It sounds like you want to just fill an order but your code is attempting to do it through meta transactions, which is what executeTransaction() does.
To execute a fill through a meta-transaction, the taker will need to sign the meta-transaction object as well, and that is the signature that goes into executeTransaction(). @0x/order-utils has helpers for ...
There's no standard way to generate tokenIds, developers have ample freedom to create them.
The signature requirements implies that only the owner's key can be used to authorize a new tokenId. Once a tokenId was signed then any account can mint that tokenId.
Based on diagram above, sending the JSON data from client to backend is duplicative. That information is already public and well-known (it's published on the blockchain).
Instead, the request from client to backend should simply be like "tell me about token 15". And the server should know everything everything about token 15 at that time.
you can use Infura services. infura provide the web3.
first you have to create acc in infura after that you should make project. and at least you can use your own Id in this code : web3 = new Web3(new Web3.providers.HttpProvider("https://ropsten.infura.io/v3/3c68ea1...your ID...f301753"));
also you can use main net or ropsten network.
please check ...
It is important to differentiate between tx and message (aka internal tx). Based on this link.
A transaction is a cryptographically signed message that specifies what change is to be made, and it is sent to any node in the network.
The message that makes up the transaction is an RLP-encoded array that specifies the details of the transaction such as ...
Starting v1.0 you can use web3.eth.accounts.recover
// message, signature
web3.eth.accounts.recover('Some data', '0xb91467e570a6466aa9e9876cbcd013baba02900b8979d43fe208a4a4f339f5fd6007e74cd82e037b800186422fc2da167c747ef045e5d18a5f5d4300f8e1a0291c');
Most answers for verification are outdated.
Something like the following worked for me.
var msg = Buffer.from(msgstr);
const prefix = Buffer.from("\x19Ethereum Signed Message:\n");
var prefixedMsg = Buffer.concat([prefix,
prefixedMsg = Web3.utils.keccak256(prefixedMsg);
The signature has extra data at the beginning (they seems to be an 32 bytes offset, and 32 bytes string length).
Ideally the signature would look like this
If you ...
You can get this and more information by looking up RLP Encoding in Ethereum's Yellow Paper, as is explained here. To directly answer your question for your case:
Signature format is v ++ (length(r) + 0x80 ) ++ r ++ (length(s) + 0x80) ++ s, where + means addition and ++ means concatenation. Notice that length here means the amount of bytes, so that means the ...