Cannot convert string to buffer. toBuffer only supports 0x-prefixed hex strings

Question

Getting error while creating ethereum raw transaction

var rawTx = {
  nonce: '0x2a',
  gasPrice: '0x4a717c800',
  gasLimit: '0xc340',
  to: '0x73F7Ced8cc9D27DC426210c32fc6d0a40f941eE1',
  value: '0x2386f26fc10000',
  data: '',
  chainID: 4 
}      
var cTx = await new EthereumTx(rawTx, { 'chain': 'rinkeby' });
cTx.sign(privateKeyInBuffer);

score 14 · Accepted Answer · answered Jul 01 '20 at 06:49

14

try change data :'' to data:"0x"

answered Jul 01 '20 at 06:49

曹海涛

156
1
3

why does this work? – lhay86 Aug 18 '20 at 09:54

score 4 · Answer 2 · answered Oct 10 '20 at 13:03

4

ethereum-utils checks string fields if they are hex. When you send data field as empty, then it throws the error. You can send data as '0x' like they said above.

answered Oct 10 '20 at 13:03

ikc1903

41
1

score 2 · Answer 3 · answered Feb 29 '20 at 11:47

2

Replace privateKey with Buffer.from(privateKey.slice(2), "hex").

answered Feb 29 '20 at 11:47

goodvibration

26,003
5
46
86

i am already using privatekey in buffer – Ishwar Chandra Tiwari Mar 04 '20 at 06:13
@IshwarChandra: Did this method not work for you? If yes, then please elaborate on what error it gives you. – goodvibration Mar 04 '20 at 07:51
i have used your given solution but i am still getting same error – Ishwar Chandra Tiwari Mar 04 '20 at 08:16

Miroslav Nedelchev · Answer 4 · 2020-02-29T11:56:31.187

This might be happening, because you are trying to sign the raw transaction with private key in string format, but it has to be hex. Change:

cTx.sign(privateKey)

To:

cTx.sign(new Buffer(privateKey, 'hex'))

And on a side note, here var cTx = await new EthereumTx(rawTx, { 'chain': 'rinkeby' }); you don't have to pass chain parameter, you already specified to which blockchain network the transaction should be sent in rawTx where you placed this parameter chainID: 4. Full list with blockchain networks can be found here.

score 1 · Answer 5 · answered May 01 '21 at 12:17

Simple solution

 var rawTx = {
      nonce: '0x2a',
      gasPrice: '0x4a717c800',
      gasLimit: '0xc340',
      to: '0x73F7Ced8cc9D27DC426210c32fc6d0a40f941eE1',
      value: '0x2386f26fc10000',
      data: '0x',=====================>>**change empty data string to 0x**
      chainID: 4 
    }

Cannot convert string to buffer. toBuffer only supports 0x-prefixed hex strings

5 Answers5

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