wownero-python/docs/source/address.rst
Michał Sałaban c51e3672a6 Update docs
2019-01-03 18:04:42 +00:00

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Addresses and payment IDs
=========================
In Monero v0.11.x the wallet had only one address. This is changing now. A
concept of **subaddress** has been introduced.
The first, original address of the wallet is usually known as the *master
address*. All others are just *subaddresses*, even if they represent a separate
account within the wallet.
Monero addresses are base58-encoded strings. You may disassemble each of them
using the excellent `address analysis tool`_ from *luigi1111*.
While the ordinary string representation is perfectly valid to use, you may
want to use validation and other features provided by the ``monero.address``
package.
.. _`address analysis tool`: https://xmr.llcoins.net/addresstests.html
Address validation and instatination
------------------------------------
The function ``monero.address.address()`` will recognize and validate Monero
address, returning an instance that provides additional functionality.
The following example uses addresses from the wallet :doc:`we have generated in
the previous chapter <wallet>`.
Let's start with the master address:
.. code-block:: python
In [1]: from monero.address import address
In [2]: a = address('A2GmyHHJ9jtUhPiwoAbR2tXU9LJu2U6fJjcsv3rxgkVRWU6tEYcn6C1NBc7wqCv5V7NW3zeYuzKf6RGGgZTFTpVC4QxAiAX')
In [3]: a.is_testnet()
Out[3]: True
In [4]: a.spend_key()
Out[4]: 'f0481b63cb937fa5960529247ebf6db627ff1b0bb88de9feccc3c504c16aa4b0'
In [5]: a.view_key()
Out[5]: '2c5ba76d22e48a7ea4ddabea3cce66808ba0cc91265371910f893962e977af1e'
In [6]: type(a)
Out[6]: monero.address.Address
We may use a subaddress too:
.. code-block:: python
In [7]: b = address('BenuGf8eyVhjZwdcxEJY1MHrUfqHjPvE3d7Pi4XY5vQz53VnVpB38bCBsf8AS5rJuZhuYrqdG9URc2eFoCNPwLXtLENT4R7')
In [8]: b.is_testnet()
Out[8]: True
In [9]: b.spend_key()
Out[9]: 'ae7e136f46f618fe7f4a6b323ed60864c20070bf110978d7e3868686d5677318'
In [10]: b.view_key()
Out[10]: '2bf801cdaf3a8b41020098a6d5e194f48fa62129fe9d8f09d19fee9260665baa'
In [11]: type(b)
Out[11]: monero.address.SubAddress
These two classes, ``Address`` and ``SubAddress`` have similar functionality
but one significant difference. Only the former may form *integrated address*.
Generating subaddresses
-----------------------
It is possible to get subaddresses in two ways:
1. Creating them in the wallet file by calling ``.new_address()`` on ``Account`` or ``Wallet``
instance. In properly synced wallet this will return an address that is guaranteed to be fresh
and unused. It is the right way if you plan to use one-time addresses to identify payments or
to improve your privacy by avoiding address reuse.
2. Requesting arbitrary subaddress by calling ``Wallet.get_address(major, minor)`` where ``major``
is the account index and ``minor`` is the index of the address within an account. Addresses
obtained this way are not guaranteed to be fresh and **will not be saved as already generated
within the wallet file**. (Watch out for unintentional address reuse!)
Payment IDs and integrated addresses
------------------------------------
Each Monero transaction may carry a **payment ID**. It is a 64 or 256-bit long
number that carries additional information between parties. For example, a
merchant can generate a payment ID for each order, or an exchange can assign
one to each user. The customer/user would then attach the ID to the transaction,
so the site operator would know what is the purpose of incoming payment.
A short, 64-bit payment ID can be integrated into an address, creating, well...
an **integrated address**.
.. code-block:: python
In [12]: ia = a.with_payment_id(0xfeedbadbeef)
In [13]: ia
Out[13]: ABySz66nm1QUhPiwoAbR2tXU9LJu2U6fJjcsv3rxgkVRWU6tEYcn6C1NBc7wqCv5V7NW3zeYuzKf6RGGgZTFTpVC623BT1ptXvVU2GjR1B
In [14]: ia.base_address()
Out[14]: A2GmyHHJ9jtUhPiwoAbR2tXU9LJu2U6fJjcsv3rxgkVRWU6tEYcn6C1NBc7wqCv5V7NW3zeYuzKf6RGGgZTFTpVC4QxAiAX
In [15]: ia.base_address() == a
Out[15]: True
In [16]: ia.payment_id()
Out[16]: 00000feedbadbeef
Since subaddresses have been introduced, merchants may generate a separate
address for each order, user or any other object they expect the payments
coming to. Therefore, it has been decided that `subaddresses cannot generate
integrated addresses`_.
.. _`subaddresses cannot generate integrated addresses`: https://monero.stackexchange.com/questions/6606/how-to-make-an-integrated-address-based-on-a-subaddress
.. code-block:: python
In [17]: b.with_payment_id(0xfeedbadbeef)
---------------------------------------------------------------------------
TypeError Traceback (most recent call last)
<ipython-input-23-5a5811a6962a> in <module>()
----> 1 b.with_payment_id(0xfeedbadbeef)
~/devel/monero-python/monero/address.py in with_payment_id(self, _)
99
100 def with_payment_id(self, _):
--> 101 raise TypeError("SubAddress cannot be integrated with payment ID")
102
103
TypeError: SubAddress cannot be integrated with payment ID
The ``monero.numbers.PaymentID`` class validates payment IDs. It accepts both
integer and hexadecimal string representations.
.. code-block:: python
In [18]: from monero.numbers import PaymentID
In [19]: p1 = PaymentID(0xfeedbadbeef)
In [20]: p2 = PaymentID('feedbadbeef')
In [21]: p1 == p2
Out[21]: True
In [22]: p1.is_short()
Out[22]: True
In [23]: p3 = PaymentID('1234567890abcdef0')
In [24]: p3
Out[24]: 000000000000000000000000000000000000000000000001234567890abcdef0
In [25]: p3.is_short()
Out[25]: False
Long payment IDs cannot be integrated:
.. code-block:: python
In [26]: a.with_payment_id(p3)
---------------------------------------------------------------------------
TypeError Traceback (most recent call last)
<ipython-input-31-7098746f0b69> in <module>()
----> 1 a.with_payment_id(p3)
~/devel/monero-python/monero/address.py in with_payment_id(self, payment_id)
73 payment_id = numbers.PaymentID(payment_id)
74 if not payment_id.is_short():
---> 75 raise TypeError("Payment ID {0} has more than 64 bits and cannot be integrated".format(payment_id))
76 prefix = 54 if self.is_testnet() else 19
77 data = bytearray([prefix]) + self._decoded[1:65] + struct.pack('>Q', int(payment_id))
TypeError: Payment ID 000000000000000000000000000000000000000000000001234567890abcdef0 has more than 64 bits and cannot be integrated
API reference
-------------
.. automodule:: monero.address
:members: