765d192765311bddc76a4fa60311f8af36bbf6fb06")
+        self.assertTrue(seed.validate_checksum())
+        self.assertEqual(seed.phrase, "wedge going quick racetrack auburn physics lectures light waist axes whipped habitat square awkward together injury niece nugget guarded hive obnoxious waxing faked folding square")
+
+        # Known good 13 word seed phrases should construct a class, validate checksum, and register valid hex
+        seed = Seed("ought knowledge upright innocent eldest nerves gopher fowls below exquisite aces basin fowls")
+        self.assertTrue(seed.validate_checksum())
+        self.assertEqual(seed.hex, "932d70711acc2d536ca11fcb79e05516")
+
+        # Known good 12 word seed phrases should construct a class, store phrase with valid checksum, and register valid hex
+        seed = Seed("ought knowledge upright innocent eldest nerves gopher fowls below exquisite aces basin")
+        seed.encode_seed()
+        self.assertTrue(seed.validate_checksum())
+        self.assertEqual(seed.hex, "932d70711acc2d536ca11fcb79e05516")
+
+        # Known good 13 word hexadecimal strings should construct a class, store phrase with valid checksum, and register valid hex
+        seed = Seed("932d70711acc2d536ca11fcb79e05516")
+        self.assertTrue(seed.validate_checksum())
+        self.assertEqual(seed.phrase, "ought knowledge upright innocent eldest nerves gopher fowls below exquisite aces basin fowls")
+
+        # Generated seed phrases should be 25 words, validate checksum, register valid hex, and return matching outputs for decode/encode
+        seed = Seed()
+        seed_split = seed.phrase.split(" ")
+        self.assertTrue(len(seed_split) == 25)
+        self.assertTrue(seed.validate_checksum())
+        self.assertTrue(len(seed.hex) % 8 == 0)
+        self.assertEqual(seed.hex, seed.decode_seed())
+        self.assertEqual(seed.phrase, seed.encode_seed())
+
+        # Invalid phrases should not be allowed
+        with self.assertRaises(ValueError) as ts:
+            Seed("oh damn you thought fool")
+        self.assertEqual(ts.expected, ValueError)
+        with self.assertRaises(ValueError) as ts:
+            Seed("Thi5isMyS3cr3tPa55w0rd")
+        self.assertEqual(ts.expected, ValueError)
+        with self.assertRaises(ValueError) as ts:
+            Seed(" ")
+        self.assertEqual(ts.expected, ValueError)
+        with self.assertRaises(ValueError) as ts:
+            Seed("\\x008")
+        self.assertEqual(ts.expected, ValueError)
+
+if __name__ == "__main__":
+    unittest.main()