lightning: kivy: open channel button in invoice

gui/kivy/uix/dialogs/lightning_payer.py

@@ -1,7 +1,9 @@
+import binascii
 from kivy.lang import Builder
 from kivy.factory import Factory
 from electrum_gui.kivy.i18n import _
 import electrum.lightning as lightning
+from electrum.lightning_payencode.lnaddr import lndecode
 
 Builder.load_string('''
 <LightningPayerDialog@Popup>
@@ -31,6 +33,11 @@ Builder.load_string('''
             Button:
                 text: _('Clear')
                 on_release: s.do_clear()
+        Button:
+            size_hint: 1, None
+            height: '48dp'
+            text: _('Open channel to pubkey in invoice')
+            on_release: s.do_open_channel()
         Button:
             size_hint: 1, None
             height: '48dp'
@@ -63,7 +70,13 @@ class LightningPayerDialog(Factory.Popup):
         self.invoice_data = contents
     def do_clear(self):
         self.invoice_data = ""
+    def do_open_channel(self):
+        compressed_pubkey_bytes = lndecode(self.invoice_data).pubkey.serialize()
+        hexpubkey = binascii.hexlify(compressed_pubkey_bytes).decode("ascii")
+        local_amt = 100000
+        push_amt = 0
+        lightning.lightningCall(self.app.wallet.network.lightningrpc, "openchannel")(hexpubkey, local_amt, push_amt)
     def do_pay(self):
         lightning.lightningCall(self.app.wallet.network.lightningrpc, "sendpayment")("--pay_req=" + self.invoice_data)
-    def on_lightning_qr(self):
+    def on_lightning_qr(self, data):
-        self.app.show_info("Lightning Invoice QR scanning not implemented") #TODO
+        self.invoice_data = str(data)

lib/lightning_payencode/FORKED

@@ -0,0 +1 @@
+This was forked from https://github.com/rustyrussell/lightning-payencode/tree/acc16ec13a3fa1dc16c07af6ec67c261bd8aff23

lib/lightning_payencode/bech32.py

@@ -0,0 +1,123 @@
+# Copyright (c) 2017 Pieter Wuille
+#
+# 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.
+
+"""Reference implementation for Bech32 and segwit addresses."""
+
+
+CHARSET = "qpzry9x8gf2tvdw0s3jn54khce6mua7l"
+
+
+def bech32_polymod(values):
+    """Internal function that computes the Bech32 checksum."""
+    generator = [0x3b6a57b2, 0x26508e6d, 0x1ea119fa, 0x3d4233dd, 0x2a1462b3]
+    chk = 1
+    for value in values:
+        top = chk >> 25
+        chk = (chk & 0x1ffffff) << 5 ^ value
+        for i in range(5):
+            chk ^= generator[i] if ((top >> i) & 1) else 0
+    return chk
+
+
+def bech32_hrp_expand(hrp):
+    """Expand the HRP into values for checksum computation."""
+    return [ord(x) >> 5 for x in hrp] + [0] + [ord(x) & 31 for x in hrp]
+
+
+def bech32_verify_checksum(hrp, data):
+    """Verify a checksum given HRP and converted data characters."""
+    return bech32_polymod(bech32_hrp_expand(hrp) + data) == 1
+
+
+def bech32_create_checksum(hrp, data):
+    """Compute the checksum values given HRP and data."""
+    values = bech32_hrp_expand(hrp) + data
+    polymod = bech32_polymod(values + [0, 0, 0, 0, 0, 0]) ^ 1
+    return [(polymod >> 5 * (5 - i)) & 31 for i in range(6)]
+
+
+def bech32_encode(hrp, data):
+    """Compute a Bech32 string given HRP and data values."""
+    combined = data + bech32_create_checksum(hrp, data)
+    return hrp + '1' + ''.join([CHARSET[d] for d in combined])
+
+
+def bech32_decode(bech):
+    """Validate a Bech32 string, and determine HRP and data."""
+    if ((any(ord(x) < 33 or ord(x) > 126 for x in bech)) or
+            (bech.lower() != bech and bech.upper() != bech)):
+        return (None, None)
+    bech = bech.lower()
+    pos = bech.rfind('1')
+    if pos < 1 or pos + 7 > len(bech): #or len(bech) > 90:
+        return (None, None)
+    if not all(x in CHARSET for x in bech[pos+1:]):
+        return (None, None)
+    hrp = bech[:pos]
+    data = [CHARSET.find(x) for x in bech[pos+1:]]
+    if not bech32_verify_checksum(hrp, data):
+        return (None, None)
+    return (hrp, data[:-6])
+
+
+def convertbits(data, frombits, tobits, pad=True):
+    """General power-of-2 base conversion."""
+    acc = 0
+    bits = 0
+    ret = []
+    maxv = (1 << tobits) - 1
+    max_acc = (1 << (frombits + tobits - 1)) - 1
+    for value in data:
+        if value < 0 or (value >> frombits):
+            return None
+        acc = ((acc << frombits) | value) & max_acc
+        bits += frombits
+        while bits >= tobits:
+            bits -= tobits
+            ret.append((acc >> bits) & maxv)
+    if pad:
+        if bits:
+            ret.append((acc << (tobits - bits)) & maxv)
+    elif bits >= frombits or ((acc << (tobits - bits)) & maxv):
+        return None
+    return ret
+
+
+def decode(hrp, addr):
+    """Decode a segwit address."""
+    hrpgot, data = bech32_decode(addr)
+    if hrpgot != hrp:
+        return (None, None)
+    decoded = convertbits(data[1:], 5, 8, False)
+    if decoded is None or len(decoded) < 2 or len(decoded) > 40:
+        return (None, None)
+    if data[0] > 16:
+        return (None, None)
+    if data[0] == 0 and len(decoded) != 20 and len(decoded) != 32:
+        return (None, None)
+    return (data[0], decoded)
+
+
+def encode(hrp, witver, witprog):
+    """Encode a segwit address."""
+    ret = bech32_encode(hrp, [witver] + convertbits(witprog, 8, 5))
+    assert decode(hrp, ret) is not (None, None)
+    return ret
+

lib/lightning_payencode/lnaddr.py

@@ -0,0 +1,385 @@
+#! /usr/bin/env python3
+import traceback
+import ecdsa.curves
+from ..bitcoin import MyVerifyingKey, GetPubKey
+from .bech32 import bech32_encode, bech32_decode, CHARSET
+from binascii import hexlify, unhexlify
+from bitstring import BitArray
+from decimal import Decimal
+
+import bitstring
+import hashlib
+import math
+import re
+import sys
+import time
+
+
+# BOLT #11:
+#
+# A writer MUST encode `amount` as a positive decimal integer with no
+# leading zeroes, SHOULD use the shortest representation possible.
+def shorten_amount(amount):
+    """ Given an amount in bitcoin, shorten it
+    """
+    # Convert to pico initially
+    amount = int(amount * 10**12)
+    units = ['p', 'n', 'u', 'm', '']
+    for unit in units:
+        if amount % 1000 == 0:
+            amount //= 1000
+        else:
+            break
+    return str(amount) + unit
+
+def unshorten_amount(amount):
+    """ Given a shortened amount, convert it into a decimal
+    """
+    # BOLT #11:
+    # The following `multiplier` letters are defined:
+    #
+    #* `m` (milli): multiply by 0.001
+    #* `u` (micro): multiply by 0.000001
+    #* `n` (nano): multiply by 0.000000001
+    #* `p` (pico): multiply by 0.000000000001
+    units = {
+        'p': 10**12,
+        'n': 10**9,
+        'u': 10**6,
+        'm': 10**3,
+    }
+    unit = str(amount)[-1]
+    # BOLT #11:
+    # A reader SHOULD fail if `amount` contains a non-digit, or is followed by
+    # anything except a `multiplier` in the table above.
+    if not re.fullmatch("\d+[pnum]?", str(amount)):
+        raise ValueError("Invalid amount '{}'".format(amount))
+
+    if unit in units.keys():
+        return Decimal(amount[:-1]) / units[unit]
+    else:
+        return Decimal(amount)
+
+# Bech32 spits out array of 5-bit values.  Shim here.
+def u5_to_bitarray(arr):
+    ret = bitstring.BitArray()
+    for a in arr:
+        ret += bitstring.pack("uint:5", a)
+    return ret
+
+def bitarray_to_u5(barr):
+    assert barr.len % 5 == 0
+    ret = []
+    s = bitstring.ConstBitStream(barr)
+    while s.pos != s.len:
+        ret.append(s.read(5).uint)
+    return ret
+
+def encode_fallback(fallback, currency):
+    """ Encode all supported fallback addresses.
+    """
+    if currency == 'bc' or currency == 'tb':
+        fbhrp, witness = bech32_decode(fallback)
+        if fbhrp:
+            if fbhrp != currency:
+                raise ValueError("Not a bech32 address for this currency")
+            wver = witness[0]
+            if wver > 16:
+                raise ValueError("Invalid witness version {}".format(witness[0]))
+            wprog = u5_to_bitarray(witness[1:])
+        else:
+            addr = base58.b58decode_check(fallback)
+            if is_p2pkh(currency, addr[0]):
+                wver = 17
+            elif is_p2sh(currency, addr[0]):
+                wver = 18
+            else:
+                raise ValueError("Unknown address type for {}".format(currency))
+            wprog = addr[1:]
+        return tagged('f', bitstring.pack("uint:5", wver) + wprog)
+    else:
+        raise NotImplementedError("Support for currency {} not implemented".format(currency))
+
+def parse_fallback(fallback, currency):
+    return None # this function disabled by Janus to avoid base58 dependency
+    if currency == 'bc' or currency == 'tb':
+        wver = fallback[0:5].uint
+        if wver == 17:
+            addr=base58.b58encode_check(bytes([base58_prefix_map[currency][0]])
+                                        + fallback[5:].tobytes())
+        elif wver == 18:
+            addr=base58.b58encode_check(bytes([base58_prefix_map[currency][1]])
+                                        + fallback[5:].tobytes())
+        elif wver <= 16:
+            addr=bech32_encode(currency, bitarray_to_u5(fallback))
+        else:
+            return None
+    else:
+        addr=fallback.tobytes()
+    return addr
+
+
+# Map of classical and witness address prefixes
+base58_prefix_map = {
+    'bc' : (0, 5),
+    'tb' : (111, 196)
+}
+
+def is_p2pkh(currency, prefix):
+    return prefix == base58_prefix_map[currency][0]
+
+def is_p2sh(currency, prefix):
+    return prefix == base58_prefix_map[currency][1]
+
+# Tagged field containing BitArray
+def tagged(char, l):
+    # Tagged fields need to be zero-padded to 5 bits.
+    while l.len % 5 != 0:
+        l.append('0b0')
+    return bitstring.pack("uint:5, uint:5, uint:5",
+                          CHARSET.find(char),
+                          (l.len / 5) / 32, (l.len / 5) % 32) + l
+
+# Tagged field containing bytes
+def tagged_bytes(char, l):
+    return tagged(char, bitstring.BitArray(l))
+
+# Discard trailing bits, convert to bytes.
+def trim_to_bytes(barr):
+    # Adds a byte if necessary.
+    b = barr.tobytes()
+    if barr.len % 8 != 0:
+        return b[:-1]
+    return b
+
+# Try to pull out tagged data: returns tag, tagged data and remainder.
+def pull_tagged(stream):
+    tag = stream.read(5).uint
+    length = stream.read(5).uint * 32 + stream.read(5).uint
+    return (CHARSET[tag], stream.read(length * 5), stream)
+
+def lnencode(addr, privkey):
+    if addr.amount:
+        amount = Decimal(str(addr.amount))
+        # We can only send down to millisatoshi.
+        if amount * 10**12 % 10:
+            raise ValueError("Cannot encode {}: too many decimal places".format(
+                addr.amount))
+
+        amount = addr.currency + shorten_amount(amount)
+    else:
+        amount = addr.currency if addr.currency else ''
+
+    hrp = 'ln' + amount
+
+    # Start with the timestamp
+    data = bitstring.pack('uint:35', addr.date)
+
+    # Payment hash
+    data += tagged_bytes('p', addr.paymenthash)
+    tags_set = set()
+
+    for k, v in addr.tags:
+
+        # BOLT #11:
+        #
+        # A writer MUST NOT include more than one `d`, `h`, `n` or `x` fields,
+        if k in ('d', 'h', 'n', 'x'):
+            if k in tags_set:
+                raise ValueError("Duplicate '{}' tag".format(k))
+
+        if k == 'r':
+            route = bitstring.BitArray()
+            for step in v:
+                pubkey, channel, feebase, feerate, cltv = step
+                route.append(bitstring.BitArray(pubkey) + bitstring.BitArray(channel) + bitstring.pack('intbe:32', feebase) + bitstring.pack('intbe:32', feerate) + bitstring.pack('intbe:16', cltv))
+            data += tagged('r', route)
+        elif k == 'f':
+            data += encode_fallback(v, addr.currency)
+        elif k == 'd':
+            data += tagged_bytes('d', v.encode())
+        elif k == 'x':
+            # Get minimal length by trimming leading 5 bits at a time.
+            expirybits = bitstring.pack('intbe:64', v)[4:64]
+            while expirybits.startswith('0b00000'):
+                expirybits = expirybits[5:]
+            data += tagged('x', expirybits)
+        elif k == 'h':
+            data += tagged_bytes('h', hashlib.sha256(v.encode('utf-8')).digest())
+        elif k == 'n':
+            data += tagged_bytes('n', v)
+        else:
+            # FIXME: Support unknown tags?
+            raise ValueError("Unknown tag {}".format(k))
+
+        tags_set.add(k)
+
+    # BOLT #11:
+    #
+    # A writer MUST include either a `d` or `h` field, and MUST NOT include
+    # both.
+    if 'd' in tags_set and 'h' in tags_set:
+        raise ValueError("Cannot include both 'd' and 'h'")
+    if not 'd' in tags_set and not 'h' in tags_set:
+        raise ValueError("Must include either 'd' or 'h'")
+
+    # We actually sign the hrp, then data (padded to 8 bits with zeroes).
+    privkey = secp256k1.PrivateKey(bytes(unhexlify(privkey)))
+    sig = privkey.ecdsa_sign_recoverable(bytearray([ord(c) for c in hrp]) + data.tobytes())
+    # This doesn't actually serialize, but returns a pair of values :(
+    sig, recid = privkey.ecdsa_recoverable_serialize(sig)
+    data += bytes(sig) + bytes([recid])
+
+    return bech32_encode(hrp, bitarray_to_u5(data))
+
+class LnAddr(object):
+    def __init__(self, paymenthash=None, amount=None, currency='bc', tags=None, date=None):
+        self.date = int(time.time()) if not date else int(date)
+        self.tags = [] if not tags else tags
+        self.unknown_tags = []
+        self.paymenthash=paymenthash
+        self.signature = None
+        self.pubkey = None
+        self.currency = currency
+        self.amount = amount
+
+    def __str__(self):
+        return "LnAddr[{}, amount={}{} tags=[{}]]".format(
+            hexlify(self.pubkey.serialize()).decode('utf-8'),
+            self.amount, self.currency,
+            ", ".join([k + '=' + str(v) for k, v in self.tags])
+        )
+
+def lndecode(a, verbose=False):
+    hrp, data = bech32_decode(a)
+    if not hrp:
+        raise ValueError("Bad bech32 checksum")
+
+    # BOLT #11:
+    #
+    # A reader MUST fail if it does not understand the `prefix`.
+    if not hrp.startswith('ln'):
+        raise ValueError("Does not start with ln")
+
+    data = u5_to_bitarray(data);
+
+    # Final signature 65 bytes, split it off.
+    if len(data) < 65*8:
+        raise ValueError("Too short to contain signature")
+    sigdecoded = data[-65*8:].tobytes()
+    data = bitstring.ConstBitStream(data[:-65*8])
+
+    addr = LnAddr()
+    addr.pubkey = None
+
+    m = re.search("[^\d]+", hrp[2:])
+    if m:
+        addr.currency = m.group(0)
+        amountstr = hrp[2+m.end():]
+        # BOLT #11:
+        #
+        # A reader SHOULD indicate if amount is unspecified, otherwise it MUST
+        # multiply `amount` by the `multiplier` value (if any) to derive the
+        # amount required for payment.
+        if amountstr != '':
+            addr.amount = unshorten_amount(amountstr)
+
+    addr.date = data.read(35).uint
+
+    while data.pos != data.len:
+        tag, tagdata, data = pull_tagged(data)
+
+        # BOLT #11:
+        #
+        # A reader MUST skip over unknown fields, an `f` field with unknown
+        # `version`, or a `p`, `h`, or `n` field which does not have
+        # `data_length` 52, 52, or 53 respectively.
+        data_length = len(tagdata) / 5
+
+        if tag == 'r':
+            # BOLT #11:
+            #
+            # * `r` (3): `data_length` variable.  One or more entries
+            # containing extra routing information for a private route;
+            # there may be more than one `r` field, too.
+            #    * `pubkey` (264 bits)
+            #    * `short_channel_id` (64 bits)
+            #    * `feebase` (32 bits, big-endian)
+            #    * `feerate` (32 bits, big-endian)
+            #    * `cltv_expiry_delta` (16 bits, big-endian)
+            route=[]
+            s = bitstring.ConstBitStream(tagdata)
+            while s.pos + 264 + 64 + 32 + 32 + 16 < s.len:
+                route.append((s.read(264).tobytes(),
+                              s.read(64).tobytes(),
+                              s.read(32).intbe,
+                              s.read(32).intbe,
+                              s.read(16).intbe))
+            addr.tags.append(('r',route))
+        elif tag == 'f':
+            fallback = parse_fallback(tagdata, addr.currency)
+            if fallback:
+                addr.tags.append(('f', fallback))
+            else:
+                # Incorrect version.
+                addr.unknown_tags.append((tag, tagdata))
+                continue
+
+        elif tag == 'd':
+            addr.tags.append(('d', trim_to_bytes(tagdata).decode('utf-8')))
+
+        elif tag == 'h':
+            if data_length != 52:
+                addr.unknown_tags.append((tag, tagdata))
+                continue
+            addr.tags.append(('h', trim_to_bytes(tagdata)))
+
+        elif tag == 'x':
+            addr.tags.append(('x', tagdata.uint))
+
+        elif tag == 'p':
+            if data_length != 52:
+                addr.unknown_tags.append((tag, tagdata))
+                continue
+            addr.paymenthash = trim_to_bytes(tagdata)
+
+        elif tag == 'n':
+            if data_length != 53:
+                addr.unknown_tags.append((tag, tagdata))
+                continue
+            addr.pubkey = secp256k1.PublicKey(flags=secp256k1.ALL_FLAGS)
+            addr.pubkey.deserialize(trim_to_bytes(tagdata))
+        else:
+            addr.unknown_tags.append((tag, tagdata))
+
+    if verbose:
+        print('hex of signature data (32 byte r, 32 byte s): {}'
+              .format(hexlify(sigdecoded[0:64])))
+        print('recovery flag: {}'.format(sigdecoded[64]))
+        print('hex of data for signing: {}'
+              .format(hexlify(bytearray([ord(c) for c in hrp])
+                              + data.tobytes())))
+        print('SHA256 of above: {}'.format(hashlib.sha256(bytearray([ord(c) for c in hrp]) + data.tobytes()).hexdigest()))
+
+    # BOLT #11:
+    #
+    # A reader MUST check that the `signature` is valid (see the `n` tagged
+    # field specified below).
+    if addr.pubkey: # Specified by `n`
+        # BOLT #11:
+        #
+        # A reader MUST use the `n` field to validate the signature instead of
+        # performing signature recovery if a valid `n` field is provided.
+        addr.signature = addr.pubkey.ecdsa_deserialize_compact(sigdecoded[0:64])
+        if not addr.pubkey.ecdsa_verify(bytearray([ord(c) for c in hrp]) + data.tobytes(), addr.signature):
+            raise ValueError('Invalid signature')
+    else: # Recover pubkey from signature.
+        addr.pubkey = SerializableKey(MyVerifyingKey.from_signature(sigdecoded[:64], sigdecoded[64], hashlib.sha256(bytearray([ord(c) for c in hrp]) + data.tobytes()).digest(), curve = ecdsa.curves.SECP256k1))
+
+    return addr
+
+class SerializableKey:
+    def __init__(self, pubkey):
+        self.pubkey = pubkey
+    def serialize(self):
+        return GetPubKey(self.pubkey.pubkey, True)