Extract Metadata From Bytecode

There could be a metadata on the deployed bytecode. The current version of the Solidity compiler usually adds the following to the end of the deployed bytecode

0xa2
0x64 'i' 'p' 'f' 's' 0x58 0x22 <34 bytes IPFS hash>
0x64 's' 'o' 'l' 'c' 0x43 <3 byte version encoding>
0x00 0x33

It is explained in the documentation deeply. So we know that ipfs keyword's hex value is 69706673.

>>> 'ipfs'.encode('utf-8').hex() 
'69706673'

So if we see that sign in the deployed contract, we can retrieve the ipfs data and take a look it with given script

import base58
import requests

bytecode = "0x6080604052348015600f57600080fd5b5060043610603c5760003560e01c80630dbe671f1460415780634df7e3d014605b578063cc8e2394146075575b600080fd5b6047608f565b6040516052919060b8565b60405180910390f35b60616095565b604051606c919060b8565b60405180910390f35b607b609b565b6040516086919060b8565b60405180910390f35b60005481565b60015481565b60025481565b6000819050919050565b60b28160a1565b82525050565b600060208201905060cb600083018460ab565b9291505056fea264697066735822122054c3e28cded5e23f5b3ee244c86c623b672d772b268fdc5e76e4fe131e690bea64736f6c634300060b0033"

ipfs_prefix = "a264697066735822"
ipfs_prefix_index = bytecode.find(ipfs_prefix)

if ipfs_prefix_index != -1:
    ipfs_hash_bytes_start = ipfs_prefix_index + len(ipfs_prefix)
    ipfs_hash_bytes_end = ipfs_hash_bytes_start + 68
    ipfs_hash_bytes = bytecode[ipfs_hash_bytes_start:ipfs_hash_bytes_end]
    print("IPFS Hash Bytes:", ipfs_hash_bytes)

    # Convert to Multihash
    multihash = base58.b58encode(bytes.fromhex(ipfs_hash_bytes)).decode("utf-8") 
    print("IPFS Multihash:", multihash)
    print("IPFS could be found here:" , 'https://ipfs.io/ipfs/'+str(multihash))
else:
    print("IPFS prefix not found")

> python get_ipfs.py
IPFS Hash Bytes: 122054c3e28cded5e23f5b3ee244c86c623b672d772b268fdc5e76e4fe131e690bea
IPFS Multihash: QmU3YCRfRZ1bxDNnxB4LVNCUWLs26wVaqPoQSQ6RH2u86V
IPFS could be found here: https://ipfs.io/ipfs/QmU3YCRfRZ1bxDNnxB4LVNCUWLs26wVaqPoQSQ6RH2u86V