Here is the script to generate Ethereum address in Node.JS
How can i use the below script in Flutter to generate Ethereum address?
const hdwallet = hdkey.fromMasterSeed(seed); // used bip39 to get seed
const itsMyWallet = hdwallet.derivePath("m/44'/60'/0'/0").getWallet();
console.log(`Address: ${itsMyWallet.getAddressString()}`);
console.log(`Private Key: ${itsMyWallet.getPrivateKeyString()}`);
I know how to generated mnemonic in flutter with bip39 package, some coding part i have added below,
Problem is i am not getting ethereumjs-wallet/hdkey package in flutter packages
You could try and use a flutter package for Ethereum known as ethereum 4.0.1 which can be found here. It may have what you are looking for, but if it doesn't it is because it is still currently in development, but it does implement most of the standard Ethereum api's
You can use my gist
Basically it will
Convert the privateKey to bigInt
Extract PublicKey
addressDigest = keccak256(publicKey)
address = last 20 bytes of addressDigest
You can also use my toChecksumAddress gist to convert above address to checksumAddress
Related
I'm following this Elrond NFTs smart contracts (from scratch part 2) tutorial: https://www.youtube.com/watch?v=jpJQ-YB4NnQ
I successfully compile the smart contract but when I use . interaction/devnet.snippets.sh I do not get the smart contract address, as can be seen in this log.
Because of this, I cannot run the issueToken function.
can anyone help?
INFO:accounts:Account.sync_nonce()
INFO:accounts:Account.sync_nonce() done: 10733
INFO:cli.contracts:Contract address: erd1qqqqqqqqqqqqqpgq093ggau3mcjq4p5ln7skvtrk4wjhyfpwd8ssjj45qw
INFO:utils:View this contract address in the Elrond Devnet Explorer: https://devnet-explorer.elrond.com/accounts/erd1qqqqqqqqqqqqqpgq093ggau3mcjq4p5ln7skvtrk4wjhyfpwd8ssjj45qw
INFO:transactions:Transaction.send: nonce=10733
INFO:transactions:Hash: 4f25756f9246985732038eccc0cbc4fda480b8409fcc70dff089c1d59684e652
INFO:utils:View this transaction in the Elrond Devnet Explorer: https://devnet-explorer.elrond.com/transactions/4f25756f9246985732038eccc0cbc4fda480b8409fcc70dff089c1d59684e652
WARNING:cli.data:Always review --expression parameters before executing this command!
WARNING:cli.data:Always review --expression parameters before executing this command!
WARNING:cli.data:Never use this command to store sensitive information! Data is unencrypted.
INFO:cli.data:Data has been stored at key = 'address-devnet', in partition = '*'.
WARNING:cli.data:Never use this command to store sensitive information! Data is unencrypted.
INFO:cli.data:Data has been stored at key = 'deployTransaction-devnet', in partition = '*'.
Smart contract address:
The outfile log structure changed in the meantime and you're most likely still looking for data in the old structure.
Now, the address in the new log structure is stored under the ['contractAddress'] key instead of ['emitted_tx']['address'], respectively transaction hash into ['emittedTransactionHash'] instead of ['emitted_tx']['address'].
Therefore, you have to change these lines:
TRANSACTION=$(erdpy data parse --file="${MY_LOGS}/deploy-devnet.interaction.json" --expression="data['emitted_tx']['hash']")
ADDRESS=$(erdpy data parse --file="${MY_LOGS}/deploy-devnet.interaction.json" --expression="data['emitted_tx']['address']")
to these:
TRANSACTION=$(erdpy data parse --file="${MY_LOGS}/deploy-devnet.interaction.json" --expression="data['emittedTransactionHash']")
ADDRESS=$(erdpy data parse --file="${MY_LOGS}/deploy-devnet.interaction.json" --expression="data['contractAddress']")
I am stumbling my way through writing a dissector for our custom protocol in Lua. While I have basic field extraction working, many of our fields have scale factors associated with them. I'd like to present the scaled value in addition to the raw extracted value.
It seems to me tree_item:add_packet_field is tailor-made for this purpose. Except I can't get it to work.
I found Mika's blog incredibly helpful, and followed his pattern for breaking my dissector into different files, etc. That's all working.
Given a packet type "my_packet", I have a 14-bit signed integer "AOA" that I can extract just fine
local pref = "my_packet"
local m = {
aoa = ProtoField.new("AOA", pref .. ".aoa", ftypes.INT16, nil, base.DEC, 0x3FFF, "angle of arrival measurement"),
}
local option=2
local aoa_scale = 0.1
function m.parse(tree_arg, buffer)
if option == 1 then
-- basic field extraction. This works just fine. The field is extracted and added to the tree
tree_arg:add(m.aoa, buffer)
elseif option == 2 then
-- This parses and runs. The item is decoded and added to the tree,
-- but the value of 'v' is always nil
local c,v = tree_arg:add_packet_field(m.aoa, buffer, ENC_BIG_ENDIAN)
-- this results in an error, doing arithmetic on 'nil'
c:append_text(" (scaled= " .. tostring(v*aoa_scale) .. ")")
end
end
(I use ProtoField.new instead of any of the type-specific variants for consistency in declaring my fields)
The documentation for add_packet_field says that the encoding argument is mandatory.
There is a README in the source code that says ENC_BIG_ENDIAN should be specified for network byte-order data (mine is). I know that section is for proto_tree_add_item, but I traced the code far enough to see that add_packet_field ends up passing the encoding to proto_tree_add_item.
Basically, at this point, I'm lost. I did find this post from 2014 that suggested limited support for add_packet_field but surely by now something as basic as an integer value is supported?
Also, I do know how to declare a Field and extract the value after tree:add does the parsing; worst case I'll fall back to that, but surely there is a more expedient way to access the just-parsed value added to the tree?
Wireshark Version
3.2.4 (v3.2.4-0-g893b5a5e1e3e)
Compiled (64-bit) with Qt 5.12.8, with WinPcap SDK (WpdPack) 4.1.2, with GLib
2.52.3, with zlib 1.2.11, with SMI 0.4.8, with c-ares 1.15.0, with Lua 5.2.4,
with GnuTLS 3.6.3 and PKCS #11 support, with Gcrypt 1.8.3, with MIT Kerberos,
with MaxMind DB resolver, with nghttp2 1.39.2, with brotli, with LZ4, with
Zstandard, with Snappy, with libxml2 2.9.9, with QtMultimedia, with automatic
updates using WinSparkle 0.5.7, with AirPcap, with SpeexDSP (using bundled
resampler), with SBC, with SpanDSP, with bcg729.
Running on 64-bit Windows 10 (1803), build 17134, with Intel(R) Xeon(R) CPU
E3-1505M v6 # 3.00GHz (with SSE4.2), with 32558 MB of physical memory, with
locale English_United States.1252, with light display mode, without HiDPI, with
Npcap version 0.9991, based on libpcap version 1.9.1, with GnuTLS 3.6.3, with
Gcrypt 1.8.3, with brotli 1.0.2, without AirPcap, binary plugins supported (19
loaded).
Built using Microsoft Visual Studio 2019 (VC++ 14.25, build 28614).
Looking at the try_add_packet_field() source code, only certain FT_ types are supported, namely:
FT_BYTES
FT_UINT_BYTES
FT_OID
FT_REL_OID
FT_SYSTEM_ID
FT_ABSOLUTE_TIME
FT_RELATIVE_TIME
None of the other FT_ types are supported [yet], including FT_UINT16, which is the one you're interested in here, i.e., anything else just needs to be done the old fashioned way.
If you'd like this to be implemented, I'd suggest filing a Wireshark enhancement bug request for this over at the Wireshark Bug Tracker.
I am trying to create my composite LWM2M object by using objlink type.
For Leshan, the only source on how to write the spec file in JSON seems to be the official oma-objects-spec.json, which does not contain examples of objlinks.
Can anyone provide an example on how to create an objlink object?
If it is not possible in Leshan, have anyone tried other implementations?
Hope it's not too late.
As of now there is no support of OBJLNK in Leshan API.
I was also needed OBJLNK support in Leshan so i have modified and created a pull request for supporting OBJLNK.
If you want to have objlnk support can use my branch which is forked from Leshan.
https://github.com/DevendraKurre/leshan
Leshan has added support to this feature. I have tested it with version 0.1.11-M14.
Reading can be done as usual, and writing is done as follows.
WriteRequest writeReq = new WriteRequest(
WriteRequest.Mode.UPDATE,
9, 0,
LwM2mSingleResource.newObjectLinkResource(
13,
new ObjectLink(5566, 7788)
)
);
I'll be using window.postMessage("", "*", [transferableData]) to send data between two browser windows. However, I didn't find any straight answer on how to convert types into Transferables.
So, in order for me to start learning this, it would be great to know how to convert a simple String into an Transferable (ByteBuffer) and read it on the other side (the side that is getting the message with the data). This would help me solving my problem and learning about this concept.
IMPORTANT UPDATE:
This question led me here: Dart Language: printing reports
Transferable Objects are not yet implemented on Dart VM (http://dartbug.com/4149). That means, if you're running your application via Dartium (Dart VM) the other window will be receiving and processing the first argument of postMessage, and not the Transferable Object. However, JavaScript does the job: the object gets transfered and the original array, emptied.
import 'dart:convert';
var list = Utf8.encode('xxx');
var data = list is Uint8List ? list.buffer : new Uint8List.fromList(list).buffer;
to send the data using window.PostMessage use
window.postMessage({'data': data}, '*', [data]);
and read it on the receiver side like
var string = Utf8.decode(message.data['data']);
See also http://dartbug.com/19968 for the status of transferrables.
The recent Dart dev channel release already ships with Dartium 38.xxx as far as I know.
Here is a small test case for transferrables https://code.google.com/p/dart/source/browse/branches/bleeding_edge/dart/tests/html/transferables_test.dart
I've been trying to find a way to connect my Windev application using the Quickbooks SDK.
I wish to connect to my local QB instance using the qbXML API.
I've been able to get a reference to the library using :
myconnection = new object Automation "QBXMLRP2.RequestProcessor"
However, when it comes to the OpenConnection2 method, I only get errors. Either "missing parameter" or "invalid parameter". I am aware that I should pass a "localQBD" type to the function, but I have not found out how to reference it. The following represents my invalid script.
myconnection>>OpenConnection2("","My Test App", localQBD)
How can I achieve a connection to QB through Windev?
After much searching, I have found that I was on the right path using the automation variable type.
However, I have yet to find how to reference the constants provided by the library. Instead, I declare them beforehand like so
CONSTANT
omSingleUser = 0
omMultiUser = 1
omDontCare = 2
qbStopOnError = 0
qbContinueOnError = 1
ctLocalQBD = 1
ctLocalQBDLaunchUI = 3
FIN
Which gives us this working example
myconnection = new object Automation "QBXMLRP2.RequestProcessor"
ticket = myconnection>>BeginSession("",::omDontCare)
XMLresponse = myconnection>>ProcessRequest(ticket,XMLrequest)
myconnection>>EndSession(ticket)
myconnection>>CloseConnection()
delete myconnection
A huge thanks goes to Frank Cazabon for showing me the proper constant values.
I have a complete external WinDev component that accesses QB and a helper program that can generate the WinDev calls in the correct order with the correct spelling and provides an OSR for all the QuickBooks fields and modules.
I have a similar product for the Clarion language and am in the final stages of the WinDev version. Contact me if you are interested. qbsnap at wybatap.com