Questions tagged [decoding]

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How to decode a transaction to verify its signature in Javascript?

I noticed that it's possible to sign a transaction with a wrong private key. I took the following example found at https://github.com/ethereumjs/ethereumjs-tx const EthereumTx = require('ethereumjs-...
2
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1answer
1k views

How to unpack/decode parameters encoded with web3.eth.abi.encodeParameters in Solidity?

My client app (nodejs) packs some arguments to pass to a smart contracts as bytes _data (similar to ERC223 calls with fallback). I pack the arguments in my JS client like this: const packedArgs = ...
1
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0answers
32 views

Given just an Etheruem address, is there any way to tell if it's an ERC20 and/or an ERC721

If I have only an Ethereum address and only a locally running node (using a third party such as EtherScan or Alethio is cheating), is there any way to tell if that address is an ERC20 or an ERC721 ...
1
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0answers
240 views

How to decode Tx data? Online tool?

Is there a fast way to decode the data returning from a Smart Contract call? I know there are github projects with JS libraries to decode this kind of data (such as https://github.com/ConsenSys/abi-...
1
vote
0answers
451 views

How to decode the input data in java?

I receive the input data as the image shows. And when I try to decode it with the method: String inputdata = null; Optional<Transaction> tx = web3.ethGetTransactionByHash(txHash).send()....
0
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0answers
12 views

Solidity beginner exercise: Santa'slist

I am trying to implement the following exercise "Santa's list": Build a system for tracking who is on their nice list and who is on their naughty list. Furthermore, I do not want duplicates ...
0
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0answers
15 views

Ethereum Input Data Decoding

I Have the following input: ...
0
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0answers
15 views

Method's parameters: a way to know a uint256 is a token amount and its number of decimals?

When decoding transaction actions or logs, I never know how to human-read uint256 values when they are token amounts and, if so, how to know how many decimals they are. For the decimals, do I always ...
0
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0answers
46 views

How to read all logs from a transaction without having each contract ABI?

From a transaction logs, how do I decode every logs since I don't have all contracts ABI? Do I have to fetch the ABI every time I encounter an unknown contract? How do apps that display all logs deal ...
0
votes
1answer
55 views

Is Ethereum block header a list?

Decoding a RLP encoded block using Eth specifications do we get header as list? But as per format i.e., [[blockHeader,transactionList,uncleList],totalDifficulty], blockHeader should have been string. ...