mcamou/py-multiformats

Python implementation of multiformat protocols.

multiformats: Python implementation of multiformat protocols

Multiformats is a compliant implementation of multiformat protocols:

Contents

• Install
• Usage
  • Varint encode/decode
  • Multicodec wrap/unwrap
  • Multibase encode/decode
  • Multihash digest
  • Multihash wrap/unwrap
  • CID encode/decode
  • PeerID creation
  • Multiaddr parse/decode
  • Multiaddr protocols/addresses
  • Multiaddr encapsulation/decapsulation
• API
• Contributing
• License

Install

You can install the latest release from PyPI as follows:

$ pip install --upgrade multiformats

The following are mandatory dependencies for this module:

• typing-extensions, for backward compatibility of static typing.
• typing-validation, for dynamic typechecking
• bases, for implementation of base encodings used by Multibase

The following are optional dependencies for this module:

• pysha3, for the keccak hash functions.
• blake3, for the blake3 hash function.
• pyskein, for the skein hash functions.
• mmh3, for the murmur3 hash functions.
• pycryptodomex, for the ripemd-160 hash function, the kangarootwelve hash function and the sha2-512-224/sha2-512-256 hash functions.

You can install the latest release together with all optional dependencies as follows:

$ pip install --upgrade multiformats[full]

Usage

You can import multiformat protocols directly from top level:

>>> from multiformats import *

The above will import the following names:

varint, multicodec, multibase, multihash, multiaddr, CID

The first five are modules implementing the homonymous specifications, while CID is a class for Content IDentifiers. Below are some basic usage examples, to get you started: for detailed documentation, see https://multiformats.readthedocs.io/

Varint encode/decode

>>> varint.encode(128)
b'\x80\x01'
>>> varint.decode(b'\x80\x01')
128

Multicodec wrap/unwrap

Procedural style:

>>> raw_data = bytes([192, 168, 0, 254])
>>> multicodec_data = multicodec.wrap("ip4", raw_data)
>>> raw_data.hex()
  'c0a800fe'
>>> multicodec_data.hex()
'04c0a800fe'
>>> codec, _raw_data = multicodec.unwrap(multicodec_data)
>>> _raw_data.hex()
  'c0a800fe'
>>> codec
Multicodec(name='ip4', tag='multiaddr', code='0x04',
           status='permanent', description='')

Object-oriented style:

>>> ip4 = multicodec.get("ip4")
>>> ip4
Multicodec(name='ip4', tag='multiaddr', code='0x04',
           status='permanent', description='')
>>> raw_data = bytes([192, 168, 0, 254])
>>> multicodec_data = ip4.wrap(raw_data)
>>> raw_data.hex()
  'c0a800fe'
>>> multicodec_data.hex()
'04c0a800fe'
>>> ip4.unwrap(multicodec_data).hex()
  'c0a800fe'

Multibase encode/decode

Procedural style:

>>> multibase.encode(b"Hello World!", "base32")
'bjbswy3dpeblw64tmmqqq'
>>> multibase.decode('bjbswy3dpeblw64tmmqqq')
b'Hello World!'

Object-oriented style:

>>> base32 = multibase.get("base32")
>>> base32.encode(b"Hello World!")
'bjbswy3dpeblw64tmmqqq'
>>> base32.decode('bjbswy3dpeblw64tmmqqq')
b'Hello World!'

Multihash digest

Procedural style:

>>> data = b"Hello world!"
>>> digest = multihash.digest(data, "sha2-256")
>>> digest.hex()
'1220c0535e4be2b79ffd93291305436bf889314e4a3faec05ecffcbb7df31ad9e51a'

Object-oriented style:

>>> sha2_256 = multihash.get("sha2-256")
>>> digest = sha2_256.digest(data)
>>> digest.hex()
'1220c0535e4be2b79ffd93291305436bf889314e4a3faec05ecffcbb7df31ad9e51a'

Optional truncated digests:

>>> digest = multihash.digest(data, "sha2-256", size=20)
#        optional truncated hash size, in bytes ^^^^^^^
>>> digest.hex()
'1214c0535e4be2b79ffd93291305436bf889314e4a3f'

Multihash wrap/unwrap

Procedural style:

>>> digest.hex()
'1214c0535e4be2b79ffd93291305436bf889314e4a3f'
>>> raw_digest = multihash.unwrap(digest)
>>> raw_digest.hex()
    'c0535e4be2b79ffd93291305436bf889314e4a3f'
>>> multihash.wrap(raw_digest, "sha2-256").hex()
'1214c0535e4be2b79ffd93291305436bf889314e4a3f'

Object-oriented style:

>>> sha2_256 = multihash.get("sha2-256")
>>> raw_digest = sha2_256.unwrap(digest)
>>> raw_digest.hex()
    'c0535e4be2b79ffd93291305436bf889314e4a3f'
>>> sha2_256.wrap(raw_digest).hex()
'1214c0535e4be2b79ffd93291305436bf889314e4a3f'

CID encode/decode

Decoding from multibase encoded strings:

>>> cid = CID.decode("zb2rhe5P4gXftAwvA4eXQ5HJwsER2owDyS9sKaQRRVQPn93bA")
>>> cid
CID('base58btc', 1, 'raw',
  '12206e6ff7950a36187a801613426e858dce686cd7d7e3c0fc42ee0330072d245c95')
>>> cid.base
Multibase(name='base58btc', code='z',
          status='default', description='base58 bitcoin')
>>> cid.codec
Multicodec(name='raw', tag='ipld', code='0x55',
           status='permanent', description='raw binary')
>>> cid.digest.hex()
'12206e6ff7950a36187a801613426e858dce686cd7d7e3c0fc42ee0330072d245c95'
>>> cid.hashfun
Multicodec(name='sha2-256', tag='multihash', code='0x12',
           status='permanent', description='')
>>> cid.raw_digest.hex()
    '6e6ff7950a36187a801613426e858dce686cd7d7e3c0fc42ee0330072d245c95'

Multibase encoding:

>>> str(cid) # encode with own multibase 'base58btc'
'zb2rhe5P4gXftAwvA4eXQ5HJwsER2owDyS9sKaQRRVQPn93bA'
>>> cid.encode("base32") # encode with different multibase
'bafkreidon73zkcrwdb5iafqtijxildoonbwnpv7dyd6ef3qdgads2jc4su'

PeerID creation

Creation of CIDv1 PeerIDs:

>>> pk_bytes = bytes.fromhex( # hex-string of 32-byte Ed25519 public key
... "1498b5467a63dffa2dc9d9e069caf075d16fc33fdd4c3b01bfadae6433767d93")
>>> peer_id = CID.peer_id(pk_bytes)
>>> peer_id
CID('base32', 1, 'libp2p-key',
'00201498b5467a63dffa2dc9d9e069caf075d16fc33fdd4c3b01bfadae6433767d93')
#^^   0x00 = 'identity' multihash used (public key length <= 42)
#  ^^ 0x20 = 32-bytes of raw hash digest length
>>> str(peer_id)
'bafzaaiautc2um6td375c3soz4bu4v4dv2fx4gp65jq5qdp5nvzsdg5t5sm'

Multiaddr parse/decode

>>> s = '/ip4/127.0.0.1/udp/9090/quic'
>>> multiaddr.parse(s)
Multiaddr(Addr('ip4', '127.0.0.1'), Addr('udp', '9090'), Proto('quic'))
>>> b = bytes.fromhex('047f00000191022382cc03')
>>> multiaddr.decode(b)
Multiaddr(Addr('ip4', '127.0.0.1'), Addr('udp', '9090'), Proto('quic'))

Multiaddr protocols/addresses

Accessing multiaddr protocols:

>>> ip4 = multiaddr.proto("ip4")
>>> ip4
Proto("ip4")
>>> udp = multiaddr.proto("udp")
>>> quic = multiaddr.proto("quic")

Creating protocol addresses from human-readable strings:

>>> a = ip4/"192.168.1.1"
>>> a
Addr('ip4', '192.168.1.1')
>>> str(a)
'/ip4/192.168.1.1'
>>> a.value
'192.168.1.1'
>>> bytes(a).hex()
'04c0a80101'
>>> a.value_bytes.hex()
  'c0a80101'

Creating protocol addresses from bytestrings:

>>> a = ip4/bytes([192, 168, 1, 1])
>>> a
Addr('ip4', '192.168.1.1')

Multiaddr encapsulation/decapsulation

Creating multiaddresses by protocol encapsulation:

>>> ma = ip4/"127.0.0.1"/udp/9090/quic
>>> ma
Multiaddr(Addr('ip4', '127.0.0.1'), Addr('udp', '9090'), Proto('quic'))
>>> str(ma)
'/ip4/127.0.0.1/udp/9090/quic'

Bytes for multiaddrs are computed according to the (TLV)+ multiaddr format:

>>> bytes(ip4/"127.0.0.1").hex()
'047f000001'
>>> bytes(udp/9090).hex()
          '91022382'
>>> bytes(quic).hex()
                  'cc03'
>>> bytes(ma).hex()
'047f00000191022382cc03'

Protocol decapsulation by indexing and slicing:

>>> ma[0]
Addr('ip4', '127.0.0.1')
>>> ma[:2]
Multiaddr(Addr('ip4', '127.0.0.1'), Addr('udp', '9090'))
>>> ma[1:]
Multiaddr(Addr('udp', '9090'), Proto('quic'))

API

For the full API documentation, see https://multiformats.readthedocs.io/

The tables specifying all multicodecs and multibases known to this package are maintained as part of the multiformats-config repository.

Contributing

Please see CONTRIBUTING.md.

License

MIT © Hashberg Ltd.