reconstruct_grin_transaction_history.py

# Scans all blocks from a Grin archive node to reconstruct a wallet's transaction history. All applicable UTXOs and when they were spent are logged to a file, and a brief overview of the wallet's transaction history is shown in the console. This code lacks any error checking. A wallet's rewind hash can be obtained by running the command `grin-wallet rewind_hash` with the Grin CLI wallet, https://github.com/mimblewimble/grin-wallet.


# Imports
from secp256k1_zkp_mw import *
from hashlib import blake2b
import requests
import time
from datetime import datetime


# Constants

# Rewind hash
REWIND_HASH = bytes.fromhex('99d92c1264de3edab618eeeb024533447c30c4d6549d70efc745fe385bd2862b')

# Server
SERVER = 'http://localhost:3413'


# Functions

# Format number
def formatNumber(number):

    # Return formatted number
    return '{:.9f}'.format(number / 1E9).rstrip('0').rstrip('.')


# Main function

# Create context
context = secp256k1_context_create(SECP256K1_CONTEXT_VERIFY | SECP256K1_CONTEXT_SIGN)

# Get the tip height from the node
tipHeight = requests.post(SERVER + '/v2/foreign', json = {
    'jsonrpc': '2.0',
    'id': 1,
    'method': 'get_tip',
    'params': []
}).json()['result']['Ok']['height']

# Set file name
fileName = 'transaction history ' + str(datetime.now()).split('.')[0] + '.txt'

# Display start message
print('Scanning to block %d and writing the transaction history to \'%s\' for the wallet with the rewind hash %s.' % (tipHeight, fileName, REWIND_HASH.hex()))

# Initialize current outputs
currentOutputs = {}

# Open file
with open(fileName, 'w') as file:

    # Initialize last percent time
    lastPercentTime = time.time()

    # Initialize mined amount
    minedAmount = 0
    
    # Initialized mined start block
    minedStartBlock = 0

    # Go through all blocks
    for i in range(tipHeight + 1):

        # Get block from the node
        block = requests.post(SERVER + '/v2/foreign', json = {
            'jsonrpc': '2.0',
            'id': 1,
            'method': 'get_block',
            'params': [
                i,
                None,
                None
            ]
        }).json()['result']['Ok']

        # Initialize spent amount
        spentAmount = 0

        # Initialize received amount
        receivedAmount = 0

        # Go through all inputs in the block
        for input in block['inputs']:

            # Check if input is a current outputs
            if input in currentOutputs:

                # Add input's amount to spent amount
                spentAmount += currentOutputs[input]

                # Write spent output message to file
                file.write('Spent output %s containing %s Grin in block %d at %s\n' % (input, formatNumber(currentOutputs[input]), i, block['header']['timestamp']))

                # Remove input from current outputs
                del currentOutputs[input]

        # Go through all outputs in the block
        for output in block['outputs']:

            # Get commit and proof from the output
            commit = bytes.fromhex(output['commit'])
            proof = bytes.fromhex(output['proof'])

            # Get rewind nonce for the commit
            rewindNonce = blake2b(REWIND_HASH, digest_size = 32, key = commit).digest()

            # Check if the output belongs to the wallet
            internalCommit = secp256k1_pedersen_commitment_parse(context, commit)
            outputData = secp256k1_bulletproof_rangeproof_rewind(context, proof, 0, internalCommit, secp256k1_generator_const_h, rewindNonce, None)

            if outputData is not None:

                # Get amount from the output data
                amount = outputData[0]

                # Check if output is a coinbase reward
                if output['output_type'] == 'Coinbase':

                    # Add output's amount to mined amount
                    minedAmount += amount

                # Otherwise
                else:

                    # Add output's amount to received amount
                    receivedAmount += amount

                # Write received output message to file
                file.write('Received %s output %s containing %s Grin in block %d at %s\n' % ('coinbase' if output['output_type'] == 'Coinbase' else 'transaction', output['commit'], formatNumber(amount), i, block['header']['timestamp']))

                # Add output to current outputs
                currentOutputs[output['commit']] = amount

        # Check if amount was spent or received
        if spentAmount != 0 or receivedAmount != 0:

            # Check if mined amount exists
            if minedAmount != 0:

                # Show mined amount message
                print('You mined %s Grin from block %d to block %d.' % (formatNumber(minedAmount), minedStartBlock, i))

                # Reset mined amount
                minedAmount = 0
                
                # Reset mined start block
                minedStartBlock = i + 1

            # Check if more was spent than received
            if spentAmount > receivedAmount:

                 # Show spent and received amount message
                print('You spent %s Grin and received %s Grin in block %d at %s. You probably sent someone %s Grin including fees.' % (formatNumber(spentAmount), formatNumber(receivedAmount), i, block['header']['timestamp'], formatNumber(spentAmount - receivedAmount)))

            # Otherwise
            else:

                # Show spent and received amount message
                print('You spent %s Grin and received %s Grin in block %d at %s.' % (formatNumber(spentAmount), formatNumber(receivedAmount), i, block['header']['timestamp']))

        # Get current time
        currentTime = time.time()

        # Check if a minute has passed since the last percent time
        if currentTime - lastPercentTime >= 60:

            # Show percent complete message
            print('%s%% complete.' % ('{:.9f}'.format(i / tipHeight * 100).rstrip('0').rstrip('.')))

            # Update last percent time
            lastPercentTime = currentTime

    # Check if mined amount exists
    if minedAmount != 0:

        # Show mined amount message
        print('You mined %s Grin from block %d to block %d.' % (formatNumber(minedAmount), minedStartBlock, tipHeight))

# Show done scanning message
print('Done scanning.')

# Initialize balance
balance = 0

# Go through all current outputs
for output in currentOutputs:

    # Add output's amount to balance
    balance += currentOutputs[output]

# Show current balance message
print('Current balance is %s Grin.' % (formatNumber(balance)))

# Destroy the context
secp256k1_context_destroy(context)