Merge pull request #13 from muun/privkey

[WIP] PrivateKey backed by cryptography

bitforge/__init__.py

@@ -1,10 +1,14 @@
+from network import Network
 from privkey import PrivateKey
 from pubkey import PublicKey
-from address import Address
-from script import Script
-from hdprivkey import HDPrivateKey
-from network import Network
-import network
-import ecdsa
+# from address import Address
+# from script import Script
+# from hdprivkey import HDPrivateKey
 from unit import Unit
-from uri import URI
+# from uri import URI
+
+import network
+import privkey
+import pubkey
+import unit
+# import uri

bitforge/address.py

@@ -1,120 +1,135 @@
-import binascii, collections
-from enum import Enum
+import collections
 
-import network, utils
-from network import Network
-from encoding import *
-from errors import *
-# from script import Script
+import enum
 
+from bitforge import encoding, error, network
 
-BaseAddress = collections.namedtuple('Address', ['phash', 'network', 'type'])
 
-class Address(BaseAddress):
+class Type(enum.Enum):
+    PublicKey = 'pubkey_hash'
+    Script    = 'script_hash'
+
+
+class Error(error.BitforgeError):
+    pass
+
 
-    class Type(Enum):
-        PublicKey = 'pubkeyhash'
-        Script    = 'scripthash'
+class InvalidEncoding(Error):
+    pass
 
-    class Error(BitforgeError):
-        pass
 
-    class UnknownNetwork(Error, Network.UnknownNetwork):
-        "No network for Address with an attribute '{key}' of value {value}"
+class InvalidHashLength(Error, error.StringError):
+    "The address hash {string} should be 20 bytes long, not {length}"
 
-    class InvalidVersion(Error, NumberError):
-        "Failed to detect Address type and network from version number {number}"
 
-    class InvalidBase58h(Error, InvalidBase58h):
-        "The Address string {string} is not valid base58/check"
+class InvalidType(Error, error.ObjectError):
+    "{object} is not a valid address type"
 
-    class InvalidHex(Error, InvalidHex):
-        "The Address string {string} is not valid hexadecimal"
 
-    class InvalidHashLength(Error, StringError):
-        "The address hash {string} should be 20 bytes long, not {length}"
+BaseAddress = collections.namedtuple('Address', [
+    'hash',
+    'type',
+    'network',
+])
 
-    class InvalidBinaryLength(Error, StringError):
-        "The binary address {string} should be 21 bytes long, not {length}"
 
-    class InvalidType(Error, ObjectError):
-        "Address type {object} is not an instance of Address.Type"
+class Address(BaseAddress):
+    """Bitcoin address."""
+
+    def __new__(cls, hash, type=Type.PublicKey, network=network.default):
+        """TODO"""
 
+        if not isinstance(type, Type):
+            raise InvalidType(type)
 
-    def __new__(cls, phash, network = network.default, type = Type.PublicKey):
-        if not isinstance(type, Address.Type):
-            raise Address.InvalidType(type)
+        if len(hash) != 20:
+            raise InvalidHashLength(hash)
 
-        if len(phash) != 20:
-            raise Address.InvalidHashLength(phash)
+        return super(Address, cls).__new__(cls, hash, type, network)
 
-        return super(Address, cls).__new__(cls, phash, network, type)
+    @classmethod
+    def from_string(cls, string):
+        """TODO"""
 
-    @staticmethod
-    def from_string(string):
         try:
-            bytes = decode_base58h(string)
-        except InvalidBase58h:
-            raise Address.InvalidBase58h(string)
+            data = encoding.a2b_base58check(string)
+
+        except encoding.InvalidEncoding as e:
+            raise InvalidEncoding(e.message)
+
+        return cls.from_bytes(data)
 
-        return Address.from_bytes(bytes)
+    @classmethod
+    def from_bytes(cls, data):
+        """TODO"""
 
-    @staticmethod
-    def from_bytes(bytes):
-        if len(bytes) != 21:
-            raise Address.InvalidBinaryLength(bytes)
+        if len(data) != 21:
+            raise InvalidEncoding('Invalid address length')
 
-        network, type = Address.classify_bytes(bytes)
+        type_, network_ = cls.classify_bytes(data)
 
-        return Address(bytes[1:], network, type)
+        return cls(data[1:], type_, network_)
+
+    @classmethod
+    def from_hex(cls, string):
+        """TODO"""
 
-    @staticmethod
-    def from_hex(string):
         try:
-            bytes = decode_hex(string)
-        except InvalidHex:
-            raise Address.InvalidHex(string)
+            data = encoding.a2b_hex(string)
+
+        except encoding.InvalidEncoding as e:
+            raise InvalidEncoding(e.message)
+
+        return cls.from_bytes(data)
+
+    @classmethod
+    def classify_bytes(cls, data):
+        """TODO"""
 
-        return Address.from_bytes(bytes)
+        data = bytearray(data)
+        version = data[0]
 
-    @staticmethod
-    def classify_bytes(bytes):
-        version = decode_int(bytes[0])
+        network_ = network.Network.get_by_field('pubkey_hash_prefix', version, raises=False)
+        if network_ is not None:
+            return (Type.PublicKey, network_)
 
-        network = Network.get_by_field('pubkeyhash', version, raises = False)
-        if network is not None:
-            return (network, Address.Type.PublicKey)
+        network_ = network.Network.get_by_field('script_hash_prefix', version, raises=False)
+        if network_ is not None:
+            return (Type.Script, network_)
 
-        network = Network.get_by_field('scripthash', version, raises = False)
-        if network is not None:
-            return (network, Address.Type.Script)
+        raise InvalidEncoding('Invalid version number')
 
-        raise Address.InvalidVersion(version)
+    @classmethod
+    def from_public_key(cls, pubkey):
+        """TODO"""
 
-    @staticmethod
-    def from_public_key(pubkey):
-        phash = ripemd160(sha256(pubkey.to_bytes()))
-        return Address(phash, pubkey.network, Address.Type.PublicKey)
+        return pubkey.address()
 
     def to_bytes(self):
+        """TODO"""
+
         version = getattr(self.network, self.type.value)
-        return chr(version) + self.phash
+        return chr(version) + self.hash
 
     def to_string(self):
-        return encode_base58h(self.to_bytes())
+        """TODO"""
+
+        return encoding.b2a_base58check(self.to_bytes())
 
     def to_hex(self):
-        return encode_hex(self.to_bytes())
+        """TODO"""
+
+        return encoding.b2a_hex(self.to_bytes())
 
     # TODO: all keys should be from the same network
-    # @staticmethod
+    # @classmethod
     # def from_public_keys(pubkeys, threshold):
     #     return Address.from_script(
     #         Script.buildMultisigOut(pubkeys, threshold),
     #         pubkeys[0].network
     #     )
 
-    # @staticmethod
+    # @classmethod
     # def from_script(script, network = networks.default):
     #     if not isinstance(script, Script):
     #         raise ValueError('Expected instance of Script, not %s' % script)

bitforge/encoding.py

@@ -1,68 +1,67 @@
-import utils, binascii, hashlib
-from errors import StringError
+import binascii
+import hashlib
 
+from bitforge import error
+from bitforge.utils import encoding
 
-class EncodingError(StringError):
-    "The string {string} is not properly encoded"
 
+class Error(error.BitforgeError):
+    pass
 
-class InvalidBase58h(EncodingError):
-    "The string {string} is not valid base58/check"
 
+def b2a_hex(data):
+    """Convert a byte buffer to an hexadecimal string."""
 
-class InvalidHex(EncodingError):
-    "The string {string} is not valid hexadecimal"
+    return binascii.b2a_hex(data)
 
 
-def encode_base58h(bytes):
-    return utils.encoding.b2a_hashed_base58(bytes)
+def a2b_hex(string):
+    """Convert an hexadecimal string to a byte buffer."""
 
+    if len(string) % 2 == 1:
+        string = '0' + string
 
-def decode_base58h(string):
     try:
-        return utils.encoding.a2b_hashed_base58(string)
+        return binascii.a2b_hex(string.encode('ascii'))
+    except TypeError:
+        raise Error('Invalid hexadecimal string')
 
-    except utils.encoding.EncodingError:
-        raise InvalidBase58h(string)
 
+def b2i_bigendian(data):
+    """Convert a big endian byte buffer to an unsigned big integer."""
 
-def encode_int(integer, big_endian = True):
-    bytes = bytearray()
+    # Encoding and decoding from hexa appears to be way faster than manually
+    # decoding the buffer in python.
+    return int(b2a_hex(data), 16)
 
-    while integer > 0:
-        bytes.append(integer & 0xff)
-        integer >>= 8
 
-    if big_endian:
-        bytes.reverse()
+def i2b_bigendian(number, num_bytes = 0):
+    """Convert an unsigned big integer to a zero-padded big endian byte buffer.
+    """
 
-    return str(bytes)
+    # Encoding and decoding from hexa appears to be way faster than manually
+    # decoding the buffer in python.
+    return a2b_hex('%0*x' % (2 * num_bytes, number))
 
 
-def decode_int(bytes, big_endian = True):
-    if not big_endian:
-        bytes = reversed(bytes)
+# TODO: implement these functions
 
-    integer = 0
+def b2a_base58check(data):
+    """Convert a byte buffer to a base58check string."""
 
-    for char in bytes:
-        integer <<= 8
-        integer += ord(char)
+    return encoding.b2a_hashed_base58(data)
 
-    return integer
 
+def a2b_base58check(string):
+    """Convert a base58check string to a byte buffer."""
 
-def encode_hex(bytes):
-    return binascii.hexlify(bytes)
-
-
-def decode_hex(string):
     try:
-        return binascii.unhexlify(string)
-    except:
-        # unhexlify() throws 2 different exceptions (length, and alphabet)
-        raise InvalidHex(string)
+        return encoding.a2b_hashed_base58(string)
+    except encoding.EncodingError:
+        raise Error('Invalid base58check string')
+
 
+# TODO: these are not encodings, they shouldn't be here
 
 def sha256(bytes):
     return hashlib.sha256(bytes).digest()

bitforge/error.py

@@ -1,34 +1,39 @@
-
 class BitforgeError(Exception):
+
     def __init__(self, *args, **kwargs):
         self.cause = kwargs.pop('cause', None)
         self.prepare(*args, **kwargs)
         self.message = self.__doc__.format(**self.__dict__)
 
-    def prepare(self):
-        pass
+    def prepare(self, message=None):
+        if message is not None:
+            self.__doc__ = message
 
     def __str__(self):
         return self.message
 
 
 class ObjectError(BitforgeError):
+
     def prepare(self, object):
         self.object = object
 
 
 class StringError(BitforgeError):
+
     def prepare(self, string):
         self.string = repr(string)
         self.length = len(string)
 
 
 class NumberError(BitforgeError):
+
     def prepare(self, number):
         self.number = number
 
 
 class KeyValueError(BitforgeError):
+
     def prepare(self, key, value):
         self.key   = key
         self.value = value