Questions tagged [keccak]
keccak is a cryptographic family which is used in ethereum and nowerdays provides the standards for sha-3
194
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Verify signature from dApp on contract
I am creating a signed message using a user address, nonce and number (amount of eth to send) like this:
const ammount = 1;
const userAddr = await otherAccount.address
const nonce = ...
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1
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How to detect `Keccak256` collision inputs
I'm trying to solve this -simple- small CTF challenge, the goal is to change the solver value to our address by calling the talk function:
// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8....
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1
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Signing message using web3 and using ethers gives different result. Why?
I'm encoding a message using ethers' solidityPackedKeccak256()
const encodedMessage = ethers.solidityPackedKeccak256(
["address", "uint256", "uint256"],
...
1
vote
1
answer
21
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How to create a hash based on struct array types?
I have the following arguments to call a function in a smart contract:
ERC20Reward[] calldata _erc20Rewards
ERC721Reward[] calldata _erc721Rewards
ERC1155Reward[] calldata _erc1155Rewards
...
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How to reverse keccak256 in solidity
I need help with the following code where I'm given the keccak256 of a parameter and need to reverse it to find the parameter to solve the challenge
contract LessonFive is AFoundryCourseChallenge {
...
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1
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179
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How to use ethers.js keccak256 along with a salt phrase so that it's compatible with Solidity keccak256 function?
I have a Solidity 0.4.26 smart contract. I'm using a commit-reveal pattern to hide to first user's commitment move.
I have a helper contract Hasher that hashes the user's commitment with a hash() ...
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How to manually hash blocks and transactions to get a better feel for the Ethereum protocol?
Is there a way to easily get a transaction, the full transaction payload, and then hash it with keccak256 using a hash tool, to get a better feel for how the protocol works?
Ditto for full blocks.
I ...
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209
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"invalid signature length" when trying to verify signature
I'm using the entire source code to sign and verify messages from https://solidity-by-example.org/signature/ on Remix. But when I go through the process of running the functions getMessageHash, ...
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1
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1
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82
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Does casting a Keccak256 hash to a uint256 increase likelihood of a collision?
I have a smart contract with 50+ trillion possible NFT names that could be minted (all have unique names), is there any chance that this method could cause a collision of token ID's? -
uint256 tokenID ...
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40
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Custom digital signature of a wallet
I would like to get a custom signature from a wallet. What I mean is, according to EIP-712 the signature algorithm used in Ethereum is kekkac256; I would like instead to use a custom signature ...
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MerkleTree hashing keccak256 in golang is different with in js
I am dealing with hashing keccak256 of address and amount to push to merkle tree in golang. I try to hash in js by using https://github.com/OpenZeppelin/merkle-tree lib and it is valid. but in golang ...
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141
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Python | eth_utils | Public Ethereum Address derivation from Public key not working
I have the below, trying to derive the Ethereum Address from public key (working) using keccak and to_checksum_address on eth_util, but doesn't match up with derivation on iancoleman.io or miguelmota....
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2
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1
answer
39
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Verifying OTP on-chain (keccak vs ecdsa)
I am looking to build a smart contract that enables a user to withdraw the contract funds via a one-time-password provided by the creator.
My idea was to hash a password off-chain and store that ...
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4
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1
answer
547
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The Solidity 'keccak256' and the Javascript ethers.js 'solidityKeccak256' produces different output
I'm trying to code a signature like opensea does for approving the Terms of Service.
To do so I'm using the ECDSA library.
This code in javascript using ethers:
const message = ethers.utils....
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242
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The definition and Implementation of the Keccak256() function
So I don't know if this is a silly/obvious question or not but after many hours I turn to the community for help.
So for the past few days I've been writing my own C++ code to take an input public key ...
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3
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1
answer
234
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calldata ambiguity - likelihood of hash collision
To call a function in a smart contract, a transaction (or a message call depending on where it originates from) is sent to the contract address with a data field that has the encoded function ...
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38
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To hash or not to hash strings for bytes32 AccessControl roles
Is there a preferred/safest way to declare roles for Openzeppelin's AccessControl.sol?
I would imagine a straight assignment of a bytes32 from a string would be sufficient for role creation as long as ...
2
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3
answers
388
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possible to calculate keccak256(abi.encodePacked("abc")) in DAPP layer?
In my solidity code, I am doing a lot of stuff like this:
keccak256(abi.encodePacked("abc", "def"))
And then returning the value in an event, which is picked up in dapp.
Now, since ...
- 265
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118
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How to use keccak256 in assembly instead of keccack256(abi.encodePacked(address))?
I'm trying to use assembly to compare the gas usage of two implementations of the same function.
The following works correctly:
// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.17;
import ...
0
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2
answers
501
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Blockhash and Block Timestamp manipulation in PoS
I was looking at generating some psuedo-random numbers in an Etheresum smart contract and understand that it is possible for miners to manipulate the blockhash and block.timestamp. The Solidity ...
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2
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How come these 2 Ethereum addresses are identical except for 1 character?
I always assumed that Ethereum addresses were, more or less, uniformly (randomly) distributed over their 40-char hex representation.
Is that not the case?
I've found these 2 addresses that only differ ...
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69
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Getting wrong signature while using etherjs in react native
I'm trying to get the signature using etherjs in a react native project which should be compatible with ECDSA.sol,
When i try to get the signature with metamask it returns totally fine. but when i try ...
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1
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76
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I want to encode and store the address variable and the uint256 variable
I am currently using it as follows.
bytes memory _byte = abi.encode(ca, tokenId);
I learned that this method can take different variables and produce the same results.
If I use the keccak256 function,...
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1
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167
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Same value for keccak256 in different contracts
In Solidity, let's say there are two contracts A and B with the same code as in the following example. By the way, do they return the same bytes32 value when retrieving ROLE? Why do we use keccak256 ...
- 375
1
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1
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594
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Recover public key from signature and address only works with MetaMask provider
I have to implement a login system with a web3modal using WalletConnect & MetaMask.
After many attempts, it seems that all the existing source codes about this on the internet only work with ...
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0
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174
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EIP712 - Unable to verify signature return from js
I am trying to verify a signed message in my smart contract that I generated from javascript. I followed another example but for some reason can't figure out why the verify function keeps returning ...
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1
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1
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204
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Whta's difference between web3.utils.toHex() and web3.utils.keccak256()?
I've been practicing Ethernaut CTF and I'm stuck on the Delegation problem.
First, I tried to approach this in the console. But I couldn't get ownership.
var pwn = web3.utils.toHex("pwn()")
...
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221
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Keccak256 hashing of types and values in Java
I'm trying to use the Web3j library (or any other library for that matter) to Keccak256-hash a list of types and a list of values to sign a quote. Specifically, I need to implement the second code ...
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57
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Convert kecka256 hash string back to bytes32
I am storing kecccak256 to hash some string value and store it as mapping.
mapping(bytes32 => address) internal _owners;
and my mint function looks like this -
function _mint(address to, string ...
2
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1
answer
45
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What information can I get from a hash?
Say i have a hash - I think sha256/keccak:
90ad6dec4ce7167e92c7a7122232d48a1fd5e6c5e81cb3f45c147424b6728437
What do i do with it?
Is there something on etherscan that can decipher it or show what it ...
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2
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1
answer
77
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Question about the namehash algorithm in EIP-137
I am trying to recreate the namehash algorithm from EIP-137.
After spending a lot of time trying to create my own algorithm, I tried to find a working python3 package online and couldn't find any.
I ...
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1
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1
answer
103
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Cannot generate Ethereum address from private key
I am trying to use the Bitcoin ECDSA Library to generate an Ethereum address from a private key. I took the private key from my Metamask wallet then used the following code to generate the public key.
...
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1
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306
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What's the probability of getting the same signature using ECDSA?
If I hash the message "HELLO" - keccak256("Hello")
then run it to an ECDSA, what's the probability that I will get the same r, s and v value everytime?
Do I need to add some unique ...
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1
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333
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ecrecover returns incorrect address
I use these contract functions to verify signed message:
function verify(
address to,
uint256 amount,
uint256 nonce,
bytes memory signature
) public view returns (...
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votes
1
answer
139
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Signature from array of tokenId's isn't verifying
The domain message is:
struct Offer{
address from;
address to;
uint256 nonce;
uint256[] tokenIds;
uint256 duration;
}
bytes32 constant ...
0
votes
1
answer
370
views
Why does web3j and javascript keccak256 return different hashes if '0x' is at the start of the string?
We are trying to build a merkle tree in web3j and put the root for verification into the smart contract. Due to this problem we can't generate the same route between web3j and solidity/js...
In ...
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vote
1
answer
61
views
How to compare string and bytes32 in an optimal way?
I have keccak256 string encrypt in blockchain and keccak256(decrypt) bytes in function.
This code works well. I pass an unencrypted string to the function and check it for validity.
// SPDX-License-...
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1
vote
2
answers
172
views
Cannot get correct MethodID from a function
I am trying to derive the MethodID from the function, based on this post.
However, when I look at this transaction on Etherscan, I cannot see how swapExactTokensForETHSupportingFeeOnTransferTokens(...
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vote
1
answer
414
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Python Merkle Tree Libraries Don't Produce The Same Merkle Root As Node.js's "merkletreejs"
I have been trying to create merkle tree proofs in python.
In a whitelisted NFT project, I've used npm's merkletreejs which is a JavaScript library and it worked beautifully. Here is the Github page ...
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679
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Recover Parameter from given signed message
I got a problem with keccak hashing.
The Goal:
A Server should create a parameter list and a sign. (I try it here with just one uint256 parameter)
The Contract should check if the sign fits with the ...
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1
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20
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missing encodePacket / .abi + keccak256
I'm not 100% sure how to describe my issue, total noob following the BlindAuction solidity tutorial and stuck unable to compile. any help is much appreciated.
function generateBlindedBidBytes32(uint ...
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1
answer
491
views
generate function name yielding a specific function selector
Suppose I have a function with arguments (address _to, uint256 number)
The function selector is found using
let signature = "name(address,uint256)";
let selector = Keccack256(signature) ;
I ...
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1
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180
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Need help trying to replicate ethers.utils.solidityKeccak256 in a Rails 6 controller
I'm not super familiar with Ruby or Rails, but I basically need to replicate this Javascript that uses ethersjs and call it from a Rails 6 controller. Anyone have any ideas how to achieve this? I've ...
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1
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1
answer
1k
views
use javascript merkle tree to generate hex proof for solidity merkletree validation
Here is my js code of generating hex proof for solidity verification
const express = require('express')
const { MerkleTree } = require('merkletreejs');
const { bufferToHex } = require('ethereumjs-util'...
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1
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34
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when i call my function metamask telling "this operation is expected to fail"
Hi guys im trying to create question challenge dapp and i have a checkAnswer() function can accessable from frontend.
My question struct:
struct Question{
string qDesc;
uint qPrize;...
0
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1
answer
258
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Recover address from signature works only with MetaMask
I try to implement Web3 login to my page. It works with MetaMask, but with other wallets (like LRC, Coinbase or Argent) it doesn't - recovered address differs from the original one.
Ethereum\EcRecover ...
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1
vote
1
answer
728
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How to hash an address?
I just want to hash the senders' address
function myHash() public returns(string memory){
return(keccak256(abi.encodePacked(msg.sender)));
}
but no matter what I do I get the ...
- 67
1
vote
1
answer
275
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What is the max number of inputs that can be entered in a keccak256(abi.encodePacked()) function?
I'm learning to use the keccak function on an online Solidity tutorial, and seeing that this function takes three inputs:
uint(keccak256(abi.encodePacked(now, msg.sender, randNonce)))
made me wonder ...
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1
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552
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Different keccak256 for the same string
What is the reason that when i try to get the keccak256 values for the same string (which is "0x0000000000000000000000000000000000000000000000000000000000000001" or simply value of 1 in ...
0
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0
answers
24
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Go Ethereum "invalid signature recovery id" when recovery byte is >= 4 [duplicate]
I have a signed message that was generated by Metamask. It looks like this: ...
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