Adds support for Pay-To-Script-Hash (P2SH) multi-signature contracts.

The multi-signature scheme is compatible with Bitcoin Core, and therefore partially-signed transactions can be co-signed between both implementations.

New classes:

MultiSig and MultiSigTestnet.

Example usage:

from bit import *

# Creating three private keys:
key1 = PrivateKeyTestnet("cNZYKrewErp2wG9LXiAU4H6dzgtyYsSm78tSU14QST9Hu57CMRaJ")
key2 = PrivateKeyTestnet("cMgHThJYoUYc19UjMWn1xabRJLh3PCKyKfiTM1ssV2ZPe7V6eaBL")
key3 = PrivateKeyTestnet("cR1C9ZB7qoVktmQDQsUP8KcTM37G1PYN3oR2B6ua27EycGDVN6fE")

# Making a list containing the public keys in hex:
key1p = key1.pub_to_hex()
key2p = key2.pub_to_hex()
key3p = key3.pub_to_hex()
plist = [key1p, key2p, key3p]

# Creating a P2SH multi-signature contract instance with key1 requiring two signatures from the total of three keys:
multi = MultiSigTestnet(key1, plist, 2)

# Showing the multi-signature address to send (testnet) bitcoins to:
multi.address
# 2MvkZtmW1w7hBPMSjQmEhHzrtcgiQGEBrtD

# Create and partially-sign a new transaction spending from the multi-signature contract:
tx = multi.create_transaction([], fee=21, leftover='mpDJqjKMyQaFjEMwYHKJBP3mM4rM2ejJdk')

# Create another instance of the multi-signature contract with key2:
multi2 = MultiSigTestnet(key2, plist, 2)

# Fully sign the spending transaction using our second instance of the multi-signature contract:
tx_signed = multi2.sign_transaction(tx)

This is only thought of as a first start to implement P2SH and therefore bugs are still expected and more rigorous testing and optimization may be necessary.

Hi

I'm looking for 2 features that existing popular wallets already offer:

1. Sign a message using private keys
2. Verify a message, given the message and signature

Is this possible? I dont see it in the documentation

When I try to create a transaction, it gives an error that there are not enough funds on the balance: bit.exceptions.InsufficientFunds: Balance 54022 is less than 60800 (including fee).

key.send([(address, 0.0001, 'btc')], fee=200) 0.0001 btc = 10000 satoshi. So total is 30000 satoshi (0.0003 btc).

Why im getting error? I noticed that when transferring the indicated amount, it is added to the whole balance and is trying to transfer it.

This PR adds a method allowing the NetworkAPI to connect to a remote Bitcoin node instead of relying on web APIs. It is marked as a work-in-progress to allow testing, code improvements and test cases to be added.

It has been implemented in a way to minimize changes to the codebase and to not break already existing tests. Any suggestions however on how to better connect the new class bit.network.services.RPCHost with the NetworkAPI is welcome! Right now inside NetworkAPI it simply overrides its web-API values using the RPCHost instead.

This implementation also allows to connect to two different Bitcoin nodes: one for mainnet and one for testnet; and keeps them separate.

Example code

import bit

# To connect to a remote Bitcoin node:
from bit.network import NetworkAPI
NetworkAPI.connect_to_node(user='user', password='password', host='localhost', port='18443', use_https=False, testnet=True)

# We could additionally choose to connect to some mainnet node:
NetworkAPI.connect_to_node(user='user', password='password', host='domain', port='8332', use_https=True, testnet=False)

# Do some bit stuff...
k_test = bit.PrivateKeyTestnet()
k_test.get_unspents()  # will use the testnet node for API
k_main = bit.PrivateKey()
k_main.get_unspents()  # will use the mainnet node for API
# ...

Remarks

Bitcoin Core is not a blockchain explorer and thus only keeps full track of addresses in its wallet! Therefore to use it as a remote node all addresses generated with Bit and that should be tracked must be added as (watch-only) addresses to Bitcoin Core as follows:

>>> bitcoin-cli importaddress "WATCH_ONLY_ADDRESS"

See importaddress for more details.

It may be useful to add a helper function that can add generated Bit addresses to the Bitcoin Core wallet.

Bitcoin Core RPC behaves particular with regard to coinbase transactions

Coinbase transactions directly received inside a Bitcoin Core wallet address will as expected be returned as a list of Unspent objects when using PrivateKey().get_unused(). However, they will not show up when using PrivateKey().get_transactions(). A fix would be to rewrite the RPCHost method get_transactions to use the RPC method listsinceblock, which returns all transactions associated to the Bitcoin Core wallet but hence also requires Bit to filter them by addresses. As this is an edge case and wasteful for big wallets it has been ignored (for now). See the discussion here.

TODOs

• ~~Add test cases~~
• ~~Add helper function adding addresses as watch-only to the node~~
• ~~Add documentation~~
• ~~Check SSL to allow self-signed certs (rpcssl is deprecated, see https://bitcoin.org/en/release/v0.12.0#rpc-ssl-support-dropped)~~

Due to time-out errors adding more network API's makes it even more difficult to pass all the tests. This problem still persists with this PR and may make it worse due to the three new APIs!

Fix for testing balance > 0

This PR fixes the testing error from test_get_balance_main_used inside BitpayAPI, BlockchainAPI and SmartbitAPI.

The reason was that the address being checked was used up and has a balance of 0, while the tests are asserting that the balance must be greater than 0.

It has been fixed by referring to Counterparty's burn-of-proof address 1CounterpartyXXXXXXXXXXXXXXXUWLpVr and should therefore always have a balance greater than 0.

Adding network APIs

The PR further adds three new network APIs:

• Btc.com,
• Blockstream.info, and
• Blockchair.com.

Blockchair was the most straight-forward to implement as it includes a "context" with each response that is very useful in case the immediate response does not include information that we need (e.g. confirmations, scriptPubKey, etc.). However for the first two APIs there were minor issues that I want to mention and eventually discuss:

1. For the new BTCcomAPI and BlockstreamAPI: When unspents are returned the scriptPubKey of the address is not included with the response. We must therefore calculate it from the address using our helper function address_to_scriptpubkey found inside bit.transaction.
2. For the new BlockstreamAPI: When unspents are returned it will include the block number the transaction was confirmed in, but neither include the number of confirmations nor the current block height. We must therefore first poll the current block height to then be able to calculate the confirmations for each unspent transaction returned.
3. For the new BlockstreamAPI: Returned unspents are not sorted by any metric and appear to be random. To compare them directly with unspents returned from other APIs the returned unspents are immediately sorted by their confirmation number.

Future development

If this PR has been checked and should be approved, then the next step will be to add a features-supported functionality, allowing NetworkAPI to poll the APIs with required features supported depending on the use-case, e.g. for bech32 addresses.

I'm not sure where else to ask, but I can't seem to generate a public address(for sending transactions). According to your wiki after generating a private key via key = Key() I should be able to use the address attribute. but key.address give back the private key again and key.public_key generates something unusable (at least by a novice).

What am I doing wrong?

Hello,

I know the content of a balance, a quantity and I have 3 outputs: A, B and C and I'm using a segwit address. My quantity is at least equals to my balance.

• I want to send 1% of the quantity to A. if my balance is superior enough to my quantity:
• I want to send 99% (the rest of the quantity) to B.
• Use C as a leftover address (the tx fee will be deducted from what he will receive) else:
• I will use B as a leftover address, so he will receive 99% minus the tx fee. C will not receive anything

My question is: how to detect my balance is sufficient to send the rest of the quantity, pay the fees and add a leftover? I looked into the code and found this: https://github.com/ofek/bit/blob/defa2e6b9afe9f45e5d0928489dcfc888a706d81/bit/transaction.py#L180

But I don't understand how to use it (I think it is not in the documentation).

Thanks for your help, Thomas

When I go to run a program based on this, I get: Traceback (most recent call last): File "C:\Users*\Desktop\bit-master\bitcoin2.py", line 1, in from bit import Key File "C:\Users*\Desktop\bit-master\bit_init_.py", line 1, in from bit.format import verify_sig File "C:\Users***\Desktop\bit-master\bit\format.py", line 2, in from coincurve import * ImportError: No module named 'coincurve'

The problem is I imported coincurve directly into my folder as well as installing it with pip. Further I tried to look for verify_sig anywhere and could not find it.

In continuation of #86

• Removes Bitpay API
• Adds three new APIs
• Adds new test address with many unspents and guaranteed > 0 balance
• Increases timeout for network testing

Hi,

This seems to be the only sanest python bitcoin library. Truely, great work there.

I would love to use this library but unfortunately local nodes are not supported.

Do you have any timeline to support the local nodes?

Do you need funding or donation?

Please, let me know.

I'm working on escrow/multisig system. Bit is great and I'd be sad to not implement it just because it doesn't support generating multisig addresses. I understand this behavior might not be the priority (https://github.com/ofek/bit/issues/6), but here I go.

I plan to use couple of Multisig instances, which will share the same Key as private_key, as all the paths the trade could get. For this it should be enough to write function which will calculate the appropriate values for this universal Key: address, public_key etc.. Am I thinking right or is it more complicated?

Thanks.

Why the maximum possible from_int() value is 115792089237316195423570985008687907852837564279074904382605163141518161494337

but the maximum number of possible bitcoin address is 1,461,501,637,330,902,918,203,684,832,716,283,019,655,932,542,976

?

I've followed the docs and managed to only be able to produce an uncompressed address however Bitcoin has both compressed and uncompressed for P2PKH. I can do it in go using btcutils, but I can't find documentation on how to do it with bit. Additionally this library's documentation also seem to lack documentation for generating addresses that aren't either Legacy or Legacy Segwit addresses.

How can I generate compressed addresses?

@ofek

Is it possible to pay fee from transaction and not the whole amount of available currency?

For instance, when you send 0.01 BTC you pay a fee from your wallet, but I want to pay fee from this exact amount and the client will receive 0.01 - fee BTC.

How can I do this?

@ofek

Imagine I have 1 USD on my account, which is something near 0.000059. So key.get_balance('btc') equals to 0.000059.

Then, I am trying to send this amount using leftover like this:

key.send([], leftover='<addr>')

But have Insufficient funds error.

I think this is because the amount which is on my wallet is too small and even less than the transaction fee. Then, how to send this amount?

Waiting for your reply, Thanks

Hi everyone,

I make a transaction with this code:

txHex = my_key.send([(to, amount,'btc')])

Yesterday works fine for me but today, impossible, I get this message: ConnectionError: Transaction broadcast failed, or Unspents were already used.

And I have founds inside, in fact finally, I make a transaction with Coinomi Wallets and works perfect...

Any idea??

Thanks