Add NAME_IMPORT operation

blockstore/lib/operations/nameimport.py

@@ -0,0 +1,169 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+"""
+    Blockstore
+    ~~~~~
+    copyright: (c) 2014 by Halfmoon Labs, Inc.
+    copyright: (c) 2015 by Blockstack.org
+    
+    This file is part of Blockstore
+    
+    Blockstore is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+    
+    Blockstore is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+    You should have received a copy of the GNU General Public License
+    along with Blockstore.  If not, see <http://www.gnu.org/licenses/>.
+"""
+
+from pybitcoin import embed_data_in_blockchain, \
+    analyze_private_key, serialize_sign_and_broadcast, make_op_return_script, \
+    make_pay_to_address_script, b58check_encode, b58check_decode
+ 
+from pybitcoin.transactions.outputs import calculate_change_amount
+from utilitybelt import is_hex
+from binascii import hexlify, unhexlify
+
+from ..b40 import b40_to_hex, bin_to_b40, is_b40
+from ..config import *
+from ..scripts import blockstore_script_to_hex, add_magic_bytes
+from ..hashing import hash256_trunc128
+
+def calculate_basic_name_tx_fee():
+    return DEFAULT_OP_RETURN_FEE
+
+
+def get_import_update_hash_from_outputs( outputs, recipient ):
+    """
+    Given the outputs from a name import operation, and the
+    recipient's script_pubkey string, find the update hash output.
+    
+    By construction, it will be the address of the second non-OP_RETURN 
+    output (i.e. the third output).  By process of 
+    elimination, it will be the only non-OP_RETURN output 
+    that is not the recipient.
+    """
+    
+    ret = None
+    count = 0
+    for output in outputs:
+       
+        output_script = output['scriptPubKey']
+        output_asm = output_script.get('asm')
+        output_hex = output_script.get('hex')
+        output_addresses = output_script.get('addresses')
+        
+        if output_asm[0:9] != 'OP_RETURN' and output_hex is not None and output_hex != recipient:
+            
+            ret = b58check_decode( str(output_addresses[0]) )
+            break
+            
+    if ret is None:
+       raise Exception("No update hash found")
+    
+    return ret 
+
+
+def build(name, testset=False):
+    """
+    Takes in a name to import.  Name must include the namespace ID.
+    
+    Record format:
+    
+    0    2  3                             39
+    |----|--|-----------------------------|
+    magic op   name.ns_id (34 bytes)
+    
+    The transaction itself will have two outputs:
+    * the recipient
+    * the hash of the name's associated data
+    """
+    
+    if not is_b40( name ) or "+" in name or name.count(".") > 1:
+       raise Exception("Name '%s' has non-base-38 characters" % name)
+    
+    name_hex = hexlify(name)
+    if len(name_hex) > LENGTHS['blockchain_id_name'] * 2:
+       # too long
+      raise Exception("Name '%s' too long (exceeds %d bytes)" % (fqn, LENGTHS['blockchain_id_name']))
+    
+    readable_script = "NAME_IMPORT 0x%s" % (hexlify(name))
+    hex_script = blockstore_script_to_hex(readable_script)
+    packaged_script = add_magic_bytes(hex_script, testset=testset)
+    
+    return packaged_script
+
+
+def make_outputs( data, inputs, new_name_owner_address, change_address, update_hash_b58, format='bin', fee=None, op_return_amount=DEFAULT_OP_RETURN_VALUE, name_owner_amount=DEFAULT_DUST_SIZE):
+    """
+    Builds the outputs for a name import:
+    * [0] is the OP_RETURN 
+    * [1] is the new owner (recipient)
+    * [2] is the update hash
+    * [3] is the debit to the original owner
+    """
+    if fee is None:
+       fee = calculate_basic_name_tx_fee()
+        
+    total_to_send = op_return_amount + name_owner_amount + DEFAULT_DUST_SIZE
+    
+    return [
+        # main output
+        {"script_hex": make_op_return_script(data, format=format),
+         "value": op_return_amount},
+    
+        # new name owner output
+        {"script_hex": make_pay_to_address_script(new_name_owner_address),
+         "value": name_owner_amount},
+        
+        # update hash output
+        {"script_hex": make_pay_to_address_script(update_hash_b58),
+         "value": DEFAULT_DUST_SIZE},
+        
+        # change output
+        {"script_hex": make_pay_to_address_script(change_address),
+         "value": calculate_change_amount(inputs, total_to_send, fee)}
+    ]
+
+
+def broadcast(name, destination_address, update_hash, private_key, blockchain_client, fee=None, testset=False):
+   
+    nulldata = build(name, testset=testset)
+    
+    # get inputs and from address
+    private_key_obj, from_address, inputs = analyze_private_key(private_key, blockchain_client)
+    
+    # convert update_hash from a hex string so it looks like an address
+    update_hash_b58 = b58check_encode( unhexlify(update_hash) )
+    
+    # build custom outputs here
+    outputs = make_outputs(nulldata, inputs, destination_address, from_address, update_hash_b58, fee=fee, format='hex')
+    
+    # serialize, sign, and broadcast the tx
+    response = serialize_sign_and_broadcast(inputs, outputs, private_key_obj, blockchain_client)
+    
+    # response = {'success': True }
+    response.update({'data': nulldata})
+    
+    # return the response
+    return response
+
+
+def parse(bin_payload, recipient, update_hash ):
+    """
+    # NOTE: first three bytes were stripped
+    """
+    
+    fqn = bin_payload
+    
+    return {
+        'opcode': 'NAME_IMPORT',
+        'name': fqn,
+        'recipient': hexlify(recipient),
+        'update_hash': hexlify(update_hash)
+    }